Method and apparatus for detecting fault conditions in a vehicle data recording device to detect tampering or unauthorized access

• US 5,586,130 A
• Filed: 10/03/1994
• Issued: 12/17/1996
• Est. Priority Date: 10/03/1994
• Status: Expired due to Term

• Current Assignee: Omnitracs LLC (Solera Holdings Incorporated)
• Original Assignee: Qualcomm, Inc.
• Inventors: Doyle, Thomas F.
• Primary Examiner(s): Beausoliel, Jr., Robert W.
• Assistant Examiner(s): VALES, PHILLIP
• Application Number:
  US08/316,746
• Time in Patent Office: 806 Days
• Field of Search: 395/575, 346/33 R, 346/33 D, 324/110, 368/8, 377/15, 377/16, 377/19, 377/20, 377/23, 377/24, 377/24.1, 371/60, 371/61, 371/62, 364/424.03, 364/424.04, 340/438, 340/439
• US Class Current: 714/815
• CPC Class Codes: G01R 31/007 using microprocessors or computers
• CPC Class Codes: G07C 5/008 communicating information to a remotely located station transmission systems for measured values G08C
• CPC Class Codes: G07C 5/085 using electronic data carriers

Abstract

A system and method for detecting fault conditions within a vehicle recording device are disclosed herein. The fault detection technique may be implemented in a vehicle in which are incorporated one or more vehicle sensors for monitoring one or more operational parameters of the vehicle. A recording device disposed within the vehicle is used to collect vehicle operation data produced by the one or more vehicle sensors.

The fault detection technique of the invention contemplates storing a current time value at regular intervals during periods in which the recording device is provided with a source of main power. Time differences are determined between consecutive ones of the stored time values, and the time differences compared to a predetermined maximum value. A power loss fault condition is registered when at least one of the time differences exceeds the predetermined maximum value. In a preferred implementation an indication of the existence of the power loss fault condition is transmitted to a central control station.

Fault detection may also be effected within a vehicle recording device by repeatedly storing a cumulative value of an operational parameter registered by a sensor unit incorporated within the vehicle. The last stored cumulative value is compared to a cumulative value currently registered the sensor unit, and difference value is determined therebetween. A fault condition is indicated when the difference value exceeds a predetermined maximum value. Again, an indication of the existence of the fault condition may then be transmitted to a central control station.

Claims

1. In a vehicle including one or more vehicle sensors for monitoring one or more operational parameters of said vehicle, said vehicle including a recording device for collecting vehicle operation data produced by said one or more vehicle sensors, a method for detecting fault conditions within said recording device comprising the steps of:

providing a wake-up signal during each of a sequence of intervals of predefined duration;

storing a current time value in response to each said wake-up signal when said recording device is provided with a source of main power;

determining time differences between consecutive ones of said stored time values; and

comparing said time differences to said predefined duration, and registering a power loss fault condition when at least one of said time differences exceeds said predefined duration.

2. In a vehicle including one or more vehicle sensors for monitoring one or more operational parameters of said vehicle, said vehicle including a recording device for collecting vehicle operation data produced by said one or more vehicle sensors, a method for detecting fault conditions within said recording device comprising the steps of:

storing a current time value at regular intervals during periods in which said recording device is provided with a source of main power, said step of storing including the step of storing current time values at a first rate during periods when an ignition line of said vehicle is in a first logical state and the step of storing current time values at intervals substantially equivalent to a predetermined maximum value when said vehicle ignition line is in a second logical state;

determining time differences between consecutive ones of said stored time values; and

comparing said time differences to said predetermined maximum value, and registering a power loss fault condition when at least one of said time differences exceeds said predetermined maximum value.

3. In a system including a fleet of vehicles in communication with a central control station wherein a first of said vehicles includes one or more vehicle sensors for monitoring one or more operational parameters and a mobile communications terminal linked to said one or more vehicle sensors, said mobile communications terminal including a recording device for collecting vehicle operation data produced by said one or more vehicle sensors, a method for detecting fault conditions within said recording device comprising the steps of:

providing a wake-up signal during each of a sequence of wake-up periods of predefined duration;

storing a current time value within said mobile communications terminal in response to each said wake-up signal when said recording device is provided with a source of main power;

determining time differences between consecutive ones of said stored time values;

comparing said time differences to said predefined duration; and

transmitting a power loss fault condition to said central control station when at least one of said time differences exceeds said predefined duration of said wake-up periods.

4. In a system including a fleet of vehicles in communication with a central control station wherein a first of said vehicles includes one or more vehicle sensors for monitoring one or more operational parameters and a mobile communications terminal linked to said one or more vehicle sensors, said mobile communications terminal including a recording device for collecting vehicle operation data produced by said one or more vehicle sensors, a method for detecting fault conditions within said recording device comprising the steps of:

storing a current time value within said mobile communications terminal at regular intervals during periods in which said recording device is provided with a source of main power, said step of storing including the step of storing current time values at a first rate during periods when an ignition line of said vehicle is in a first logical state and the step of storing current time values at intervals substantially equivalent to a predetermined wake-up period when said vehicle ignition line is in a second logical state;

determining time differences between consecutive ones of said stored time values;

comparing said time differences to said predetermined wake-up period; and

transmitting a power loss fault condition to said central control station when at least one of said time differences exceeds said predetermined wake-up period.

5. In a vehicle including one or more vehicle sensors for monitoring one or more operational parameters of said vehicle, said vehicle including a recording device for collecting vehicle operation data produced by said one or more vehicle sensors, a fault detection system for detecting fault conditions within said recording device, said system comprising:

a wake-up timer for providing a wake-up signal at a predefined rate;

a date-time module for generating a current time value at regular intervals, each of said current time values being stored within memory of said recording device at least at said predefined rate during periods in which said recording device is provided with a source of main power; and

a fault detection system controller for;

(i) determining time differences between consecutive ones of said stored time values,

(ii) comparing said time differences to a predetermined maximum value related to a period of said wake-up signal, and

(iii) registering a power loss fault condition when at least one of said time differences exceeds said predetermined maximum value.

6. In a vehicle including one or more vehicle sensors for monitoring one or more operational parameters of said vehicle, said vehicle including a recording device for collecting vehicle operation data produced by said one or more vehicle sensors, a fault detection system for detecting fault conditions within said recording device, said system comprising:

a date-time module for generating a current time value at regular intervals during periods in which said recording device is provided with a source of main power, each of said current time values being stored within memory of said recording device at a first rate during periods when an ignition line of said vehicle is in a first logical state, and each of said current time values being stored at intervals substantially equivalent to a predetermined maximum value when said vehicle ignition line is in a second logical state; and

a fault detection system controller for;

(i) determining time differences between consecutive ones of said stored time values,

(ii) comparing said time differences to said predetermined maximum value, and

(iii) registering a power loss fault condition when at least one of said time differences exceeds said predetermined maximum value.

7. In a system including a fleet of vehicles in communication with a central control station wherein a first of said vehicles includes one or more vehicle sensors for monitoring one or more operational parameters and a mobile communications terminal linked to said one or more vehicle sensors, said mobile communications terminal including a recording device for collecting vehicle operation data produced by said one or more vehicle sensors, a recording device fault detection system comprising:

a wake-up timer for providing a wake-up signal at a predefined rate;

a date-time module for generating a current time value at regular intervals, each of said current time values being stored within memory of said recording device at least at said predefined rate during periods in which said recording device is provided with a source of main power; and

a fault detection system controller for;

(i) determining time differences between consecutive ones of said stored time values, and

(ii) comparing said time differences to a predetermined wake-up period;

wherein said mobile communications terminal is disposed to transmit a power loss fault condition to said central control station when at least one of said time differences exceeds said predetermined wake-up period.

8. The system of claim 7 wherein said date-time module operates to store current time values at a first rate during periods when an ignition line of said vehicle is in a first logical state, and to store current time values at intervals substantially equivalent to said predetermined wake-up period when said vehicle ignition line is in a second logical state.

9. In a vehicle including at least one vehicle sensor unit for monitoring an operational parameter of said vehicle and for registering a cumulative value of said parameter, said vehicle including a recording device connected to said one vehicle sensor unit, a method for detecting fault conditions within said recording device comprising the steps of:

providing a wake-up signal at a predefined rate;

repeatedly storing a cumulative value registered by said sensor unit at least at said predefined rate during periods in which said recording device is provided with a source of main power;

comparing the last stored cumulative value to a cumulative value currently registered by said sensor unit and determining a difference value therebetween; and

indicating a fault condition when said difference value exceeds a period of said wake-up signal.

10. The method of claim 9 wherein said operational parameter comprises engine run time.

11. The method of claim 9 wherein said operational parameter is selected from the set consisting of:

fuel consumption, distance traveled and engine idle time.

12. The method of claim 9 further including the step transmitting a message indicative of a fault condition when said difference value exceeds a predetermined value, said message being received by a base station in communication with said vehicle.

13. In a vehicle including at least one vehicle sensor unit for monitoring an operational parameter of said vehicle and for registering a cumulative value of said parameter, said vehicle including a recording device connected to said one vehicle sensor unit, a fault detection system for detecting fault conditions within said recording device, said fault detection system comprising:

means for providing a wake-up signal at a predefined rate;

a memory within said recording device; and

a controller for;

repeatedly storing within said memory a cumulative value registered by said sensor unit at least at said predefined rate during periods in which said recording device is provided with a source of main power,

comparing the cumulative value last stored within said memory to a cumulative value currently registered by said sensor unit and determining a difference value therebetween, and

indicating a fault condition when said difference value exceeds a period of said wake-up signal.

14. The system of claim 13 wherein said operational parameter comprises engine run time.

15. The system of claim 13 wherein said operational parameter is selected from the set consisting of:

fuel consumption, distance traveled and engine idle time.

16. The system of claim 13 wherein said sensor unit comprises a vehicle speed sensor.

17. The system of claim 13 wherein said sensor unit comprises a vehicle engine speed (RPM) sensor.

18. In a vehicle including one or more vehicle sensors for monitoring one or more operational parameters of said vehicle, said vehicle including a recording device for collecting vehicle operation data produced by said one or more vehicle sensors, a method for detecting fault conditions within said recording device comprising the steps of:

storing a current time value during periods in which said recording device is provided with a source of main power, said current time value being stored at a first rate when an ignition line of said vehicle is in a first state and at a second rate when said ignition line is in a second state;

determining time differences between consecutive ones of said stored time values; and

comparing said time differences to a predetermined maximum value, and registering a power loss fault condition when at least one of said time differences exceeds said predetermined maximum value.

19. In a vehicle including one or more vehicle sensors for monitoring one or more operational parameters of said vehicle, said vehicle including a recording device for collecting vehicle operation data produced by said one or more vehicle sensors, a fault detection system for detecting fault conditions within said recording device, said system comprising:

means for storing a current time value during periods in which said recording device is provided with a source of main power, said current time value being stored at a first rate when an ignition line of said vehicle is in a first state and at a second rate when said ignition line is in a second state; and

a fault detection controller for;

determining time differences between consecutive ones of said stored time values; and

comparing said time differences to a predetermined maximum value, and registering a power loss fault condition when at least one of said time differences exceeds said predetermined maximum value.