ADAPTIVE COMMUNICATION IN AN ELECTRONIC TOLL COLLECTION SYSTEM

• US 20100237998A1
• Filed: 03/19/2010
• Published: 09/23/2010
• Est. Priority Date: 03/20/2009
• Status: Active Grant

• Current Assignee: Mark IV Industries Corporation
• Original Assignee: Mark IV Industries Corporation
• Inventors: Lee, Mike, Kohli, Japjeev, Malarky, Alastair
• Granted Patent: US 8,508,341 B2
• Time in Patent Office: Days
• US Class Current: 340/10.100
• CPC Class Codes: G07B 15/063 using wireless information transmission between the vehicle and a fixed station identification of vehicles G08G

Abstract

An adaptive communication system and method for use in an electronic toll collection system utilizing transponders located in vehicles travelling on a toll roadway. A transponder memory stores configuration type data that identifies the type of the vehicle carrying the transponder, the transponder or the transponder'"'"'s mounting. The transponder transmits the configuration type data to the communication system. The communication system includes a memory which contains a database of predetermined communication parameters for various types of configuration types. The communication system looks up the predetermined communication parameters for the configuration type and adjusts variable communication parameters accordingly. Predetermined communication variables may include the transmit power of an antenna, or the receive sensitivity of the antenna or the position of the vehicle in order to maximize the likelihood of a successful communication.

Claims

1. An adaptive communication system for communicating with a transponder located in a moving vehicle travelling on a roadway, the transponder having a transponder memory for storing configuration type data the system comprising:

at least one antenna having a coverage area that includes at least a portion of the roadway for receiving the configuration type data from the transponder memory;

a system memory having a database stored thereon, the database listing at least one predetermined communication parameter for each of at least two types of configuration; and

a control device connected to the antennas and the system memory, the control device being configured to determine from the database the predetermined communication parameters corresponding to the configuration type data received at the antenna and to subsequently adjust at least one variable communication parameter based on the predetermined communication parameters determined to correspond to the received configuration type data.

2. The adaptive communication system of claim 1, wherein the configuration type data includes at least one of a vehicle type, a vehicle size, a transponder type or a transponder mounting location.

3. The adaptive communication system of claim 1, wherein at least one of the predetermined communication parameters for each type of configuration and at least one of the variable communication parameters represents a transmit power level and wherein the control device comprises at least one attenuator for adjusting the transmit power level of at least one of the antennas.

4. The adaptive communication system of claim 1, wherein at least one of the predetermined communication parameters for each type of configuration and at least one of the variable communication parameters represents an antenna receive sensitivity and wherein the control device comprises at least one attenuator for adjusting the antenna receive sensitivity of at least one of the antennas.

5. The adaptive communication system of claim 1, wherein the configuration type data comprises data representing the make and model of the vehicle and wherein the database is indexed by vehicle make and model.

6. The adaptive communication system of claim 1, wherein the configuration type data comprises data representing the size of the vehicle and wherein the database is indexed by vehicle size.

7. The adaptive communication system of claim 1, wherein the configuration type data comprises data representing the transponder type, and wherein the database is indexed by transponder type.

8. The adaptive communication system of claim 1, wherein the configuration type data comprises data representing the transponder mounting location on the vehicle, and wherein the database is indexed by transponder mounting location.

9. The adaptive communication system of claim 1 wherein the predetermined communication parameters maximize the likelihood of successful communications with the transponder.

10. The adaptive communication system of claim 1, wherein at least one of the predetermined communication parameters represents a predetermined communication position of the transponder and at least one of the variable communication parameters represents a time slot for communicating with the transponder, the control device further comprising a vehicle position tracking module for tracking the position of the transponder and communicating with the transponder during a time slot during which the transponder is in a position corresponding to the predetermined communication position.

11. The adaptive communication system claimed in claim 10, wherein the control device is further configured to cause the antenna to periodically transmit an interrogation signal and wherein the transponder is configured to transmit a response signal containing at least some of the contents of the transponder memory in response to receipt of an interrogation signal.

12. The adaptive communication system in claim 11, further comprising a vehicle velocity determining module for determining and reporting a velocity of the vehicle to the control device, the control device being configured to determine the time slot during which the transponder is in the position corresponding to the predetermined communication position based on a time at which the response signal is first received from the transponder and the velocity of the vehicle and the predetermined communication position.

13. The adaptive communication system in claim 12, wherein the predetermined communication position is a distance from a point of entry of the coverage area.

14. The adaptive communication system in claim 11, further comprising:

a vehicle velocity determining module for determining and reporting a velocity of the vehicle to the control device; and

a signal power level sensing module for sensing and reporting to the control device a power level of a transmission from the transponder is received by at least one of the antennas,

wherein the control device is configured to determine the approximate position of the transponder based on the signal power level, and wherein the control device is configured to determine the time slot during which the transponder is in the position corresponding to the predetermined communication position based on the approximate position of the transponder and the velocity of the vehicle and the time at which the transmission from the transponder was received.

15. The adaptive communication system in claim 14, wherein the system memory contains a look-up-table for translating at least one power level into an approximate position of the transponder.

16. The adaptive communication system claimed in claim 15, wherein the control device is configured to interpolate within the look-up-table if the power level is not listed in the distance look up table.

17. The adaptive communication system of claim 10, wherein the control device is configured to reserve an adjacent time slot if the time slot is already reserved.

18. The adaptive communication system of claim 1, wherein the control device further comprises a vehicle lateral position determination system connected to the control device for determining a lateral position of the vehicle in the roadway, wherein the control device is configured to adjust the variable communication parameters for the antenna that corresponds to the lateral position of the vehicle.

19. A method of adjusting at least one variable communication parameter in a system for communicating with a transponder, the transponder being located in a moving vehicle travelling in a roadway, the transponder having a transponder memory for storing configuration type data, the communication system having at least one antenna having a coverage area that includes at least a portion of the roadway and a system memory having a database stored thereon, the database listing at least one predetermined communication parameter for each of at least two configuration types, the method comprising the steps of:

receiving at the antenna the configuration type data from the transponder memory;

looking up in the database the predetermined communication parameter that corresponds to the received configuration type data; and

adjusting at least one of the variable communication parameters for the communication system based on the predetermined communication parameter.

20. The method of claim 19, wherein the configuration type data includes at least one of a vehicle type, a vehicle size, a transponder type or a transponder mounting location.

21. The method of claim 19, wherein the predetermined communication parameter represents a transmit power level of the antenna and wherein the step of adjusting includes adjusting the transmit power level of the antenna.

22. The method of claim 19, wherein the predetermined communication parameter represents a receive sensitivity of the antenna and wherein the step of adjusting includes adjusting the receive sensitivity of the antenna.

23. The method of claim 19, further comprising a step of determining which antenna is best positioned for communicating with the transponder and wherein the step of adjusting includes adjusting the variable communication parameter for the antenna that is best suited for communicating with the transponder.

24. The method of claim 19, wherein the predetermined communication parameter represents a predetermined communication position of the transponder and wherein the method further comprises the steps of:

determining a time slot during which the transponder will be in the position corresponding to the predetermined communication position based on the velocity of the vehicle.

25. The method of claim 24 further comprising steps of:

determining the time of entry of the transponder into the coverage area; and

determining a velocity of the vehicle,

and wherein the step of determining a time slot further comprises a step of calculating the time slot based on the velocity of the vehicle and the time of entry of the transponder into the coverage area and the predetermined communication position.

26. The method of claim 24, further comprising steps of:

determining a signal power level of a signal received from the transponder;

determining the time of receipt of the signal from the transponder; and

determining the velocity of the vehicle,

wherein the step of determining a time slot further comprises a step of calculating the time slot based on the signal power level and the time of receipt and the velocity of the vehicle.

27. The method of claim 26, wherein the system memory contains a look-up-table for translating at least one power level into an approximate position of the transponder and wherein the step of determining a time slot further value comprises the step of:

looking up in the distance look up table the approximate position which corresponds to the signal power level.