JP3440863B2 - Vehicle sensor abnormality detection device - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motion sensor mounted on a vehicle for detecting a physical quantity related to a vertical movement of the vehicle and a physical quantity related to a steering angle of a steering wheel. The present invention relates to a vehicle sensor abnormality detection device that detects an abnormality of a steering sensor to be detected. 2. Description of the Related Art Conventionally, for example, Japanese Unexamined Patent Publication No.
As shown in the publication, in a vehicle equipped with a vehicle speed sensor for detecting the vehicle speed and a steering angle sensor for detecting the steering angle of the steering wheel, the vehicle speed detected by the vehicle speed sensor is equal to or higher than a certain speed, and 2. Description of the Related Art There has been known a sensor abnormality detection device which determines an abnormality of a steering angle sensor when a signal obtained from the angle sensor does not change for a predetermined time. [0003] However, in the above-described abnormality detection of the conventional steering angle sensor, even when the vehicle is running at a speed equal to or higher than the predetermined speed, a signal obtained from the steering angle sensor has a certain degree. It may not change over time. Therefore, in order to avoid erroneous determination of abnormality of the steering angle sensor, it is necessary to set the predetermined time to a relatively long time,
For this reason, even when an abnormality occurs in the steering angle sensor, there is a problem that a delay occurs from the occurrence of the abnormality to the abnormality determination. SUMMARY OF THE INVENTION The present invention has been made in order to address the above-described problem, and has as its object to detect a malfunction of a steering sensor for detecting a physical quantity related to a steering angle of a steering wheel with a simple configuration. The present invention provides a vehicle abnormality detection device that can be detected in a short time from occurrence of a vehicle, and that can also detect in a short time an abnormality of a motion sensor that detects a physical quantity related to the vertical movement of the vehicle. . In order to achieve this object, the present invention provides a motion sensor for detecting a physical quantity related to the vertical movement of a vehicle, a steering sensor for detecting a physical quantity related to a steering angle of a steering wheel, and the motion sensor. The said thing detected
The logical amount is larger than a predetermined value and is detected by the steering sensor.
When the physical quantity does not change, the steering sensor
Before it is detected by the steering sensor
The physical quantity is larger than a predetermined value and detected by the motion sensor.
The motion sensor when the physical quantity is not changed
Abnormality determination means for determining that there is an abnormality in the vehicle.
In the sensor abnormality detection device, the motion sensor and the steering
Unsprung resonance included in each physical quantity detected by the sensor
Frequency components for deriving the frequency components of the frequency band
Deriving means is provided, and the abnormality determining means
Either frequency component of both frequency components
When the other frequency component does not change
The motion sensor or the steering sensor for detecting the other frequency component.
The present invention provides a sensor abnormality detection device for a vehicle, which is a determination means for determining that there is an abnormality in the sensor. [0006] The sensor abnormality detection of the vehicle configured as described above.
The frequency component deriving means.
One of the two frequency components
If the other frequency component is larger than the value and has not changed
The motion sensor for detecting the other frequency component or
Determining means for determining that the steering sensor is abnormal;
Function, the motion sensor or steering sensor is abnormal.
Can be detected in a short time from the occurrence of the abnormality. [0007] In particular, the sensor abnormality detection of the vehicle according to the present invention.
In the device, the vehicle is easy to vibrate and can be easily taken out
Motion sensor and steering sensor in the unsprung resonance frequency band of
Each frequency included in the physical quantity detected by each
The frequency component deriving means is configured to derive a component.
Is not obtained by the driver's steering wheel operation.
The motion sensor and steering by a very high frequency component
Detects sensor errors without being affected by steering wheel operation
Can be issued. An embodiment of the present invention will be described below with reference to the drawings. In the embodiment, a motion sensor and a steering sensor mounted on a vehicle according to the present invention will be described. This is applied to vehicle suspension control. This vehicle has suspension mechanisms 11 to 14 mounted on the vehicle body 10 at each wheel position. The suspension mechanisms 11 to 14 are configured by known mechanisms, and include electric actuators 11 a to 14 a for changing the damping force of the vibration of the vehicle body 10 (spring member) with respect to the wheel (unsprung member). . This vehicle is equipped with a vehicle speed sensor 21, an acceleration sensor 22, and a steering angle sensor 23. The vehicle speed sensor 21 detects the vehicle speed V based on the rotation speed of the output shaft (or wheels) of the transmission, and outputs a detection signal indicating the vehicle speed V. The acceleration sensor 22 corresponds to the motion sensor according to the present invention, detects a vertical acceleration G representing the vertical motion of the vehicle body 10, and outputs a detection signal representing the acceleration G. The acceleration G is positive in the upward direction and negative in the downward direction. The steering angle sensor 23 corresponds to the steering sensor according to the present invention, and is attached to the steering shaft 15a of the steering handle 15 to detect a left-right rotation angle from the neutral position of the steering handle 15 as a steering angle θ, A detection signal representing the steering angle θ is output. Note that this steering angle θ
Indicates that turning from the neutral position of the steering wheel 15 to the left is positive and turning to the right is negative. A microcomputer 24 is connected to each of the sensors 21 to 23. The microcomputer 24 executes the program shown in the flowchart of FIG. 2, and based on the detection signals of these sensors 21 to 23, the acceleration sensor 22 and the steering angle sensor 2
3 and the two sensors 22 and 23
The damping force by the suspension mechanisms 11 to 14 is controlled based on the detection signal. Next, the operation of the embodiment configured as described above will be described with reference to the flowchart of FIG. When the ignition switch is turned on, the microcomputer 24 starts operating and starts executing the program in step 100 of FIG. 2, and then in step 102, the steering angle sensor flag SF and the acceleration sensor flag GF are set to "0". Initially set to "". Both flags SF, GF
Indicates that the steering angle sensor 23 and the acceleration sensor 22
Of the steering angle sensor 23 and the abnormality of the acceleration sensor 22 are each represented by "1". After the initial setting in step 102, the microcomputer 24 inputs a detection signal indicating the vehicle speed V from the vehicle speed sensor 21 in step 104, and
Is determined to be greater than or equal to a small predetermined vehicle speed (for example, 5 km / h) to determine whether the vehicle is traveling. If the vehicle is almost stopped and the vehicle speed V is lower than the predetermined vehicle speed, the determination in step 104 is “NO” and the determination process of step 104 is repeatedly executed. If the vehicle is running and the vehicle speed V is equal to or higher than the predetermined vehicle speed, it is determined “YES” in step 104, and
Step 10
Steps 4 to 132 are repeatedly executed. In step 106, a detection signal representing the vertical acceleration G is input from the acceleration sensor 22, and the input vertical acceleration G is subjected to band-pass filter processing, absolute value processing, and averaging processing. The processed vertical acceleration G is set as a comparative vertical acceleration Gc. The band-pass filter process is a process for extracting a frequency component near the unsprung resonance frequency included in the vertical acceleration G of the vehicle body 10 as a frequency component that greatly affects the steering angle θ. Somewhat different,
The input vertical acceleration G is subjected to a 9-13 Hz band-pass filter processing operation. The absolute value conversion process converts a negative value of the vertical acceleration G subjected to the band-pass filter process into a positive value so that positive and negative cancellation do not occur in an averaging process described later. The absolute value of the acceleration G is calculated. The averaging process is to improve the detection accuracy of the vertical acceleration G by preventing the influence of noise that changes sporadically.
The average value of the vertical acceleration G subjected to the absolute value processing over the past predetermined time is calculated. In step 108, the steering angle sensor 2
3, a detection signal representing the steering angle θ is input, the input steering angle θ is subjected to band-pass filter processing, absolute value processing, and averaging processing, and the steering angles θ subjected to the respective processing are compared. It is set as the steering angle θc. The band-pass filtering is a process for extracting a frequency component near the unsprung resonance frequency included in the steering angle θ in order to extract the same frequency component as the band-pass filtering of the vertical acceleration G. 9-1 similar to the above for the steering angle θ
A 3 Hz band pass filter processing operation is performed. In the absolute value conversion process, the absolute value of the steering angle θ subjected to the band pass filter process is calculated in the same reason and method as in the case of the vertical acceleration G. The averaging process is performed by the absolute valued steering angle θ for the same reason and method as in the case of the vertical acceleration G.
Is to calculate the average value. After the processing of step 108, step 1
At 10, it is determined whether the derived comparative vertical acceleration Gc is greater than a predetermined threshold value Gref. If the comparative vertical acceleration Gc is larger than the threshold Gref, the vertical vibration of the vehicle body 10 affects the steering angle θ of the steering wheel 15 and the steering angle θ detected by the steering angle sensor 23. Is also set to a value large enough to superimpose a vibration component due to the vertical vibration of the vehicle body 10. Now
If the comparative vertical acceleration Gc is greater than the threshold value Gref, “YES” is determined in step 110 and the program proceeds to step 112. In step 112, it is determined whether the derived comparative steering angle θc has changed. This determination is made based on whether or not there is a difference between the past comparative steering angle θc and the current comparative steering angle θc by a predetermined value or more. If there is a change in the comparative steering angle θc,
In step 112, "YES" is determined, and step 1
At 14, the steering angle sensor flag SF and the acceleration sensor flag GF are set to "0" indicating that the steering angle sensor 23 and the acceleration sensor 22 are normal. On the other hand, if there is no change in the comparative steering angle θc, “NO” is determined in step 112, and in step 116, the steering angle sensor flag SF is set to “1” indicating abnormality of the steering angle sensor 23, and the acceleration is determined. The sensor flag GF indicates that the acceleration sensor 22 is normal. "
0 "is set. The comparative vertical acceleration Gc is set to the threshold Gre.
If f is equal to or smaller than “f” and “NO” is determined in step 110, the program proceeds to step 118. In step 118, it is determined whether or not the derived comparative vertical acceleration Gc has changed. This determination is made based on whether or not the difference between the past comparative vertical acceleration Gc and the current comparative vertical acceleration Gc is greater than or equal to a predetermined value.
If there is a change in the comparative vertical acceleration Gc, “NO” is determined in step 118, and the program is executed in step 1
Proceed to 24. In this case, the steering angle sensor flag SF
And the acceleration sensor flag GF is maintained at the previous value. On the other hand, if there is no change in the comparative vertical acceleration Gc, "YES" is determined in step 118, and the program proceeds to step 120. In step 120, it is determined whether or not the derived comparative steering angle θc is larger than a predetermined threshold value θref. This threshold θr
ef is set to a relatively large value that if the comparative steering angle θc is larger than this value, the vehicle body 10 is vibrating up and down and the vertical acceleration G detected by the acceleration sensor 22 should also be changing. I have. Now, the comparative steering angle θc
Is larger than the threshold value θref, it is determined as “YES” in a step 120, and in a step 122, the steering angle sensor flag SF is set to “0” indicating that the steering angle sensor 23 is normal, and the acceleration sensor The flag GF is set to "1" indicating an abnormality of the acceleration sensor 22. On the other hand, if the comparative steering angle θc is equal to or smaller than the threshold value θref, step 120
Is determined to be "NO", and the program proceeds to step 124 while maintaining the steering angle sensor flag SF and the acceleration sensor flag GF at the previous values as described above. In steps 124 and 126, the steering angle sensor flag SF and the acceleration sensor flag GF are set to "1".
Is determined. Then, both flags S
If F and GF are both “0” and both the steering angle sensor 23 and the acceleration sensor 22 are normal, steps 124 and 1
Based on the determination of both being “NO” in step 26, in step 128, by the normal processing using the steering angle θ and the vertical acceleration G detected by the two sensors 23 and 22,
The damping force of the suspension mechanisms 11 to 14 is set and controlled. In this normal processing, for example, a steering angle θ detected by the steering angle sensor 23, a steering speed dθ / dt obtained by differentiating the steering angle θ, a predetermined frequency component extracted from the vertical acceleration G detected by the acceleration sensor 22, and the like are used. The target damping force of each of the suspension mechanisms 11 to 14 is calculated, and the electric actuators 11a to 14a in each of the suspension mechanisms 11 to 14 are driven and controlled, so that the damping force of each of the suspension mechanisms 11 to 14 is calculated. The target damping force is set. On the other hand, when the steering angle sensor flag SF is "0" and the steering angle sensor 23 is normal, but the acceleration sensor flag GF is "1" and the acceleration sensor 22 is abnormal. Is based on the determinations of “NO” and “YES” in steps 124 and 126,
At 30, the steering angle θ detected by the steering angle sensor 23
The damping force of the suspension mechanisms 11 to 14 is set and controlled by the first fail processing using only the first fail processing. In the first fail process, for example, without using the vertical acceleration G detected by the acceleration sensor 22, only the steering angle θ detected by the steering angle sensor 23 and the steering speed dθ / dt obtained by differentiating the steering angle θ are used. Is used to calculate the target damping force of each of the suspension mechanisms 11 to 14, and the damping force of each of the suspension mechanisms 11 to 14 is set to the target damping force in the same manner as described above. On the other hand, if the acceleration sensor flag GF is "0" and the acceleration sensor 22 is normal, but the steering angle sensor flag SF is "1" and the steering angle sensor 23 is abnormal, Is "YES" in step 124.
In step 132, the second acceleration using only the vertical acceleration G detected by the acceleration sensor 22 is determined.
The fail processing sets and controls the damping force of the suspension mechanisms 11 to 14. In the second fail process, for example, the steering angle θ detected by the steering angle sensor 23
, The target damping force of each of the suspension mechanisms 11 to 14 is calculated using only a predetermined frequency component or the like extracted from the vertical acceleration G detected by the acceleration sensor 22. The damping forces 11 to 14 are respectively set to the target damping forces. As can be understood from the above description of the operation, in the above embodiment, the processing in steps 106 and 108 is performed based on the vertical acceleration G and the steering angle θ detected by the acceleration sensor 22 and the steering angle sensor 23. The comparative vertical acceleration Gc and the comparative steering angle θc representing the magnitude of the frequency component in the vicinity of the unsprung resonance frequency, which is a frequency component that easily vibrates and can be easily extracted, are derived. Then, by the processing of steps 110 and 112, the comparative vertical acceleration G
The abnormality of the steering angle sensor 23 is determined based on the fact that the comparative steering angle θc has not changed despite the fact that c is large. Also, by the processing of steps 118 and 120,
The abnormality of the acceleration sensor 23 is determined based on the fact that the comparative vertical acceleration Gc has not changed despite the comparative steering angle θc being large. In this case, if a vertical motion occurs in the vehicle and the vertical acceleration of the vehicle body 10 increases to some extent, the vertical motion is also transmitted to the steering handle 15 and the handle 15 should vibrate at the same time. Therefore, according to the above embodiment, the vertical acceleration G and the steering angle θ
With a simple configuration in which the relative relationship between the acceleration sensor 22 and the steering angle sensor 23 can be determined in a short time. Moreover, the comparative steering angle θc is a frequency component near the unsprung resonance frequency, and is a high frequency component that cannot be obtained by the driver's operation of the steering wheel. I do not receive it. As a result, the suspension mechanisms 11 to 1
The control of the damping force of No. 4 can be quickly and accurately dealt with. In the above embodiment, the body 1 is used as a sensor for detecting a physical quantity related to the vertical movement of the vehicle.
Although the acceleration sensor 22 that detects the vertical acceleration G of 0 is adopted, the acceleration sensor 22 may be a speed sensor that detects the vertical speed of the vehicle body 10, a vehicle height sensor that detects the height from the road surface, A stroke sensor (a type of vehicle height sensor) for detecting the relative height of the vehicle body 10 to the wheels,
Any sensor can be used as long as it detects a physical quantity related to the vertical movement of the vehicle, such as a speed sensor that detects the vertical speed of the vehicle body 10 relative to the wheels, a sensor that detects the vertical vibration of the wheels, and the like. It is. Further, in the above embodiment, only one acceleration sensor 22 of the vehicle body 10 is provided and each suspension mechanism 1 is provided.
1 to 14 are commonly controlled. However, the same acceleration sensor as described above is provided for each wheel position, and each suspension mechanism 11 to 14 is used by using the acceleration of each wheel position detected by each acceleration sensor. May be respectively controlled. In this case, the acceleration sensor flag GF of the above embodiment is provided for each acceleration sensor, and the abnormality determination process including steps 102, 106, and 110 to 122 is performed for each acceleration sensor.
The damping force control process consisting of 4 to 132 may be performed for each acceleration sensor. The same applies to the case where a sensor for detecting a physical quantity related to the vertical movement of the vehicle is used instead of the acceleration sensor 22 as described above. In the above embodiment, the steering angle sensor 23 for detecting the rotation angle of the steering shaft 15a is used as a sensor for detecting a physical quantity related to the steering angle of the steering wheel. 23, the steering shaft 15
Any sensor can be used as long as it detects a physical quantity related to the steering angle of the steering wheel 15 such as the rotation speed and angular acceleration of a. In the above-described embodiment, in steps 106 and 108, an absolute value conversion process for converting a negative value into a positive value to derive the magnitude of the vertical acceleration G and the steering angle θ is performed. However, instead of this, an absolute value conversion process may be performed such that the vertical acceleration G and the steering angle θ are squared. In the above embodiment, the bandpass filter processing for extracting the frequency components near the unsprung resonance frequency from the vertical acceleration G and the steering angle θ is performed in steps 106 and 108. Then, high-pass filter processing of the same cutoff frequency for extracting each component of a predetermined frequency or more may be applied to the vertical acceleration G and the steering angle θ. Further, although the accuracy of the abnormality detection is reduced, for the sake of simplicity of the processing, neither the band-pass filter processing nor the high-pass filter processing is performed, and the magnitude of the detected vertical acceleration G and the detected steering angle θ change. Sensor 22 and steering angle sensor 2
3 may be detected.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an overall schematic diagram of a vehicle according to an embodiment of the present invention. FIG. 2 is a flowchart of a program executed by the microcomputer of FIG. 1; [Description of Signs] 10: Vehicle body, 11 to 14: Suspension mechanism, 11a
14a: electric actuator, 21: vehicle speed sensor, 2
2 ... acceleration sensor, 23 ... steering angle sensor, 24 ... microcomputer.

Continuation of front page (58) Fields investigated (Int.Cl. ⁷ , DB name) G01M 17/06 B62D 6/00 B60G 17/015

Claims (1)

(1) A motion sensor for detecting a physical quantity related to a vertical movement of a vehicle, a steering sensor for detecting a physical quantity related to a steering angle of a steering wheel, and detection by the motion sensor.
The measured physical quantity is larger than a predetermined value.
Operation when the physical quantity detected by
It is determined that the steering sensor is abnormal, and the steering sensor
If the detected physical quantity is larger than a predetermined value,
When the physical quantity detected by the sensor has not changed
Abnormality determination means for determining that the movement sensor has an abnormality.
In the sensor abnormality detecting device for a vehicle provided with, each physical detected by the motion sensor and the steering sensor
Frequency component of the unsprung resonance frequency band
Providing frequency component deriving means for deriving each
Determining means for determining one of the frequency components
The frequency component is larger than the specified value and the other frequency component
When not being converted, the other frequency component is detected.
Judgment that the motion sensor or steering sensor is abnormal
Means for detecting sensor abnormality of a vehicle.