DETAILED DESCRIPTION OF THE INVENTION

[0043] The following invention is a continuation-in-part application of Pending Patent Application No. 09/542,772, entitled “Method and apparatus for detecting a container proximate to a transportation vessel hold,” filed on Apr. 4, 2000, which is incorporated herein by reference in its entirety. Referring now to the drawings in general, it will be understood that the illustrations are for the purpose of describing a preferred embodiments of the invention and are not intended to limit the invention thereto.

[0044] Before discussing the particular aspects of the present invention wherein the electronic device detects the proximity of a transportation vessel and deactivates its field-emitting device, the electronic device 100 and its components are first described below.

[0045] FIG. 1 is a schematic illustration of an electronic device 100 that may be used with the present invention. The electronic device 100 includes a control system 102 to control the operation of the electronic device 100 . The control system 102 includes a microprocessor 103 operatively connected with a memory 104 , an input/output interface 106 , and a timer circuit 108 . The microprocessor 103 interfaces with devices outside the control system 102 through the input/output interface 106 . If the microprocessor 103 needs to carry out instructions or operations based on time, the microprocessor 103 uses the timer circuit 108 . Note that the microprocessor 103 may be any type of micro-controller or electronic circuitry that is capable of controlling the operation of the electronic device 100 .

[0046] The electronic device 100 includes a field-emitting device 101 . The field-emitting device 101 comprises electronics or other circuitry that emits electric, magnetic and/or electromagnetic signals. The field-emitting device 101 may emit a field by design to carry out an intended function. For example, the field-emitting device 101 may be communication electronics and an antenna (not shown) that communicates information to and from a cellular phone electronic device 100 . Alternatively, the field-emitting device 101 may emit a field as a byproduct of a function. For example, the field-emitting device 101 may be a computer display that emits a field when a cathode ray tube directs electrons to a screen to display information. Regardless of purpose and intent, the field-emitting device 101 encompasses any electric, magnetic, and/or electro-magnetic signals emitted by the electronic device 100 .

[0047] The field emitted by a field-emitting device 101 may interfere with systems on a transportation vessel during its operation, potentially creating a dangerous condition. For example, aircraft include communication systems for communication to a tower for air traffic control and for navigational purposes. If a field-emitting device 101 emits a field interferes with the aircraft communication systems, the aircraft communication systems may not operate properly, thereby jeopardizing the aircraft's communication of information critical to the aircraft's safe operation.

[0048] The electronic device 100 may also include a local access port 122 . A computing device, such as a laptop computer with the proper software, may access the electronic device 100 electronically by connecting to the local access port 122 .

[0049] A power system 110 supplies power to the electronic device 100 and its components, including the field-emitting device 101 . The electronic device 100 contains its own power system 110 , but the power system 110 may also be connected to an external power source as well to conserve power. The control system 102 controls which components within the electronic device 100 receive power for operation by controlling the distribution of the power system 110 . The control system 102 can deactivate a particular component within the electronic device 100 by decoupling the component from the power system 110 .

[0050] The electronic device 100 may be associated with one or more sensors 118 , 120 to determine if the electronic device 100 is in proximity to a transportation vessel. The sensors 118 , 120 are coupled to the input/output interface 106 .

[0051] The sensors 118 , 120 may be divided into two types of sensors: environmental sensors 118 and cooperative marker sensors 120 . Environmental sensors 118 detect environmental conditions surrounding the electronic device 100 to determine whether the electronic device 100 is in proximity to a transportation vessel. Cooperative marker sensors 120 detect cooperative markers positioned within or in proximity to a transportation vessel so that the electronic device 100 can determine when it is in proximity to a transportation vessel. More information on examples of sensors 118 , 120 that may be used with the present invention are described later herein.

[0052] The electronic device 100 deactivates the field-emitting device 101 and/or other systems depending on the design and operation of the control system 102 . In the present invention, the term “deactivation” and the like is defined as disabling the field-emitting device 101 and/or other systems and elements of the electronic device 100 that may cause interference with the transportation vessel. Deactivation may include disabling, shutting down, and/or decoupling power from one or all of the components of the electronic device 100 depending upon the specifics of each embodiment, as described below. The control system 102 may also generate an alarm, which may be audio or visual, indicating the proximity of a transportation vessel 50 .

[0053] The electronic device 100 may also include a tracking device 118 A. The tracking device 118 A is characterized as an environmental sensor 118 since the tracking device 118 A senses environmental information indicative of positioning information. In one embodiment, the tracking device 118 is a global positioning system (GPS) receiver that receives electronic signals containing positioning information representing the location of the electronic device 100 . One example of the GPS receiver is described in U.S. Pat. No. 5,648,763, entitled “Method and apparatus for global position responsive security system,” incorporated herein by reference in its entirety.

[0054] The positioning information from the tracking device 118 A is received by the microprocessor 103 through the input/output interface 106 . The microprocessor 103 may store the positioning information of the electronic device 100 in memory 104 . The microprocessor 103 may also send the positioning information of the electronic device 100 to a remote communication device 112 via the input/output device 106 . The remote communication device 112 may communicate the positioning information of the electronic device 100 to a remote site 130 , such as a host computer system. The remote communication device 112 may transmit the positioning information by a wired communication, such as a telephone modem, or through wireless communication, such as through a cellular phone modem. Alternatively, the remote communication device 112 may send out the positioning information to the remote site 130 in the form of radio-frequency communication signals to a radio-frequency reception device, such as a satellite.

[0055] The electronic device 100 may be associated with a container 10 that is designed to be transported on a transportation vessel, as illustrated in FIGS. 2 and 3 . A container 10 is provided that is especially suited for the cargo hold of an aircraft, such as those containers manufactured and distributed by Envirotainer Group Companies. The electronic device 100 is associated with the container 10 for determining its geographic position during the shipping process. The electronic device 100 may be placed internally within the container 10 , or the electronic device 100 may be positioned on an outer surface for communication with a cooperative marker 60 ( FIG. 3 ) for detection by the cooperative marker sensor 120 . The electronic device 100 is placed in a position such that it will not interfere with or be damaged by the material handling system, generally designated 40 (see FIG. 3 ).

[0056] The container 10 may take a variety of forms depending upon the type of materials and goods being shipped. The container 10 may also be constructed to provide for temperature sensitive materials that range from insulated packaging, refrigeration units using dry ice, and thermostat equipped containers using aircraft power to run refrigeration and heating systems. FIG. 3 illustrates the container 10 being loaded into the loading port 65 of an aircraft transportation vessel 50 . The container 10 is equipped to be handled by a material handling system 40 , and the container 10 may include openings for mounting the blades of a forklift or a protective outer layer allowing for moving the container 10 into the aircraft 50 . One skilled in the art will understand that there are a plethora of containers 10 and many different types of transportation vessels 50 , such as aircraft 50 , ships, and trains that are all applicable to the present invention.

[0057] By way of example, FIGS. 4A, 4B and 4 C illustrate other types of electronic devices 100 that contain a field-emitting device 101 and which may be used with the present invention. FIG. 4A is an illustration of a typical cellular phone. A cellular phone 100 A contains a field-emitting device 101 A in the form of communication electronics that communicates data in the form of radio-frequency signals. FIG. 4B is an illustration of a typical personal digital assistant 100 B that includes a field-emitting device 101 B in the form of a radio-frequency transmitter/receiver. FIG. 4C is an illustration of a typical laptop computer 100 C that includes a field-emitting device 101 C in the form of a monitor display . All of the aforementioned electronic devices 100 A, 100 B, 100 C contain field-emitting devices 101 A, 101 B, 101 C that may be used with the present invention and include a control system 102 similar to that illustrated in FIG. 1 to deactivate their respective field-emitting devices 101 A, 101 B, 101 C and/or other systems upon detection of the proximity of a transportation vessel 50 , such as aircraft transportation vessel 50 .

[0058] FIG. 5 illustrates one embodiment of a GPS system 200 that communicates with the tracking device 118 A so that the electronic device 100 can determine its position. The GPS system 200 is a space-based radio positioning network for providing users equipped with suitable receivers highly accurate position, velocity, and time (PVT) information. The illustrated space-based embodiment of the GPS system 200 includes a constellation of GPS satellites 201 in non-geosynchronous twelve-hour orbits around the earth. The GPS satellites 201 are located in six orbital planes 202 with four of the GPS satellites 201 in each plane, plus a number of “on orbit” spare satellites (not shown) for redundancy.

[0059] GPS position determination is based upon a concept referred to as time of arrival (TOA) ranging. Each of the orbiting GPS satellites 201 broadcasts spread spectrum microwave signals encoded with positioning data and satellite ephemeris information. The signals are broadcast on two essential frequencies at precisely known times and at precisely known intervals. The signals are encoded with their precise time of transmission.

[0060] The tracking device 118 A receives the signals from the GPS satellites 201 and times the signals and demodulates the GPS satellite 201 orbital data contained in the signals. Using the orbital data, the tracking device 118 A determines the time between transmission of the signal by the GPS satellite 201 and reception by the tracking device 118 A. Multiplying this by the speed of light gives what is termed the “pseudo range measurement” of that satellite. If a clock within the tracking device 118 A were perfect, this would be the range measurement for that GPS satellite 201 , but the imperfection of the clock causes it to differ by the time offset between actual time and receiver time. Thus, the measurement is called a pseudo range, rather than a range. However, the time offset is common to the pseudo range measurements of all the satellites.

[0061] By determining the pseudo ranges of four or more GPS satellites 201 , the tracking device 118 A is able to determine its location in three dimensions, as well as the time offset. Thus, an electronic device 100 equipped with a proper tracking device 118 A is able to determine its PVT with great accuracy. The tracking device 118 A of the present embodiment determines positioning information accurately when three or more satellite signals are received, but it is still possible for the tracking device 118 A to successfully determine location from positioning information from two or less GPS satellites 201 . This technology is well known, such as that disclosed in U.S. Pat. No. 6,031,488, entitled “Method and system for an efficient low cost PPS GPS receiver,” incorporated herein by reference in its entirety.

[0062] FIG. 6 illustrates the basic operation of the present invention when sensors 118 , 120 are used to determine if the electronic device 100 is in proximity to an aircraft 50 . The operation starts (step 300 ) and information from the sensor(s) 118 , 120 are passed through the input/output interface 106 to the control system 102 (step 302 ). The control system 102 determines, based on the information received from the sensor(s) 118 , 120 , whether the electronic device 100 is in proximity to an aircraft 50 and/or its cargo hold (decision 304 ). In the embodiment where the electronic device 100 includes a tracking device 118 A, the control system 102 determines that the electronic device 100 is not in proximity to the aircraft 50 and/or its cargo hold, the positioning information is then received by the tracking device 118 A and is communicated through the remote communication device 112 to the remote site 130 (step 306 ) to allow tracking of the electronic device 100 and the process returns to the beginning (step 300 ) and the process is repeated. In an embodiment where the electronic device 100 does not include a tracking device 118 A, if the control system 102 determines that the electronic device 100 is not in proximity to the aircraft 50 and/or its cargo hold, the process simply returns to the beginning (step 300 ) and the process is repeated. If the control system 102 determines that the electronic device 100 is in proximity to the aircraft 50 and/or its cargo hold, the control system 102 performs a deactivation and reactivation procedure (step 308 ). When the reactivation process is completed, the process returns back to the beginning (step 300 ) and the process is repeated.

[0063] The electronic device 100 may contain either a single sensor 118 , 120 or multiple sensors 118 , 120 for transferring information to the control system 102 via the input/output interface 106 to deactivate the field-emitting device 101 (step 308 ) when the electronic device 100 is in proximity to the aircraft 50 and/or its cargo hold. If the electronic device 100 is coupled to a second sensor 118 , 120 or a multitude of sensors 118 , 120 , the control system 102 may wait until signals are received from more than one sensor 118 , 120 prior to performing the deactivation and reactivation procedure (step 308 ).

[0064] FIG. 7 describes the deactivation/reactivation procedure of the field-emitting device 101 (step 308 ) illustrated in FIG. 6 for an embodiment where the electronic device 100 includes a tracking device 118 A. The deactivation process begins (step 330 ), the control system 102 directs the power system 110 to decouple power from the field-emitting device 101 (step 332 ). The control system 102 then determines if the field-emitting device 101 has been disabled due to lack of reception of positioning information signals from the tracking device 118 A (discussed below) (decision 333 ). If yes, the control system 102 reads memory 104 to determine if any additional systems in the electronic device 100 should be disabled (decision 335 ), and such disabling is carried out if programmed (step 337 ). The control system 102 then continually checks to see if positioning information has been received by the tracking device 118 A until positioning information signals are received (decision 339 ). The electronic device 100 is able to perform this function since the deactivation process may not deactivate the reception of the tracking device 118 A. When positioning information is received successfully again by the tracking device 118 A, the electronic device 100 is reactivated and resumes the transmission of positioning information concerning the location of the electronic device 100 to the remote site 130 (step 308 in FIG. 5 ).

[0065] If the control system 102 determines that deactivation was not a result of the tracking device 101 failing to receive positioning information signals from the GPS system 200 (decision 333 ), the control system 102 determines if the electronic device 100 is to be disabled for a specified period of time (decision 334 ). If yes, the control system 102 reads the specified time from memory 104 (step 342 ) and programs the timer circuit 108 (step 344 ). The control system 102 waits until the timer circuit 108 indicates the specified time has lapsed (decision 346 ) before the electronic device 100 reactivates previously deactivated systems in the electronic device 100 , including the field-emitting device 101 (step 347 ), and ends (step 348 ), returning back to the process illustrated in FIG. 6 (step 308 ).

[0066] If the control system 102 determines that the electronic device 100 is not to be deactivated for a specified period of time (decision 334 ), the control system 102 determines if the deactivation period should be based on the itinerary of the electronic device 100 (decision 338 ). For instance, the desired period of deactivation may extend until the aircraft 50 is scheduled to land and/or reach its final destination. If the answer to itinerary-based deactivation is yes (decision 338 ), the control system 102 calculates the arrival time (step 340 ) and programs the timer circuit 108 (step 344 ). The control system 102 waits until the timer circuit 108 indicates the arrival time has passed (decision 346 ) before the electronic device 100 reactivates previously deactivated systems in the electronic device 100 , including the field-emitting device 101 (step 347 ), and ends (step 348 ), returning back to the process illustrated in FIG. 6 (step 308 ).

[0067] If the control system 102 determines that the deactivation should not be based on the itinerary of the electronic device 100 (decision 338 ), the control system 102 determines if the electronic device 100 is outside the proximity of the aircraft 50 (decision 345 ) by checking status of sensor(s) 118 , 120 and waiting until the electronic device 100 is actually outside the proximity of the aircraft 50 at which time the electronic device 100 reactivates previously deactivated systems, including the field-emitting device 101 (step 347 ), and ends (step 348 ), returning back to the process illustrated FIG. 6 (step 308 ).

[0068] Please note that the control system 102 may determine to perform the reactivation process based on a combination of events occurring together rather than just relying on one event. The combination of events may include, but is not limited to, expiration of a time, the arrival of the electronic device 100 at its final destination, and/or the electronic device 100 not being in proximity to the transportation vessel 50 .

[0069] During the deactivated state, the control system 102 may deactivate all elements and only maintain enough power to periodically detect the electronic device 100 position and/or its proximity to the transportation vessel 50 . Alternatively, the control system 102 may deactivate only those elements that may interfere with the aircraft's 50 systems, including the field-emitting device 101 , and maintain the activated state for the other components.

[0070] Alternatively, the control system 102 may send a location signal through the remote communication device 112 such that the tracking party will know the last available geographic location of the electronic device 100 prior to deactivation. The control system 102 may also remain in an activated state for a predetermined period of time until deactivation. The predetermined period of time provides for the assumption that the electronic device 100 will be placed onto the aircraft 50 some time before takeoff and that there will be spare time in which interference with aircraft 50 systems is not an issue.

[0071] Environmental Sensors

[0072] There are various types of environmental sensors 118 that may be coupled to the electronic device 100 to detect environmental conditions indicative of the proximity of a transportation vessel 50 . These environmental sensors include the tracking device 118 A, an acoustic sensor 118 B, a frequency detector 118 C, a barometric pressure sensor 118 D, a motion sensor 118 E, a capacitance sensor 118 F, an imaging sensor 118 G, and a hazardous material sensor 118 H. Each of these environmental sensors 118 is capable of detecting the proximity of a transportation vessel 50 when the electronic device 100 is placed onto the transportation vessel 50 or is about to be placed onto the transportation vessel 50 and is used for executing step 304 in FIG. 6 , the logic of which has been previously discussed above. Additionally, more than one type of environmental sensor 118 may be used individually or in combination to make this detection.

[0073] GPS System

[0074] When the electronic device 100 coupled to the tracking device 118 A is placed into the transportation vessel 50 , the satellite signals may be blocked by the transportation vessel 50 and may not reach the tracking device 118 A. The tracking device 118 A communicates to the control system 102 that the signals are not being received, which the control system 102 via the input/output device 106 equates to the electronic device 100 being in proximity to or being placed into the transportation vessel 50 . As the electronic device 100 is being loaded into the transportation vessel 50 as illustrated in FIG. 3 , the tracking device 118 A may receive only a limited number of signals or positioning information from the satellites 201 . The “one-sided” signal reception is a result of some of the satellite positioning information being blocked by the transportation vessel 50 , while others still reach the tracking device 118 A. Therefore, the control system 102 may identify the electronic device 100 as being in proximity to or being placed into the transportation vessel 50 if only one or two satellite signals are received by the tracking device 118 A. The “one-sided” signal reception may be the primary indication for the control system 102 to deactivate the field-emitting device 102 , or it may be a redundant check also requiring a full loss of signals prior to deactivation.

[0075] Acoustic Sensor

[0076] The electronic device 100 is capable of detecting the proximity of the transportation vessel 50 by detecting characteristics of the sound and vibration in the transportation vessel 50 . For example, a transportation vessel 50 with jet engines, for example, tends to produce a substantial amount of vibration. This vibration is radiated in the form of sound waves and is coupled to the transportation vessel 50 structure on which the engines are mounted. Detection of the electronic device 100 in the aircraft 50 may be accomplished by detecting this sound and vibration. An example of such a sensor is described in U.S. Pat. No. 5,033,034, entitled “Onboard acoustic tracking system,” incorporated herein by reference in its entirety. An acoustic sensor 118 B allows the electronic device 100 to monitor the operation of the transportation vessel 50 by detecting distinctive sounds or a acoustic signature specifically made by transportation vessel 50 using microphones to capture sounds made in the air and through the body of the transportation vessel 50 .

[0077] FIG. 8 illustrates a block diagram of an acoustic sensor 118 B coupled to the electronic device 100 to detect the proximity of a transportation vessel 50 . An air microphone 400 is placed in the transportation vessel 50 to detect the substantial engine sounds when the transportation vessel 50 is operating, such as during the pre-operation checks, taxi, and takeoff of an aircraft transportation vessel 50 . The signals from the air microphone 400 are coupled to a digital signal processor (DSP) 404 for processing. Additionally, a contact microphone 402 may be provided and placed in contact with the transportation vessel 50 structure to detect vibrations within the transportation vessel 50 , with the signals from the contact microphone 402 also coupled to the DSP 404 . The DSP 404 is a processor especially suited for processing of numeric applications. In the present embodiment, the DSP 404 takes the signals from both the air microphone 400 and the contact microphone 402 and runs a Fast Fourier Transform (FFT) on the signals to convert the signals from the time domain to the frequency domain. A modified-FFT may also be used that achieves adequate results for most purposes.

[0078] Once the signals are represented in the frequency domain, this representation is communicated to the microprocessor 103 of control system 102 via the input/output interface 106 to compare the frequency and amplitude of the detected signal pattern with that of a pre-defined jet engine and/or transportation vessel 50 engine signal pattern stored in memory 104 . Deactivation results when the signal patterns match or fall within a predefined range.

[0079] Frequency Detector

[0080] The electronic device 100 is capable of detecting the proximity of a transportation vessel 50 using a frequency detector 118 C, as illustrated in FIG. 9 , if the transportation vessel 50 emits frequency signals during its normal operation that are detectable by the frequency detector 118 C. An aircraft transportation vessel 50 with jet engines, for example, may produce specific frequencies during operations, such as take off, landing, taxiing, and preflight checks. Detection of the electronic device 100 in the aircraft transportation vessel 50 may be accomplished by detecting specific emitted frequencies that are unique to the aircraft transportation vessel 50 .

[0081] FIG. 9 illustrates a frequency detector 118 C according to one preferred embodiment for detecting a signal in the range of 400 Hz. Aircraft power systems use an AC 400 Hz power distribution system that is somewhat unique to an aircraft 50 engine, as described in U.S. Pat. No. 5,835,322, entitled “Ground fault interrupt circuit apparatus for 400-Hz aircraft electrical systems,” incorporated herein by reference in its entirety. A frequency detector 118 C that detects a signal at approximately 400 Hz may indicate that the transportation vessel is power and/or that the electronic device 100 is in proximity to the aircraft transportation vessel 50 and that the field-emitting device 101 should be deactivated in accordance with the deactivation process.

[0082] The preferred embodiment of the frequency detector 118 C includes three receiving elements 440 orthogonal to each other in three dimensions. The receiving elements 440 may be coils with tuned circuits to detect the desired frequency, or magnetometers designed to sensitively measure AC field strengths, both of which are well known and commonplace.

[0083] The purpose of including more than one receiving element 440 and placing a plurality of receiving elements 440 orthogonal to each other is to create an orientation-independent receiving structure to ensure that signals are picked up regardless of the orientation of the electronic device 100 and/or the frequency detector 118 C. In a preferred embodiment, three receiving elements 440 are placed orthogonally to each other to create detection devices in all three dimensions. A summer 441 sums the squares of the signal patterns from the receiving elements 440 to eliminate any nulls. In this manner, there is always a signal generated from at least one receiving element 440 that is not null, thereby making the frequency detector independent of orientation.

[0084] The summed signals from the summer 441 are received by the control system 102 through the input/output interface 106 . If the control system 102 detects a significant signal from the receiving elements 440 that are tuned to receive 400 Hz signals, the control system 102 is programmed to recognize that the electronic device 100 is in proximity to the aircraft transportation vessel 50 and to perform the deactivation procedure.

[0085] A spectrum analyzer may be used as a frequency detector 118 C to determine the presence of a particular frequency signal in a manner such as that described in U.S. Pat. No. 3,418,574, incorporated herein by reference in its entirety. The spectrum analyzer scans a band of signal frequencies in order to determine the frequency spectrum of any signal emitted by the aircraft transportation vessel 50 . There are other methods of detecting particular frequency signals so as to provide a frequency detector 118 C, and the preferred embodiments are not intended to limit the present invention from using such other methods.

[0086] It is also noted that other frequency signals may be emitted when the electronic device 100 is in proximity to an aircraft transportation vessel 50 , such as at an aircraft field. Aircraft towers or other communication devices may emit FM signals that can be detected by the frequency detector 118 C to indicate that the electronic device 100 is either in an aircraft transportation vessel 50 or proximate to an aircraft transportation vessel 50 such that the deactivation process should be performed. Therefore, the present invention is not limited to detection of any specific frequency signals and the signals do not necessarily have to be emitted from the transportation vessel 50 itself.

[0087] Pressure Sensor

[0088] A barometric pressure sensor 118 D may be used in combination with the tracking device 118 A for determining when the electronic device 100 is positioned within a transportation vessel 50 . The barometric pressure sensor 118 D determines the air pressure being exerted on the electronic device 100 as it moves during the shipping process. The air pressure reading sensed by the barometric pressure sensor 118 D is received by the control system 102 through the input/output interface 106 . If the air pressure reading received from the pressure sensor 118 D exceeds a certain threshold value, the control system 102 can use this information as indicative of the electronic device 100 traveling at a height or depth above or below the height relative to the threshold value. The term “exceed” may be the pressure sensor 118 D reading falling either below a threshold value or going above a threshold value. Various types of pressure sensors 118 D to determine altitude are available, such as that described in U.S. Pat. 5,224,029, entitled “Power factor and harmonic correction circuit including ac startup circuit,” incorporated herein by reference in its entirety, and the present invention is not limited to any particular type of pressure sensor 118 D.

[0089] The positioning information received by the tracking device 118 A indicates the geographic position of the electronic device 100 , but does not indicate the height of the electronic device 100 above sea level. A barometric pressure sensor 118 D may be used to ascertain the height of the electronic device 100 above sea level, but it cannot by itself determine whether the height above sea level is still on the ground or in the air. For instance, the city of Denver, Colo. has a ground level that is already approximately one mile above sea level. A reading by the barometric pressure sensor 118 D attached to the electronic device 100 will not by itself indicate the height above ground level. Therefore, it is advantageous to use the altitude indication from the barometric pressure sensor 118 D, in combination with the positioning information from the tracking device 118 A, to ascertain the height of the electronic device 100 above ground level and, thereby, to determine whether the electronic device 100 is in proximity to a transportation vessel 50 .

[0090] FIG. 10 illustrates the process used by the control system 102 to determine height of the electronic device 100 above ground level using the barometric pressure sensor 118 D. The operation begins (step 370 ), and the control system 102 determines the reading from the barometric pressure sensor 118 D to correlate such reading to altitude and stores such in memory 104 (step 372 ). The control system 102 next reads the positioning information from the tracking device 118 A to ascertain the geographic location of the electronic device 100 (step 374 ). The control system 102 determines the approximate ground level value by correlating the particular geographic region determined by the positioning information received from the tracking device 118 A to data either stored in memory 104 or also received remotely by the tracking device 118 A, and the control system 102 stores the approximate ground level value in memory 104 (step 376 ). The control system 102 subtracts the ground level from the altitude previously stored in memory 104 to determine the height of the electronic device 100 above ground level (step 378 ). If this value is greater than zero, the electronic device 100 is above ground level value and may be in a transportation vessel 50 . The process ends (step 380 ) and returns back to FIG. 6 in which the electronic device 100 detects the proximity of the transportation vessel 50 (decision 306 ) by determining if the electronic device 100 is above ground level. After deactivation (step 308 ) due to detecting the electronic device 100 above ground level, the control system 102 may perform the deactivation/reactivation procedure (step 308 ) when the difference (i.e. altitude less ground level value) reaches some minimal value since topologies can vary in any given area. In one embodiment, this minimal value is 200 feet.

[0091] Motion Sensor

[0092] A movement or motion sensor 118 E may be used for determining when the electronic device 100 is either being moved, jostled, or placed at an angle. There are many different motion and acceleration sensors 118 E that may be used to detect movement and/or acceleration of the electronic device 100 and/or the transportation vessel 50 . For instance, U.S. Pat. No. 5,033,824, entitled “Convertible analog-digital mode display device,” incorporated herein by reference in its entirety, describes a vibration/acceleration sensor that is fixed to a casing to measure the vibrations. Such a sensor could be mounted to the body of the transportation vessel 50 to perform the same functionality. A piezoelectric device is used to detect mechanical vibration and to generate an electrical charge representative of such vibration. The electrical charge is read by the control system 102 through the input/output interface 106 and compared with a predetermined value in memory 104 to determine whether the electronic device 100 is in proximity to the transportation vessel 50 and, thus, whether the deactivation function should be performed as described above in FIG. 7 .

[0093] Alternatively, or additionally, a mercury switch may be used as a movement sensor 118 E to indicate if the electronic device 100 is positioned at an angle. When the electronic device 100 is loaded into the transportation vessel 50 , the electronic device 100 is placed at an angle with respect to the ground when placed on the conveyor system 40 , as illustrated in the embodiment of FIG. 2 where the electronic device 100 is associated with a container 10 . The mercury switch tilts and causes the mercury liquid to either become open or closed, thereby indicating movement of the electronic device 100 . The control system 102 receives this signal from the movement sensor 118 E through the input/output interface 106 , thereby indicating that the electronic device 100 is at an angle and being loaded into a transportation vessel 50 . The control system 102 can then initiate the deactivation and reactivation procedures as previously described in FIG. 7 .

[0094] Capacitance Sensor

[0095] The electronic device 100 can detect the proximity of a transportation vessel 50 by using a capacitance sensor 118 F to detect a change in capacitance. For example, when the electronic device 100 is placed into an aircraft transportation vessel 50 , the electronic device 100 may be associated with a container 10 that is placed into the cargo hold. The container 10 may be constructed to conform to the dimensions of the cargo hold to reduce or eliminate any non-usable space. As such, the containers 10 are often placed in proximity to or against the inner walls of the cargo hold. The body of the transportation vessel 50 may be made out of special materials with defined thicknesses and other characteristics that affect the capacitance of the container 10 when placed in close proximity thereto. The electronic device 100 may include a capacitance sensor 118 F to sense the capacitance of the container 10 . One such sensor is described in U.S. Pat. No. 4,219,740, entitled “Proximity sensing system and inductance measuring technique,” incorporated herein by reference in its entirety, that describes using a variable inductance/capacitance measuring device to monitor the proximity of a target object.

[0096] In the present invention, the transportation vessel 50 itself is the target object. In one embodiment, the container 10 is constructed out of steel and is therefore conductive. The value sensed by the capacitance sensor 118 F is received by the control system 102 via the input/output interface 106 . The capacitance of the capacitance sensor 118 F changes in accordance with the proximity of the container 10 to the body of the transportation vessel 50 . This change is compared by the control system 102 to values stored in memory 104 representative of the conductance of an transportation vessel 50 body (to which the container 10 would be proximate if loaded onto the transportation vessel 50 ), to determine when the container 10 with the associated electronic device 100 is loaded onto the transportation vessel 50 so as to initiate the deactivation and reactivation procedures as described above in FIG. 7 .

[0097] Imaging Sensor

[0098] The electronic device 100 can also detect the proximity of a transportation vessel 50 by detecting the curvature of its cargo hold. For example, aircraft 50 cargo holds have distinctive shapes due to the curvature of the body of the aircraft 50 . An imaging sensor or light sensor 118 G may emit a spectrum of light during the shipment of the electronic device 100 and read the reflection to determine if the electronic device 100 has been placed in an area containing a curvature like that of the cargo hold.

[0099] FIG. 11 illustrates one example of an imaging sensor 118 G which comprises an imaging emitter 506 and detector 509 . The imaging sensor 118 G uses an imaging emitter 506 to scan the area of interest with a beam 500 . The scanning is achieved by moving a mirror, such as a reflector 502 that is rotated about a rotational axis 504 . The light source emitted by the imaging emitter 506 may be a laser or laser diode. An optical lens 508 converts the light into a beam 500 . The beam 500 scans the aircraft surface 501 and the reflected light passes through an imaging detector 509 that is comprised of an optical lens 510 that produces an image of the scanned area on photo detectors 512 , which generate electrical signals representing the surface 501 . A detecting system 514 then determines the pattern or width of the electrical signals to translate such signals to information.

[0100] The imaging emitter 506 continues to emit a spectrum of signals, such as infrared signals, from the electronic device 100 during shipment. The imaging detector 509 receives the reflection of the light emitted by the imaging emitter 506 . Bends or curves in a reflected surface bend or curve the light received from by the imaging detector 509 . The control system 102 , via the input/output interface 106 , continually monitors the reading from the imaging detector 509 and compares it to a predefined reading stored in memory 104 . If the image received by the imaging detector 509 indicates that the electronic device 100 is in proximity to the transportation vessel 50 cargo hold, the control system 102 carries out the deactivation and reactivation process as described above in FIG. 7 .

[0101] Cooperative Marker Sensors

[0102] Cooperative marker sensors 120 detect markers purposefully placed within or proximate to the transportation vessel 50 . For example, as illustrated in FIG. 3, a cooperative marker 60 may be positioned immediately within or proximate to the aircraft loading port 65 . A number of cooperative markers 60 may be positioned within the transportation vessel 50 at various positions. Additionally, more than one type of cooperative marker 60 may be used in combination within a single transportation vessel 50 . Cooperative marker sensors 120 are associated with the electronic device 100 to detect the cooperative markers 60 , which are typically placed within the transportation vessel 50 , but may be placed slightly away from or proximate to the transportation vessel 50 to be encountered by the electronic device 100 before the electronic device 100 is carried onto or loaded into the transportation vessel 50 .

[0103] The cooperative marker sensors 120 may be active devices that pick up signals from emitters placed purposely in proximity to the transportation vessel 50 and/or its cargo hold. Alternatively, the cooperative marker sensors 120 may be passive devices that differ from active devices in that emitters are not placed in or proximate to the transportation vessel 50 or its cargo hold. Instead, for passive devices, cooperative markers 60 are placed in or proximate top the transportation vessel 50 or its cargo hold that are not active devices, such as emitters, but simply represent codes or markings that are detected by passive cooperative marker sensors 120 to relay information.

[0104] Cooperative marker sensors 120 may include an optical marker sensor 120 A, a capacitance marker sensor 120 B, an ultrasonic marker sensor 120 C, an infrared beacon sensor 120 D, a frequency beacon detector 120 E, and/or a magnetic marker sensor 120 F. Each of the cooperative markers 60 sensed are used for executing step 304 in FIG. 6 , the logic of which has been previously discussed above.

[0105] Optical Marker Sensor

[0106] An optical marker sensor 120 A may be used by the electronic device 100 to sense the presence of a cooperative marker 60 positioned in proximity to the transportation vessel 50 . In one embodiment, the optical marker sensor 120 A includes an infrared illuminator using a bank of LED's or a laser similar to that described above with respect to FIG. 11 . A cooperative marker 60 is positioned in proximity to the transportation vessel 50 that contains specific coded information indicating that the electronic device 100 is being loaded into the transportation vessel 50 or is about to be loaded into a transportation vessel 50 . This cooperative marker 60 code could be a bar code or the two-dimensional code illustrated in FIG. 12 marketed under the trademark Snowflake™ 520 owned by the assignee of the present invention. The article entitled “The Marconi Data Systems Snowflake Code” discusses the advantages and features of the Snowflake® code 520 and is incorporated herein by reference in its entirety.

[0107] The optical marker sensor 120 A may also distinguish reading the cooperative marker 60 from left to right or top to bottom depending on the alignment of the cooperative marker 60 to indicate the direction of movement of the electronic device 100 with respect to the cooperative marker 60 .

[0108] Similar to that illustrated in FIG. 11 above, the optical marker sensor 120 A emits spectrum signals such as an infrared signal or laser signal from the electronic device 100 during shipment. The optical marker sensor 120 A receives the reflection of the light emitted to determine if the optical marker sensor 120 a is picking up information from the relevant cooperative marker 60 , such as a Snowflake® code 520 . When information is detected by the optical marker sensor 120 A from the Snowflake code 520 , the optical marker sensor 120 A passes such information to the control system 102 through the input/output interface 106 . The control system 102 determines whether the information read from the Snowflake code 520 indicates that the electronic device 100 is in proximity to the transportation vessel 50 , in which case the control system 102 carries out the deactivation and reactivation process, as described above in FIG. 7 .

[0109] Capacitance Marker Sensor

[0110] FIG. 13 illustrates metal plates or markers 530 that are placed on the transportation vessel 50 proximate to the electronic device 100 , with associated container 10 , when the container 10 is loaded into the transportation vessel 50 cargo hold. In this manner, a capacitance marker sensor 120 B can detect the change in capacitance to indicate that the electronic device 100 is proximate to or being loaded into the transportation vessel 50 . The sensing process for this method is the same as that described above for capacitance sensor 118 F. In this particular method, plates 530 placed into the transportation vessel 50 may allow better determination of the change in capacitance proximate to the electronic device 100 by the control system 102 .

[0111] Ultrasonic Marker Sensor

[0112] The ultrasonic marker sensor arrangement 120 C senses the presence of a cooperative marker 60 that resonates at particular frequencies. In one embodiment, the ultrasonic marker sensor 120 C associated with the electronic device 100 includes is an ultrasonic transponder 602 that receives ultrasonic signals at certain defined frequencies. The ultrasonic marker sensor 120 C also includes an ultrasonic emitter 600 . The ultrasonic marker sensor 120 C emits frequencies using the ultrasonic emitter 600 and picks up response frequencies received by the ultrasonic transponder 602 . If specific frequencies indicative of a transportation vessel 50 , such as an aircraft ,are received by the ultrasonic transponder 602 in response to frequencies emitted by the ultrasonic emitter 600 , then the electronic device 100 is in proximity to the transportation vessel 50 . The control system 102 of the electronic device 100 communicates with the ultrasonic marker sensor 120 C via the input/output interface 106 .

[0113] In one embodiment, pipes 604 with specific resonant frequencies are placed in proximity to or within the transportation vessel 50 . The control system 102 , via the input/output interface 106 , causes the ultrasonic emitter 600 to transmit frequencies across a band in which resonant frequencies are expected to occur. The control system 102 receives response frequencies from the ultrasonic transponder 602 in response to signals emitted by the ultrasonic emitter 600 and compares them in memory 104 to signals expected to be received when the electronic device 100 is in proximity to the transportation vessel 50 with pipes 604 . If the control system 102 receives signals from the ultrasonic transponder 602 that are expected when the electronic device 100 is in proximity to the transportation vessel 50 , this indicates that the electronic device 100 is in proximity to the transportation vessel 50 , in which case the control system 102 carries out the deactivation and reactivation process. Although the reactivation procedure for this method (i.e., the detection of when the electronic device 100 is no longer in proximity to the transportation vessel 50 ) requires transmission of an ultrasonic or sonic acoustic, these signals are considered similar to the acoustic emissions from parts of the transportation vessel 50 , such as from pumps, motors and engines, and therefore will not effect the transportation vessel 50 systems. Transportation vessels 50 are designed to operate properly in the presence of vibration or noise.

[0114] Alternatively, the control system 102 may cause the ultrasonic emitter 600 to transmit bursts of acoustic noise covering the desired band of frequencies. When the transmitted signals are stopped, the pipes 604 will continue to resonate at their resonant frequency and the control system 102 will be able to continue to receive their response signals through the ultrasonic transponder 602 .

[0115] Additional ultrasonic marker sensors 120 C and sensing systems, such as that described in U.S. Pat. No.4,779,240, entitled “Ultrasonic sensor system,” incorporated herein by reference in its entirety, can be used to sense the frequency response of emitted signals to markers placed purposely in proximity to a transportation vessel 50 , and the present invention is not limited to any particular type of ultrasonic marker sensor 120 C or sensing system.

[0116] Infrared Beacon Sensor

[0117] The infrared beacon sensor 120 D is an active sensor that senses the presence of a cooperative marker 60 that emits a specific beacon of light like that described in U.S. Pat. No. 5,165,064, entitled “Mobile robot guidance and navigation system,” incorporated herein by reference in its entirety. The electronic device 100 is associated with an infrared beacon sensor 120 D that detects infrared signals emitted by an infrared beacon marker placed in the transportation vessel 50 .

[0118] The cooperative infrared beacon marker 60 placed in the transportation vessel 50 emits a light in the cargo hold area. The infrared beacon sensor 120 D detects light emitted in its path and transmits signals to the control system 102 of the electronic device 100 through the input/output interface 106 . If the control system 102 receives signals from the infrared beacon sensor 120 D associated with the detection of light from a cooperative infrared beacon marker 60 placed in proximity to a transportation vessel 50 , this indicates that the electronic device 100 is proximate to a transportation vessel 50 , in which case the control system 102 carries out the deactivation and reactivation procedure as previously described in FIG. 7 .

[0119] Frequency Beacon Detector

[0120] The electronic device 100 may determine if the electronic device 100 is in proximity to a transportation vessel 50 by using a frequency beacon detector 120 E that detects frequencies emitted by a frequency beacon (not shown) in proximity to the transportation vessel 50 . The frequency beacon detector 120 E may be the same as that described for the frequency detector 118 C. In one embodiment, the frequency beacon emits a signal frequency of 400 Hz, which is the same frequency emitted by the aircraft transportation vessel 50 AC power distribution systems. In this manner, a redundancy is built into the system automatically. The frequency beacon detector 120 E will detect 400 Hz signals whether they are from the frequency beacon or from the transportation vessel 50 AC power distribution system, as described previously, thereby adding an extra measure of reliability and accuracy. However, it should be noted that a frequency beacon may be used that does not emit frequencies that are the same as those emitted naturally by a transportation vessel 50 and/or its systems as the sole method of determining whether or not an electronic device 100 is in proximity to a transportation vessel 50 .

[0121] A frequency beacon detector 118 E that detects 400 Hz signals could indicate that the electronic device 100 is in proximity to the transportation vessel 50 so that the electronic device 100 can perform the deactivation procedure. Three receiving elements 440 , as previously illustrated in FIG. 9 , that are orthogonal to each other in three dimensions may be used as the frequency beacon detector 120 E for detecting the desired frequency signals. The receiving elements 440 may be tuned circuits to detect the desired frequency, or magnetometers designed to sensitively measure AC field strengths, both of which are well known and commonplace.

[0122] The control system 102 of the electronic device 100 receives signals from the frequency beacon detector 120 E via the input/output interface 106 . If the control system 102 reads a signal from the frequency beacon detector 120 E that is known to be the frequency of the frequency beacon, the microprocessor 103 of the control system 102 will know that the electronic device 100 is in the transportation vessel 50 and will initiate the deactivation/reactivation procedure as previously described in FIG. 7 .

[0123] Magnetic Marker Sensor

[0124] As illustrated in FIGS. 15A and 15B , a magnetic marker sensor 120 F may be used by the electronic device 100 to sense the presence of a cooperative marker 60 that is positioned in proximity to or within the transportation vessel 50 . Information is placed in the cooperative marker 60 in the form of magnetic patterns 642 . Such a cooperative magnetic marker 60 is then placed in proximity to or within the transportation vessel 50 , as illustrated in FIG. 15A . The magnetic patterns 642 may contain information in a pattern like that of the Snowflake code 520 previously discussed above and illustrated in FIG. 12 . The magnetic marker sensor 120 F may also distinguish reading the cooperative magnetic marker 60 from left to right or top to bottom, depending on the alignment of the cooperative magnetic marker 60 to indicate the direction of movement of the electronic device 100 with respect to the cooperative magnetic marker 60 .

[0125] The magnetic marker sensor 120 F receives magnetic signals from an array of magnetically charged patterns 642 made out of conductive material, as illustrated in FIG. 15A . The magnetic marker sensor 120 F is in the form of an array of coils 643 that receives magnetic signals of the patterns 642 . The magnetic marker sensor 120 F passes the magnetic information to the microprocessor 103 of the control system 102 through the input/output interface 106 . Based on the information read from the cooperative magnetic marker 60 , the control system 102 determines whether the electronic device 100 is proximate to a transportation vessel 50 , in which case the control system 102 carries out the deactivation and reactivation process.

[0126] When more than one sensor 118 , 120 is coupled to the electronic device 100 for detection of the proximity of the transportation vessel 50 , the control system 102 may determine deactivation upon receiving signals from one or more sensors 118 , 120 . In a configuration in which the control system 102 deactivates upon receiving only one signal, the sensors 118 , 120 work as redundant systems to reduce the likelihood that the electronic device 100 could be placed on the transportation vessel 50 without deactivation. A redundant system allows for one of the sensors to be miscalibrated or damaged without impacting the deactivation process. Conversely, when the control system 102 requires more than one signal, the field-emitting device 101 is not deactivated by a sensor transmitting false proximity readings.

[0127] Within both the environmental sensor 118 and cooperative marker sensor 120 embodiments, the control system 102 is sent signals that are interpreted as requiring deactivation. Immediately upon receiving a signal, the control system 102 may deactivate the tracking system as previously described in FIG. 7 .

[0128] The sensors 118 , 120 may also be used for determining when the electronic device 100 enters an intrinsically safe area. If the electronic device 100 is prohibited from entering areas that require intrinsic safety, this could restrict routes available for the electronic device's 100 travel and may further restrict the utility of the electronic device 100 for shipping applications.

[0129] Section 500-2 of the National Electrical Code Handbook (NEC), incorporated herein by reference in its entirety, indicates that “intrinsically safe” equipment is electrical equipment that “operates at a low voltage and are designed safe, regardless of short circuits, ground, over-voltage, equipment damage, or component failure.” A wide range of industries such as, for example, electric utilities, power plants, oil refineries, off shore oil rigs, gas ethylene companies, chemical plants, coal mining operations, coal prep plants and transfer stations, gas pipelines, plastic manufacturers, granaries, etc. present very hazardous environments in which electrical equipment must be used. Because of these dangerous environments, various standards have been imposed by the NEC and by Underwriters Laboratories (UL) for the design of electrical equipment for hazardous areas.

[0130] The hazardous material sensor 118 H is an environmental sensor 118 that senses when the electronic device 100 is in the presence of hazardous materials, including gas, liquids, or solids, and deactivates the field-emitting device 101 . One type of hazardous material sensor 118 H for sensing hydrocarbons that are present in fuels is disclosed in U.S. Pat. No. 5,782,275, entitled “Onboard vapor recovery detection,” incorporated herein by reference in its entirety.

[0131] Additionally, the electronic device 100 may use cooperative marker sensors 120 , described above, to detect when it is in or proximate to an intrinsically safe area. Cooperative markers 120 such as the optical marker sensor 120 A, the ultrasonic marker sensor 120 C, the infrared beacon sensor 120 D, the frequency beacon detector 120 E, and the magnetic marker sensor 120 F all may be used individually or in combination to provide such functionality.

[0132] Certain modifications and improvements will occur to those skilled in the art upon a reading of the foregoing description. It should be understood that the present invention is not limited to any particular type of electronic device 100 , field-emitting device 101 , sensors 118 , 120 and transportation vessel 50 . For the purposes of this application, couple, coupled, or coupling is defined as either a direct connection or a reactive coupling. Reactive coupling is defined as either capacitive or inductive coupling.

[0133] One of ordinary skill in the art will recognize that there are different manners in which these elements can accomplish the present invention. The present invention is intended to cover what is claimed and any equivalents. The specific embodiments used herein are to aid in the understanding of the present invention, and should not be used to limit the scope of the invention in a manner narrower than the claims and their equivalents.