System and method for managing time for vehicle fault diagnostic apparatus

• US 6,012,004 A
• Filed: 11/20/1997
• Issued: 01/04/2000
• Est. Priority Date: 05/25/1995
• Status: Expired due to Fees

• Current Assignee: Komatsu Ltd.
• Original Assignee: Komatsu Ltd.
• Inventors: Shimura, Hiroshi, Sugano, Yukio
• Primary Examiner(s): Nguyen, Tan
• Application Number:
  US08/952,727
• Time in Patent Office: 775 Days
• Field of Search: 701/29, 701/30, 701/31, 701/33, 701/35, 395/290, 395/286, 395/559, 395/297
• US Class Current: 701/33
• CPC Class Codes: B60R 16/0315 using multiplexing techniques multiplexing for transmission of signals G08C15/00; multiplexing for electrical communication in general H04J
• CPC Class Codes: G06F 11/1679 at clock signal level
• CPC Class Codes: G06F 11/1691 using a quantum
• CPC Class Codes: G07C 5/0808 Diagnosing performance data testing of vehicles G01M17/00; testing of electrical installation on vehicles G01R31/005

Abstract

The present invention relates to a system and a method for managing time for a vehicle fault diagnostic apparatus by which temporal contradictions and errors between controllers are eliminated, and fault diagnosis is reliably performed by accurate time. To this end, the system includes a master controller (1) for transmitting a counted time as a standard time, and a plurality of controllers (11a, 11b, 11c, . . . , 11n) for determining the time relating to the fault diagnosis on the basis of the received standard time when fault data of sensors, etc., are detected.

Claims

1. A vehicle fault diagnostic apparatus comprising:

a communication network;

a plurality of controllers, each of said plurality of controllers having connected thereto at least one of a respective sensor and a respective actuator for detecting a fault of the respective at least one and for transmitting detected fault data through said communication network; and

a master controller for receiving said detected fault data from said communication network;

wherein said master controller transmits a counted time to each of said plurality of controllers as a standard time; and

wherein each respective one of said plurality of controllers, when detecting a fault of the respective at least one to produce detected fault data, determines a time relating to a fault diagnosis on a basis of the standard time which was transmitted by the master controller to the respective one of said plurality of controllers.

2. Apparatus in accordance with claim 1, wherein each of said plurality of controllers comprises a fault information storage means for storing said detected fault data and at least one of a fault occurrence time and an elapsed time, determined on a basis of said standard time.

3. Apparatus in accordance with claim 1, wherein each of said plurality of controllers comprises:

a vehicle condition storage means, for storing at least one of a signal input condition from a sensor and a signal output condition to an actuator, and for storing an occurrence time of said at least one of a signal input condition and a signal output condition, determined on a basis of said standard time.

4. Apparatus in accordance with claim 1, wherein each of said plurality of controllers comprises an exchange time storage means for storing an exchange time of a respective one of said plurality of controllers, determined on a basis of said standard time.

5. Apparatus in accordance with claim 1, wherein said master controller comprises:

a standard time counter for counting said standard time; and

a controller for transmitting said standard time to each of said plurality of controllers through said communication network.

6. Apparatus in accordance with claim 5, wherein each of said plurality of controllers comprises a fault information storage means for storing said detected fault data and at least one of a fault occurrence time and an elapsed time, determined on a basis of said standard time.

7. Apparatus in accordance with claim 5, wherein each of said plurality of controllers comprises:

a vehicle condition storage means, for storing at least one of a signal input condition from a sensor and a signal output condition to an actuator, and for storing an occurrence time of said at least one of a signal input condition and a signal output condition, determined on a basis of said standard time.

8. Apparatus in accordance with claim 5, wherein each of said plurality of controllers comprises an exchange time storage means for storing an exchange time of a respective one of said plurality of controllers, determined on a basis of said standard time.

9. Apparatus in accordance with claim 1, wherein each of said plurality of controllers comprises:

a standard time storage means for storing standard time; and

a controller for renewing the standard time, which is stored in said standard time storage means, on a basis of the standard time transmitted by said master controller, and for determining a time relating to a fault diagnosis on a basis of the resulting renewed standard time when a fault occurs.

10. Apparatus in accordance with claim 9, wherein each of said plurality of controllers comprises a fault information storage means for storing said detected fault data and at least one of a fault occurrence time and an elapsed time, determined on a basis of said standard time.

11. Apparatus in accordance with claim 9, wherein each of said plurality of controllers comprises:

a vehicle condition storage means, for storing at least one of a signal input condition from a sensor and a signal output condition to an actuator, and for storing an occurrence time of said at least one of a signal input condition and a signal output condition, determined on a basis of said standard time.

12. Apparatus in accordance with claim 9, wherein each of said plurality of controllers comprises an exchange time storage means for storing an exchange time of a respective one of said plurality of controllers, determined on a basis of said standard time.

13. A method of managing time for a vehicle fault diagnostic apparatus in which each of a plurality of controllers is connected to at least one of a respective sensor and a respective actuator for detecting a fault of said at least one, said method comprising the steps of:

transmitting to each of said plurality of controllers a standard time;

storing, in each of said plurality of controllers which detects a fault, detected fault data and at least one of an occurrence time of said fault and an elapsed time, whereby at least one of said occurrence time and said elapsed time is regarded as a time relating to the detected fault; and

each of said plurality of controllers determining a time relating to a fault, detected by a respective controller, on a basis of said standard time.

14. A method in accordance with claim 13, wherein the step of transmitting is accomplished from a master controller through a network.

15. A method in accordance with claim 13, wherein the step of determining a time comprises:

storing, in each of said plurality of controllers, a standard time which has been transmitted in the step of transmitting;

renewing the thus stored standard time in each of said plurality of controllers with a new standard time which is transmitted in the step of transmitting; and

storing the thus renewed standard time, in a respective one of said plurality of controllers which detects a fault, as the occurrence time of said fault.

16. A method in accordance with claim 15, further comprising:

replacing one of said plurality of controllers with a different controller; and

then storing in said different controller a standard time which has been transmitted in the step of transmitting.

17. A method in accordance with claim 15, wherein the step of transmitting is accomplished from a master controller through a network.

18. A method in accordance with claim 17, further comprising transmitting, from a respective one of said plurality of controllers which has detected a fault, to said master controller detected fault data and at least one of an occurrence time of said fault and an elapsed time, whereby said at least one of said occurrence time and said elapsed time is regarded as a time relating to the detected fault.

19. A method in accordance with claim 18, further comprising storing in said master controller each detected fault data and associated time relating to the detected fault to provide a stored fault history.

20. A method in accordance with claim 19, further comprising analyzing the stored fault history.