Apparatus for detecting abnormality of a vehicle sensor and method

• US 20010044688A1
• Filed: 03/15/2001
• Published: 11/22/2001
• Est. Priority Date: 03/21/2000
• Status: Active Grant

• Current Assignee: Advics Company Limited (Aisin Corp.), DENSO Corporation, Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Tanaka, Akira, Okita, Toshinori, Sawada, Mamoru, Yasui, Yoshiyuki, Sugiura, Noboru
• Granted Patent: US 6,434,457 B2
• Time in Patent Office: Days
• US Class Current: 701/92
• CPC Class Codes: B60T 2210/12 Friction
• CPC Class Codes: B60T 2270/413 Plausibility monitoring, cross check, redundancy
• CPC Class Codes: B60T 2270/416 Wheel speed sensor failure
• CPC Class Codes: B60T 8/885 using electrical circuitry
• CPC Class Codes: B60W 2050/0054 Cut-off filters, retarders, delaying means, dead zones, threshold values or cut-off frequency
• CPC Class Codes: B60W 2510/20 Steering systems
• CPC Class Codes: B60W 2520/10 Longitudinal speed
• CPC Class Codes: B60W 2520/125 Lateral acceleration
• CPC Class Codes: B60W 2520/28 Wheel speed
• CPC Class Codes: B60W 2540/18 Steering angle
• CPC Class Codes: B60W 2555/20 Ambient conditions, e.g. wind or rain
• CPC Class Codes: B60W 40/064 Degree of grip
• CPC Class Codes: B60W 50/029 Adapting to failures or work around with other constraints, e.g. circumvention by avoiding use of failed parts

Abstract

An apparatus for detecting abnormality of a vehicle sensor and a method are provided. The apparatus is capable of preventing erroneous detection of abnormalities of sensors. The apparatus has a grip degree detecting device for detecting grip degree of a wheel of the vehicle with respect to a road surface. In a case in which the grip degree is lower than a predetermined degree, detection for presence of an abnormality of a yaw rate sensor, a cross acceleration sensor and a steering angle sensor are prohibited.

Claims

1. An apparatus for detecting abnormality of a vehicle sensor comprising:

a first sensor for detecting an operational state of a vehicle;

a second sensor, which is different from the first sensor, for detecting the operational state of the vehicle;

an abnormality detecting device for detecting for presence of an abnormality of the first sensor on the basis of a predefined operational state of the vehicle detected by the first sensor and the predefined operational state of the vehicle estimated on the basis of an output of the second sensor;

a grip degree detecting device for detecting grip degree of a wheel of the vehicle with respect to a road surface; and

a prohibiting device for prohibiting detection for presence of an abnormality of the first sensor by the abnormality detecting device in at least one case of a case in which the grip degree is lower than a predetermined degree and a case in which a cross-gradient of the road surface is equal to or more than a predetermined value.

2. The apparatus for detecting abnormality of a vehicle sensor according to

claim 1

, wherein the first sensor is at least one of a cross-acceleration sensor, a yaw rate sensor and a steering angle sensor.

3. The apparatus for detecting abnormality of a vehicle sensor according to

claim 1

, wherein the second sensor is a wheel speed sensor.

4. The apparatus for detecting abnormality of a vehicle sensor according to

claim 2

, wherein the second sensor is a wheel speed sensor.

5. The apparatus for detecting abnormality of a vehicle sensor according to

claim 1

, wherein:

a yaw rate sensor and a cross-acceleration sensor serve as the first sensor, and the abnormality detecting device detects for presence of an abnormality of the yaw rate sensor on the basis of a yaw rate detected by the yaw rate sensor and a yaw rate estimated on the basis of the output of the second sensor;

in a case where an abnormality of the yaw rate sensor is not detected, the cross-acceleration sensor serves as the first sensor, the yaw rate sensor serves as the second sensor, and the abnormality detecting device detects for presence of an abnormality of the cross-acceleration sensor on the basis of a cross-acceleration detected by the cross-acceleration sensor and a cross-acceleration estimated on the basis of an output of the yaw rate sensor; and

in a case where an abnormality of the yaw rate sensor is detected, the cross-acceleration sensor serves as the first sensor, a sensor other than the yaw rate sensor serves as the second sensor, and the abnormality detecting device detects for presence of an abnormality of the cross-acceleration sensor on the basis of the cross-acceleration detected by the cross-acceleration sensor and a cross-acceleration estimated on the basis of an output of the sensor other than the yaw rate sensor.

6. The apparatus for detecting abnormality of a vehicle sensor according to

claim 1

, wherein:

a yaw rate sensor and a cross-acceleration sensor serve as the first sensor, a wheel speed sensor serves as the second sensor,

the abnormality detecting device detects for presence of an abnormality of the yaw rate sensor on the basis of a yaw rate detected by the yaw rate sensor and a yaw rate estimated on the basis of an output of the wheel speed sensor;

the abnormality detecting device detects for presence of an abnormality of the cross-acceleration sensor on the basis of a cross-acceleration detected by the cross-acceleration sensor and a cross-acceleration estimated on the basis of the output of the wheel speed sensor.

7. The apparatus for detecting abnormality of a vehicle sensor according to

claim 6

, wherein:

in a case where the abnormality detecting device detects presence of an abnormality of the cross-acceleration sensor on the basis of the cross-acceleration detected by the cross-acceleration sensor and the cross-acceleration estimated on the basis of the output of the wheel speed sensor, on the basis of the cross-acceleration detected by the cross-acceleration sensor and a cross-acceleration estimated on the basis of an output of a predetermined measuring device, which of;

an abnormality of the cross-acceleration sensor itself, or

a cause other than the abnormality of the cross-acceleration sensor itself, is a cause of detection of the abnormality of the cross-acceleration sensor, is determined.

8. The apparatus for detecting abnormality of vehicle sensor according to

claim 7

, wherein the predetermined measuring device is a slip angle measuring device for measuring a vehicle body slip angle, and the abnormality detecting device determines, on the basis of the cross-acceleration detected by the cross-acceleration sensor and a cross-acceleration estimated on the basis of an output of the slip angle measuring device, whether

the detection of the abnormality of the cross-acceleration sensor is due to the abnormality of the cross-acceleration sensor itself, or

the detection of the abnormality of the cross-acceleration sensor is rather than due to the abnormality of the cross-acceleration sensor itself, due to the cross-gradient being larger than a predetermined value.

9. The apparatus for detecting abnormality of vehicle sensor according to

claim 6

, wherein the grip degree detecting device judges whether or not that three or more wheels of the vehicle, including an unsteered wheel, are in grip state with respect to the road surface.

10. The apparatus for detecting abnormality of vehicle sensor according to

claim 1

, further comprising:

a cross-gradient detecting device for detecting the cross-gradient of the road surface,

wherein before the abnormality detecting device detecting for presence of an abnormality of the first sensor, the grip degree and the cross-gradient of the road surface is detected.

11. The apparatus for detecting abnormality of vehicle sensor according to

claim 10

, wherein the grip degree detecting device judges whether or not that at least two wheels of the vehicle at diagonally opposed positions are in a grip state with respect to the road surface.

12. A method for detecting abnormality of a vehicle sensor comprising:

detecting an operational state of a vehicle by a first sensor;

detecting the operational state of the vehicle by a second sensor, which is different from the first sensor;

detecting presence of an abnormality of the first sensor on the basis of a predefined operational state of the vehicle detected by the first sensor and the predefined operational state of the vehicle estimated on the basis of an output of the second sensor;

detecting grip degree of a wheel of the vehicle with respect to a road surface; and

prohibiting detection for presence of an abnormality of the first sensor in at least one case of a case in which the grip degree is lower than a predetermined degree and a case in which a cross-gradient of the road surface is equal to or more than a predetermined value.

13. A method for detecting abnormality of a vehicle sensor according to

claim 12

, wherein the first sensor is at least one of a cross-acceleration sensor, a yaw rate sensor and a steering angle sensor.

14. A method for detecting abnormality of a vehicle sensor according to

claim 12

, wherein the second sensor is a wheel speed sensor.

15. A method for detecting abnormality of a vehicle sensor according to

claim 12

, wherein a yaw rate sensor and a cross-acceleration sensor serve as the first sensor, the method further comprising:

detecting presence of an abnormality of the yaw rate sensor on the basis of a yaw rate detected by the yaw rate sensor and a yaw rate estimated on the basis of the output of the second sensor;

in a case where an abnormality of the yaw rate sensor is not detected, the cross-acceleration sensor serves as the first sensor, the yaw rate sensor serves as the second sensor, detecting presence of an abnormality of the cross-acceleration sensor on the basis of a cross-acceleration detected by the cross-acceleration sensor and a cross-acceleration estimated on the basis of an output of the yaw rate sensor;

or,

in a case where an abnormality of the yaw rate sensor is detected, the cross-acceleration sensor serves as the first sensor, a sensor other than the yaw rate sensor serves as the second sensor, detecting presence of an abnormality of the cross-acceleration sensor on the basis of the cross-acceleration detected by the cross-acceleration sensor and a cross-acceleration estimated on the basis of an output of the sensor other than the yaw rate sensor.

16. A method for detecting abnormality of a vehicle sensor according to

claim 12

, wherein a yaw rate sensor and a cross-acceleration sensor serve as the first sensor, a wheel speed sensor serves as the second sensor, the method further comprising:

detecting presence of an abnormality of the yaw rate sensor on the basis of a yaw rate detected by the yaw rate sensor and a yaw rate estimated on the basis of an output of the wheel speed sensor; and

detecting presence of an abnormality of the cross-acceleration sensor on the basis of a cross-acceleration detected by the cross-acceleration sensor and a cross-acceleration estimated on the basis of the output of the wheel speed sensor.

17. A method for detecting abnormality of a vehicle sensor according to

claim 12

, wherein before detecting for presence of an abnormality of the first sensor, the grip degree and the cross-gradient of the road surface is detected.

18. An apparatus for detecting abnormality of a vehicle sensor comprising:

a first sensor for detecting an operational state of a vehicle;

a second sensor, which is different from the first sensor, for detecting the operational state of the vehicle;

an abnormality detecting device for detecting for presence of an abnormality of the first sensor on the basis of a predefined operational state of the vehicle detected by the first sensor and the predefined operational state of the vehicle estimated on the basis of an output of the second sensor;

a grip degree detecting device for detecting grip degree of a wheel of the vehicle with respect to a road surface; and

a prohibiting device for prohibiting detection for presence of an abnormality of the first sensor by the abnormality detecting device in at least one case of a case in which the grip degree is lower than a predetermined degree and a case in which a cross-gradient of the road surface is equal to or more than a predetermined value,

wherein the first sensor is at least one of a cross-acceleration sensor, a yaw rate sensor and a steering angle sensor, and the second sensor is a wheel speed sensor.