Vehicle controller

• US 20050234614A1
• Filed: 02/10/2005
• Published: 10/20/2005
• Est. Priority Date: 04/20/2004
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Shimamura, Kotaro, Morita, Yuichiro, Kanekawa, Nobuyasu, Sasaki, Shoji, Sakurai, Kohei
• Granted Patent: US 7,376,498 B2
• Time in Patent Office: Days
• US Class Current: 701/29
• CPC Class Codes: B62D 5/049 detecting sensor failures
• CPC Class Codes: B62D 5/0493 detecting processor errors, e.g. plausibility of steering direction

Abstract

A vehicle controller which can realize a reduced cost and high reliability at the same time. A control target status signal outputted from a control target is inputted to a monitoring unit. The monitoring unit compares a control command value with the control target status signal to determine whether the control target operates normally as per the control command value. When the monitoring unit determines that the control target does not operate normally, it outputs a failure detected signal to an actuator driving unit.

Claims

1. A vehicle controller comprising:

a control circuit receiving a first signal from an exterior and outputting a driving signal;

an actuator driving circuit receiving the driving signal from said control circuit and outputting a second signal to the exterior; and

a monitoring circuit for comparing the first signal with a third signal from the exterior and outputting a failure detected signal to said actuator driving circuit when a difference between the first signal and the third signal exceeds a predetermined value.

2. A vehicle controller according to claim 1, wherein said monitoring circuit comprises:

a comparing unit for comparing the first signal with the third signal; and

a comparison trigger signal generator for generating a trigger signal to start a comparison in said comparing unit.

3. A vehicle controller according to claim 1, wherein said monitoring circuit receives the first signal from the exterior via said control circuit.

4. A vehicle controller according to claim 1, wherein said monitoring circuit sends a normal operation confirmation signal to said control circuit.

5. A vehicle controller according to claim 4, wherein the normal operation confirmation signal is periodically sent, and if said control circuit cannot receive the normal operation confirmation signal for a predetermined period, said control circuit outputs a second failure detected signal, and

supply of power to an external actuator is cut off with outputting of one of the failure detected signal from said monitoring circuit and the second failure detected signal from said control circuit.

6. A vehicle controller according to claim 1, wherein the logical product of the driving signal and the failure detected signal is computed such that supply of power to an external actuator is cut off when any of said control circuit and said monitoring circuit is failed.

7. A vehicle controller according to claim 1, wherein said vehicle controller is a device for controlling a steering motor which generates a steering force depending on a steering operation input, and

the first signal represents a steering angle command value of a vehicle which is produced in accordance with a signal value from a sensor for measuring a steering operation input.

8. A vehicle controller comprising:

control means receiving a control command value from an exterior and outputting a driving signal;

actuator driving means receiving the driving signal from said control means and driving an external actuator; and

monitoring means for comparing the control command value with a control target status signal outputted from an external control target and outputting a failure detected signal to said actuator driving means when a difference between the control command value and the control target status signal exceeds a predetermined value.

9. A vehicle controller according to claim 8, wherein said monitoring means comprises:

a comparing unit for comparing the control command value with the control target status; and

a comparison trigger signal generator for generating a trigger signal to start a comparison in said comparing unit.

10. A vehicle controller according to claim 8, wherein said monitoring means receives the control command value from the exterior via said control means.

11. A vehicle controller according to claim 8, wherein said monitoring means sends a normal operation confirmation signal to said control means.

12. A vehicle controller according to claim 11, wherein the normal operation confirmation signal is periodically sent, and if said control means cannot receive the normal operation confirmation signal for a predetermined period, said control means outputs a second failure detected signal, and

supply of power to said external actuator is cut off with outputting of one of the failure detected signal from said monitoring means and the second failure detected signal from said control means.

13. A vehicle controller according to claim 8, wherein when said monitoring means outputs the failure detected signal, said actuator driving means stops supply of power to said external actuator and said control means stops reception of the control command value.

14. A vehicle controller according to claim 8, wherein said vehicle controller is a device for controlling a motor which generates a braking force, and

the control command value is a command value indicating a force applied to press a brake pad against a disk rotor in accordance with a signal value from a brake pedal position sensor for measuring a brake pedal operation input.

15. A vehicle controller comprising:

a communication driver receiving a steering command value from an exterior;

a main microcomputer connected to said communication driver and outputting a driving signal;

a 3-phase bridge circuit receiving the driving signal and driving an external motor; and

a monitoring microcomputer connected to said communication driver,

wherein said monitoring microcomputer receives a control target status signal outputted from an exterior steering angle sensor and outputs a failure detected signal to said 3-phase bridge circuit when a difference between the steering command value and the control target status signal exceeds an allowable error range.

16. A vehicle controller according to claim 15, wherein said monitoring microcomputer comprises:

a comparing unit for comparing the steering command value with the control target status signal; and

a comparison trigger signal generator for generating a trigger signal to start a comparison in said comparing unit.

17. A vehicle controller according to claim 15, wherein said monitoring microcomputer receives the steering command value from the exterior via said main microcomputer.

18. A vehicle controller according to claim 15, wherein said monitoring microcomputer sends a normal operation confirmation signal to said main microcomputer.

19. A vehicle controller according to claim 18, wherein the normal operation confirmation signal is periodically sent, and if said main microcomputer cannot receive the normal operation confirmation signal for a predetermined period, said main microcomputer outputs a second failure detected signal, and

supply of power to said external motor is cut off with outputting of one of the failure detected signal from said monitoring microcomputer and the second failure detected signal from said main microcomputer.

20. A vehicle controller according to claim 15, wherein the logical product of the driving signal and the failure detected signal is computed such that supply of power to said external motor is cut off when any of said main microcomputer and said main microcomputer is failed.