Title:
CONTROL SYSTEM FOR INDIVIDUALLY DRIVEN VEHICLES IN A TRAIN OF SUCH VEHICLES
United States Patent 3745933


Abstract:
Control system for trains of the type in which each car in the train is powered by its own drive motor means (e.g., a commuter train). Cars are addressed individually by train lines including an advance control train line which facilitates picking up an advance relay in each car successively by increasing the voltage on the advance train line in steps. The system minimizes the number of required train lines while insuring smooth acceleration and deceleration of the train.



Inventors:
Eisele, Hermann (Nellingen, DT)
Lewis, Robert R. (Pittsburgh, PA)
Application Number:
05/167140
Publication Date:
07/17/1973
Filing Date:
07/29/1971
Assignee:
WESTINGHOUSE ELECTRIC CORP,US
Primary Class:
Other Classes:
318/91
International Classes:
B60L15/32; H02P5/685; (IPC1-7): H02P1/58; B60L15/32
Field of Search:
318/90,91,102 105
View Patent Images:
US Patent References:



Primary Examiner:
Forlenza, Gerald M.
Assistant Examiner:
Libman, George H.
Attorney, Agent or Firm:
SPENCER & FRANK (WASHINGTON, DC, US)
Claims:
We claim as our invention

1. In a control system for selectively increasing and decreasing the torque exerted by each of plurality of vehicle cars operative as a vehicle train, each such vehicle car having individual vehicle car drive means controlled by a plurality of bistable devices, the combination comprising:

2. In a control system for selectively increasing and decreasing the torque exerted by each of a plurality of vehicle cars operative as a vehicle train, each such vehicle car having individual vehicle car drive means controlled by a plurality of bistable devices, the combination comprising:

3. The combination claimed in claim 2, wherein at least one of the remaining bistable devices in each vehicle car changes state for increasing torque in response to a third one of said control signals being provided and said second one of said bistable devices having previously changed state for increasing torque.

4. In a control system for selectively increasing and decreasing the torque exerted by each of a plurality of vehicle cars operative as a vehicle train, each such vehicle car having individual vehicle car drive means controlled by a plurality of bistable devices, the combination comprising:

5. The combination claimed in claim 4 including a third one of said plurality of bistable devices on said given vehicle car being responsive to either one of (a) a third one of said plurality of control signals or (b) said first one of said plurality of control signals and said second one of said plurality bistable devices being in the second bistable state, for changing from a first bistable state to a second bistable state for further increasing the torque exerted by said given vehicle car.

6. The combination claimed in claim 5 including a fourth one of said plurality of bistable devices on said given vehicle car being responsive to said third one of said plurality of control signals and said second one of said plurality of bistable devices being in the second bistable state, for changing from a first bistable state to a second bistable state for further increasing the torque exerted by said given vehicle car.

7. The combination claimed in claim 6 including a fourth one of said plurality of control signals, which functions as a holding signal and is applied to said third and fourth ones of said plurality of bistable devices when said third and fourth ones of said plurality of bistable devices are respectively in the second bistable state for maintaining said bistable devices in the second bistable state.

8. The combination claimed in claim 4 including a third one of said plurality of bistable devices on said given vehicle car being responsive to a third one of said plurality of control signals for changing from a first bistable state to a second bistable state for further increasing the torque exerted by said given vehicle car.

9. The combination claimed in claim 8 including a fourth one of said plurality of bistable devices on said given vehicle car being responsive to a fourth one of said plurality of control signals for changing from a first bistable state to a second bistable state for further increasing the torque exerted by said given vehicle car, and including means for maintaining said fourth bistable device in said second bistable state in response to said first one of said plurality of control signals and either one of said second or third ones of said plurality of bistable devices, being in the second bistable state.

10. The combination claimed in claim 9 including a fifth one of said plurality of bistable devices on said given vehicle car being responsive to (a) said fourth one of said plurality of control signals and (b) said second and third ones of said plurality of bistable devices being concurrently in the second bistable state, for changing from a first bistable state to a second bistable state for further increasing the torque exerted by said given vehicle car.

11. The combination claimed in claim 10 including means for maintaining said fifth one of said plurality of bistable devices in said second bistable state in response to either one of said second and third ones of said plurality of bistable devices being in the second bistable state.

Description:
BACKGROUND OF THE INVENTION

In a conventional subway system or the like, all the cars in the train are controlled simultaneously by train lines. As soon as a train line is energized or deenergized, a relay is picked up or dropped in every car while the whole train moves to a higher or lower power position. With a control system of this type, the torque in the motoring mode can only be changed in coarse steps for positions which allow continuous operation. This ordinarily results in rough operation (e.g., jerks) during acceleration or deceleration. This is due, at least in part, to the normal play in the couplers between cars.

The operation of a train of this type can be improved with a control system wherein the head-end can address each car individually in sequence. That is, a smoother ride can be effected by addressing cars individually with a so-called "advance control train line" which allows picking up advance relays successively in each car by increasing the voltage on an advance train line in steps. In this way, one car after another will move successively to the next higher power position; the smoothness of the ride will be improved; and the cars can only be apart by one step from any other car in the train.

In any advance control train line system of this type, it is naturally desirable to use as few individual train lines as possible. An advance control train line system can be effected utilizing only two or three train lines, when three train lines are used one is an advance train line and the other two of which have steady-state voltages selectively applied thereto. The problem with systems utilizing only two or three individual train lines, however, is that they require perfect timing of the voltage signals applied to the main train lines and the advance control train line, combined with a guaranteed fast response of the advance train line relays and slow response of the main relays. In an actual application with many subway cars, for example, this represents an impractical solution because of the tight tolerances required.

SUMMARY OF THE INVENTION

In accordance with the present invention, a control system is provided for addressing powered cars in a train individually in an advance control train line arrangement wherein the train lines need only be energized in a given sequence, without regard to accurate timing. This requires the addition of a another train line which, while increasing the complexity of the system slightly, enables the cars of the train to be addressed in sequence without precise timing.

The above and other objects and features of the invention will become apparent from the following detailed description taken in connection with the accompanying drawings which form a part of this specification, and in which:

FIG. 1 is a schematic circuit diagram of a type of circuit for sequentially energizing electrical relays, usable in the circuitry of the invention;

FIG. 2A is a schematic circuit diagram of one embodiment of the invention for addressing cars in a train sequentially;

FIG. 2B is a timing diagram showing the sequence of operation of the relays of FIG. 2A;

FIG. 3A is a schematic circuit diagram of another embodiment of the invention; and

FIG. 3B illustrates the timing sequence of the relays for the embodiment of the invention shown in FIG. 3A.

With reference now to the drawings, and particularly to FIG. 1, the circuit shown is adapted to energize relays in sequence as a source of voltage applied to a train line is increased. This circuitry is utilized in the present invention and is the subject of copending application entitled "Apparatus For Sequentially Electrical Utilization Devices," Ser. No. 167,139, filed July 29, 1971, on behalf of Thomas C. Matty and Robert H. Perry and assigned to the Assignee of the present application. A train control circuit or controller 10 is connected between a train line A and a common bus 12 as shown. The train control circuit 10 is adapted to produce an output between line A and bus 12 which increases in steps, as hereinafter described in detail. Included in series in train line A are two diode bridge circuits 14 and 16 each comprised of four diodes D1, D2, D3 and D4 placed around a relay Rx or Ry. The relays R1 and R2 are connected in series with transistors 18 and 20 between the upper terminal 22 of each bridge 14 or 16 and the bus 12. The upper terminal 22 of the bridge 14 is connected through a voltage divider arrangement comprising Zener diode Z1 and resistor 24 to the power bus 12, the junction of Zener diode Z1 and resistor 24 being connected to the base of transistor 18. In a similar manner, terminal 22 of bridge 16 is connected through Zener diode Z2 and a resistor 26 to the power bus 12, the junction of Zener diode Z2 and resistor 26 being connected to the base of transistor 20.

Because of the diode bridge circuits 14 and 16, the circuit of FIG. 1 will operate to energize the relays Rx and Ry in response to a voltage applied to either end of a string of such relays connected between conductors A and 12. It is necessary only that the train line A be positive with respect to bus 12 so as to reverse bias the Zener diodes Z1, Z2, and so on.

With no voltage applied across conductors A and 12 from the train control circuit 10, both relays Rx and Ry will be deenergized. However, if a step voltage from train control circuit 10 is applied across conductors A and 12, relay Rx will be initially energized through diode D1 and transistor 18 until the point is reached where Zener diode Z1 breaks down, thereby cutting off the PNP transistor 18 because of the rise in voltage at its base. The current through relay Rx is now diverted through diode D3 of bridge 14 and the diode D1 in bridge 16 to relay Ry and transistor 20, which is now conducting. This will continue until the voltage from train control circuit 10 reaches the point where Zener diode Z2 breaks down and cuts off PNP transistor 20; whereupon the current through relay Ry will now be diverted through the next relay, and so on, until the entire string of relays is energized in sequence. Thus, increases in the voltage across conductors A and 12 cause successive relay energizations with an approximate constant current load on the line. As will be seen hereinafter, the relays Rx, Ry, and so on, are carried on successive cars in a train of cars such that the torque exerted by the cars will be increased or decreased one after the other as the voltage from train control circuit 10 is increased in steps.

With reference now to FIG. 2A, a complete train control system is shown which again includes the train control circuit 10 having four train lines 1, 2, A and D. Relays RA for car Nos. 1 and 2 in FIG. 2A correspond to and perform the same function as relays R1 and R2, respectively in FIG. 1. That is, successive ones of the relays in the Zener diode sequential firing circuitry of FIG. 1 are carried on successive cars on the train the relay RA in car 1 and car 2 respectively is shown connected directly to the lower bus bar for ease of illustration only. Also carried on each car are additional relays RD, R3, R2, and R1. Relay R1 is connected between train line 1 and common bus 12 and is energized when train line 1 is energized. The relay R2 is connected between train line 2 and common bus 12 through diode 32 in each car and can be energized through that diode when train line 2 is energized or when relays RA and RD are energized and train line 1 is energized. That is, when relays RA and RD are energized, contacts A-1 and D-1 will close, thereby enabling energization of relay R2 through the aforesaid contacts A-1 and D-1 and diode 34. Relay RD is energized in each car only when train line D is energized.

Relay R3 can be energized when train line 2 is energized and when relays RA and RD are energized, thereby closing contacts A-2 and D-2. In this case, the relay R3 in any car is energized through contacts A-2 and D-2 and diode 36.

The drive motor system for each car is simplified in FIG. 2A for purposes of explanation. The drive motors for each car in a train are identified in FIG. 2A as M1, M2, M3 and M4. These can be connected in series through normally closed contacts 3-4; or, when contacts 3-4 open and contacts 3--3 and 3-5 close, motors M1 and M2 will be connected in parallel with motors M3 and M4. The armatures of all motors M1-M4 are connected in series with resistors 38, 40 and 42, with resistors 38 and 40 being shunted by normally open contacts 2-3 and 2-4 of relay R2. Power is initially supplied to the motors M1 through M4 when relay R1 is energized and contacts 1--1 close.

The manner in which the torque produced by the drive motors is successively increased or decreased will now be described in connection with FIG. 2B. Regardless of whether it is desired to increase or decrease torque, the train line 1 must be energized, thereby energizing relay R1. This, then, closes contacts 1--1 in each car. Additionally, when it is desired to increase torque and accelerate, the relay RD must be energized; however during deceleration when torque is decreasing, relay RD is deenergized, as is the train line D.

Assuming, for the moment, that it is desired to increase torque, train line D will be energized as will relay RD, thereby closing contacts D-1 and D-2. At time t1 in FIG. 2B, a step voltage is applied to train line A, thereby causing the circuit 28, similar to one of the diode bridge circuits of FIG. 1, to energize the relay RA in car 1. When relay RA in car 1 is energized, contacts A-1 close and relay R2 is energized through train line 1, contacts A-1 and D-1 and diode 34. When relay R2 is energized, contacts 2-3 and 2-4 are closed, thereby shorting out resistors 38 and 40 in series with the motors M1-M4 as the counterelectromotive force of the motor increases. At time t2, the voltage on train line A is again increased, whereupon relay RA for car 2 is energized, and contacts 2-3 and 2-4 for car 2 close; whereupon the torque produced by the motors for car 2 increases. At time t3, train line A is deenergized as are relays RA in each car. Then, at time t4, train line 2 is energized, but nothing happens at this precise time since relay R3 cannot be energized with contacts A-2 open. At time t5, relay RA in car 1 again becomes energized, whereupon relay R3 becomes energized since contacts A-2 are now closed. When relay R3 becomes energized, contacts 3-4 open and contacts 3--3 and 3-5 close, thereby connecting the motors M1-M4 in a series-parallel arrangement whereby the torque of the car is increased while its speed increases. At time t6, the voltage on train line A is increased, whereupon relay RA for car 2 becomes energized and motors M1-M4 for car 2 are connected in a series-parallel arrangement similar to the motors for car 1. This progresses down the string of cars from one car to another in succession until all of the motors in the respective cars are connected in a series-parallel arrangement.

Now, if it is desired to decrease the torque of the motors at time t7, for example, the train line D is deenergized. Thereafter, at time t8, the voltage on train line A is decreased; whereupon relay RA for car 2 becomes deenergized as does relay R3 for car 2 such that the motors M1-M4 for car 2 are again connected in series. At time t9, train line A is deenergized, which deenergizes relay RA for car 1, causing relay R3 for car 1 to drop out and connecting motors M1-M4 for car 1 in series. At time t10, train line A is again energized to a voltage level where relays RA in both cars 1 and 2 will be energized; at time t11, train line 2 is deenergized; and at time t12, the voltage on train line A is decreased to the point where relay RA in car 2 drops out, whereupon relay R2 for car 2 drops out also and contacts 2-3 and 2-4 for car 2 again open to insert resistors 38 and 40 in series with the motors M1-M4. At time t13, train line A is deenergized and the same action takes place for car 1 with relay R2 dropping out and resistor 38 and 40 again being inserted in series with the armatures of motors M1-M4 for car 1.

In FIGS. 3A and 3B, an arrangement similar to that of FIGS. 2A and 2B is shown, except that instead of providing a directional train line, a hold train line H is provided. In this case, relay R1 is energized from train line 1 as in the embodiment of FIG. 2A. Relay R2 in any car can be energized through diode 43 from train line 2 or through diode 44 and hold line H when contacts 2-1 of relay R2 are energized. Finally, relay R2 can be energized from train line 1, assuming that contacts A-1 of relay RA are closed. Relay R3 can be energized from hold line H through diode 46 and contacts 3-1 of relay R3 or from train line 2 through contacts A-2 if relay RA is energized. The relays RA in each car are again energized from train line A through circuits 48 and 50 which comprise Zener diode delay circuits similar to those shown in FIG. 1. The motor circuits for the respective cars are not shown in FIG. 3A; however it will be appreciated that the relays R1, R2 and R3 perform the same functions as they did in the embodiment of FIG. 2A.

The operation of the embodiment of the invention shown in FIG. 3A can best be understood by reference to FIG. 3B. Regardless of whether the tractive effort is being increased or decreased, train line 1 is energized, as are relays R1 in each car 1 and 2. At time t1, train line A is energized to energize relay RA for car 1. When relay RA becomes energized, contacts A-1 close, thereby energizing relay R2. At time t2, the same action occurs for car 2 in response to an increase in voltage on train line A, thereby energizing relay R2 for car 2. At time t3, the hold line H is energized; and since contacts 2-1 of relay R2 are closed at this time, relay R2 remains energized even though the voltage on train line A should drop to zero. At time t4, train line 2 becomes energized, whereupon relay R2 will remain energized through diode 43. Up to this point, therefore, the relays R2 in cars 1 and 2 have been energized in succession. At time t5, the hold train line H is deenergized; however this has no effect since the relay R2 remains energized through train line 2 which is now energized. At time t6, the train line A is again energized to energize relay RA; and at time t7, the voltage on train line A is increased to energize the relay RA in car 2. This has the effect of energizing relays R3 in cars 1 and 2 at times t6 and t7, respectively.

During a deceleration cycle, the process is reversed. At time t8, the voltage on train line A is decreased, thereby deenergizing relay RA for car 2 and deenerging relay R3. At time t9, the voltage on train line A drops to zero, deenergizing relays RA and R3 in car 1. At time t10, the hold line H is again energized; and at time t11, the voltage on train line 2 drops to zero; however relay R2 remains energized through the hold line H, diode 44 and contacts 2-1 in each car. At time t12, the voltage on train line A is increased to the point where both relays RA in cars 1 and 2 are energized; and at time t13, the hold line voltage decreases to zero. Therefore, when the voltage on train line A at time t14 drops to one-half its original value, relay RA in car 2 becomes deenergized as does relay R2. At time t15, the voltage on train line A drops to zero, relay RA for car 1 becomes deenergized, and so also does the relay R2 for car 1 because contacts A-1 are now open.

It can be seen that the sequence of operations is similar to that for the embodiment shown in FIGS. 2A and 2B, with the exception that a hold voltage is employed rather than a directional voltage on one of the train lines.

Although the invention has been shown in connection with certain specific embodiments, it will be readily apparent to those skilled in the art that various changes in form and arrangement of parts may be made to suit requirements without departing from the spirit and scope of the invention.