Title:
Field Unit of Game Machine
Kind Code:
A1


Abstract:
The invention provides a field unit of a game machine, wherein a lower-stage running surface on which a self-running body is placed can be maintained efficiently. The field unit of a game machine includes a lower-stage running surface on which a self-running body runs; and an upper-stage running surface on which a model following up the self-running body runs. In the field unit of a game machine, the lower-stage running surface is formed in a lower structure, and the upper-stage running surface is formed in an upper structure which is liftably combined with the lower structure. The upper structure is raised and lowered with a lift drive device.



Inventors:
Miyata, Hideaki (Tokyo, JP)
Kasuya, Yasufumi (Tokyo, JP)
Ishimaru, Tetsuo (Tokyo, JP)
Application Number:
11/814605
Publication Date:
09/18/2008
Filing Date:
01/18/2006
Assignee:
KONAMI DIGITAL ENTERTAINMENT CO., LTD. (Tokyo, JP)
Primary Class:
International Classes:
A63F9/14
View Patent Images:
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Primary Examiner:
BALDORI, JOSEPH B
Attorney, Agent or Firm:
LOCKE LORD LLP (BOSTON, MA, US)
Claims:
1. A field unit of a game machine, comprising: a lower-stage running surface on which a self-running body runs; an upper-stage running surface on which a model following up the self-running body runs; a lower structure in which the lower-stage running surface is formed; an upper structure liftably combined with the lower structure, in the upper structure the upper-stage running surface being formed; and a lift drive device which raises and lowers the upper structure.

2. The field unit according to claim 1, wherein a power-supply surface facing the lower-stage running surface is formed in the upper structure, and the range of downward move of the upper structure is set such that the self-running body contacts with the power-supply surface when the upper structure is lowered.

3. The field unit according to claim 1, wherein the range of upward move of the upper structure is set so as to generate a space which at least an upper body of an operator can enter between the lower-stage running surface and the power-supply surface when the upper structure is raised.

4. The field unit according to claim 1, wherein the lift drive device comprises: a hydraulic cylinder attached between the lower structure and the upper structure such that the working direction of the hydraulic cylinder is vertically oriented; and an oil pressure generating device which supplies oil pressure to the hydraulic cylinder.

5. The field unit according to claim 1, wherein the lift drive devices comprises a plurality of hydraulic cylinders separately arranged around the field unit, and each of the lift drive devices comprises: a hydraulic cylinder attached between the lower structure and the upper structure such that the working direction of the hydraulic cylinder is vertically oriented; and an oil pressure generating device which supplies oil pressure to the hydraulic cylinder.

6. The field unit according to claim 5, wherein the lower structure and the upper structure are respectively divided into sub-units of a same number, and the hydraulic cylinder is provided to each of the sub-units.

7. The field unit according to claim 5, wherein a cylinder tube of the hydraulic cylinder is attached to one of the lower structure and the upper structure, and a piston rod of the hydraulic cylinder is coupled to the other structure through an adjusting device providing end play to the other structure.

8. The field unit according to claim 2, wherein the range of upward move of the upper structure is set so as to generate a space which at least an upper body of an operator can enter between the lower-stage running surface and the power-supply surface when the upper structure is raised.

9. The field unit according to claim 8, wherein the lift drive device comprises: a hydraulic cylinder attached between the lower structure and the upper structure such that the working direction of the hydraulic cylinder is vertically oriented; and an oil pressure generating device which supplies oil pressure to the hydraulic cylinder.

10. The field unit according to claim 8, wherein the lift drive devices comprises a plurality of hydraulic cylinders separately arranged around the field unit, and each of the lift drive devices comprises: a hydraulic cylinder attached between the lower structure and the upper structure such that the working direction of the hydraulic cylinder is vertically oriented; and an oil pressure generating device which supplies oil pressure to the hydraulic cylinder.

11. The field unit according to claim 10, wherein the lower structure and the upper structure are respectively divided into sub-units of a same number, and the hydraulic cylinder is provided to each of the sub-units.

12. The field unit according to claim 11, wherein a cylinder tube of the hydraulic cylinder is attached to one of the lower structure and the upper structure, and a piston rod of the hydraulic cylinder is coupled to the other structure through an adjusting device providing end play to the other structure.

13. The field unit according to claim 10, wherein a cylinder tube of the hydraulic cylinder is attached to one of the lower structure and the upper structure, and a piston rod of the hydraulic cylinder is coupled to the other structure through an adjusting device providing end play to the other structure.

14. The field unit according to claim 2, wherein the lift drive device comprises: a hydraulic cylinder attached between the lower structure and the upper structure such that the working direction of the hydraulic cylinder is vertically oriented; and an oil pressure generating device which supplies oil pressure to the hydraulic cylinder.

15. The field unit according to claim 3, wherein the lift drive device comprises: a hydraulic cylinder attached between the lower structure and the upper structure such that the working direction of the hydraulic cylinder is vertically oriented; and an oil pressure generating device which supplies oil pressure to the hydraulic cylinder.

16. The field unit according to claim 2, wherein the lift drive devices comprises a plurality of hydraulic cylinders separately arranged around the field unit, and each of the lift drive devices comprises: a hydraulic cylinder attached between the lower structure and the upper structure such that the working direction of the hydraulic cylinder is vertically oriented; and an oil pressure generating device which supplies oil pressure to the hydraulic cylinder.

17. The field unit according to claim 16, wherein the lower structure and the upper structure are respectively divided into sub-units of a same number, and the hydraulic cylinder is provided to each of the sub-units.

18. The field unit according to claim 16, wherein a cylinder tube of the hydraulic cylinder is attached to one of the lower structure and the upper structure, and a piston rod of the hydraulic cylinder is coupled to the other structure through an adjusting device providing end play to the other structure.

19. The field unit according to claim 3, wherein the lift drive devices comprises a plurality of hydraulic cylinders separately arranged around the field unit, and each of the lift drive devices comprises: a hydraulic cylinder attached between the lower structure and the upper structure such that the working direction of the hydraulic cylinder is vertically oriented; and an oil pressure generating device which supplies oil pressure to the hydraulic cylinder.

20. The field unit according to claim 19, wherein the lower structure and the upper structure are respectively divided into sub-units of a same number, and the hydraulic cylinder is provided to each of the sub-units.

Description:

TECHNICAL FIELD

The present invention relates to a field unit of a game machine having a lower-stage running surface and an upper-stage running surface.

BACKGROUND ART

There is known a game machine in which a self-running body and a model are placed respectively on a lower-stage running surface and an upper-stage running surface provided in a field unit, and which allows the self-running body to self-run on the lower-stage running surface. The self-running body and the model are attracted each other by a magnetic force, whereby the model is caused to run while following up the self-running body (for example, see Patent Document 1). In this type of game machine, marks for controlling a running direction of the self-running body or a degree of progress, such as guide lines, measurement lines, are provided on the lower-stage running surface.

Patent Document 1: Japanese Patent Application Laid-Open No. 2003-38841.

DISCLOSURE OF THE INVENTION

Problem to be Solved by the Invention

In the above game machine, an error occurs in running control of the self-running due to smear of the lower-stage running surface or adhesion of a foreign matter. Accordingly, the lower-stage running surface needs to be inspected periodically and cleaned if necessary. However, the lower-stage running surface is hidden under the upper-stage running surface in the structure in which the upper-stage running surface is arranged above the lower-stage running surface. Accordingly, the maintenance work of the lower-stage running surface cannot be performed efficiently. In the case where a power supply surface for supplying electric power to the self-running body is provided on the backside of the upper-stage running surface, similar problem arises for maintaining the power supply surface.

Thus, an object of the invention is to provide a field unit of a game machine, wherein a lower-stage running surface on which a self-running body is placed can be maintained efficiently.

Means for Solving the Problem

In order to solve the above problem, a field unit of a game machine according to the invention includes a lower-stage running surface on which a self-running body runs; an upper-stage running surface on which a model following up the self-running body runs; a lower structure in which the lower-stage running surface is formed; an upper structure liftably combined with the lower structure, in the upper structure the upper-stage running surface being formed; and a lift drive device which raises and lowers the upper structure.

According to the field unit of the invention, the upper structure is raised with the lift drive device to enlarge the space between the backside of the upper-stage running surface and the lower-stage running surface, which improves the access to the lower-stage running surface. Accordingly, the maintenance work can be performed efficiently to the lower-stage running surface.

In one aspect of the invention, a power-supply surface facing the lower-stage running surface may be formed in the upper structure, and the range of downward move of the upper structure may be set such that the self-running body contacts with the power-supply surface when the upper structure is lowered. According to the aspect, when the upper structure is lowered, the power supply surface contacts with the self-running body so that electric power is reliably supplied to the self-running body. At the same time, in the maintenance work of the lower-stage running surface, a sufficient space is generated between the lower-stage running surface and the power supply surface irrespective of the height of the self-running body, so that the lower-stage running surface and the power supply surface can be inspected or cleaned easily.

In one aspect of the invention, the range of upward move of the upper structure may be set so as to generate a space which at least the upper body of an operator can be put between the lower-stage running surface and the power-supply surface when the upper structure is raised. When the upper structure is raised to the above extent, the operator can inspect or clean the lower-stage running surface while putting the body of the operator to the inner side (backend side) of the lower-stage running surface.

In one aspect of the invention, the lift drive device may include a hydraulic cylinder attached between the lower structure and the upper structure such that the working direction of the hydraulic cylinder is vertically oriented; and an oil pressure generating device which supplies an oil pressure to the hydraulic cylinder. When the hydraulic cylinder is used as an actuator for raising and lowering the upper structure, the lift drive device can be configured relatively simply.

In one aspect of the invention, the lift drive devices may include plural hydraulic cylinders separately arranged around the field unit, and each of the lift drive devices includes a hydraulic cylinder attached between the lower structure and the upper structure such that the working direction of the hydraulic cylinder is vertically oriented; and an oil pressure generating device which supplies oil pressure to the hydraulic cylinder. When the plural hydraulic cylinders are provided around the field unit, the upper structure can be raised and lowered smoothly even in a large-size field unit.

In one aspect of the invention, the lower structure and the upper structure may be respectively divided into sub-units of a same number. In this case the hydraulic cylinder may be provided to each of the sub-units. Accordingly, the force of the hydraulic cylinder is equally distributed to and exerted on the sub-units so that the load exerted on a connecting section between the sub-units when the upper structure is raised or lowered can be reduced.

In one aspect of the invention, a cylinder tube of the hydraulic cylinder may be attached to one of the lower structure and the upper structure, and a piston rod of the hydraulic cylinder is coupled to the other structure through an adjusting device providing end play to the other structure. Therefore, by using the adjusting device, the plural hydraulic cylinders can work without interfering with each another, so that the upper structure can be raised and lowered smoothly.

EFFECT OF THE INVENTION

As described above, according to the field unit of the invention, using the lift drive device, the upper structure is raised to enlarge the space between the backside of the upper-stage running surface and the lower-stage running surface, which improves the access to the lower-stage running surface. Therefore, the maintenance work can be performed efficiently to the lower-stage running surface.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram showing a schematic configuration of a game system into which a game machine according to an embodiment of the invention is incorporated;

FIG. 2 is a perspective view showing a field unit when a stage is raised;

FIG. 3 is a side view showing the field unit when the stage is raised;

FIG. 4 is a perspective view showing the field unit when the stage is lowered;

FIG. 5 is a side view showing the field unit when the stage is lowered;

FIG. 6 is an exploded perspective view of the field unit;

FIG. 7 is a perspective view showing the part VII of FIG. 2 viewed from the below;

FIG. 8 is a view showing cross sections of top boards provided in the field unit and a motor vehicle and a model which run on running surfaces formed on the top boards;

FIG. 9 is a view showing a guide line and a magnetic measurement line formed on a lower-stage running surface;

FIG. 10 is a plan view showing a round track formed on the lower-stage running surface;

FIG. 11 is an enlarged view showing a corner section of the round track;

FIG. 12 is a view showing an internal structure of the self-running body;

FIG. 13 is a bottom view of the self-running body;

FIG. 14 is a sectional view taken along the line XIV-XIV of FIG. 13;

FIG. 15 is an enlarged front view of a line sensor;

FIG. 16 is an enlarged bottom view of the line sensor;

FIG. 17A is a view showing a relationship between an output of a magnetic sensor and a magnetic measurement line when the self-running body runs in a straight section, and showing a relationship between the magnetic sensor and the magnetic measurement line;

FIG. 17B is a view showing a relationship between the output of the magnetic sensor and the magnetic measurement line when the self-running body runs in a straight section, and showing outputs of detecting elements of the magnetic sensor;

FIG. 18A is a view showing a relationship between the output of the magnetic sensor and the magnetic measurement line when the self-running body runs in a corner section of a lane except for an innermost lane, and showing a relationship between the magnetic sensor and the magnetic measurement line;

FIG. 18B is a view showing a relationship between the output of the magnetic sensor and the magnetic measurement line when the self-running body runs in the corner section of the lane except for the innermost lane, and showing the outputs of the detecting elements of the magnetic sensor;

FIG. 19 is a diagram showing a schematic configuration of a control system of a game machine;

FIG. 20 is a block diagram showing a control system provided to a motor vehicle;

FIG. 21 is a view showing a degree of progress of the motor vehicle, a position in a transverse direction, and a concept of control concerning a direction;

FIG. 22 is a functional block diagram of a motor vehicle control device;

FIG. 23 is a flowchart showing a procedure of progress management in a progress management device;

FIG. 24 is a flowchart showing a procedure of computing a target speed in a target speed computation device;

FIG. 25 is a view showing a relationship among the number of counted inversions, an inversion reference time, a remaining time, and a progress shortage amount;

FIG. 26 is a flowchart showing a procedure of managing a direction in a direction management device;

FIG. 27 is a flowchart showing a procedure of computing a direction correction amount in a direction correction amount computation device;

FIG. 28 is a flowchart showing a procedure of managing a lane in a lane management device;

FIG. 29 is a view showing a correlation between position shift of the line sensor to the guide line and the output of the line sensor;

FIG. 30 is a flowchart showing a procedure of computing a lane correction amount in a lane correction amount computation device;

FIG. 31 is a flowchart showing a procedure of inspecting a line width in a line width inspection device;

FIG. 32 is a flowchart showing a procedure of transmitting line width inspection data from the motor vehicle control device to a main control device;

FIG. 33 is a flowchart showing a procedure of managing the line width inspection data in the main control device;

FIG. 34 is a flowchart showing a procedure of managing running surface check in the main control device;

FIG. 35 is a view showing an example of a running surface check screen; and

FIG. 36 is a flowchart showing a process in a maintenance mode at the main control device.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 is a diagram showing a schematic configuration of a game system into which a game machine according to an embodiment of the invention is incorporated. A game system 1 is used to perform a horse-racing game. The game system 1 includes plural game machines 2A, 2B, and 2C, a center server 3, a maintenance server 4, and a maintenance client 5 which are connected to each another through a communication network 6. The plural game machines 2A to 2C have the same configuration in the game system 1. Accordingly, the plural game machines 2A to 2C are collectively referred to as game machine 2 unless distinction is necessary. Although the three game machines 2 are shown in FIG. 1, the number of game machines 2 included in the game system 1 is not limited to three.

The center server 3 mainly processes data concerning a game according to a request of the game machine 2. The maintenance server 4 stores data concerning the maintenance such as error log information on the game system 1 in a maintenance storage device 4a which is a storage device of the maintenance server 4, and manages the data concerning the maintenance. The maintenance client 5 is installed in, e.g., a maintenance service division which collectively manages the maintenance of the game system 1, and the maintenance client 5 performs analysis and study of the maintenance of the game system 1 using the data stored in the maintenance storage device 4a. For example, the Internet is used as the communication network 6.

The game machine 2 is configured in the form of a commercial game machine installed in a store and allowing a user to play the game in exchange for an economic value. A chassis (game machine main body) 10 of the game machine 2 includes a field unit 11, plural station devices 12, . . . , 12 arranged so as to surround the field unit 11, and a monitor device 13 arranged at one end of the field unit 11. The field unit 11 provides running surfaces 18 and 19 to a motor vehicle (self-running body) 30 and a race-horse model 31 shown in FIG. 8, respectively. The motor vehicle 30 and the race-horse model 31 are shown in FIG. 8. The plural motor vehicles 30 and the models 31 are placed on the field unit 11, and the horse-racing game is realized by competition of the plural motor vehicles 30 and the models 31. The station device 12 performs paying out of a game value for a player while accepting various operations of the player concerning the horse-racing game. The monitor device 13 includes a main monitor 13a which displays game information and the like.

FIG. 2 is a perspective view of the field unit 11, and FIG. 3 is a side view thereof. As shown in FIGS. 2 and 3, the field unit 11 includes a base 14 which is a lower structure and a stage 15 which is an upper structure placed over the base 14. Both the base 14 and the stage 15 have a frame-work structure formed by a combination of steel products. Top boards 16 and 17 are attached to upper surfaces of the base 14 and stage 15, respectively. A lower-stage running surface 18 on which the motor vehicle 30 runs is formed on the upper surface of the top board 16 of the base 14. An upper-stage running surface 19 on which the model 31 runs is formed on the upper surface of the top board 17 of the stage 15, and a power supply surface 20 for the motor vehicle 30 is formed on the lower surface of the top board 17.

The stage 15 is liftably provided to the base 14. FIGS. 2 and 3 show the stage 15 in the raised state. FIGS. 4 and 5 show the stage 15 in the lowered state. FIG. 4 is a perspective view corresponding to FIG. 2, and FIG. 5 is a side view corresponding to FIG. 3. The lift range of the stage 15 is as follows. As shown in FIG. 5, when the stage 15 is lowered to come into contact with a receiving section 14a of the base 14a, a space SP exists between the lower-stage running surface 18 and the power supply surface 20. Then, the height Hd (see FIG. 5) of the space SP at this point is a suitable value for accommodating the motor vehicle 30. On the other hand, when the stage 15 is raised up, the height Hu (see FIG. 3) of the space SP is enlarged to such an extent that an operator can put his/her upper half body into the space SP. Preferably, the height Hu of at least 400 mm is ensured as a rough measure. Furthermore, for the sake of carrying in and out the field unit 11, the base 14 and the stage 15 can be respectively divided into three sub-devices 14A to 14C and 15A to 15C in a horizontal direction, as shown in FIG. 6. The top board 16 of the base 14 is divided into three parts in accordance with the sub-devices 14A to 14C. The sub-devices 14A to 14C are coupled to one another with coupling means such as a bolt. The same holds for the sub-devices 15A to 15C.

As shown in FIGS. 2 and 3, a stage drive device (lift drive device) 21 is provided in the field unit 11 to drive the stage 15 vertically. The stage drive device 21 includes plural hydraulic cylinders (actuator) 22 arranged around the field unit 11 at an appropriate interval, and an oil pressure generating device 23 serving as a power source for supplying oil pressure to each hydraulic cylinder 22. The hydraulic cylinder 22 is provided such that a piston rod 22a is orientated upwardly. One hydraulic cylinder 22 is provided to each of both sides of the sub-devices 14A to 14C, namely, six hydraulic cylinders 22 are provided in total. However, the number of hydraulic cylinders 22 is not limited to six. but at least one hydraulic cylinder 22 may be provided for each of the sub-devices 14A to 14C. As shown in FIG. 7, a cylinder tube 22b of the hydraulic cylinder 22 is fixed to the base 14, and a leading end of the piston rod 22a is coupled to the stage 15 through an adjuster device 24. Accordingly, the stage 15 is raised by supplying oil pressure to the hydraulic cylinder 22 to extend the piston rod 22a.

The adjuster device 24 includes an adjuster 24a fixed to the leading end of the piston rod 22a and an adjuster receiver 24b fixed to the stage 15. The adjuster 24a is not fixed to the adjuster receiver 24b but inserted into the adjuster receiver 24b with some play. Consequently, shift of an axis of the piston rod 22a is allowed in the operation of the hydraulic cylinder 22, and thus the plural hydraulic cylinders 22 can be operated without interference to raise and lower the stage 15 smoothly. The oil pressure generating device 23 is driven by electric power supplied to the game machine 2 so as to generate oil pressure suitable to the hydraulic cylinder 22. The operation of the oil pressure generating device 23 is controlled by a main control device 100 (see FIG. 19) which controls the whole operation of the game machine 2.

FIG. 8 is a view showing cross sections of the top boards 16 and 17 and the motor vehicle 30 and model 31 which run on the running surfaces 18 and 19 of the top boards 16 and 17. The top board 16 of the base 14 is constructed from a white resin board, a line sheet 32 is provided on the lower-stage running surface 18 of the upper surface of the top board 16, and a magnet (permanent magnet) 33 is provided on the lower surface of the top board 16. As shown in FIG. 9, the line sheet 32 is used to form plural guide lines 34 for guiding the motor vehicle 30 on the lower-stage running surface 18. The guide line 34 is colored with a color (for example, black) having a contrast in a visible range to a base color of the top board 16. A width Wg of the guide line 34 is set to a half of a pitch (interval) Pg between the adjacent guide lines 34. For example, the width Wg is set to 6 mm, and the pitch Pg is set to 12 mm. As shown in FIG. 10, the guide lines 34 are provided so as to form a round track 35. The round track 35 is formed by connecting straight sections 35a in which the guide lines 34 extending parallel to one another and corner sections 35b in which the guide lines 34 are curved in a semi-circle shape. In both the straight section 35a and the corner section 35b, the width Wg and pitch PTg of the guide line 34 are constant. In the corner section 35b, the guide lines 34 have the same center of curvature CC.

In the game machine 2, the guide line 34 is rated as a mark indicating a lane of the round track 35. For example, the innermost guide line 34 corresponds to a first lane, and subsequently the guide lines 34 are correlated with the lane numbers: a second lane, a third lane, . . . toward the outer circumference. In the game machine 2, a position of the motor vehicle 30 in a transverse direction (direction orthogonal to the guide line 34) of the round track 35 is recognized with the lane number. The motor vehicle 30 controls its operation so as to run along the guide line 34 corresponding to the current lane unless it is instructed to change lanes by the main control device 100. Although the number of guide lines 34 is six in FIG. 10, the number of guide lines 34 may appropriately be changed according to the number of horses to be used in the horse-racing game.

As shown in FIG. 9, the magnets 33 are arranged such that an S pole and an N pole are arranged alternately. The magnet 33 in the straight section 35a has a strip shape extending in the transverse direction, whereas the magnet 33 in the corner section 35b has an arc shape expanding toward the outer circumference. Therefore, on the lower-stage running surface 18, many magnetic measurement lines 36 extending in the transverse direction of the round track 35 are formed repeatedly along a longitudinal direction of the round track 35 at a boundary section between the S pole and the N pole. The magnetic measurement line 36 is used as a mark indicating the position or a degree of progress of the motor vehicle 30 on the round track 35. That is, in the game machine 2, the degree of progress of the motor vehicle 30 in the longitudinal direction of the round track 35 is managed by the number of magnetic measurement lines 36 with reference to a particular position on the round track 35 (for example, the position Pref in FIG. 10). For example, when the motor vehicle 30 is placed on a hundredth magnetic measurement line 36 from the reference position Pref, the degree of progress of the motor vehicle 30 is recognized as 100 by the game machine 2.

The pitch (interval) between the magnetic measurement lines 36 in the straight section 35a is set to a constant value PTm. Hereinafter the pitch PTm is referred to as reference pitch. As shown in FIG. 11, the pitch between the magnetic measurement lines 36 in the corner section 35b is set such that a pitch Ptin between the magnetic measurement lines 36 along the innermost guide line 34 is equal to the reference pitch PTm. Accordingly, the pitch between the magnetic measurement lines 36 in the corner section 35b is enlarged toward the outer circumference. For example, in the case of the reference pitch PTm of 8 mm, a pitch (maximum pitch) PTout on the outermost guide line 34 is about 30 mm.

As shown in FIG. 10, absolute-position indicating devices 37 are provided at appropriate positions on the round track 35 (in the example of FIG. 10, at both end zones of the straight section 35a and at the center of the corner section 35b). As shown in FIG. 8, the absolute-position indicating device 37 includes an indication lamp 38 arranged on the lower surface of the top board 18. An infrared LED which emits an infrared ray is used as the indication lamp 38. As shown in FIG. 9, the indication lamp 38 is provided on the lower surface of each guide line 34. In one absolute-position indicating device 37, the indication lamps 38 are arranged in the transverse direction of the round track 35. Openings are formed in the top board 18 and in the magnet 33 right above the indication lamps 38. At least right above the indication lamps 38, the guide lines 34 are formed with an IR ink which is transparent to the infrared ray.

The position of the indication lamp 38 in the longitudinal direction of the round track 35 is set in a gap between the magnetic measurement lines 36. On the infrared ray emitted from each indication lamp 38 of the absolute-position indicating device 37, data respectively indicating an absolute position and the lane number of the indication lamp 38 on the round track 35 are superposed. That is, the absolute-position indicating device 37 functions as a device for providing information respectively indicating the absolute position and the lane on the round track 35. In this case, the absolute position of the indication lamp 38 may be correlated with the degree of progress using the magnetic measurement lines 36. For example, the absolute-position indicating device 37 located at the reference position Pref is set to the degree of progress of 0, and the degree of progress of 100 may be transmitted as the position information from the indication lamp 38 arranged between the clockwise (or counterclockwise) 100th magnetic measurement line 36 and the 101st magnetic measurement line 36. Furthermore, the number of absolute-position indicating devices 37 counted from the reference position Pref may be transmitted as the position information from the indication lamp 38, and then the number of absolute-position indicating devices 37 may be substituted with the degree of progress using an internal table of the game machine 2.

As shown in FIG. 8, the motor vehicle 30 is placed between the lower-stage running surface 18 and the power supply surface 20, and the model 31 is placed on the upper-stage running surface 19. A magnet 40 is provided on top of the motor vehicle 30. The model 31 stands itself on the upper-stage running surface 19 through a wheel 31a. However, the model 31 has no self drive device, and runs on the upper-stage running surface 19 so as to follow up the motor vehicle 30 while attracted to the motor vehicle 30 by the magnet 40 of the motor vehicle 30. That is, the running of the model 31 on the upper-stage running surface 19 is realized through the running control of the motor vehicle 30.

FIGS. 12 to 14 show the detail of the motor vehicle 30. The horizontal direction in FIGS. 12 and 13 correspond to the longitudinal direction of the motor vehicle 30. The right side of FIGS. 12 and 13 corresponds to the front side of the motor vehicle 30. As shown in FIG. 12, the motor vehicle 30 includes a lower device 41A and an upper device 41B. As shown in FIG. 13, the lower device 41A includes a pair of drive wheels 42 used for self-running on the lower-stage running surface 18, a pair of motors 43 used to drive the drive wheels 42 independently, and assist wheels 44F and 44R arranged in front end section 30a and rear end section 30b of the motor vehicle 30, respectively. A moving direction of the motor vehicle 30 can be changed by imparting a difference in rotating speed between the motors 43. Four vertically extended guide shafts 45 are provided in the lower device 41A, and the upper device 41B is provided along the guide shafts 45 while being able to be raised and lowered. A helical spring 46 is provided in the guide shaft 45, and the upper device 41B is biased upward by a repulsion force of the helical spring 46 such that a wheel 47 and a power supply brush 48 of the upper device 41B are pressed against the power supply surface 20. The power supply brush 48 is brought into contact with the power supply surface 20, which allows the electric power to be supplied from the chassis 10 to the motor vehicle 30. However, FIG. 12 shows the state in which the stage 15 is lowered, and the power supply surface 20 is sufficiently separated from the power supply brush 48 and the like when the stage 15 is raised.

As shown in FIG. 12, the assist wheel 44F in the front side of the lower device 41A is arranged slightly biased upward with respect to the drive wheel 42. Assist wheels 49F and 49R are also arranged on the front and rear sides of the upper device 41B, and the assist wheel 49R is arranged while slightly biased downward with respect to the drive wheel 47. Accordingly, the motor vehicle 30 can vibrate vertically with the drive wheel 42 as the axis, and the vibration of the motor vehicle 30 is transmitted to the model 31 through the magnet 40. As a consequence, the situation is expressed in which the race horse runs while vibrating vertically.

As shown in FIG. 13, a line sensor 50, an absolute position detecting sensor 51, and a magnetic sensor 52 are arranged in the lower surface of the motor vehicle 30. The line sensor 50 is provided to detect the guide line 34, the absolute position detecting sensor 51 is provided to detect the light emitted from the indication lamp 38, and the magnetic sensor 52 is provided to detect the magnetic measurement line 36.

The line sensor 50 includes a pair of light emitting devices 53 provided in a symmetrical manner in the front end section 30a of the motor vehicle 30, and a light-receiving device 54 arranged between the light emitting devices 53. The light emitting device 53 emits visible light having a predetermined wavelength range to the lower-stage running surface 18, and the light-receiving device 54 accepts the light reflected from the lower-stage running surface 18. The detection wavelength range of the light-receiving device 54 is restricted to the wavelength range of the visible light emitted from the light emitting device 53 such that the light emitted from the indication lamp 38 is not wrongly detected. FIGS. 15 and 16 show the detailed line sensor 50. The light emitting devices 53 are symmetrically provided in relation to a center plane PC which divides the motor vehicle 30 laterally into two equal portions, and the light emitting directions of the light emitting devices 53 are orientated obliquely inward.

The light-receiving device 54 includes a sensor array 55 which is provided so as to be equally extended across the center plane CP in the lateral direction of the motor vehicle 30, and an imaging lens 56 which focuses the image on the lower-stage running surface 18, formed by the light reflected from the lower-stage running surface 18, onto the sensor array 55. For example, the sensor array 55 is formed by arranging many CMOS light-receiving elements in line. The sensor array 55 detects a luminance distribution in the lateral direction of the motor vehicle 30 with fine resolution relative to the width Wg of the guide line 34. For example, the resolution is set such that the width 1.5 times the pitch PTg of the guide line 34 is detected while divided into 128 dots. In other words, when the center plane CP is located in the center of the width direction of the guide line 34, a region formed by the guide line 34 and a blank portion adjacent to the guide line 34 is set to a detection region, and the resolution of the sensor array 55 is set such that the detection region is detected with the resolution of 128 dots. For example, when the pitch PTg of the guide line 34 is set to 12 mm, the sensor array 55 has the detection width of 18 mm, and the sensor array 55 detects the luminance distribution with the resolution of 0.14 mm per one dot.

The imaging lens 56 is provided to upwardly separate the sensor array 55 from the lower-stage running surface 18. This is because the vertical vibration of the motor vehicle 30 caused by the position shift of the assist wheels 44F and 44R is prevented from influencing the accuracy of detecting the luminance distribution.

As shown in FIG. 13, the absolute position detecting sensor 51 includes a light-receiving device 58 which is arranged on the center plane PC of the motor vehicle 30. The absolute position detecting sensor 51 accepts the infrared light emitted from the indication lamp 38, and the absolute position detecting sensor 51 outputs a signal corresponding to the absolute position and lane number included in the infrared light.

The magnetic sensor 52 includes plural detecting elements 60 arranged at a constant pitch PTms in the longitudinal direction of the motor vehicle 30. In the following description, sometimes the detecting element 60 is divided into a detecting element #1, a detecting element #2, and . . . in the order from the front end portion 30a of the motor vehicle 30. Each detecting element 60 detects a magnetic field in the lower-stage running surface 18, and outputs signals corresponding to the S pole and N pole, respectively. For example, the detecting element 60 outputs a Low signal when detecting the S pole, and outputs a High signal when detecting the N pole. Accordingly, the magnetic measurement line 36 can be detected by the inversion of the signal of each detecting element 60. Therefore, the magnetic sensor 52 functions as a measurement line detecting device. As shown in FIG. 17A, the number of detecting elements 60 and a pitch PTms between the detecting elements 60 in the longitudinal direction are correlated with the reference pitch PTm of the magnetic measurement line 36. That is, the pitch PTms of the detecting element 60 is set to a half of the reference pitch PTm of the magnetic measurement line 36. In other words, the reference pitch PTm is double the pitch PTms of the detecting element 60. The number of detecting elements 60 is set such that a product of the number of detecting elements 60 and the pitch PTms is larger than the outermost pitch (maximum pitch) PTout of the corner section 35b. In FIG. 17A, the reference pitch PTm is set to 8 mm, the maximum pitch PTout is set to 30 mm, the pitch PTms of the detecting elements is set to 4 mm, and the number of detecting elements 60 is set to eight.

FIG. 17B shows an example of the output signal of the magnetic sensor 52 when the magnetic sensor 52 runs at a speed Vact along the guide line 34 of the straight section 35a or the guide line 34 of the first lane of the corner section 35b. It is assumed that the detecting element #1 (60) reaches the magnetic measurement line 36 at time t1 and the output signal is inverted from Low to High, and that the detecting element #1 (60) reaches the next magnetic measurement line 36 at time t3 and the output signal is inverted from High to Low. In this case, the output signal of the detecting element #2 (60) is inverted from Low to High at time t2 between time t1 and time t3. Although the output signal of the detecting element #3 (60) is inverted from Low to High at time t3, the output signal of the detecting element #1 (60) is inverted at the same time because the pitch PTms is the half of the reference pitch PTm. Accordingly, in the case of FIG. 17B, the degree of progress and the speed of the motor vehicle 30 can be controlled with the resolution of the half of the reference pitch PTm using only the output signals of the detecting elements #1 and #2 (60). It is not necessary to use the output signals of the detecting element #2 (60) and subsequent detecting elements 60. For example, only the output signals of the detecting elements #1 and #2 (60) may be used in the case when the running of the motor vehicle 30 is controlled based on a difference between the current speed Vact of the motor vehicle 30 and a target speed required on the game. The current speed Vact is obtained by dividing the pitch PTms of the detecting element 60 by inverting time interval (t1 and t2, t2 and t3) of the output signal of each detecting element 60.

However, in the case when the motor vehicle 30 runs in the lane except for the first lane of the corner section 35b, circumstances differ from those of FIG. 17B because the pitch between the magnetic measurement lines 36 is extended larger than the reference pitch PTm. An example thereof will be described with reference to FIGS. 17 and 18. In FIG. 18A, it is assumed that the motor vehicle 30 runs at the speed Vact along the guide line 34 in the second lane or the lane outside the second lane of the corner section 35b and the pitch between the magnetic measurement lines 36 in the lane is PTx (however, Pm<PTx≦PTout). In this case, as shown in FIG. 18B, the time interval (t1 and t6) between time t1, at which the detecting element #1 (60) reaches the magnetic measurement line 36 to invert the output signal from Low to High, and time t6, at which the detecting element #1 (60) reaches the next magnetic measurement line 36 to invert the output signal from High to Low, is extended by the extended pitch PTx. On the other hand, the time interval (t1 and t2) between time t1 and time t2, at which the output signal of the detecting element #2 (60) is inverted from Low to High, is equal to the time interval of FIG. 17B. Therefore, the time interval between time t2 and time t1 is smaller than the time interval between time t2 and time t6. Accordingly, when the current speed Vact of the motor vehicle 30 is determined from the inversion time intervals of the output signals of the detecting elements #1 and #2 (60) and the pitch PTms of the detecting elements 60, the speed obtained in the time interval between time t2 and time t6 includes an error because the precondition of PTms=PTm/2 does not hold, and the speed of the motor vehicle 30 is wrongly controlled when the speed obtained in the time interval between time t2 and time t6 is used.

On the other hand, in FIG. 18B, the detecting elements #2 to #5 (60) sequentially reach the same magnetic measurement line 36 in the time interval between time t1 and time t6, and the output signals of the detecting elements #2 to #5 (60) are inverted in the time interval between time t2 and time t5. The time intervals between time t2 and time t3, time t3 and time t4, and time t4 and time t5 are equal to a value obtained by dividing the pitch PTms of the detecting elements 60 by the current speed Vact. Therefore, in the case of FIG. 18B, when the current speed Vact is detected using the output signals of the #1 to #5 detecting elements 60, the error is not generated in the speed detection. In order to enable the speed detection in all the lanes, as described above, it is only necessary that the product of the number of detecting elements 60 and the pitch PTms is set larger than the outermost maximum pitch PTout of the magnetic measurement line 36 in the corner section 35b. In the above example, the pitch PTms of the detecting elements 60 is 4 mm and the maximum pitch PTout of the magnetic measurement line 36 is 30 mm, so that the condition is satisfied when the number of detecting elements 60 is set to eight.

Then, a control system of the game machine 2 will be described. FIG. 19 shows a schematic configuration of the control system of the game machine 2. The game machine 2 includes the main control device 100 for controlling the whole operation of the game machine 2, plural communication devices 101 for performing communication between the main control device 100 and the motor vehicle 30, and a relay device 102 which relays communication between the communication device 101 and the main control device 100. The main control device 100 is configured by a personal computer, for example. The main control device 100 controls the progress and development of the horse-racing game performed in the game machine 2 according to a predetermined game program, and provides instructions of the degree of progress and the lane of each motor vehicle 30 through the communication device 101. For example, the main control device 100 provides, to each motor vehicle 30, the instructions of the degree of progress and the lane number which the motor vehicle 30 should reach after a predetermined device time. As described above, the degree of progress is a value expressed by the number of magnetic measurement lines 36 from the reference position Pref of FIG. 10. The motor vehicle 30 is individually managed while numbered (#1, #2, and . . . ).

The main control device 100 exchanges the information with the center server 3 and the maintenance server 4 through the network 6 of FIG. 1. The relay device 102 can be configured by a switching hub, for example. As shown in FIG. 10, the communication devices 101 are arranged around the round track 35 at predetermined intervals. Although the ten communication devices 101 are arranged in the drawing, the number of communication devices 101 may be arbitrarily changed as long as all the circumferences of the round track 35 are covered with the communication devices 101. A radio wave or the infrared ray may be used in the communication between the communication device 101 and the motor vehicle 30.

FIG. 20 shows a control system provided in the motor vehicle 30. The control system of the motor vehicle 30 includes a motor vehicle control device 110. The motor vehicle control device 110 is configured as a computer device including a microprocessor. The motor vehicle control device 110 controls the running of the motor vehicle 30 according to a predetermined motor vehicle control program, and also controls the communication with the main control device 100. The line sensor 50, the absolute position detecting sensor 51, and the magnetic sensor 52, which act as the input device for running control, are connected to the motor vehicle control device 110 through an interface (not shown). A gyro sensor 111 which acts as the input device is also connected to the motor vehicle control device 110. The gyro sensor 111 is incorporated into the motor vehicle 30 to detect an attitude of the motor vehicle 30, i.e., an orientation of the motor vehicle 30. The gyro sensor 111 detects an angular velocity about a turning axis (for example, a vertical axis line passing through an intersection point of an axis line of the drive wheel 42 and the center plane PC) of the motor vehicle 30, integrates the angular velocity twice to convert the angular velocity into an angle change amount, and outputs the angle change amount to the motor vehicle control device 110. Alternatively, the gyro sensor 111 may output an angular acceleration to allow the motor vehicle control device 110 to convert the angular acceleration into the angle change amount.

A transmitter 112 and a receiver 113 are connected to the motor vehicle control device 110 through a communication control circuit 114 to conduct communication with the communication device 101. As described above, the main control device 100 gives the information for instructing the target progress and target lane of the motor vehicle 30 at predetermined intervals during the game. The motor vehicle control device 110 computes a target speed, a direction correction amount, and the like of the motor vehicle 30 based on the given target progress and target lane and the output signals of various sensors 50 to 52 and 111, so as to provide speed instructions VL and VR to the motor drive circuit 115 based on the computation results The motor drive circuit 115 controls the drive current or voltage supplied to each motor 43 such that the given speed instructions VL and VR are obtained.

FIG. 21 shows a concept of running control of the motor vehicle 30 by the motor vehicle control device 110. In FIG. 21, it is assumed that ADcrt is the current degree of progress of the motor vehicle 30, ADtgt is the target progress given from the main control device 100, Dref is the lane direction, i.e., the direction of the guide line 34, and Dgyr is the direction in which the motor vehicle 30 is orientated. The motor vehicle control device 110 controls the speed of the motor 43 such that the motor vehicle 30 reaches a target position Ptgt given by the intersection point of the center line of the target lane and the target progress ADtgt by predetermined time from the current position Pcrt and such that the direction Dgyr of the motor vehicle 30 is in agreement with the lane direction Dref. That is, the motor vehicle control device 110 increases or decreases the drive speed of each motor 43 according to a progress shortage amount ΔAD between the current degree of progress ADcrt and the target progress ADtgt, and also controls a speed ratio between the motors 43 such that the motor vehicle 30 is moved in the transverse direction of the round track 35 by a lane correction amount ΔYamd which is given as a distance from the current position Pcrt to the center line of the target lane and such that the direction Dgyr of the motor vehicle 30 is corrected by an angle correction amount Δθamd which is given as a shift amount of a current direction θgyr to the lane direction Dref at the target position Ptgt.

Because the progress shortage amount ΔAD is given as the number of magnetic measurement lines 36, the progress shortage amount ΔAD is determined by subtracting the current degree of progress ADcrt from the target progress ADtgt in both the straight section 35a and the corner section 35b. In the corner section 35b, however, a distance Ltr corresponding to the progress shortage amount ΔAD is changed by the position of the motor vehicle 30 in the transverse direction of the round track 35, and thus, it is necessary to control the speed in consideration of the changed progress shortage amount ΔAD. The lane correction amount ΔYamd is determined by subtracting the shift amount ΔY between the current position Pcrt of the motor vehicle 30 and the current lane from a lane interval Ychg corresponding to a distance between the target lane and the lane on which the motor vehicle 30 runs currently. In the case when the target lane is in agreement with the current lane, namely, in the case when the instruction for changing the lane is not provided, the lane correction amount ΔYamd is equal to the shift amount ΔY. A straight-ahead direction from the reference position Pref of FIG. 10 is set to an absolute reference direction Dabs, and angles θref and θgyr are set with respect to the absolute reference direction Dabs, which allows the lane direction Dref and the motor vehicle direction Dgyr to be specified. In the straight section 35a, the angle θref is 0° or 180°. In the corner section 35b, the angle formed by a tangential direction of the guide line 34 in the degree of progress ADcrt and the absoluter reference direction Dabs can be specified as θref. The tangential direction is uniquely determined by the degree of progress, and the tangential direction is kept constant irrespective of the lane in the case of the same degree of progress.

FIG. 22 is a functional block diagram of the motor vehicle control device 110. The motor vehicle control device 110 includes a game information analysis device 120 which analyzes the game information given from the main control device 100 to make the determination of the target progress ADtgt and the target lane of the motor vehicle 30; a progress counter 121 which stores therein the current degree of progress ADcrt of the motor vehicle 30; a progress management device 122 which computes the current speed Vact of the motor vehicle 30 while updating a value of the progress counter 121 according to the outputs of the absolute position detecting sensor 51 and the magnetic sensor 52; a lane counter 123 which stores therein the lane number on which the motor vehicle 30 runs currently; a lane management device 124 which, on the basis of the output of the line sensor 50 and the absolute position detecting sensor 51 to update the value of the lane counter 123, and detects the lane shift amount ΔY of the motor vehicle 30 relative to the lane; a gyro counter 125 which stores therein the angle θgyr indicating the direction of the motor vehicle 30; and a direction management device 126 which determines the angle θgyr of the motor vehicle 30 to update a value of the gyro counter 125 based on the output of the gyro sensor 111.

The motor vehicle control device 110 also includes a target speed computation device 127 which computes the target speed Vtgt of the motor vehicle 30 based on the target progress ADtgt, the degree of progress ADcrt stored in the progress counter 121, and the lane number stored in the lane counter 123; a speed setting device 128 which sets the drive speed of the motor 43 of the motor vehicle 30 based on the target speed Vtgt; a speed FB-correction device 129 which performs feedback correction to the set drive speed according to a difference between the target speed Vtgt and the current speed Vact; a lane correction amount computation device 130 which computes the lane correction amount ΔYamd of the motor vehicle 30 based on the target lane, the lane number of the lane counter 123, and the lane shift amount ΔY of the motor vehicle 30 determined by the lane management device 124; a direction correction amount computation device 131 which computes the direction correction amount Δθamd of the motor vehicle 30 based on the degree of progress ADtgt stored in the progress counter 121 and the angle θgyr stored in the gyro counter 125; and a speed-ratio setting device 133 which sets a speed ratio between the motors 43 based on the lane correction amount ΔYamd and the direction correction amount Δθamd. The speed-ratio setting device 133 determines the speed instructions VL and VR of the right and left motors 43, and the instructions are outputted to the motor drive circuit 115 of FIG. 20. The motor vehicle control device 110 further includes a line width inspection device 136 which inspects the line width of the guide line 34 based on the output of the line sensor 50, the degree of progress ADcrt stored in the progress counter 121, and the direction correction amount Δθamd computed by the direction correction amount computation device 131.

Processes of the devices in the motor vehicle control device 110 will be described below with reference to FIGS. 23 to 30. FIG. 23 is a flowchart showing a process at the progress management device 122. The progress management device 122 monitors the output of the magnetic sensor 52 to mange the degree of progress ADcrt of the progress counter 121, and computes the current speed Vact of the motor vehicle 30. That is, in Step S101, the progress management device 122 determines whether or not the output of the detecting element #1 (60) of the magnetic sensor 52 is inverted. When the output of the detecting element #1 (60) is inverted, the progress management device 122 adds one to the value ADcrt of the progress counter 121 in Step S102. In Step S103, the progress management device 122 sets a variable m for identifying a detecting element's number to two. When the output of the detecting element #1 (60) is not inverted, the flow skips Steps S102 and S103. In Step S104, the progress management device 122 determines whether or not the output of the detecting element #m (60) is inverted. When the output of the detecting element #m (60) is inverted, the flow goes to Step S105 to compute the current speed Vact. Assuming that tact is the time interval between the previous output inversion of the detecting element # (m−1) (60) and the output inversion of the sensor at this time, the current speed Vact can be computed by dividing the pitch PTms of the detecting element 60 by the time interval tact (for example, the time interval between t1 and t2 in FIG. 17B). That is, Vact=PTms/tact.

After the current speed Vact is computed, the variable m is incremented by one in Step S106. In Step S107, the progress management device 122 determines whether or not the absolute position detecting sensor 51 detects the absolute position, namely, whether or not the absolute position detecting sensor 51 detects the infrared light from the indication lamp 38. When the absolute position detecting sensor 51 does not detect the infrared light from the indication lamp 38, the flow returns to Step S101. On the other hand, when the absolute position detecting sensor 51 detects the infrared light from the indication lamp 38 in Step S107, the progress management device 122 determines the progress information coded in the infrared light, and corrects the progress counter 121 such that the determined progress matches with the degree of progress ADcrt of the progress counter 121. Then, the flow returns to Step S101. When the output of the detecting element #m (60) is not inverted in Step S104, the flow skips Steps S105 and S106 to go to Step S107.

According to the above process, the value ADcrt of the progress counter 121 is incremented by one in each time the detecting element #1 (60) measures the magnetic measurement line 36. Additionally, the absolute position detecting sensor 51 detects the signal from the absolute-position indicating device 37, which appropriately corrects the degree of progress ADcrt. Therefore, the position of the motor vehicle 30 in the longitudinal direction of the round track 35 can be recognized from the value of the progress counter 121. The current speed Vact of the motor vehicle 30 is computed in each time the motor vehicle 30 moves by the pitch PTms of the detecting element 60 of the magnetic sensor 52.

FIG. 24 is a flowchart showing a procedure of computing a target speed performed by the target speed computation device 127. In Step S121, the target speed computation device 127 obtains the value ADcrt of the progress counter 121. In Step S122, the target speed computation device 127 determines whether or not the progress counter 121 is updated after the previous process. When the progress counter 121 is not updated, the flow returns to Step S121. When the progress counter 121 is updated, the flow goes to Step S123. In Step S123, the progress shortage amount ΔAD (=ADtgt−ADcrt) is determined by subtracting the value ADcrt of the progress counter from the target progress ADtgt. In Step S124, the current lane is obtained from the lane counter 123.

In Step S125, the target speed computation device 127 estimates the number of times Nx of the output inversion of the magnetic sensor 52 (number of counted inversions), which should be detected before the motor vehicle 30 reaches the next degree of progress on the basis of the current degree of progress ADcrt and the lane on which the motor vehicle 30 runs currently. That is, the target speed computation device 127 estimates, as the number of counted inversions Nx, a value (quotient) obtained by dividing the pitch PTx of the magnetic measurement line 36 between the current degree of progress ADcrt and the next degree of progress ADcrt+1 by the pitch PTms of the detecting element 60. When a fraction after decimal point is included in the quotient, the quotient is rounded to the whole number by counting the fraction as one or zero or rounding it off. The lane number is used to specify the pitch PTx. In a case when the motor vehicle 30 runs in the straight section 35a and on the innermost lane of the corner section 35b, the reference pitch PTm of FIG. 9 is equal to the pitch PTx of the detecting element 60. On the other hand, when the target speed computation device 127 determines that the motor vehicle 30 runs on the corner section 35b base on the degree of progress ADcrt, the target speed computation device 127 can obtain the pitch PTx corresponding to the lane number from previously prepared data such as a table.

After the number of counted inversions Nx is estimated, the flow goes to Step S126 to compute an inversion reference time tx. As shown in FIG. 25, assuming that Trmn is a remaining time from the current time to the time when the motor vehicle 30 should reach the target progress ADtgt and that the output of each of the detecting elements 60 of the magnetic sensor 52 is sequentially inverted in a constant interval of time tx in the remaining time Trmn, the remaining time Trmn is given by a product of time tx multiplied by the number of counted inversions Nx and the progress shortage amount ΔAD. That is, in order that the motor vehicle 30 reaches the target progress ADtgt at a time to attain the target progress, the motor vehicle 30 has to run a distance corresponding to the progress shortage amount ΔAD at such a speed that the output of the detecting element 60 is inverted at the interval of time tx. Due to the above relationship, the inversion reference time tx is determined by dividing the remaining time Trmn by the product of the number of counted inversions Nx and the progress shortage amount ΔAD (tx=Trmn/(Nx·ΔAD)). In other words, when the progress is incremented by one when the output inversions are detected N-times in the inversion reference time tx, and this is repeated the number of times corresponding to the progress shortage amount ΔAD, the motor vehicle 30 reaches the target progress ADtgt at the time to attain the target progress. For example, the time to attain the target progress can be set to a time when the next target progress and target lane are given by the main control device 100 of the game machine 2 or a constantly delayed time relative to the above time. However, it is necessary that the times to attain the target progress are equally set for all the motor vehicles 30 used in a same race.

Returning to FIG. 24, after the inversion reference time tx is computed, the flow goes to Step S127, the quotient is obtained as the target speed Vtgt by dividing the pitch PTms of the detecting element 60 by the inversion reference time tx. The target speed Vtgt is the speed of the motor vehicle 30 necessary to invert the outputs of the magnetic sensor 52 sequentially at the interval of inversion reference time tx. After the target speed Vtgt is obtained in Step S127, the flow returns to Step S121. Accordingly, the progress shortage amount ΔAD is updated in each time the value ADcrt of the progress counter is updated, and the number of counted inversions Nx is estimated based on the number of lanes at that time so as to determine the target speed Vtgt. That is, the target speed Vtgt is updated in each time the progress of the motor vehicle 30 is incremented by one.

As described in FIG. 22, the target speed Vtgt computed by the target speed computation device 127 is given to the speed setting device 128 and the speed FB-correction device 129. The speed setting device 128 sets the drive speed of the motor 43 such that the given target speed Vtgt is obtained, and the speed FB-correction device 129 gives an FB-correction amount according to the difference between the target speed Vtgt and the current speed Vact with respect to the drive speed. Alternatively, feedback control or feedforward control of the speed may be performed to enhance the accuracy of speed control, response and the like using a derivative value or an integration value of the speed difference.

FIG. 26 is a flowchart showing a procedure of managing the value of the gyro counter 125, which is performed by the direction management device 126. In Step S141, the direction management device 126 obtains the angle change amount outputted from the gyro sensor 111. In Step S142, the direction management device 126 updates the value θgyr of the gyro counter 125 by adding the angle change amount to the value θgyr of the gyro counter 125 or by subtracting the angle change amount from the value θgyr of the gyro counter 125. As a consequence, the angle θgyr indicating the current direction of the motor vehicle 30 is stored in the gyro counter 125. Desirably the calibration is performed at proper timing in order that the angle θgyr of the gyro counter 125 is set to 0° when the motor vehicle 30 is orientated toward the absolute reference direction Dabs. The calibration is realized as follows. The determination whether or not the motor vehicle 30 runs on the straight section 35a from the reference position Pref in parallel with the lane direction is made based on the degree of progress ADcrt of the progress counter 121 and the output of the line sensor 50, and the angle θgyr is reset to 0° when the motor vehicle 30 runs in parallel with the lane direction. The calibration may be performed during the horse-racing game or the calibration may be performed at proper timing before the race, e.g., in starting up the game machine 2.

FIG. 27 is a flowchart showing a procedure of computing the direction correction amount Δθamd, which is performed by the direction correction amount computation device 131. In Step S161, the direction correction amount computation device 131 obtains the value ADcrt of the progress counter. In Step S162, the direction correction amount computation device 131 determines the angle θref of the reference direction from the degree of progress ADcrt. As described above, the angle θref of the reference direction is uniquely determined while correlated with the degree of progress AD. The angle θref of the reference direction is 0° or 180° in the straight section 35a, and is the tangential direction of the guide line 34 in the corner section 35b. When the correlation between the degree of progress AD and the reference direction θref is previously stored in data such as a table, the angle θref of the reference direction can immediately be determined from the value ADcrt of the progress counter. In Step S163, the direction correction amount computation device 131 obtains the value θgyr of the gyro counter 125. In Step S164, the direction correction amount computation device 131 computes the difference between the angle θref and the angle θgyr as the direction correction amount Δθamd (see FIG. 21). Then, the flow returns to Step S161. The determined direction correction amount Δθamd is given to the speed-ratio setting device 133, and the direction correction amount Δθamd is also given to the lane management device 124 and the line width inspection device 136.

FIG. 28 is a flowchart showing a process performed by the lane management device 124. The lane management device 124 determines the lane shift amount ΔY (see FIG. 21) by referring to the output of the line sensor 50 and the direction correction amount Δθamd, and also manages the value of the lane counter 123 using the lane shift amount ΔY. In Step S181, the lane management device 124 obtains the direction correction amount Δθamd from the direction correction amount computation device 131. In Step S182, the lane management device 124 captures the output of the line sensor 50 to detect the lane shift amount ΔY. FIG. 29 shows an example of a correlation between the output of the line sensor 50 and the lane shift amount ΔY. An analog signal is outputted from the line sensor 50 according to intensity of the reflected light, and a rectangular wave corresponding to the guide line 34 and the blank portion between the guide lines 34 is obtained when the analog signal is binarized with a proper threshold. The number of dots ΔNdot between the center of the detection region of the line sensor 50 and the center of the luminous region corresponding to the guide line 34 (the center of the lane) is determined from the rectangular wave. The number of dots ΔNdot corresponds to the lane shift amount ΔY, and the line width per one dot can be multiplied by the number of dots ΔNdot to determine the lane shift amount ΔY. However, in the case when the direction of the motor vehicle 30 is shifted from the reference direction Dref (see FIG. 21), the line sensor 50 is also inclined with respect to the direction orthogonal to the guide line 34. As a result, the number of dots ΔNdot is also increased according to the inclination. Therefore, it is necessary that the correct lane shift amount ΔY be obtained by multiplying the lane shift amount ΔY obtained from the number of dots ΔNdot by a cosine value cos Δθamd of the direction correction amount. Accordingly, it is necessary to obtain the direction correction amount Δθamd in Step S181 of FIG. 28. In FIG. 29, the width Wg (see FIG. 9) of the guide line 34 can be detected by similarly correcting the number of dots ΔNdot included in the luminous region corresponding to the guide line 34 using the direction correction amount Δθamd.

Returning to FIG. 28, after the lane shift amount ΔY is detected in Step S182, the flow goes to Step S183. In Step S183, the lane management device 124 determines whether or not the motor vehicle 30 is moved to the next lane. For example, in the case when the lane shift amount ΔY is larger than the half of the pitch PTg of the guide line 34, the lane management device 124 can determine that the motor vehicle 30 is moved to the next lane. Alternatively, the distances to the guide line 34 detected on both sides of the center of the line sensor 50 are compared to each other, and the lane management device 124 may determine that the motor vehicle 30 is moved to the next lane when the magnitude correlation is inverted. When the lane management device 124 determines that the motor vehicle 30 is moved to the next lane in Step S183, the value of the lane counter 123 is updated to the value corresponding to the next lane. When the lane management device 124 determines that the motor vehicle 30 is not moved to the next lane in Step S183, the flow skips Step S184.

In Step S185, the lane management device 124 determines whether or not the absolute position detecting sensor 51 detects the absolute position. When the absolute position detecting sensor 51 does not detect the absolute position, the flow returns to Step S181. On the other hand, when the lane management device 124 determines that the absolute position detecting sensor 51 detects the absolute position in Step S185, the lane management device 124 determines the lane number coded in the infrared light from the absolute-position indicating device 37, and corrects the value of the lane counter 123 such that the determined lane number is equal to the value of the counter 123. Then, the flow returns to Step S181. The lane shift amount ΔY determined in the above process is given to the lane correction amount computation device 130.

FIG. 30 is a flowchart showing a procedure in which the lane correction amount computation device 130 computes the lane correction amount ΔYamd. In Step S201, the lane correction amount computation device 130 obtains the target lane from the game information analysis device 120. In Step S202, the lane correction amount computation device 130 obtains the value (current lane number) of the lane counter 123. In Step S203, the lane correction amount computation device 130 obtains the lane shift amount ΔY from the lane management device 124. In Step S204, the lane correction amount computation device 130 determines whether or not the target lane is matched with the lane. When the target lane is matched with the lane, the flow goes to Step S205. In Step S205, the lane correction amount computation device 130 sets the lane shift amount ΔY to the lane correction amount ΔYamd. Then, the flow returns to Step S201. When the target lane is not matched with the lane in Step S204, the flow goes to Step S206. In Step S206, the lane correction amount computation device 130 sets the value obtained by adding the lane interval Ychg (see FIG. 21) to the lane shift amount ΔY, to the lane correction amount ΔYamd. Then, the flow returns to Step S201. The lane shift amount Ychg is obtained by multiplying the difference in number between the target lane and the current lane by the pitch PTg (see FIG. 10) of the guide line 34.

Through the process of FIG. 30, the distance in the transverse direction in which the motor vehicle 30 should be moved to the target lane is computed as the lane correction amount ΔYamd. As described in FIG. 22, the computed lane correction amount ΔYamd is given to the speed-ratio setting device 133. The speed-ratio setting device 133 determines the speed ratio, generated between the motors 43, based on the given lane correction amount ΔYamd and the direction correction amount Δθamd. The speed-ratio setting device 133 increases or decreases the drive speed, given from the speed FB-correction device 129, according to the speed ratio to determine the speed instructions VL and VR to the right and left motors 43. At this point, a difference in speed between the motors 43 is generated according to the speed ratio, and the speed instructions VL and VR are generated such that the drive speed obtained by combining the speeds is equal to the drive speed given from the speed FB-correction device 129. The generated speed instructions VL and VR are given to the motor drive circuits 115 of FIG. 19. The drive circuits 115 drive the motors 43 at instructed speeds, whereby the motor vehicle 30 reaches the target progress ADtgt in a predetermined time and the control is performed such that the direction Dgyr of the motor vehicle 30 is matched with the reference direction Dref. The feedback control or the feed forward control may be performed to the speed ratio to enhance a tracking property to the target lane, the accuracy of direction correction control, the responsibility and the like using the derivative values and integration values of the lane correction amount ΔYamd and direction correction amount Δθamd and the angular acceleration detected by the gyro sensor 111.

According to the series of processes described above, the target speed Vtgt of the motor vehicle 30 is given in each time the degree of progress of the motor vehicle 30 is incremented by one, and the current speed Vact of the motor vehicle 30 is sequentially computed in each time the motor vehicle 30 is moved by the distance corresponding to the pitch PTms of the detecting element 60. Therefore, the speed of the motor vehicle 30 can be controlled rapidly and accurately. The detecting elements 60 enough to cover the maximum pitch PTms of the magnetic measurement line 36 therewith are provided in the magnetic sensor 52. As a consequence, the current speed Vact can be detected with high resolution according to the pitch PTms irrespective of the pitch PTx of the magnetic measurement line 36 even if the motor vehicle 30 runs in any lane of the corner section 35b. Accordingly, the error of the speed control in which the current speed Vact is used can be restrained to a low level, and a speed fluctuation can effectively be restrained when the motor vehicle 30 runs on the corner section 35b.

The gyro sensor 111 is provided to detect the direction of the motor vehicle 30, and the shift between the detected direction and the direction of the target lane is given as the direction correction amount Δθamd to the speed-ratio setting device 133. Therefore, the accuracy of control is improved compared with the case in which the position and direction in the transverse direction of the motor vehicle 30 are controlled based on only the output of the line sensor 50. The angle change amount, the angular velocity change, or the angular acceleration is determined using the output of the gyro sensor 111 to be used in the direction control of the motor vehicle 30. Therefore, the motor vehicle 30 is converged to the target lane more smoothly and rapidly, and the orientation of the motor vehicle 30 can be matched with the target direction correctly and rapidly.

The direction correction amount Δθamd to the target direction of the motor vehicle 30 can immediately be determined from the output of the gyro sensor 111. In the determination of the lane shift amount ΔY with the output of the line sensor 50, the shift amount ΔY can correctly be detected using the direction correction amount Δθamd. Accordingly, it is possible to improve the accuracy of lane tracking of the motor vehicle 30 or the accuracy of moving control to the target lane.

FIG. 31 is a flowchart showing a process in a line width inspection device 136. In Step S221 of FIG. 31, the line width inspection device 136 obtains the value ADcrt of the progress counter 121. The line width inspection device 136 obtains the value of the lane counter 123 in Step S222, and obtains the direction correction amount Δθamd in Step S223. In Step S224, the line width inspection device 136 computes the line width of the current lane from the output of the line sensor 50. As described in FIG. 29, in order to determine the line width, the number of dots Ndot is determined from the output of the line sensor 50, the line width per dot is multiplied by the number of dots Ndot, and the correction is performed to the computed line width according to the direction correction amount Δθamd. In Step S225, the line width inspection device 136 determines whether or not the computed line width exists within a predetermined allowable range. When the computed line width exists within the predetermined allowable range, the flow returns to Step S221. When the computed line width exists exceeds the predetermined allowable range line width, the flow goes to Step S226. In Step S226, the data in which the detected line width is correlated the detection position, i.e., the value ADcrt of the progress counter and the value of the lane counter is stored as the line width inspection data in the storage device of the motor vehicle control device 110. Then, the flow returns to Step S221. The allowable range of the line width can be determined in consideration of an error generation frequency in the running control of the motor vehicle 30, which is obtained by increasing or decreasing the line width of the guide line 34 with respect to the original line width Wg. For example, when the original width Wg of the guide line 34 is 6 mm while the actual line width is in the range of ±2 mm, the allowable range can be set in the range of 4 to 8 mm in the case when a trouble is not actually generated in the running control of the motor vehicle 30.

The apparent increase or decrease in width of the guide line 34 due to, for example, the dirt of the lower-stage running surface 18, the mixture of the foreign matter, and the peel-off of the guide line 34 can be detected through the above process. The generation of the dirt, flaw or the like in the linear shape which is wrongly detected as the guide line can be detected as the anomaly of the line width. The abnormal point of the line width can also be detected by the degree of progress and lane of the round track 35 using the stored data. In the embodiment, the output of the line sensor 50 is referred to in the detection of the lane shift amount ΔY, the determination of the current lane, and the computation of the lane correction amount ΔYamd. Therefore, in the case when the width of the guide line 34 is changed due to the dirt or the like, the tracking property of the motor vehicle 30 to the guide line 34 is degraded by the influence of the changed width, and malfunction such as unstable behavior in changing the lane is possibly generated. Accordingly, the periodic check and cleaning of the lower-stage running surface 18 are required. The data produced by the line width inspection device 136 can effectively be used in such work operations.

Although the number of dots Ndot is converted into the line width in the above process, it may be determined whether or not the line width exists within the allowable range using the value in which the number of dots Ndot is corrected by the angle Δθamd. The angle correction may be neglected to determine whether or not the line width exists within the allowable range using the number of dots Ndot. For example, in the case when the running control is performed such that the direction correction amount Δθamd of the motor vehicle 30 is restricted to a constant range, the number of dots Ndot on the line sensor 50 is previously determined, and it may be determined that the line width exceeds the allowable range when the detected number of dots exceeds the number of dots Ndot on the line sensor 50. The number of dots Ndot on the line sensor 50 corresponds to the guide line width Wg in the case when the direction correction amount Δθamd becomes the maximum. In this case, it is not necessary that the inclination be corrected with the direction correction amount Δθamd. On the other hand, for the lower limit value of the line width, on the basis of the detected number of dots corresponding to the line width Wg in the case when the motor vehicle 30 proceeds straight along the guide line 34, it may be determined that the line width is lower than the allowable range when the detected number Ndot of dots is lower than the reference value.

The line width inspection may be performed during the horse-racing game by the line width inspection device 136 as needed or may appropriately be performed when the race is not performed. For example, in a proper period during which the race is not performed, the line width inspection may be performed such that the main control device 100 provides the instruction for performing line width inspection to cause the motor vehicle 30 to run along the round track 35 in a predetermined running pattern. In the above embodiment, the signal outputted from the line sensor 50 is binarized to distinguish the black portion in the running surface 18 from the white portion. Alternatively, the line sensor 50 outputs an analog signal waveform, and the analog signal waveform is digitalized with 256 levels of gray to detect colored portions except for the white and black portions, and the colored portion may be recognized as the dirt and the like.

The preferable mode in which the line width inspection data obtained by the line width inspection device 136 is utilized will be described below. Because the motor vehicle 30 does not have the function of displaying the line width inspection data, the motor vehicle 30 transmits the line width inspection data to the main control device 100, and the line width inspection data is transmitted to the maintenance server 4 and the like through the network 6 as necessary, which allows the line width inspection data to be effectively used. The method of utilizing the line width inspection data will be described below.

FIG. 32 is a flowchart showing a procedure of transmitting the line width inspection data from the motor vehicle 30 to the main control device 100. In Step S241, the motor vehicle control device 110 determines whether or not it is good time the line width inspection data is transmitted. When the motor vehicle control device 110 determines it is good time the line width inspection data is transmitted, the flow goes to Step S242. In Step 242, the motor vehicle control device 110 transmits the line width inspection data to the main control device 100. On the other hand, in Step S301, the main control device 100 determines whether or not the inspection data is transmitted from the motor vehicle 30. When the main control device 100 determines that the inspection data is transmitted, the flow goes to Step S302. In Step S302, the main control device 100 stores the line width inspection data in the storage device thereof. Then, the flow returns to Step S301. The time the line width inspection data is transmitted can be set to the time the transmission of the line width inspection data has no influence on the control of the horse-racing game, and the proper time after the race is ended can be set to the transmission time.

FIG. 33 is a flowchart showing a procedure of managing the line width inspection data. The procedure is performed by the main control device 100 to manage the line width inspection data transmitted from the motor vehicle 30 at an appropriate time after the main control device 100 receives the line width inspection data. In Step S321 of FIG. 33, the main control device 100 analyzes the line width inspection data received from the motor vehicle 30, and produces running surface warning data. In Step S322, the main control device 100 stores the running surface warning data in the storage device of the main control device 100. Because the line width inspection data includes the line width which is determined as out of allowable range and the detection position (degree of progress and lane number) of the line width which is determined as out of allowable range, the number of detection times is counted in each detection position, and the data in which the detection position is correlated with the number of detection times is produced and stored as the running surface warning data. The counting of the number of detection times may be neglected to retain only the detection position in the running surface warning data. The detection position may be neglected to retain only the number of detection times in the running surface warning data. It is not always necessary that the detection position be correlated with the magnetic measurement line 36 one by one, but at least two adjacent magnetic measurement lines 36 may collectively be regard as one detection position. In this case, the amount of running surface warning data can be reduced. As shown by an alternate long and short dash line in FIG. 10, the round track 35 is divided into plural zones Z1 to Z10, the number of detection times is counted in each zone, and the data in which the number of detection times is correlated with the zone may be produced as the running surface warning data.

Returning to FIG. 33, after the running surface warning data is stored; the flow goes to Step S323. In Step S323, the main control device 100 confirms the amount of running surface warning data. In Step S324, the main control device 100 determines whether or not the amount of running surface warning data exceeds a predetermined allowable amount. The main control device 100 sets the warning flag to one in Step S325, when the amount of running surface warning data exceeds the predetermined allowable amount. In Step S326, the main control device 100 transmits the running surface warning data to the maintenance server 4. Then, the process is ended. The main control device 100 sets the warning flag to one in Step S325, when the amount of running surface warning data does not exceed a predetermined allowable amount in Step S324. Then, the process is ended.

FIG. 34 is a flowchart showing a procedure of running surface check management performed by the main control device 100 to display a running surface check screen based on the running surface warning data to an operator (manager) of the game machine 2. The process of FIG. 34 is performed based on the instruction of the operator, for example, when the game machine 2 is controlled in a maintenance mode. In Step S341 of FIG. 34, the main control device 100 determines whether or not the warning flag is 1. When the warning flag is 1, the flow goes to Step S342 to display a predetermined warning. It is assumed that the warning display includes a message for urging the operator to inspect or clean the running surface. When the warning flag is not 1, the flow skips Step S342. In Step S343, the main control device 100 reads the running surface warning data. In Step S344, the main control device 100 displays the running surface check screen based on the running surface warning data. Then, the process is ended.

For example, the running surface check screen can be configured as shown in FIG. 35. In this example, a course whole view 80 in which the round track 35 is illustrated in a planar manner is displayed on the screen while dots 81 are superposed on the detection position of the course whole view 80. The number of detection times may be recognized by changing the display aspect of the dot 81 according to the number of detection times. In FIG. 35, a diameter of the dot 81 is enlarged as the number of detection times is increased. Alternatively, the color of the dot 81 may be changed according to the number of detection times. The zone where the inspection or cleaning is required may be indicated more clearly to the operator by showing the zone where the number of detection times exceeds the predetermined threshold in the mode different from other zones. In FIG. 35, the zones Z4, Z9, and Z10 are displayed in the mode different from other zones, whereby it is shown that the necessity of the inspection or cleaning is enhanced in the zones Z4, Z9, and Z10. Furthermore, the zones Z4 and Z9 are displayed in the mode different from the zone Z10, whereby it is shown that the necessity of the inspection or cleaning is further enhanced in the zones Z4 and Z9 compared with the zone Z10.

The running surface check screen is not limited to the example shown in FIG. 35. The dot 81 may be neglected to show only the zone where the inspection or cleaning is required. The display change in each zone may be neglected to show only the detection position with the dot 81. The detection position is not limited to the dot, but the detection position may be indicated by an appropriate index. The course overall view 80 is displayed as a perspective view, and a bar graph of a height according to the number of detection times may be displayed in the detection position.

In FIG. 34, when the display of the running surface check screen is instructed by the operator, the warning flag is checked to determine whether or not the warning display is required. The warning display is not limited to the example of FIG. 34, but the warning display may be performed at appropriate timing. For example, the amount of running surface warning data is recognized in starting up the game machine 2, and the warning display may be performed when the amount of running surface warning data exceeds the allowable amount. In performing the warning display, the operator may be asked whether or not the running surface check screen is displayed along with the warning display.

FIG. 36 is a flowchart showing a procedure of processing a maintenance mode which is performed by the main control device 100 when the operator instructs the maintenance mode for the purpose of the inspection, cleaning or the like of the lower-stage running surface 18. In the case when the instruction of the maintenance mode is provided, in Step S361, the main control device 100 provides for starting up the stage drive device 21 (see FIG. 3) to raise the stage 15. Because the sufficient space is generated between the lower-stage running surface 18 and the power supply surface 20 by raising the stage 15, the operator can easily inspect or clean the lower-stage running surface 18.

In Step S362, the main control device 100 determines whether or not the operator provides the instruction for ending the maintenance. When the operator provides the instruction, the flow goes to Step S363. In Step S363, the main control device 100 lowers the stage 15. In Step S364, the main control device 100 makes a confirmation to the operator whether or not the running surface warning data is deleted. In Step S365, the main control device 100 determines whether or not the operator provides the instruction for deleting the running surface warning data. When the operator provides the instruction, the main control device 100 deletes the running surface warning data, namely, the main control device 100 deletes the running surface warning data in Step S366. Then, the process is ended. On the other hand, when the operator does not provide the instruction in Step S365, the flow skips Step S366, and the process is ended.

The running surface warning data is transmitted to the maintenance server 4 in Step S326 of FIG. 33. Alternatively, the running surface check screen shown in FIG. 35 may be displayed to confirm the state of the running surface 18 by performing the process similar to that of the main control device 100 even in the maintenance server 4 which receives the running surface warning data. The running surface warning data may be analyzed more finely with the maintenance server 4. The state of the lower-stage running surface 18 is confirmed with the maintenance server 4, and the server manager may urge the operator of the store where the game machine 2 is installed to perform the cleaning and the like. The line width inspection data is transmitted to the maintenance server 4, the maintenance server 4 produces the running surface warning data, and the running surface check screen or the warning may be displayed based on the running surface warning data.

In the above embodiment, the power supply surface 20 is provided on the backside of the top board 17 of the stage 15. However, the invention can be applied to a field unit in which the power supply surface is provided in a different position. The invention can also be applied to a field unit in which the power supply surface is not provided when the motor vehicle is powered by a built-in battery. The invention is not limited to the lift drive device in which the hydraulic cylinder is used as actuator. For example, the rotational motion of the motor may be converted into the lifting motion of the upper structure by the motion-concerting mechanism such as a rack and pinion mechanism and a ball screw mechanism. The upper-stage running surface may be the surface of water.

The application of the field unit according to the invention is not limited to the game machine in which the horse racing game is performed. The invention can be applied not only to a field unit of a network connected game machine but also to a field unit of a stand-alone type game machine which is disconnected from the network.