System and method of detecting vehicle speed limiting system tampering

• US 6,573,827 B1
• Filed: 11/14/2000
• Issued: 06/03/2003
• Est. Priority Date: 11/14/2000
• Status: Expired due to Term

• Current Assignee: Detroit Diesel Corporation (Mercedes-Benz Group AG)
• Original Assignee: Detroit Diesel Corporation (Mercedes-Benz Group AG)
• Inventors: McKenzie, Ian D.
• Primary Examiner(s): Lieu, Julie
• Application Number:
  US09/712,477
• Time in Patent Office: 931 Days
• Field of Search: 340/438, 340/500, 340/988, 701/93, 701/207, 701/208, 701/213, 342/357.06, 342/351.07, 342/357.08
• US Class Current: 340/438
• CPC Class Codes: B60K 31/16 having means to prevent or discourage unauthorised use or adjusting of the controlling means vehicle theft prevention in general B60R25/00
• CPC Class Codes: B60W 2556/50 of positioning data, e.g. GPS [Global Positioning System] data
• CPC Class Codes: B60Y 2200/14 Trucks; Load vehicles, Busses
• CPC Class Codes: B60Y 2200/143 Busses
• CPC Class Codes: F02D 2200/501 Vehicle speed
• CPC Class Codes: F02D 2200/701 Information about vehicle position, e.g. from navigation system or GPS signal
• CPC Class Codes: G01P 1/103 by comparing the value of the measured signal with one or several reference values in general G01R17/00
• CPC Class Codes: G01P 1/12 Recording devices indicating working conditions of vehicles G07C5/00
• CPC Class Codes: G01P 21/02 of speedometers
• CPC Class Codes: G01S 19/14 specially adapted for specific applications
• CPC Class Codes: G01S 19/23 Testing, monitoring, correcting or calibrating of receiver elements
• CPC Class Codes: G08G 1/20 Monitoring the location of vehicles belonging to a group, e.g. fleet of vehicles, countable or determined number of vehicles

Abstract

A method and system for detecting tampering with a vehicle speed sensor by calculating an average speed based upon global positioning system data. A first position of a vehicle is learned from a global positioning system at a first time. After a time interval the system learns a second position from the GPS at a second time. Based on this information, the average speed is calculated and is then compared to a maximum speed limit value. The system checks to determine if anyone has tampered with the GPS if no over speed condition is detected. If an over speed condition is detected or if there is an indication of tampering with the global positioning system, the system integrates a vehicle speed sensor tampering system that is either logged in memory or may be used to limit engine speed by controlling the engine control module.

Claims

1. A method of detecting vehicle speed sensor tampering for a vehicle having a global positioning system (GPS), a clock and an engine control module (ECM), comprising:

storing a first position signal from the GPS;

storing a first time value substantially simultaneously with storing the first position signal;

waiting a period of time;

storing a second position signal from the GPS;

storing a second time value substantially simultaneously with storing the second position signal;

calculating the average vehicle speed over the period of time;

comparing the average vehicle speed to a stored value of a maximum vehicle speed;

generating a vehicle speed limiting system tampering signal if the average vehicle speed is greater than the maximum vehicle speed;

checking the operation of the GPS if the average vehicle speed is not greater than the maximum vehicle speed to determine if the GPS was tampered with or disabled and generating the vehicle speed limiting system tampering signal wherein the average vehicle speed is determined to be less than the maximum speed if the first position signal and the second position signal correspond with the same position or if the first position signal and the second position signal are not received from the GPS; and

controlling the ECM in response to the vehicle speed limiting system tampering signal.

2. The method of claim 1 wherein the step of controlling the ECM comprises changing the allowed engine revolutions per minute.

3. The method of claim 1 wherein the step of controlling the ECM comprises changing the allowed vehicle road speed.

4. The method of claim 1 wherein the step of controlling the ECM comprises recording in a data recorder that the vehicle speed limiting system tampering signal was generated.

5. A system for detecting vehicle speed sensor tampering in a vehicle, comprising:

an engine control module;

a global positioning receiver operatively connected to the engine control module;

a clock operatively connected to the engine control module;

the engine control module learning a first position from the global positioning receiver;

the engine control module learning a first time from the clock;

waiting a period of time;

the engine control module learning a second position from the global positioning receiver;

the engine control module learning a second time from the clock;

the engine control module calculating the average vehicle speed;

the engine control module comparing the average vehicle speed to a predetermined value corresponding to a speed limit value stored in the engine control module and generating a tampering signal if the average vehicle speed is greater than the speed limit value;

the engine control module checks the operation of the global positioning system if the average vehicle speed is not greater than the maximum vehicle speed to determine if the global positioning system was tampered with or disabled and generating the tampering signal wherein the average vehicle speed is determined to be less than the maximum speed if the first position signal and the second position signal correspond with the same position or if the first position signal and the second position signal are not received from the GPS; and

the engine control module limiting engine speed in response to the tampering signal being generated.

6. The system of claim 5 wherein the engine control module limits the engine speed by limiting the allowed number of engine revolutions per minute.

7. The system of claim 5 wherein the engine control module limits the engine speed by limiting the allowed vehicle road speed.

8. The system of claim 5 wherein engine control module records in a data recorder that the signal was generated indicating that the average vehicle speed was greater than the speed limit value.