Vehicle-mounted unit for an automatic toll collection system that prevents double toll charging

• US 5,675,494 A
• Filed: 07/18/1995
• Issued: 10/07/1997
• Est. Priority Date: 07/19/1994
• Status: Expired due to Term

• Current Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Original Assignee: Nippondenso Co., Ltd. (DENSO Corporation)
• Inventors: Matsumoto, Manabu, Sakurai, Takashi
• Primary Examiner(s): Cosimano, Edward R.
• Application Number:
  US08/503,911
• Time in Patent Office: 812 Days
• Field of Search: 340/928, 340/825.54, 364/464.01, 364/467, 364/464.27, 364/464.28, 393/213
• US Class Current: 705/417
• CPC Class Codes: G06Q 30/0284 Time or distance, e.g. usage of parking meters or taximeters
• CPC Class Codes: G07B 15/063 using wireless information transmission between the vehicle and a fixed station identification of vehicles G08G

Abstract

After a vehicle-mounted unit determines that a vehicle has entered a toll chargeable area, if communication is determined to be allowable through a flag, communication operations are performed and after finishing communication operations, the flag is set and communication operations thereafter are prohibited. Next, the unit determines if a travel distance has exceeded a toll chargeable distance. The travel distance is measured by counting the number of vehicular speed pulses received after the end of the communication operations, and the toll chargeable distance is set to be equal or greater than the travel distance needed by the vehicle to enter the communication area and leave it. If it is determined that travel distance has exceeded toll chargeable distance, the flag is reset, communication prohibition is released and communication thereafter is allowed.

Claims

1. An automatic toll collection system mounted on a vehicle, said system comprising:

toll charge processing means for executing a toll charge process by performing predetermined communication with an interrogator when said vehicle is in a toll chargeable area where said system can receive toll charge commands from said interrogator;

toll charge prohibiting means for prohibiting said toll charge processing means from executing further toll charge processes after said toll charge processing means finishes a first toll charge process;

travel distance measuring means for measuring a travel distance of said vehicle from a position of said vehicle during said first toll charging process; and

a toll charge prohibition continuation means for continuing said toll charge prohibition when said travel distance is less than a toll chargeable distance which corresponds to a size of said toll chargeable area.

2. The system of claim 1, further comprising communication prohibition release means for releasing said toll charge prohibition immediately when said travel distance exceeds said toll chargeable distance.

3. The system of claim 1, further comprising toll charge prohibition release means for releasing said toll charge prohibition when a predetermined amount of time elapses after said travel distance reaches said toll-chargeable distance.

4. The system of claim 1, wherein said toll charge prohibition means is further for prohibiting communication between said vehicle and said interrogator.

5. The system of claim 1, wherein:

a toll charge command includes information on said toll chargeable area; and

said toll charge processing means is further for receiving said toll charge command and for setting said size of said toll chargeable area based on said information on said toll chargeable area.

6. The system of claim 1, said toll charge processing means comprising:

a CPU performing toll charge processing computations; and

a carrier detector detecting a level of said toll charge command and providing a carrier detector signal to said CPU when said input is at a predetermined level;

wherein said CPU is in a sleep mode before receiving said carrier detector signal and enters a run mode after receiving said carrier detector signal.

7. The system of claim 6, wherein said CPU is in said run mode when performing said toll charge processing operations and returns to said sleep mode after completing said toll charge processing operations.

8. The system of claim 1 wherein said travel distance measuring means is for starting said travel distance measurement from said position of said vehicle at a beginning of said first toll charging process.

9. The system of claim 8, said travel distance measuring means comprising:

a CPU;

a vehicle speed sensor;

an input signal interface connected to said CPU and said vehicle speed sensor and providing a speed signal representative of an output of said speed sensor to said CPU; and

a toll charge start detector sending a detection signal to said CPU when said toll charge start detector detects said beginning of said first toll charging process;

wherein said input signal interface includes a level converter converting a level of said pulse signal from said vehicle speed sensor and generating said speed signal; and

said CPU starts said vehicle-speed pulse count computation based on said speed signal when said detection signal is received from said toll charge start detector.

10. The system of claim 9, further comprising:

an IC card storing toll charge information electrically connected to said CPU;

wherein said CPU performs toll charge information input and output operations on the IC card through a card interface.

11. The system of claim 9, further comprising:

a RAM electrically connected to said CPU;

wherein said CPU performs toll charge operations by writing and reading information stored in the RAM.

12. The system of claim 8, said travel distance measuring means comprising:

a CPU;

a vehicle speed sensor generating a pulse signal representative of a speed of said vehicle;

an input signal interface connected to said CPU and said vehicle speed sensor and providing a speed signal representative of an output of said speed sensor to said CPU; and

a toll charge start detector sending a detection signal to said CPU when said toll charge start detector detects said beginning of said first toll charging process;

wherein said input signal interface includes a level converter which converts a level of the pulse signal from the vehicle speed sensor and generates said speed signal to the CPU, a measurement counter which counts vehicle speed pulses based on the speed signal when a computation start command is received from the CPU responsive to a detection signal from the toll charging starting detection means, a setting counter storing a predetermined count corresponding to said toll chargeable distance, and a comparator which compares said predetermined count in said setting counter and a count of said measurement counter and provides a coincidence signal to the CPU when both counts are equal.

13. The system of claim 12, further comprising:

an IC card storing toll charge information electrically connected to said CPU;

wherein said CPU performs toll charge information input and output operations on the IC card through a card interface.

14. The system of claim 12, further comprising:

a RAM electrically connected to said CPU;

wherein said CPU performs toll charge operations by writing and reading information stored in the RAM.

15. A method of controlling toll charge processing operations in an automatic toll collection system mounted on a vehicle, said method comprising the steps of:

receiving a toll charge command from an interrogator;

performing toll charge processing responsive to said toll charge command;

inhibiting performance of subsequent toll charge processing;

measuring a distance travelled by said vehicle from a position of said vehicle during said toll charge processing; and

enabling performance of subsequent toll charge processing when said distance exceeds a predetermined distance.

16. The method of claim 15, said enabling step comprising the steps of:

allowing a predetermined amount of time to elapse after said distance exceeds said predetermined distance; and

enabling performance of subsequent toll charge processing after said predetermined amount of time elapses.

17. The method of claim 15, said measuring step comprising a step of measuring said distance from a position of said vehicle at a beginning of said performing step.

18. The method of claim 15, further comprising a step of reading said predetermined distance from an IC card.

19. The method of claim 15, further comprising a step of reading information corresponding to said predetermined distance from said toll charge command.

20. The method of claim 15, wherein:

said inhibiting step comprises a step of inhibiting receipt of subsequent toll charge commands; and

said enabling step comprises a step of enabling receipt of subsequent toll charge commands.

21. The method of claim 15, wherein:

said inhibiting step comprises a step of placing a CPU performing said toll charge processing in a sleep mode; and

said enabling step comprises a step of placing said CPU in a run mode.

22. The method of claim 21, said receiving step comprising a step of sending a wake-up signal to said CPU to cause said CPU to switch from said sleep mode to said run mode.