External indicator for electronic toll communications

• US 20060082470A1
• Filed: 10/20/2004
• Published: 04/20/2006
• Est. Priority Date: 10/20/2004
• Status: Active Grant

• Current Assignee: Mark IV Industries Corporation
• Original Assignee: Mark IV Industries Corporation
• Inventors: Zhu, Jeffrey, Tang, Wai-Cheung
• Granted Patent: US 7,262,711 B2
• Time in Patent Office: Days
• US Class Current: 340/928
• CPC Class Codes: G07B 15/063 using wireless information transmission between the vehicle and a fixed station identification of vehicles G08G

Abstract

An external indicator for use in proximity to an on-board unit or transponder for an electronic toll collection (ETC) system. The external indicator senses RF transmissions from the on-board unit and/or roadside readers of the ETC system and produces sensory outputs when transmissions are detected. The external indicator receives RF signals, demodulates them, and analyses the demodulated RF signals to determine if it has received a roadside reader trigger signal and/or a transponder response signal. A sensory indicator, such as a visual, auditory, or kinetic device, alerts an occupant of a vehicle to the detected RF transmissions and, accordingly, to the likely occurrence of an ETC transaction.

Claims

1. An external indicator for use in proximity to an on-board unit of an electronic toll collection system, the electronic toll collection system including a roadside unit for communicating with the on-board unit and conducting an electronic toll collection (ETC) transaction, the external indicator comprising:

an RF antenna;

an RF detector coupled to said RF antenna for demodulating an RF signal induced in said RF antenna by an RF transmission and for outputting a demodulated signal;

a processor having an input for receiving said demodulated signal and an output for providing an indicator signal, the processor having a component for determining if said demodulated signal is indicative of an ETC transmission between said on-board unit and said roadside unit and, if so, generating said indicator signal; and

an indicator device coupled to the output of said processor, said indicator device producing a sensory event in response to said indicator signal.

2. The external indicator claimed in claim 1, wherein said processor includes a signal strength component for comparing a signal strength of said demodulated signal with a first threshold level.

3. The external indicator claimed in claim 2, wherein said signal strength component outputs a detection signal if said signal strength of said demodulated signal exceeds said first threshold level, and wherein said component for determining operates in response to said detection signal.

4. The external indicator claimed in claim 2, wherein said signal strength component comprises a first comparator for applying said first threshold level.

5. The external indicator claimed in claim 4, wherein said signal strength component further includes a second comparator for applying a second threshold level, wherein said second comparator outputs said demodulated signal to said component for determining.

6. The external indicator claimed in claim 1, wherein said component for determining determines whether said demodulated signal includes predetermined characteristics.

7. The external indicator claimed in claim 6, wherein said predetermined characteristics comprise characteristics indicative of an electronic toll collection transaction.

8. The external indicator claimed in claim 7, wherein said predetermined characteristics comprise characteristics associated with a transponder response signal protocol.

9. The external indicator claimed in claim 7, wherein said predetermined characteristics comprise characteristics associated with a reader communication protocol.

10. The external indicator claimed in claim 1, wherein said indicator device comprises at least one visual device, sensory device, or kinetic device.

11. The external indicator claimed in claim 1, wherein said indicator device is selected from the group consisting of a light emitting diode, a speaker, a buzzer, a chime, a vibratory mechanism, an incandescent light, and a display screen.

12. A method of signalling detection of a likely electronic toll collection (ETC) transaction between an on-board unit and a roadside unit, the method comprising the steps of:

receiving and demodulating an RF signal to produce a demodulated signal;

determining if the demodulated signal is indicative of an ETC communication between the roadside unit and the on-board unit and, if so, generating an indicator signal; and

outputting said indicator signal to an indicator device for producing an sensory event in response to said indicator signal.

13. The method claimed in claim 12, including a step of comparing a signal strength of said demodulated signal with a first threshold level.

14. The method claimed in claim 13, including a step of outputting a detection signal based upon said step of comparing if said signal strength of said demodulated signal exceeds said first threshold level, and wherein said step of determining is performed in response to said detection signal.

15. The method claimed in claim 13, wherein said step of determining includes a second step of comparing the signal strength of said demodulated signal with a second threshold level.

16. The method claimed in claim 12, wherein said step of determining includes analyzing whether said demodulated signal includes predetermined characteristics.

17. The method claimed in claim 16, wherein said predetermined characteristics comprise characteristics indicative of an electronic toll collection communication.

18. The method claimed in claim 17, wherein said predetermined characteristics comprise characteristics associated with a transponder response signal protocol.

19. The method claimed in claim 18, wherein said step of analyzing includes digitizing said demodulated signal and comparing data content of said digitized signal with predetermined data content.

20. The method claimed in claim 17, wherein said predetermined characteristics comprise characteristics associated with a reader communication protocol.

21. The method claimed in claim 12, wherein said indicator device comprises at least one visual device, sensory device, or kinetic device.

22. The method claimed in claim 12, wherein said indicator device is selected from the group consisting of a light emitting diode, a speaker, a buzzer, a chime, a vibratory mechanism, an incandescent light, and a display screen.