MONITORING AND ADJUSTMENT OF READER IN AN ELECTRONIC TOLL COLLECTION SYSTEM

• US 20070075839A1
• Filed: 09/21/2006
• Published: 04/05/2007
• Est. Priority Date: 09/21/2005
• Status: Abandoned Application

• Current Assignee: Mark IV Industries Corporation
• Original Assignee: Mark IV Industries Corporation
• Inventors: Terrier, Daniel, Ho, Thua, Tong, Roger
• Application Number:
  US11/534,060
• Publication Number:
  US 20070075839A1
• Time in Patent Office: Days
• US Class Current: 340/10.200
• CPC Class Codes: G07B 15/06 Arrangements for road pricing or congestion charging of vehicles or vehicle users, e.g. automatic toll systems
• CPC Class Codes: G07B 15/063 using wireless information transmission between the vehicle and a fixed station identification of vehicles G08G

Abstract

An electronic toll collection system that includes a reader with internal monitoring circuitry. The reader includes a controller and transceiver, which is connected to an antenna, wherein the transceiver sends outgoing RF signals to the antenna and receives incoming RF signals from the antenna. The reader includes transceiver monitor circuitry for monitoring the characteristics of the RF signals to assess transceiver performance. The transceiver monitor circuitry provides a result signal to the controller. The controller may adjust the operation of the transceiver through adjustments to an adjustable element based upon the measurement signals. The controller may also send measurement information to a remote computer and receive instructions from the remote computer, thereby enabling remote monitoring and adjustment of the electronic toll collection system.

Claims

1. A electronic toll collection system for conducting toll transactions with vehicle-mounted transponders travelling in a roadway, the electronic toll collection system comprising:

at least one antenna having a coverage area for exchanging RF communications with a transponder in the roadway; and

a reader connected to said at least one antenna, said reader including

a transceiver having an RF port for exciting the at least one antenna with an RF output signal and for receiving RF input signals induced in the at least one antenna by the transponder, the transceiver including an adjustable element having a setting responsive to an adjustment signal,

a controller for controlling said transceiver and for outputting said adjustment signal, and

a transceiver monitor circuit connected to the RF port for measuring characteristics of the RF output signal and the RF input signal, said transceiver monitor circuit providing a result signal to said controller,

and wherein said controller is configured to generate said

adjustment signal based upon said result signal.

2. The system claimed in claim 1, wherein said adjustable element comprises a programmable attenuator.

3. The system claimed in claim 1, wherein said transceiver includes an RF output stage for generating said RF output signal, said RF output stage including said adjustable element, and wherein said setting of said adjustable element determines a power level of said RF output signal.

4. The system claimed in claim 1, wherein said transceiver includes an RF input stage for receiving and detecting said RF input signal, said RF input stage including said adjustable element, and wherein said setting of said adjustable element determines a sensitivity of said RF input stage in detecting said RF input signal.

5. The system claimed in claim 1, wherein said transceiver monitor circuit comprises a low loss directional coupler and processing circuitry, and wherein said processing circuitry includes a down-converter, a peak detector, and a comparator for determining whether the RF output signal has a power level above a minimum threshold level, and wherein the result signal indicates whether the RF output signal power level exceeds the minimum threshold level.

6. The system claimed in claim 5, wherein the controller is configured to calculate an adjustment for the adjustable element based upon the result signal and to generate said adjustment signal to implement said adjustment.

7. The system claimed in claim 1, wherein said transceiver monitor circuit comprises a low loss directional coupler and processing circuitry, and wherein said processing circuitry includes a down-converter, a peak detector, and a comparator for determining whether the RF input signal has a power level above a minimum threshold level, and wherein the result signal indicates whether the RF output signal power level exceeds the minimum threshold level.

8. The system claimed in claim 7, wherein the controller is configured to determine whether the transceiver detects the RF input signal and, if not, to calculate an adjustment for the adjustable element based upon the result signal and to generate said adjustment signal to implement said adjustment.

9. The system claimed in claim 1, wherein said transceiver monitor circuit and said controller are configured to determine the VSWR of the RF output signal and to compare the VSWR to a threshold level.

10. The system claimed in claim 1, wherein said controller is configured to generate and output a report in response to said result signal.

11. The system claimed in claim 1, wherein said controller includes a communications subsystem and a data output port, and wherein said communication subsystem is configured to output data regarding said measured characteristics of the RF output signal and the RF input signal.

12. The system claimed in claim 11, wherein the communications subsystem is configured to generate a mark-up language document containing said measured characteristics, and to transmit said mark-up language document to a remote client device in response to an authenticated request from the remote client device.

13. A method of monitoring operation of an electronic toll collection system for conducting toll transactions with vehicle-mounted transponders travelling in a roadway, the system including at least one antenna having a coverage area for exchanging RF communications with a transponder in the roadway and a reader connected to the at least one antenna, wherein the reader includes a transceiver having an RF port for exciting the at least one antenna with an RF output signal and for receiving RF input signals induced in the at least one antenna by the transponder, the transceiver including an adjustable element having a setting responsive to an adjustment signal, and a controller for controlling said transceiver and for outputting said adjustment signal, the method comprising steps of:

measuring characteristics of the RF output signal and the RF input signal;

calculating an adjustment based upon the measured characteristics; and

generating said adjustment signal to implement said calculated adjustment.

14. The method claimed in claim 14, wherein said adjustable element comprises a programmable attenuator.

15. The method claimed in claim 14, wherein said transceiver includes an RF output stage for generating said RF output signal, said RF output stage including said adjustable element, and wherein said setting of said adjustable element determines a power level of said RF output signal.

16. The method claimed in claim 14, wherein said transceiver includes an RF input stage for receiving and detecting said RF input signal, said RF input stage including said adjustable element, and wherein said setting of said adjustable element determines a sensitivity of said RF input stage in detecting said RF input signal.

17. The method claimed in claim 14, wherein said step of measuring includes determining whether the RF output signal has a power level above a minimum threshold level.

18. The method claimed in claim 17, wherein said step of calculating includes determining whether said adjustment may be implemented through the adjustable element.

19. The method claimed in claim 14, wherein said step of measuring includes determining whether the RF input signal has a power level above a minimum threshold level and, if so, determining whether the transceiver detects the RF input signal.

20. The method claimed in claim 14, wherein said step of measuring includes measuring the power of the RF output signal and measuring the reflected power and calculating the VSWR of the RF output signal.

21. The method claimed in claim 14, further including generating and outputting a report regarding said measured characteristics.

22. The method claimed in claim 21, wherein said report includes a mark-up language document containing said measured characteristics, and wherein said step of outputting includes transmitting said report to a remote client device in response to an authenticated request from the remote client device.