Sensor abnormality detection device

Abstract

The present invention is provided with a CAN input unit (travel speed input unit) for inputting the travel speed of a vehicle, and sprung acceleration input units (first sensor input unit and second sensor input unit) for inputting the signal fluctuation range (vibration level) of a sprung acceleration sensor. The ECU includes a first determination unit. And a first determination unit that determines whether the traveling speed of the CAN input unit is equal to or greater than a first threshold value (first speed), and that determines whether the traveling speed is equal to or greater than a second threshold value (second speed) as a sprung acceleration sensor value (first sensor input value) of a sprung acceleration input unit (e.g., sprung acceleration input unit) of the first sensor input unit or as a sprung acceleration sensor value (second sensor input value) of a sprung acceleration input unit (e.g., sprung acceleration input unit) of the second sensor input unit. The signal fluctuation range of one of sprung acceleration sensor values (a second sensor input value) of a sprung acceleration input unit is smaller than the first fluctuation range and smaller than the signal fluctuation range of the other one of the sprung acceleration sensor values (a second sensor input value) of the sprung acceleration input unit.

Description

Technical Field

[0001] The present disclosure relates to a sensor abnormality detection device that detects abnormality of a sensor. Background Art

[0002] Patent document 1 discloses a structure for detecting abnormality of a lateral acceleration sensor in relation to an active suspension equipped with a lateral acceleration sensor. At this time, regarding disconnection and short circuit, the abnormality is detected by observing the output value of the lateral acceleration sensor itself. That is, when the output value of the lateral acceleration sensor deviates from the normal range, it is determined that the lateral acceleration sensor is abnormal. In addition, regarding the drift of the sensor signal and the fixation of the intermediate value, the lateral acceleration is obtained based on the output value of the lateral acceleration sensor, and when the magnitude of the lateral acceleration is 0.1G or more for 10 seconds, it is determined that the lateral acceleration sensor is abnormal.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Laid-Open No. 4-87819 Summary of the invention

[0006] Problems to be solved by the invention

[0007] However, in the abnormality detection method disclosed in Patent Document 1, for example, when the vehicle is continuously performing a steady circular turn or bank driving, a lateral acceleration exceeding a certain value is continuously detected, and thus an abnormality of the lateral acceleration sensor may be erroneously detected. In addition, when such an abnormality detection method is applied to a vertical acceleration sensor, an abnormality of the sensor may also be erroneously detected when the vehicle is continuously driving on a slope or an inclined road.

[0008] One of the objects of the present invention is to provide a sensor abnormality detection device capable of detecting an abnormality of a sensor while suppressing erroneous detection.

[0009] Means for solving problems

[0010] One embodiment of the present invention is a sensor abnormality detection device for detecting abnormalities of at least two or more sensors installed in a vehicle, characterized in that it comprises: a driving speed input unit for inputting the driving speed of the vehicle; a first sensor input unit for inputting the signal fluctuation amplitude of the first sensor; a second sensor input unit for inputting the signal fluctuation amplitude of the second sensor; and a first judgment unit for judging whether the driving speed of the driving speed input unit is above a first speed and whether the signal fluctuation amplitude of one of the first sensor input value of the first sensor input unit and the second sensor input value of the second sensor input unit is smaller than the first fluctuation amplitude and smaller than the signal fluctuation amplitude of the other.

[0011] According to one embodiment of the present invention, it is possible to detect abnormality of a sensor while suppressing erroneous detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 1 is a diagram showing the overall configuration of a four-wheeled vehicle to which the ECU according to the embodiment of the present invention is applied.

[0013] Figure 2 It is a diagram schematically showing the ECU and the buffer according to the first embodiment.

[0014] Figure 3 It is a characteristic diagram showing the relationship between the output voltage of the sprung acceleration sensor and the output voltage of the unsprung acceleration sensor and the acceleration.

[0015] Figure 4 This is a characteristic diagram showing an example of time changes of the vehicle speed, the sprung acceleration sensor value, and the abnormality detection counter when the vehicle speed exceeds the first threshold value.

[0016] Figure 5 It is a diagram schematically showing an ECU and a buffer according to a second embodiment.

[0017] Figure 6 This is a characteristic diagram showing an example of time changes of the vehicle speed, the sprung acceleration sensor value, and the abnormality detection counter when the vehicle speed drops below the second threshold value.

[0018] Figure 7 It is a diagram schematically showing an ECU and a buffer according to a third embodiment.

[0019] Figure 8 This is a characteristic diagram showing an example of time changes of the vehicle speed, the sprung acceleration sensor value, and the abnormality detection counter when the vibration level of the sprung acceleration sensor value is larger than the first fluctuation range.

[0020] Fig. 9This is a characteristic diagram showing an example of time changes of the vehicle speed, the sprung acceleration sensor value, and the abnormality detection counter when the vibration level of the sprung acceleration sensor value is smaller than the second fluctuation range. DETAILED DESCRIPTION

[0021] Hereinafter, a case where the sensor abnormality detection device according to the embodiment of the present invention is applied to a four-wheel vehicle will be described in detail with reference to the drawings.

[0022] Here, Figures 1 to 4 The first embodiment of the present invention is shown. Figure 1 as well as Figure 2 In the figure, the vehicle body 1 constitutes the vehicle body. For example, left and right front wheels and left and right rear wheels (hereinafter collectively referred to as wheels 2) are provided on the lower side of the vehicle body 1. These wheels 2 are composed of tires 3. The tires 3 function as springs that absorb fine unevenness of the road surface. The vehicle body 1 and the wheels 2 constitute a vehicle.

[0023] A suspension device 4 is interposed between the vehicle body 1 and the wheel 2. The suspension device 4 is composed of a suspension spring 5 (hereinafter referred to as a spring 5) and a damping force adjustment type shock absorber 6 (hereinafter referred to as a variable damper 6), and the damping force adjustment type shock absorber 6 is interposed between the vehicle body 1 and the wheel 2 in a parallel relationship with the spring 5.

[0024] The variable dampers 6 of the suspension device 4 are respectively provided between the vehicle body 1 and the four wheels 2. The variable dampers 6 are actuators that make the force for suppressing the relative displacement between the vehicle body 1 and the wheels 2 variable. The variable dampers 6 make the force generated between the vehicle body 1 and the wheels 2 variable. In addition, the variable dampers 6 are also force generating mechanisms for adjusting the force between the vehicle body 1 and the wheels 2. The variable dampers 6 can adjust the generated force between soft (flexible) and hard (rigid).

[0025] The variable damper 6 is constructed using a hydraulic buffer of a damping force adjustment type. Figure 2 As shown, in order to continuously adjust the characteristic of generating the damping force (i.e., the damping force characteristic) from a hard characteristic (hard characteristic) to a soft characteristic (soft characteristic), a damping force variable actuator 7 composed of a damping force adjustment valve and the like is attached to the variable damper 6. The damping force variable actuator 7 is a damping force adjustment unit that adjusts the damping force according to the supplied current (driving current).

[0026] The damping force variable actuator 7 does not necessarily have to be a structure that continuously adjusts the damping force characteristics, and may be a structure that can adjust the damping force in two or more stages, for example. The variable damper 6 may be a pressure control type or a flow control type.

[0027] CAN8 (Controller Area Network) is a serial communication unit mounted on the vehicle body 1. CAN8 performs vehicle-oriented multi-channel communication between multiple electronic devices mounted on the vehicle and ECU21. CAN8 transmits vehicle driving information through CAN signals composed of serial signals. In this case, the vehicle driving information transmitted to CAN8 includes, for example, yaw rate, steering angle, vehicle speed, front and rear acceleration, brake fluid pressure, engine torque, etc.

[0028] The three sprung acceleration sensors 9A to 9C are provided on the vehicle body 1 to detect vibration acceleration in the vertical direction on the vehicle body 1 side which is the sprung side. The sprung acceleration sensors 9A to 9C constitute a sprung state detection unit that detects vibration on the sprung.

[0029] In this case, the sprung acceleration sensor 9A is mounted on the vehicle body 1, for example, at a position near the upper end side of the variable damper 6 on the left front wheel side. The sprung acceleration sensor 9B is mounted on the vehicle body 1, for example, at a position near the upper end side of the variable damper 6 on the right front wheel side. The sprung acceleration sensor 9C is mounted on the vehicle body 1 at a middle position between the left and right rear wheels. The sprung acceleration sensors 9A to 9C detect vibration acceleration in the vertical direction on the vehicle body 1 side that is the sprung side, and output the detection signal thereof to the ECU 21. The detection signals of the sprung acceleration sensors 9A to 9C are, for example, Figure 3 The output voltage shown in FIG. 1 is changed according to the acceleration. Specifically, the output voltage becomes an intermediate value when the acceleration becomes zero, becomes a smaller value as the acceleration increases on the negative side (e.g., the lower side), and becomes a larger value as the acceleration increases on the positive side (e.g., the upper side). In addition, a normal range of voltage values ​​is pre-set in the detection signal (output voltage) of the sprung acceleration sensors 9A to 9C. In this case, the normal range includes the output voltage when the acceleration is zero.

[0030] The two unsprung acceleration sensors 10A and 10B are installed on the side of the wheel 2 of the vehicle. Specifically, the unsprung acceleration sensor 10A is installed on the left front wheel of the vehicle, for example. The unsprung acceleration sensor 10B is installed on the right front wheel of the vehicle, for example. The unsprung acceleration sensors 10A and 10B detect the vibration acceleration in the vertical direction on the side of the wheel 2 that becomes the unsprung side, and output the detection signal to the ECU 21. The detection signal of the unsprung acceleration sensors 10A and 10B is, for example, Figure 3 The output voltage shown is substantially the same as the detection signal of the sprung acceleration sensors 9A to 9C. The detection signal (output voltage) of the unsprung acceleration sensors 10A and 10B is pre-set with a voltage value in a normal range. At this time, the normal range includes the output voltage when the acceleration is zero.

[0031] The ECU 21 constitutes a vehicle control device that controls the suspension device 4. The ECU 21 controls the variable damper 6 that varies the force generated between the vehicle body 1 and the wheel 2. Here, the ECU 21 is a control unit that controls the generated force of the variable damper 6 (force generating mechanism).

[0032] The ECU 21 includes a processor (not shown) as a control unit. The processor is composed of a microcomputer or the like. The ECU 21 includes a storage unit (not shown) composed of a ROM, a RAM, a nonvolatile memory or the like. The processor controls the damping force of the variable damper 6 by executing a program stored in the storage unit.

[0033] like Figure 2 As shown, the ECU 21 is connected to the CAN 8 , the sprung acceleration sensors 9A to 9C, the unsprung acceleration sensors 10A and 10B, etc. on its input side, and connected to the damping force variable actuator 7 of the variable damper 6 , etc. on its output side.

[0034] The ECU 21 includes a CAN input unit 22 that inputs a CAN signal from the CAN 8. At this time, the CAN signal includes vehicle driving information. In addition, the vehicle driving information includes the vehicle speed. Therefore, the CAN input unit 22 becomes a running speed input unit that inputs the running speed (vehicle speed) of the vehicle.

[0035] The ECU 21 includes sprung acceleration input units 23A to 23C that input detection signals from the sprung acceleration sensors 9A to 9C. At this time, one of the sprung acceleration sensors 9A to 9C (e.g., the sprung acceleration sensor 9A) becomes the first sensor. In addition, any of the remaining sprung acceleration sensors (e.g., the sprung acceleration sensor 9B) becomes the second sensor. Therefore, the sprung acceleration input unit corresponding to the first sensor (e.g., the sprung acceleration input unit 23A) becomes the first sensor input unit that inputs the signal fluctuation range of the first sensor. The sprung acceleration input unit corresponding to the second sensor (e.g., the sprung acceleration input unit 23B) becomes the second sensor input unit that inputs the signal fluctuation range of the second sensor.

[0036] In addition, the sprung acceleration sensor 9B may be used as the first sensor, or the sprung acceleration sensor 9C may be used as the first sensor. Similarly, the sprung acceleration sensor 9A may be used as the second sensor, or the sprung acceleration sensor 9C may be used as the second sensor.

[0037] The ECU 21 includes unsprung acceleration input units 24A and 24B that input detection signals from the unsprung acceleration sensors 10A and 10B. At this time, one of the unsprung acceleration sensors 10A and 10B (for example, the unsprung acceleration sensor 10A) becomes the first sensor. In addition, the other unsprung acceleration sensor (for example, the unsprung acceleration sensor 10B) becomes the second sensor. Therefore, the unsprung acceleration input unit corresponding to the first sensor (for example, the unsprung acceleration input unit 24A) becomes the first sensor input unit that inputs the signal fluctuation range of the first sensor. The unsprung acceleration input unit corresponding to the second sensor (for example, the unsprung acceleration input unit 24B) becomes the second sensor input unit that inputs the signal fluctuation range of the second sensor.

[0038] In addition, the unsprung acceleration sensor 10B may be used as the first sensor. Similarly, the unsprung acceleration sensor 10A may be used as the second sensor.

[0039] ECU21 reads the vehicle driving information from CAN8 through serial communication. ECU21 reads the sprung acceleration sensor value (sprung acceleration) through the detection signal from the sprung acceleration sensors 9A~9C. ECU21 reads the unsprung acceleration sensor value (unsprung acceleration) through the detection signal from the unsprung acceleration sensors 10A and 10B. ECU21 calculates the target damping force and the like based on the vehicle driving information, the sprung acceleration, and the unsprung acceleration. ECU21 outputs the control command based on the target damping force to the variable damper 6 to control the generated force (damping force) of the variable damper 6.

[0040] ECU21 constitutes a sensor abnormality detection device that detects abnormalities of the sprung acceleration sensors 9A~9C and the unsprung acceleration sensors 10A and 10B. ECU21 detects abnormalities of the sprung acceleration sensors 9A~9C and the unsprung acceleration sensors 10A and 10B by executing a program stored in a storage unit. ECU21 obtains the vehicle speed included in the vehicle driving information from CAN8. ECU21 obtains the respective sprung acceleration sensor values ​​(sprung acceleration) based on the detection signals from the three sprung acceleration sensors 9A~9C. ECU21 obtains the respective unsprung acceleration sensor values ​​(unsprung acceleration) based on the detection signals from the two unsprung acceleration sensors 10A and 10B.

[0041] The ECU 21 obtains the vibration levels of the sprung acceleration sensor values ​​of the sprung acceleration sensors 9A to 9C based on, for example, the maximum and minimum peak values ​​(peak-to-peak value) of the sprung acceleration sensor values. The ECU 21 obtains the vibration levels of the unsprung acceleration sensor values ​​of the unsprung acceleration sensors 10A and 10B based on, for example, the maximum and minimum peak values ​​(peak-to-peak value) of the unsprung acceleration sensor values.

[0042] The ECU 21 compares the vibration levels of any two of the three sprung acceleration sensor values ​​when the vehicle speed exceeds a first threshold value V11 serving as a first speed. The ECU 21 includes, for example, a first determination unit 25 that determines that the sprung acceleration sensor 9A is in an abnormal state and the sprung acceleration sensor value is fixed when the vibration level of the sprung acceleration sensor value of the sprung acceleration sensor 9A is smaller than the first variation range R11 and smaller than the vibration level of the sprung acceleration sensor value of the sprung acceleration sensor 9B.

[0043] At this time, the vehicle speed is added to the sensor abnormality determination condition in order to prevent an erroneous determination during parking due to a vibration input to the vehicle. That is, the first determination unit 25 detects an abnormality in the sprung acceleration sensor value using the vibration of the sprung acceleration sensor value during driving. Therefore, the first threshold value V11 is a speed at which the vibration level of the sprung acceleration sensor value can be sufficiently determined. The first threshold value V11 is set to a value within a range of 20 km / h to 40 km / h, for example. Specifically, the first threshold value V11 is appropriately set to a value of 20 km / h or more in consideration of the characteristics of the sprung acceleration sensors 9A to 9C, the characteristics of the circuit that outputs the detection signal, and the like.

[0044] The first variation range R11 is set, for example, to a value greater than the vibration level when the sprung acceleration sensor value is fixed and smaller than the vibration level of the sprung acceleration sensor value in a normal state. Specifically, the first variation range R11 is set to a value of about 2 to 3 times the vibration level when the sprung acceleration sensor value is fixed. The first variation range R11 is appropriately set in consideration of the characteristics of the sprung acceleration sensors 9A to 9C, the signal level of noise, and the like.

[0045] Similarly, the ECU 21 compares the vibration levels of the two unsprung acceleration sensor values ​​under the condition that the vehicle speed exceeds the first threshold value V12, which is the first speed. The ECU 21 includes, for example, a first determination unit 26 that determines that the unsprung acceleration sensor 10A is fixed when the vibration level of the unsprung acceleration sensor value of the unsprung acceleration sensor 10A is smaller than the first variation range R12 and smaller than the vibration level of the unsprung acceleration sensor value of the unsprung acceleration sensor 10B.

[0046] At this time, the first threshold value V12 is a speed that can sufficiently distinguish the vibration level of the unsprung acceleration sensor value. The first threshold value V12 is appropriately set based on the unsprung acceleration sensors 10A and 10B and the circuit that outputs the detection signal. The first threshold value V12 can be the same value as the first threshold value V11 or a different value.

[0047] In addition, the first variation range R12 is set, for example, to a value greater than the vibration level when the unsprung acceleration sensor value is fixed and less than the vibration level of the unsprung acceleration sensor value in a normal state. Specifically, the first variation range R12 is set to a value of about 2 to 3 times the vibration level when the unsprung acceleration sensor value is fixed. The first variation range R12 is appropriately set in consideration of the characteristics of the unsprung acceleration sensors 10A and 10B, the signal level of noise, and the like. The first variation range R12 may be the same value as the first variation range R11, or may be a different value.

[0048] Here, refer to Figure 2 The sensor abnormality detection process performed by the ECU 21 will be described.

[0049] The ECU 21 reads the program stored in the storage unit and executes the sensor abnormality detection process. Here, the first determination unit 25 that detects abnormality of the sprung acceleration sensors 9A to 9C is described as an example, but the first determination unit 26 that detects abnormality of the unsprung acceleration sensors 10A and 10B is also the same.

[0050] ECU21 receives CAN signals from CAN8 and reads detection signals from three sprung acceleration sensors 9A-9C. ECU21 obtains the vehicle speed included in the vehicle driving information from the CAN signals. ECU21 obtains three sprung acceleration sensor values ​​(sprung accelerations) based on the detection signals from the three sprung acceleration sensors 9A-9C.

[0051] ECU21 determines whether the sprung acceleration sensor value (output voltage value) is a value within the normal range. When all three sprung acceleration sensor values ​​are within the normal range, ECU21 executes the processing of the first determination unit 25. On the other hand, when at least one sprung acceleration sensor value is outside the normal range, ECU21 executes sensor abnormality processing. In the sensor abnormality processing, for example, it is determined that a sprung acceleration sensor (for example, sprung acceleration sensor 9A) that outputs a sprung acceleration sensor value outside the normal range has an abnormality, and the count of the abnormality detection counter is increased. If the count of the abnormality detection counter reaches a predetermined value, ECU21 outputs an error signal to notify the corresponding sprung acceleration sensor of the abnormality.

[0052] The first determination unit 25 determines whether the vehicle speed exceeds the first threshold value V11. When the vehicle speed is lower (smaller) than the first threshold value V11, the vibration level of the sprung acceleration sensor value may not be sufficiently increased, and the first determination unit 25 cannot perform abnormality detection based on the vibration level. Therefore, when the vehicle speed is lower than the first threshold value V11, the first determination unit 25 does not perform the determination of the vibration level of the sprung acceleration sensor value and returns.

[0053] On the other hand, when the vehicle speed is above the first threshold value V11, the first determination unit 25 determines whether the vibration level of the sprung acceleration sensor value is normal. Specifically, the first determination unit 25 selects any two sprung acceleration sensor values ​​from the three sprung acceleration sensor values. The first determination unit 25 compares the sprung acceleration sensor value of one of them with the sprung acceleration sensor value of the other. The ECU 21 performs such a comparison process on all the sprung acceleration sensor values.

[0054] At this time, the first determination unit 25 determines whether the fluctuation range (vibration level) of one sprung acceleration sensor value is smaller than the first fluctuation range R11 and the fluctuation range (vibration level) is smaller than the other sprung acceleration sensor value.

[0055] If the variation range (vibration level) of one sprung acceleration sensor value is smaller than the first variation range R11 and smaller than the variation range (vibration level) of the other sprung acceleration sensor value, it is considered that the sprung acceleration sensor corresponding to the one sprung acceleration sensor value (for example, the sprung acceleration sensor 9A) has an abnormality. Therefore, the first determination unit 25 executes the above-mentioned sensor abnormality processing.

[0056] On the other hand, when the variation range (vibration level) of one of the sprung acceleration sensor values ​​is larger than the first variation range R11, or when the variation range (vibration level) of one of the sprung acceleration sensor values ​​is larger than the variation range (vibration level) of the other sprung acceleration sensor value, the abnormality of one of the sprung acceleration sensor values ​​cannot be detected. Therefore, in order to detect the abnormality of the remaining sprung acceleration sensor values, the same comparison process is also performed on the remaining sprung acceleration sensor values. When the abnormality of all the sprung acceleration sensor values ​​is not detected, the first determination unit 25 determines that the vibration levels of all the sprung acceleration sensor values ​​are normal and returns.

[0057] The ECU 21 of the first embodiment has the above-described structure. Next, as an example of sensor abnormality detection performed by the ECU 21, the operation when an abnormality of the sprung acceleration sensor is detected is taken as an example. Figure 4 Provide explanation.

[0058] like Figure 4 As shown, when the vehicle speed exceeds the first threshold value V11, ECU21 determines whether the vibration level of the sprung acceleration sensor value is within the normal range. At this time, the vibration level of the sprung acceleration sensor value of the sprung acceleration sensors 9B and 9C increases as the vehicle speed increases, and becomes larger than the first fluctuation range R11. Therefore, the sprung acceleration sensors 9B and 9C outputting these two sprung acceleration sensor values ​​are considered normal. On the other hand, the vibration level of the sprung acceleration sensor value of the sprung acceleration sensor 9A is smaller than the first fluctuation range R11. In addition, the vibration level of the sprung acceleration sensor value of the sprung acceleration sensor 9A is a smaller value than the vibration level of any of the sprung acceleration sensor values ​​of the sprung acceleration sensors 9B and 9C. Therefore, the sprung acceleration sensor 9A outputting the sprung acceleration sensor value is considered abnormal. Therefore, ECU21 increases the count of the abnormality detection counter. When the count of the abnormality detection counter reaches a specified value, ECU21 outputs an error signal to notify that the sprung acceleration sensor 9A has an abnormality.

[0059] Thus, the ECU 21 of the first embodiment includes the CAN input unit 22 (driving speed input unit) for inputting the running speed of the vehicle and the sprung acceleration input units 23A to 23C (first sensor input unit, second sensor input unit) for inputting the signal fluctuation range (vibration level) of the sprung acceleration sensors 9A to 9C. The ECU 21 includes the first determination unit 25 for determining whether the running speed (vehicle speed) of the CAN input unit 22 is equal to or higher than the first threshold value V11 (first speed) and whether the signal fluctuation range of one of the sprung acceleration sensor value (first sensor input value) of the sprung acceleration input unit as the first sensor input unit (for example, the sprung acceleration input unit 23A) or the sprung acceleration sensor value (second sensor input value) of the sprung acceleration input unit as the second sensor input unit (for example, the sprung acceleration input unit 23B) is smaller than the first fluctuation range R11 and smaller than the signal fluctuation range of the other.

[0060] Therefore, for example, even when the sprung acceleration sensor value is fixed within a normal range, abnormality in the sprung acceleration sensor value can be detected by comparing the vibration levels (signal fluctuation widths) among the plurality of sprung acceleration sensor values.

[0061] In addition, the ECU 21 includes a first determination unit 26 that determines whether the running speed (vehicle speed) of the CAN input unit 22 is greater than or equal to a first threshold value V12 (first speed), and whether the signal fluctuation range of one of the unsprung acceleration sensor value (first sensor input value) of the unsprung acceleration input unit 24A as the first sensor input unit or the unsprung acceleration sensor value (second sensor input value) of the unsprung acceleration input unit 24B as the second sensor input unit is smaller than the first fluctuation range R12 and smaller than the signal fluctuation range of the other.

[0062] Therefore, for example, even when the unsprung acceleration sensor value is fixed in the normal range, abnormality of the unsprung acceleration sensor value can be detected by comparing the vibration levels (signal fluctuation widths) among the plurality of unsprung acceleration sensor values.

[0063] then, Figure 1 , Figure 5 as well as Figure 6 The second embodiment of the present invention is shown. The second embodiment is characterized in that the ECU includes a second judgment unit, which judges whether the driving speed is less than the second speed and whether the signal variation amplitude of one of the first sensor input value and the second sensor input value is larger than the second variation amplitude and larger than the signal variation amplitude of the other. In addition, in the second embodiment, the same reference numerals are attached to the same components as those in the first embodiment, and their descriptions are omitted.

[0064] The input side of the ECU 31 of the second embodiment is connected to the CAN 8, the sprung acceleration sensors 9A to 9C, the unsprung acceleration sensors 10A and 10B, etc., and the output side is connected to the damping force variable actuator 7 of the variable damper 6, etc. The ECU 31 is configured in the same manner as the ECU 21 of the first embodiment. The ECU 31 includes a processor as a control unit and a storage unit (not shown) composed of a ROM, a RAM, a non-volatile memory, etc. The processor controls the damping force of the variable damper 6 by executing a program stored in the storage unit.

[0065] ECU31 reads the vehicle driving information from CAN8 through serial communication. ECU31 reads the sprung acceleration sensor value (sprung acceleration) through the detection signal from the sprung acceleration sensors 9A~9C. ECU31 reads the unsprung acceleration sensor value (unsprung acceleration) through the detection signal from the unsprung acceleration sensors 10A and 10B. ECU31 calculates the target damping force and the like based on the vehicle driving information, the sprung acceleration, and the unsprung acceleration. ECU31 outputs the control command based on the target damping force to the variable damper 6 to control the generated force (damping force) of the variable damper 6.

[0066] ECU31 constitutes a sensor abnormality detection device for detecting abnormalities of sprung acceleration sensors 9A-9C and unsprung acceleration sensors 10A, 10B. ECU31 includes CAN input unit 22, sprung acceleration input units 23A-23C, and unsprung acceleration input units 24A, 24B, similarly to ECU21 of the first embodiment.

[0067] ECU31 detects abnormalities of the sprung acceleration sensors 9A-9C and the unsprung acceleration sensors 10A and 10B by executing a program stored in the storage unit. ECU31 obtains the vehicle speed included in the vehicle driving information from CAN8. ECU31 obtains the sprung acceleration sensor values ​​(sprung acceleration) of each sprung acceleration sensor based on the detection signals from the three sprung acceleration sensors 9A-9C. ECU31 obtains the unsprung acceleration sensor values ​​(unsprung acceleration) of each sprung acceleration sensor based on the detection signals from the two unsprung acceleration sensors 10A and 10B.

[0068] The ECU 31 compares the vibration levels of any two of the three sprung acceleration sensor values ​​under the condition that the vehicle speed is lower than the second threshold value V21 that is the second speed. The ECU 31 includes, for example, a second determination unit 32 that determines that the sprung acceleration sensor 9A is in an abnormal state and the sprung acceleration sensor value is vibrating abnormally when the vibration level of the sprung acceleration sensor value of the sprung acceleration sensor 9A is larger than the second variation range R21 and larger than the vibration level of the sprung acceleration sensor value of the sprung acceleration sensor 9B.

[0069] At this time, the vehicle speed is added to the judgment condition of sensor abnormality because the vibration caused by the road surface input during driving is detected by the sensor, so it is impossible to determine whether the vibration of the sensor value is caused by the road surface input or by the abnormal vibration of the sensor. That is, the second judgment unit 32 uses the vibration of the sprung acceleration sensor value when the vehicle is stopped or close to it to detect the abnormality of the sprung acceleration sensor value. Therefore, the second threshold value V21 is the speed at which the vibration level of the sprung acceleration sensor value is sufficiently reduced when the vehicle stops. The second threshold value V21 is set to a value within the range of 0.5km / h~1km / h, for example. Specifically, the second threshold value V21 is appropriately set according to the characteristics of the sprung acceleration sensors 9A~9C, the resolution of the wheel speed sensor such as the circuit that outputs the detection signal, etc.

[0070] The second variation range R21 is set to, for example, a value greater than the vibration level of the normal sprung acceleration sensor value when the vehicle is stopped, and a value smaller than the vibration level of the sprung acceleration sensor value in an abnormal state. Specifically, the second variation range R21 is set to a value of about 2 to 3 times the vibration level of the normal sprung acceleration sensor value when the vehicle is stopped. The second variation range R21 is appropriately set in consideration of the characteristics of the sprung acceleration sensors 9A to 9C, the signal level of noise, and the like.

[0071] Similarly, the ECU 31 compares the vibration levels of the two unsprung acceleration sensor values ​​under the condition that the vehicle speed is lower than the second threshold value V22 that is the second speed. The ECU 31 includes, for example, a second determination unit 33 that determines that the unsprung acceleration sensor 10A is in an abnormal state and the unsprung acceleration sensor value is vibrating abnormally when the vibration level of the unsprung acceleration sensor value of the unsprung acceleration sensor 10A is larger than the second variation range R22 and larger than the vibration level of the unsprung acceleration sensor value of the unsprung acceleration sensor 10B.

[0072] At this time, the second threshold value V22 is a speed at which the vibration level of the sprung acceleration sensor value is sufficiently reduced when the vehicle stops. The second threshold value V22 is appropriately set, for example, based on the characteristics of the unsprung acceleration sensors 10A and 10B, the resolution of the wheel speed sensor such as the circuit that outputs the detection signal. The second threshold value V22 may be the same value as the second threshold value V21, or may be a different value.

[0073] In addition, the second variation range R22 is set to a value greater than the vibration level of the normal unsprung acceleration sensor value when the vehicle is stopped and smaller than the vibration level of the unsprung acceleration sensor value in an abnormal state, for example. Specifically, the second variation range R22 is appropriately set in consideration of the characteristics of the unsprung acceleration sensors 10A and 10B, the signal level of noise, etc. The second variation range R22 may be the same value as the second variation range R21, or may be a different value.

[0074] Here, refer to Figure 5 The sensor abnormality detection process performed by the ECU 31 will be described.

[0075] The ECU 31 reads the program stored in the storage unit and executes the sensor abnormality detection process. Here, the second determination unit 32 that detects abnormality of the sprung acceleration sensors 9A to 9C is described as an example, but the second determination unit 33 that detects abnormality of the unsprung acceleration sensors 10A and 10B is also the same.

[0076] ECU31 receives CAN signals from CAN8 and reads detection signals from three sprung acceleration sensors 9A-9C. ECU31 obtains the vehicle speed included in the vehicle driving information from the CAN signals. ECU31 obtains three sprung acceleration sensor values ​​(sprung accelerations) based on the detection signals from the three sprung acceleration sensors 9A-9C.

[0077] ECU31 determines whether the sprung acceleration sensor value (output voltage value) is a value within the normal range. When all three sprung acceleration sensor values ​​are within the normal range, ECU31 executes the processing of the second determination unit 32. On the other hand, when at least one sprung acceleration sensor value is outside the normal range, ECU31 executes sensor abnormality processing. In the sensor abnormality processing, for example, it is determined that a sprung acceleration sensor (for example, sprung acceleration sensor 9A) that outputs a sprung acceleration sensor value outside the normal range has an abnormality, and the count of the abnormality detection counter is increased. If the count of the abnormality detection counter reaches a predetermined value, ECU31 outputs an error signal to notify the corresponding sprung acceleration sensor of the abnormality.

[0078] The second determination unit 32 determines whether the vehicle speed is lower than the second threshold value V21. When the vehicle speed is higher (larger) than the second threshold value V21, the sensor may detect vibration caused by the road surface input during driving, and the second determination unit 32 may not be able to perform abnormality detection based on the vibration level. Therefore, when the vehicle speed is higher than the second threshold value V21, the second determination unit 32 does not determine the vibration level of the sprung acceleration sensor value and returns.

[0079] On the other hand, when the vehicle speed is less than or equal to the second threshold value V21, the second determination unit 32 determines whether the vibration level of the sprung acceleration sensor value is normal. Specifically, the second determination unit 32 selects any two sprung acceleration sensor values ​​from among the three sprung acceleration sensor values. The second determination unit 32 compares one of the sprung acceleration sensor values ​​with the other sprung acceleration sensor value. The second determination unit 32 performs such a comparison process on all the sprung acceleration sensor values.

[0080] At this time, the second determination unit 32 determines whether the variation range (vibration level) of one sprung acceleration sensor value is larger than the second variation range R21 and larger than the variation range (vibration level) of the other sprung acceleration sensor value.

[0081] When the variation range (vibration level) of one sprung acceleration sensor value is larger than the second variation range R21 and larger than the variation range (vibration level) of the other sprung acceleration sensor value, it is considered that the sprung acceleration sensor corresponding to the one sprung acceleration sensor value (for example, the sprung acceleration sensor 9A) has an abnormality. Therefore, the second determination unit 32 executes the above-mentioned sensor abnormality processing.

[0082] On the other hand, when the fluctuation range (vibration level) of one of the sprung acceleration sensor values ​​is smaller than the second fluctuation range R21, or when the fluctuation range (vibration level) of one of the sprung acceleration sensor values ​​is smaller than the fluctuation range (vibration level) of the other sprung acceleration sensor value, the abnormality of one of the sprung acceleration sensor values ​​cannot be detected. Therefore, in order to detect the abnormality of the remaining sprung acceleration sensor values, the same comparison process is performed on the remaining sprung acceleration sensor values. When the abnormality of all the sprung acceleration sensor values ​​is not detected, the second determination unit 32 determines that the vibration levels of all the sprung acceleration sensor values ​​are normal and returns.

[0083] The ECU 31 of the second embodiment has the above-described structure. Next, as an example of sensor abnormality detection performed by the ECU 31, the operation when an abnormality of the sprung acceleration sensor is detected is taken as an example. Figure 6 Provide explanation.

[0084] like Figure 6As shown, when the vehicle speed decreases compared to the second threshold value V21, the ECU 31 determines whether the vibration level of the sprung acceleration sensor value is within the normal range. At this time, the vibration level of the sprung acceleration sensor values ​​of the sprung acceleration sensors 9B and 9C is approximately zero, which is smaller than the second variation range R21. Therefore, the sprung acceleration sensors 9B and 9C outputting these two sprung acceleration sensor values ​​are considered normal. On the other hand, the vibration level of the sprung acceleration sensor value of the sprung acceleration sensor 9A is larger than the second variation range R21. In addition, the vibration level of the sprung acceleration sensor value of the sprung acceleration sensor 9A is a larger value than the vibration level of any of the sprung acceleration sensor values ​​of the sprung acceleration sensors 9B and 9C. Therefore, the sprung acceleration sensor 9A outputting the sprung acceleration sensor value is considered abnormal. Therefore, the ECU 31 determines that the sprung acceleration sensor 9A has an abnormality, and increases the count of the abnormality detection counter. When the count of the abnormality detection counter reaches a predetermined value, the ECU 31 outputs an error signal to notify that the sprung acceleration sensor 9A has an abnormality.

[0085] In this way, the second embodiment configured in this way can also obtain the same effects as those of the first embodiment. In addition, the ECU 31 of the second embodiment includes a second determination unit 32 that determines whether the running speed (vehicle speed) of the CAN input unit 22 is less than or equal to the second threshold value V21 (second speed), and whether the signal variation range of one of the sprung acceleration sensor value (first sensor input value) of the sprung acceleration input unit (for example, the sprung acceleration input unit 23A) as the first sensor input unit or the sprung acceleration sensor value (second sensor input value) of the sprung acceleration input unit (for example, the sprung acceleration input unit 23B) as the second sensor input unit is greater than the second variation range R21 and greater than the signal variation range of the other.

[0086] Therefore, for example, even when the vehicle is parked and the sprung acceleration sensor value vibrates abnormally within the normal range, the abnormality of the sprung acceleration sensor value can be detected by comparing the vibration levels (signal fluctuation widths) among the plurality of sprung acceleration sensor values.

[0087] In addition, the ECU 31 includes a second determination unit 33 that determines whether the traveling speed (vehicle speed) of the CAN input unit 22 is less than or equal to a second threshold value V22 (second speed), and whether the signal variation range of one of the unsprung acceleration sensor value (first sensor input value) of the unsprung acceleration input unit (for example, the unsprung acceleration input unit 24A) as the first sensor input unit or the unsprung acceleration sensor value (second sensor input value) of the unsprung acceleration input unit (for example, the unsprung acceleration input unit 24B) as the second sensor input unit is greater than the second variation range R22 and greater than the signal variation range of the other.

[0088] Therefore, for example, even when the vehicle is parked and the unsprung acceleration sensor value vibrates abnormally within the normal range, the abnormality of the unsprung acceleration sensor value can be detected by comparing the vibration levels (signal fluctuation widths) among the plurality of unsprung acceleration sensor values.

[0089] Furthermore, the second embodiment may be combined with the first embodiment. That is, the ECU 31 may include the first determination units 25 and 26 of the first embodiment in addition to the second determination units 32 and 33 .

[0090] then, Figure 1 , Figures 7 to 9 The third embodiment of the present invention is shown. The third embodiment is characterized in that the ECU includes: a model estimated value calculation unit that estimates the vehicle behavior based on the vehicle model information and obtains the vehicle behavior estimated value; and a comparison judgment unit that compares the vehicle behavior estimated value with the first sensor input value or the second sensor input value. In addition, in the third embodiment, the same reference numerals are attached to the same components as those in the first embodiment, and their descriptions are omitted.

[0091] The input side of the ECU 41 of the third embodiment is connected to the CAN 8, the sprung acceleration sensors 9A to 9C, the unsprung acceleration sensors 10A and 10B, etc., and the output side is connected to the damping force variable actuator 7 of the variable damper 6, etc. The ECU 41 includes a processor as a control unit and a storage unit (not shown) composed of a ROM, a RAM, a nonvolatile memory, etc. The processor controls the damping force of the variable damper 6 by executing a program stored in the storage unit.

[0092] ECU41 reads the vehicle driving information from CAN8 through serial communication. ECU41 reads the sprung acceleration sensor value (sprung acceleration) through the detection signal from the sprung acceleration sensors 9A~9C. ECU41 reads the unsprung acceleration sensor value (unsprung acceleration) through the detection signal from the unsprung acceleration sensors 10A and 10B. ECU41 calculates the target damping force and the like based on the vehicle driving information, the sprung acceleration, and the unsprung acceleration. ECU41 outputs the control command based on the target damping force to the variable damper 6 to control the generated force (damping force) of the variable damper 6.

[0093] The ECU 41 constitutes a sensor abnormality detection device for detecting abnormalities of the sprung acceleration sensors 9A to 9C and the unsprung acceleration sensors 10A and 10B. The ECU 41 is configured substantially the same as the ECU 21 of the first embodiment. Therefore, the ECU 41 includes a CAN input unit 22, sprung acceleration input units 23A to 23C, and unsprung acceleration input units 24A and 24B.

[0094] ECU41 detects abnormalities of sprung acceleration sensors 9A-9C and unsprung acceleration sensors 10A, 10B by executing a program stored in a storage unit. ECU41 obtains the vehicle speed included in the vehicle driving information from CAN8. ECU41 obtains the respective sprung acceleration sensor values ​​(sprung acceleration) based on the detection signals from the three sprung acceleration sensors 9A-9C. ECU41 obtains the respective unsprung acceleration sensor values ​​(unsprung acceleration) based on the detection signals from the two unsprung acceleration sensors 10A, 10B.

[0095] The ECU 41 includes a model estimated value calculation unit 42 that estimates the vehicle behavior based on the vehicle model information and obtains the vehicle behavior estimated value, and a comparison determination unit 43 that compares the sprung acceleration estimated value included in the vehicle behavior estimated value with three sprung acceleration sensor values.

[0096] The model estimated value calculation unit 42 estimates the sprung acceleration based on the unsprung acceleration of each wheel and the road surface input, for example, using a 1 / 4 vehicle model of a single wheel. At this time, the ECU 41 obtains the unsprung acceleration of the front wheel, for example, based on the detection signals of the unsprung acceleration sensors 10A and 10B. The ECU 41 obtains the unsprung acceleration of the rear wheel, for example, based on the detection signals of the unsprung acceleration sensors 10A and 10B and the vehicle speed. The ECU 41 obtains the road surface input from the CAN 8, for example, based on the vehicle driving information.

[0097] In addition, the model estimated value calculation unit 42 estimates the unsprung acceleration based on the sprung acceleration of each wheel and the road surface input using, for example, a 1 / 4 vehicle model of a single wheel. In addition, the vehicle model is not limited to the 1 / 4 vehicle model, and may be a two-wheel model of a left and right set or a front and rear set, or may be a four-wheel vehicle model.

[0098] The comparison judgment unit 43 obtains the vibration level of the sprung acceleration sensor values ​​of the sprung acceleration sensors 9A to 9C based on the maximum and minimum peak values ​​(peak-to-peak value) of the sprung acceleration sensor values. The comparison judgment unit 43 calculates the difference between the vibration level of the sprung acceleration sensor values ​​of the sprung acceleration sensors 9A to 9C and the vibration level of the sprung acceleration estimated value based on the model estimated value calculation unit 42. When the absolute value of the difference in these vibration levels becomes greater than or equal to a predetermined value for a certain period of time, the comparison judgment unit 43 determines that the corresponding sprung acceleration sensor value has an abnormality.

[0099] Thus, the comparison and determination section 43 determines that the sprung acceleration sensor value of the sprung acceleration sensor 9A is fixed, for example, when the difference between the sprung acceleration sensor value of the sprung acceleration sensor 9A and the sprung acceleration estimated value based on the model estimated value calculation section 42 is large even though the vibration level of the sprung acceleration sensor value of the sprung acceleration sensors 9B and 9C is larger than the first fluctuation range R11 (constant value). In addition, the comparison and determination section 43 determines that the sprung acceleration sensor value of the sprung acceleration sensor 9A is vibrating abnormally, for example, when the difference between the sprung acceleration sensor value of the sprung acceleration sensor 9A and the sprung acceleration estimated value based on the model estimated value calculation section 42 is large even though the vibration level of the sprung acceleration sensor value of the sprung acceleration sensors 9B and 9C is smaller than the second fluctuation range R21 (constant value).

[0100] At this time, the predetermined value for determining whether the vibration level is appropriate is appropriately set to a value that takes into account a margin for noise, etc., based on the vibration level of the sprung acceleration estimate value based on the model estimate value calculation unit 42. Specifically, the predetermined value is set to a value of about 1 / 3 of the vibration level based on the sprung acceleration estimate value. In addition, the predetermined time for determining whether the vibration level is appropriate is appropriately set based on experiments using an actual vehicle, etc., in consideration of the effect of suppressing false detection, etc.

[0101] In addition, the ECU 41 includes a comparison judgment unit 44 that compares the unsprung acceleration estimated value included in the vehicle behavior estimated value with the two unsprung acceleration sensor values. The comparison judgment unit 44 obtains the vibration level of the unsprung acceleration sensor values ​​of the unsprung acceleration sensors 10A and 10B based on the maximum and minimum peak values ​​(peak-to-peak value) of the unsprung acceleration sensor values. The comparison judgment unit 44 calculates the difference between the vibration level of the unsprung acceleration sensor values ​​of the unsprung acceleration sensors 10A and 10B and the vibration level of the unsprung acceleration estimated value based on the model estimated value calculation unit 42. When the absolute value of the difference in these vibration levels becomes a predetermined value or more for a certain period of time, the comparison judgment unit 44 determines that the corresponding unsprung acceleration sensor value is abnormal.

[0102] Thus, the comparison and determination section 44 determines that the unsprung acceleration sensor value of the unsprung acceleration sensor 10A is fixed, for example, when the difference between the unsprung acceleration sensor value of the unsprung acceleration sensor 10A and the unsprung acceleration estimated value based on the model estimated value calculation section 42 is large even though the vibration level of the unsprung acceleration sensor value of the unsprung acceleration sensor 10B is larger than the first fluctuation range R12 (constant value). In addition, the comparison and determination section 44 determines that the unsprung acceleration sensor value of the unsprung acceleration sensor 10A is vibrating abnormally, for example, when the difference between the unsprung acceleration sensor value of the unsprung acceleration sensor 10A and the unsprung acceleration estimated value based on the model estimated value calculation section 42 is large even though the vibration level of the unsprung acceleration sensor value of the unsprung acceleration sensor 10B is smaller than the second fluctuation range R22 (constant value).

[0103] The ECU 41 of the third embodiment has the above-described structure. Next, as an example of sensor abnormality detection performed by the ECU 41, the operation when an abnormality of the sprung acceleration sensor is detected is taken as an example. Figure 8 as well as Fig. 9 Provide explanation.

[0104] like Figure 8 As shown, when the vibration level of the sprung acceleration sensor value of any of the sprung acceleration sensors (for example, the sprung acceleration sensors 9B and 9C) is greater than the first fluctuation range R11, the ECU 41 calculates the difference between the vibration level of the sprung acceleration sensor value of the sprung acceleration sensors 9A to 9C and the vibration level of the sprung acceleration estimated value based on the model estimated value calculation unit 42. At this time, when the absolute value of the difference in vibration level becomes a predetermined value or more for a certain period of time, the ECU 41 determines that the sprung acceleration sensor value of the sprung acceleration sensor (for example, the sprung acceleration sensor 9A) corresponding to the sprung acceleration sensor value is fixed, and increases the count of the abnormality detection counter. When the count of the abnormality detection counter reaches the predetermined value, the ECU 41 outputs an error signal to notify the corresponding sprung acceleration sensor that there is an abnormality.

[0105] like Fig. 9As shown, when the vibration level of the sprung acceleration sensor value of any of the sprung acceleration sensors (for example, the sprung acceleration sensors 9B and 9C) is smaller than the second fluctuation range R21, the ECU 41 calculates the difference between the vibration level of the sprung acceleration sensor value of the sprung acceleration sensors 9A to 9C and the vibration level of the sprung acceleration estimated value based on the model estimated value calculation unit 42. At this time, when the state where the absolute value of the difference in vibration level becomes greater than or equal to a predetermined value continues for a certain period of time, the ECU 41 determines that the sprung acceleration sensor value of the sprung acceleration sensor corresponding to the sprung acceleration sensor value (for example, the sprung acceleration sensor 9A) vibrates abnormally, and increases the count of the abnormality detection counter. When the count of the abnormality detection counter reaches the predetermined value, the ECU 41 outputs an error signal to notify that the corresponding sprung acceleration sensor has an abnormality.

[0106] Thus, in the third embodiment thus configured, the same effects as those of the first embodiment can be obtained. In addition, the ECU 41 of the third embodiment can determine that the corresponding sprung acceleration sensor value is fixed when the difference between the output of the other sprung acceleration sensor (for example, the sprung acceleration sensor 9A) and the output of the model estimated value calculation unit 42 is large even though the vibration level of the sprung acceleration sensor value of any sprung acceleration sensor (for example, the sprung acceleration sensors 9B, 9C) exceeds a certain value.

[0107] In addition, when the vibration level of the sprung acceleration sensor value of any sprung acceleration sensor (for example, sprung acceleration sensors 9B, 9C) is very small, the ECU 41 can determine that the corresponding sprung acceleration sensor value is vibrating abnormally when the difference between the output of the other sprung acceleration sensor (for example, sprung acceleration sensor 9A) and the output of the model estimated value calculation unit 42 is large.

[0108] In addition, when the vibration level of the unsprung acceleration sensor value of one unsprung acceleration sensor (for example, the unsprung acceleration sensor 10B) exceeds a certain value, the ECU 41 can determine that the corresponding unsprung acceleration sensor value is fixed when the difference between the output of the other unsprung acceleration sensor (for example, the unsprung acceleration sensor 10A) and the output of the model estimated value calculation unit 42 is large.

[0109] In addition, when the difference between the output of the unsprung acceleration sensor on one side (for example, the unsprung acceleration sensor 10A) and the output of the model estimated value calculation unit 42 is large even though the vibration level of the unsprung acceleration sensor value of one unsprung acceleration sensor (for example, the unsprung acceleration sensor 10B) is very small, the ECU 41 can determine that the corresponding unsprung acceleration sensor value is vibrating abnormally.

[0110] In addition, the comparison determination unit 43 of the third embodiment is configured to determine whether the difference between the output of the sprung acceleration sensors 9A to 9C and the output of the model estimated value calculation unit 42 is large regardless of the vehicle speed, but the present invention is not limited thereto. The comparison determination unit 43 may determine whether the difference between the output of the sprung acceleration sensors 9A to 9C and the output of the model estimated value calculation unit 42 is large when the vehicle speed satisfies a certain condition, similarly to the first determination unit 25 and the second determination unit 32 of the first and second embodiments. This is also the same in the comparison determination unit 44 of the third embodiment.

[0111] The third embodiment may be combined with the first and second embodiments. That is, the ECU 41 may include the first determination units 25 and 26 of the first embodiment and the second determination units 32 and 33 of the second embodiment in addition to the model estimated value calculation unit 42 and the comparison determination units 43 and 44 .

[0112] In the above-mentioned embodiments, the ECU 21, 31, 41 for detecting abnormalities of the sprung acceleration sensors 9A to 9C and the unsprung acceleration sensors 10A and 10B is used as an example for description, but the present invention is not limited to this. The object for the ECU to detect abnormalities can be at least two sensors mounted on the vehicle, for example, various acceleration sensors, vehicle height sensors, and gyro sensors. In addition, the ECU 21, 31, 41 controls the variable damper 6, but the present invention is not limited to this. It is also possible to have an ECU for detecting abnormalities of various sensors separately from the ECU controlling the variable damper.

[0113] In the above-mentioned embodiments, the vehicle speed is transmitted through the CAN signal and the running speed input unit is the CAN input unit 22. However, the present invention is not limited thereto. For example, when the wheel speed sensor is directly connected to the ECU, the running speed input unit may also be a wheel speed input unit to which the wheel speed from the wheel speed sensor is input.

[0114] In the above-mentioned embodiments, the case where the semi-active suspension is constituted by the variable damper 6 as the force generating mechanism is described as an example. The present invention is not limited to this, and the force generating mechanism may also constitute an active suspension that generates a force in the up-down direction between the vehicle body and the wheels. Specifically, the actuator is constituted by an electric actuator, a hydraulic actuator, etc. that generates a force in the extension direction or the contraction direction between the vehicle body and the wheels.

[0115] In the above-described embodiments, the actuator (force generating mechanism) generating an adjustable force between the vehicle body 1 and the wheel 2 is constituted by the variable damper 6 of the damping force adjustment type. The present invention is not limited to this, and for example, the actuator may be constituted by an air suspension, a stabilizer, an electromagnetic suspension, etc. in addition to the hydraulic shock absorber.

[0116] In the above-mentioned embodiments, the suspension system for a four-wheeled vehicle is described as an example, but the present invention is not limited thereto, and can also be applied to a two-wheeled or three-wheeled vehicle, or a work vehicle, a truck as a transport vehicle, a bus, etc.

[0117] The above-described embodiments are merely examples, and some of the structures described in the different embodiments may be replaced or combined.

[0118] In addition, the present invention is not limited to the above-mentioned embodiments, and includes various modified examples. For example, the above-mentioned embodiments are described in detail in order to explain the present invention in an easy-to-understand manner, and are not necessarily limited to having all the structures described. In addition, a part of the structure of a certain embodiment can be replaced with the structure of another embodiment, and in addition, the structure of another embodiment can be added to the structure of a certain embodiment. In addition, for a part of the structure of each embodiment, other structures can be added, deleted, or replaced.

[0119] This application claims the priority based on Japanese Patent Application No. 2022-199480 filed on December 14, 2022. The entire disclosure of Japanese Patent Application No. 2022-199480 filed on December 14, 2022 including the specification, claims, drawings, and abstract is incorporated herein by reference in its entirety.

[0120] Description of Reference Numerals

[0121] 1: vehicle body; 2: wheel; 4: suspension device; 6: variable damper (damping force adjustable buffer, force generating mechanism); 7: damping force variable actuator; 8: CAN; 9A~9C: sprung acceleration sensor; 10A, 10B: unsprung acceleration sensor; 21, 31, 41: ECU (sensor abnormality detection device); 22: CAN input unit (travel speed input unit); 23A~23C: sprung acceleration input unit (first sensor input unit, second sensor input unit); 24A, 24B: unsprung acceleration input unit (first sensor input unit, second sensor input unit); 25, 26: first judgment unit; 32, 33: second judgment unit; 42: model estimated value calculation unit; 43, 44: comparison judgment unit; V11, V12: first threshold value (first speed); V21, V22: second threshold value (second speed); R11, R12: first variation range; R21, R22: second variation range.

Claims

1. A sensor abnormality detection device for detecting abnormalities of at least two sensors installed in a vehicle, comprising: A driving speed input unit for inputting the driving speed of the vehicle; A first sensor input part, inputting a signal variation amplitude of a first sensor; A second sensor input part, inputting a signal variation amplitude of a second sensor; as well as The first judgment unit judges whether the driving speed of the driving speed input unit is greater than or equal to a first speed and whether a signal variation range of one of a first sensor input value of the first sensor input unit and a second sensor input value of the second sensor input unit is smaller than the first variation range and smaller than the signal variation range of the other.

2. The sensor abnormality detection device according to claim 1, further comprising: The second judgment unit judges whether the traveling speed based on the traveling speed input unit is lower than a second speed and whether the signal variation range of one of the first sensor input value of the first sensor input unit and the second sensor input value of the second sensor input unit is greater than the second variation range and greater than the signal variation range of the other.

3. The sensor abnormality detection device according to claim 1, further comprising: a model estimated value calculation unit that estimates the vehicle behavior and obtains a vehicle behavior estimated value based on the vehicle model information; and The comparison and determination unit compares the vehicle behavior estimated value with the first sensor input value or the second sensor input value.

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