Sensor abnormality detection device

Abstract

This sensor abnormality detecting device comprises a CAN input unit (traveling speed input unit) into which a traveling speed of a vehicle is input, and a sprung acceleration input unit (first sensor input unit, second sensor input unit) into which a signal fluctuation range (vibration level) of a sprung acceleration sensor is input. An ECU is provided with a first determining unit for determining whether the traveling speed obtained by the CAN input unit is at least equal to a first threshold (first speed) and the signal fluctuation range of either a sprung acceleration sensor value (first sensor input value) of the sprung acceleration input unit (for example the sprung acceleration input unit) that serves as the first sensor input unit or a sprung acceleration sensor value (second sensor input value) of the sprung acceleration input unit (for example the sprung acceleration input unit) that serves as the second sensor input unit is smaller than a first fluctuation range and is smaller than the signal fluctuation range of the other.

Description

[Technical Field]

[0001] The present disclosure relates to a sensor abnormality detection device that detects an abnormality in a sensor. [Background technology]

[0002] Patent Document 1 discloses a configuration for detecting abnormalities in a lateral acceleration sensor for an active suspension equipped with a lateral acceleration sensor. Disconnections and short circuits are detected by monitoring the output value of the lateral acceleration sensor itself. That is, if the output value of the lateral acceleration sensor falls outside the normal range, the lateral acceleration sensor is determined to be abnormal. Regarding drift or fixation of the sensor signal at an intermediate value, the lateral acceleration is acquired based on the output value of the lateral acceleration sensor, and if the magnitude of this lateral acceleration remains at or above 0.1 G for 10 seconds, the lateral acceleration sensor is determined to be abnormal. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 4-87819 Summary of the Invention [Problem to be solved by the invention]

[0004] However, the abnormality detection method disclosed in Patent Document 1 may erroneously detect an abnormality in the lateral acceleration sensor, for example, when the vehicle continues to make steady circular turns or travel on a banked road, because the lateral acceleration continues to be detected at a certain value or higher. Furthermore, if this abnormality detection method is applied to a vertical acceleration sensor, it may also erroneously detect an abnormality in the sensor when the vehicle continues to travel on a slope or banked road.

[0005] An object of the present invention is to provide a sensor abnormality detection device that can detect an abnormality in a sensor while suppressing erroneous detection. [Means for solving the problem]

[0006] One embodiment of the present invention is a sensor abnormality detection device that detects abnormalities in at least three or more sensors provided in a vehicle, the sensor abnormality detection device including: a traveling speed input unit to which a traveling speed of the vehicle is input; a first sensor input unit to which a signal fluctuation range of a first sensor is input; and a second sensor input unit to which a signal fluctuation range of a second sensor is input. a third sensor input unit to which a signal fluctuation range of the third sensor is input; the travel speed input unit is equal to or greater than a first speed, and the first sensor input value of the first sensor input unit is When the signal fluctuation range of is greater than the first fluctuation range, or a second sensor input value of the second sensor input unit faith Number fluctuation range or a signal fluctuation width of the third sensor input value of the third sensor input unit When it is greater than the first sensor input value is determined to be normal; when a signal fluctuation width of the second sensor input value of the second sensor input unit is larger than a first fluctuation width, or is larger than the signal fluctuation width of the first sensor input value of the first sensor input unit or the signal fluctuation width of the third sensor input value of the third sensor input unit, the second sensor input value is determined to be normal; when a signal fluctuation width of the third sensor input value of the third sensor input unit is larger than the first fluctuation width, or is larger than the signal fluctuation width of the first sensor input value of the first sensor input unit or the signal fluctuation width of the second sensor input value of the second sensor input unit, the third sensor input value is determined to be normal; and when any one of the first sensor input value, the second sensor input value, and the third sensor input value is smaller than the first fluctuation width, a sensor input value smaller than the first fluctuation width is determined to be abnormal. The device is characterized by having a first determination unit.

[0007] According to one embodiment of the present invention, it is possible to detect an abnormality in a sensor while suppressing false detection. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an overall configuration diagram showing a four-wheeled automobile to which an ECU according to an embodiment of the present invention is applied; [Figure 2] FIG. 2 is a diagram schematically illustrating an ECU and a shock absorber according to the first embodiment. [Figure 3] FIG. 4 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. [Figure 4] 6 is a characteristic diagram showing an example of time-dependent changes in vehicle speed, sprung acceleration sensor value, and abnormality detection counter when the vehicle speed exceeds a first threshold value. FIG. [Figure 5] FIG. 10 is a diagram schematically illustrating an ECU and a shock absorber according to a second embodiment. [Figure 6] 10 is a characteristic diagram showing an example of time-dependent changes in vehicle speed, sprung acceleration sensor value, and abnormality detection counter when the vehicle speed drops below a second threshold value. FIG. [Figure 7] FIG. 10 is a diagram schematically illustrating an ECU and a shock absorber according to a third embodiment. [Figure 8]10 is a characteristic diagram showing an example of time variations of vehicle speed, sprung acceleration sensor value, and abnormality detection counter when the vibration level of the sprung acceleration sensor value becomes larger than a first fluctuation width. FIG. [Figure 9] FIG. 10 is a characteristic diagram showing an example of time variations 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 a second fluctuation range. DETAILED DESCRIPTION OF THE INVENTION

[0009] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A sensor abnormality detection device according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings, taking as an example a case where the device is applied to a four-wheeled automobile.

[0010] 1 to 4 show a first embodiment of the present invention. In FIGS. 1 and 2, a vehicle body 1 constitutes the body of a vehicle. For example, left and right front wheels and left and right rear wheels (hereinafter collectively referred to as wheels 2) are provided on the underside of the vehicle body 1. These wheels 2 are configured to include tires 3. The tires 3 act as springs that absorb small irregularities in the road surface. The vehicle body 1 and wheels 2 constitute the vehicle.

[0011] The suspension device 4 is provided between the vehicle body 1 and the wheel 2. The suspension device 4 is composed of a suspension spring 5 (hereinafter referred to as the spring 5) and an adjustable damping shock absorber 6 (hereinafter referred to as the variable damper 6) provided in parallel with the spring 5 and interposed between the vehicle body 1 and the wheel 2.

[0012] The variable dampers 6 of the suspension device 4 are provided between the vehicle body 1 and each of the four wheels 2. The variable dampers 6 are actuators that vary the force that suppresses relative displacement between the vehicle body 1 and the wheels 2. The variable dampers 6 vary the force that is generated between the vehicle body 1 and the wheels 2. The variable dampers 6 are also force generating mechanisms that adjust the force between the vehicle body 1 and the wheels 2. The force that the variable dampers 6 generate can be adjusted between soft and hard.

[0013] The variable damper 6 is configured using a damping force adjustable hydraulic shock absorber. As shown in Fig. 2, the variable damper 6 is provided with a damping force variable actuator 7 consisting of a damping force adjustment valve and the like in order to continuously adjust the characteristics of the generated damping force (i.e., the damping force characteristics) from hard characteristics (hard characteristics) to soft characteristics (soft characteristics). The damping force variable actuator 7 is a damping force adjustment unit that adjusts the damping force according to the supplied current (drive current).

[0014] The variable damping force actuator 7 does not necessarily have to be configured to continuously adjust the damping force characteristics, but may be configured to adjust the damping force in multiple stages, for example, two or more stages. The variable damper 6 may be of a pressure control type or a flow rate control type.

[0015] The CAN8 (Controller Area Network) is a serial communication unit mounted on the vehicle body 1. The CAN8 performs in-vehicle multiplex communication between the ECU 21 and numerous electronic devices mounted on the vehicle. The CAN8 transmits vehicle driving information by means of a CAN signal consisting of a serial signal. In this case, the vehicle driving information transmitted through the CAN8 includes, for example, yaw rate, steering angle, vehicle speed, longitudinal acceleration, brake fluid pressure, engine torque, etc.

[0016] The three sprung acceleration sensors 9A to 9C are provided on the vehicle body 1 and detect vertical vibration acceleration on the sprung side of the vehicle body 1. The sprung acceleration sensors 9A to 9C constitute sprung state detection means that detects sprung vibration.

[0017] In this case, the sprung acceleration sensor 9A is attached to the vehicle body 1, for example, near the upper end of the variable damper 6 on the left front wheel side. The sprung acceleration sensor 9B is attached to the vehicle body 1, for example, near the upper end of the variable damper 6 on the right front wheel side. The sprung acceleration sensor 9C is attached to the vehicle body 1 at a midpoint between the left and right rear wheels. The sprung acceleration sensors 9A to 9C detect vertical vibration acceleration on the sprung side of the vehicle body 1 and output their detection signals to the ECU 21. The detection signals of the sprung acceleration sensors 9A to 9C are, for example, output voltages shown in FIG. 3. This output voltage varies depending on the acceleration. Specifically, the output voltage has an intermediate value when the acceleration is zero, decreases as the acceleration increases on the negative side (e.g., downward), and increases as the acceleration increases on the positive side (e.g., upward). Furthermore, the detection signals (output voltages) of the sprung acceleration sensors 9A to 9C are preset to have normal ranges of voltage values. In this case, the normal range includes the output voltage when the acceleration is zero.

[0018] Two unsprung acceleration sensors 10A, 10B are provided on the wheel 2 side of the vehicle. Specifically, the unsprung acceleration sensor 10A is provided, for example, on the left front wheel of the vehicle. The unsprung acceleration sensor 10B is provided, for example, on the right front wheel of the vehicle. The unsprung acceleration sensors 10A, 10B detect vertical vibration acceleration on the wheel 2 side, which is the unsprung side, and output the detection signal to the ECU 21. The detection signal of the unsprung acceleration sensors 10A, 10B is, for example, an output voltage shown in FIG. 3. This output voltage is substantially the same as the detection signals of the sprung acceleration sensors 9A to 9C. A normal range of voltage values ​​is preset for the detection signals (output voltages) of the unsprung acceleration sensors 10A, 10B. At this time, the normal range includes the output voltage when the acceleration is zero.

[0019] 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 wheels 2. Here, the ECU 21 is a control means that controls the force generated by the variable damper 6 (force generating mechanism).

[0020] The ECU 21 includes a processor (not shown) as a control unit. The processor is configured by a microcomputer or the like. The ECU 21 includes a storage unit (not shown) including 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.

[0021] As shown in FIG. 2, the input side of the ECU 21 is connected to the CAN 8, sprung acceleration sensors 9A to 9C, 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.

[0022] The ECU 21 includes a CAN input unit 22 to which a CAN signal is input from the CAN 8. At this time, the CAN signal includes vehicle driving information. The vehicle driving information also includes vehicle speed. Therefore, the CAN input unit 22 functions as a driving speed input unit to which the driving speed of the vehicle (vehicle speed) is input.

[0023] The ECU 21 includes sprung acceleration input units 23A to 23C to which detection signals from the sprung acceleration sensors 9A to 9C are input. At this time, one of the sprung acceleration sensors 9A to 9C (for example, the sprung acceleration sensor 9A) serves as the first sensor, and any one of the remaining sprung acceleration sensors (for example, the sprung acceleration sensor 9B) serves as the second sensor. The remaining sprung acceleration sensor (for example, sprung acceleration sensor 9C) becomes the third sensor. Therefore, the sprung acceleration input section corresponding to the first sensor (for example, sprung acceleration input section 23A) becomes a first sensor input section to which the signal fluctuation range of the first sensor is input, and the sprung acceleration input section corresponding to the second sensor (for example, sprung acceleration input section 23B) becomes a second sensor input section to which the signal fluctuation range of the second sensor is input. A sprung acceleration input section corresponding to the third sensor (for example, sprung acceleration input section 23C) serves as a third sensor input section to which the signal fluctuation width of the third sensor is input.

[0024] The sprung acceleration sensor 9B may be the first sensor, and the sprung acceleration sensor 9C may be the first sensor. Similarly, the sprung acceleration sensor 9A may be the second sensor, and the sprung acceleration sensor 9C may be the second sensor.

[0025] The ECU 21 includes unsprung acceleration input units 24A and 24B to which detection signals from the unsprung acceleration sensors 10A and 10B are input. One of the unsprung acceleration sensors 10A and 10B (e.g., unsprung acceleration sensor 10A) serves as a first sensor, while the other unsprung acceleration sensor (e.g., unsprung acceleration sensor 10B) serves as a second sensor. Therefore, the unsprung acceleration input unit corresponding to the first sensor (e.g., unsprung acceleration input unit 24A) serves as a first sensor input unit to which the signal fluctuation range of the first sensor is input. The unsprung acceleration input unit corresponding to the second sensor (e.g., unsprung acceleration input unit 24B) serves as a second sensor input unit to which the signal fluctuation range of the second sensor is input.

[0026] The unsprung acceleration sensor 10B may be the first sensor, and the unsprung acceleration sensor 10A may be the second sensor.

[0027] The ECU 21 reads vehicle driving information from the CAN 8 via serial communication. The ECU 21 reads sprung acceleration sensor values ​​(sprung acceleration) based on detection signals from the sprung acceleration sensors 9A to 9C. The ECU 21 reads unsprung acceleration sensor values ​​(unsprung acceleration) based on detection signals from the unsprung acceleration sensors 10A and 10B. The ECU 21 calculates a target damping force and the like based on the vehicle driving information, sprung acceleration, and unsprung acceleration. The ECU 21 outputs a control command based on the target damping force to the variable damper 6 to control the force (damping force) generated by the variable damper 6.

[0028] The ECU 21 constitutes a sensor abnormality detection device that detects abnormalities in the sprung acceleration sensors 9A-9C and the unsprung acceleration sensors 10A, 10B. The ECU 21 detects abnormalities in the sprung acceleration sensors 9A-9C and the unsprung acceleration sensors 10A, 10B by executing a program stored in a storage unit. The ECU 21 acquires the vehicle speed included in the vehicle driving information from the CAN 8. The ECU 21 acquires each sprung acceleration sensor value (sprung acceleration) based on detection signals from the three sprung acceleration sensors 9A-9C. The ECU 21 acquires each unsprung acceleration sensor value (unsprung acceleration) based on detection signals from the two unsprung acceleration sensors 10A, 10B.

[0029] The ECU 21 acquires 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-to-peak values ​​of the sprung acceleration sensor values.The ECU 21 acquires 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-to-peak values ​​of the unsprung acceleration sensor values.

[0030] 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, which is a first speed. The ECU 21 includes 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 stuck when, for example, the vibration level of the sprung acceleration sensor value of the sprung acceleration sensor 9A is smaller than a first fluctuation band R11 and smaller than the vibration level of the sprung acceleration sensor value of the sprung acceleration sensor 9B.

[0031] At this time, the vehicle speed is included in the conditions for determining whether a sensor abnormality exists in order to prevent erroneous determination while the vehicle is stopped due to 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 while the vehicle is moving. For this reason, 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 equal to or greater than 20 km / h, taking into consideration the characteristics of the sprung acceleration sensors 9A to 9C, the characteristics of the circuit that outputs the detection signal, and the like.

[0032] The first fluctuation range R11 is set to a value that is, for example, greater than the vibration level when the sprung acceleration sensor value is stuck and smaller than the vibration level of the sprung acceleration sensor value in a normal state. Specifically, the first fluctuation range R11 is set to a value that is approximately two to three times the vibration level when the sprung acceleration sensor value is stuck. The first fluctuation range R11 is set appropriately taking into consideration the characteristics of the sprung acceleration sensors 9A to 9C, the signal level of noise, etc.

[0033] Similarly, the ECU 21 compares the vibration levels of the two unsprung acceleration sensor values ​​when the vehicle speed exceeds a first threshold value V12, which is a first speed. The ECU 21 includes a first determination unit 26 that determines that the unsprung acceleration sensor 10A is stuck when the vibration level of the unsprung acceleration sensor value of the unsprung acceleration sensor 10A is smaller than a first fluctuation range R12 and smaller than the vibration level of the unsprung acceleration sensor value of the unsprung acceleration sensor 10B.

[0034] At this time, the first threshold value V12 is a speed at which the vibration level of the unsprung acceleration sensor value can be sufficiently determined. The first threshold value V12 is appropriately set depending on the unsprung acceleration sensors 10A, 10B as well as the circuit that outputs the detection signal. The first threshold value V12 may be the same value as the first threshold value V11 or may be a different value.

[0035] The first fluctuation range R12 is set to a value that is greater than the vibration level when the unsprung acceleration sensor value is stuck and smaller than the vibration level of the unsprung acceleration sensor value in a normal state, for example. Specifically, the first fluctuation range R12 is set to a value that is approximately two to three times the vibration level when the unsprung acceleration sensor value is stuck. The first fluctuation range R12 is set appropriately taking into consideration the characteristics of the unsprung acceleration sensors 10A, 10B, the signal level of noise, etc. The first fluctuation range R12 may be the same value as the first fluctuation range R11, or may be a different value.

[0036] Here, the sensor abnormality detection process performed by the ECU 21 will be described with reference to FIG.

[0037] The ECU 21 reads out a program stored in the storage unit and executes a sensor abnormality detection process. Here, the first determination unit 25 that performs abnormality detection for the sprung acceleration sensors 9A to 9C will be described as an example, but the same applies to the first determination unit 26 that performs abnormality detection for the unsprung acceleration sensors 10A and 10B.

[0038] The ECU 21 receives the CAN signal from the CAN 8 and reads the detection signals of the three sprung acceleration sensors 9A to 9C. The ECU 21 obtains the vehicle speed included in the vehicle driving information from the CAN signal. The ECU 21 obtains three sprung acceleration sensor values ​​(sprung acceleration) based on the detection signals of the three sprung acceleration sensors 9A to 9C.

[0039] The ECU 21 determines whether the sprung acceleration sensor values ​​(output voltage values) are within a normal range. If all three sprung acceleration sensor values ​​are within the normal range, the ECU 21 executes the processing of the first determination unit 25. On the other hand, if at least one sprung acceleration sensor value is outside the normal range, the ECU 21 executes sensor abnormality processing. In the sensor abnormality processing, for example, the ECU 21 determines that an abnormality exists in the sprung acceleration sensor (e.g., sprung acceleration sensor 9A) that output a sprung acceleration sensor value outside the normal range, and increments the count of an abnormality detection counter. When the count of the abnormality detection counter reaches a predetermined value, the ECU 21 outputs an error signal to notify that an abnormality exists in the corresponding sprung acceleration sensor.

[0040] The first determination unit 25 determines whether the vehicle speed exceeds a first threshold value V11. If the vehicle speed is lower (smaller) than the first threshold value V11, the vibration level of the sprung acceleration sensor value may not be large enough, and the first determination unit 25 cannot detect an abnormality based on the vibration level. Therefore, if the vehicle speed is lower than the first threshold value V11, the first determination unit 25 does not determine the vibration level of the sprung acceleration sensor value and returns.

[0041] On the other hand, when the vehicle speed is equal to or greater than the first threshold value V11, the first determination unit 25 determines whether the vibration level of the sprung acceleration sensor values ​​is normal. Specifically, the first determination unit 25 selects any two of the three sprung acceleration sensor values. The first determination unit 25 compares one of the selected sprung acceleration sensor values ​​with the other sprung acceleration sensor value. The ECU 21 performs this comparison process on all of the sprung acceleration sensor values.

[0042] 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 is smaller than the fluctuation range (vibration level) of the other sprung acceleration sensor value.

[0043] When the fluctuation range (vibration level) of one sprung acceleration sensor value is smaller than the first fluctuation range R11 and is smaller than the fluctuation range (vibration level) of the other sprung acceleration sensor value, it is considered that there is an abnormality in the sprung acceleration sensor corresponding to the one sprung acceleration sensor value (for example, sprung acceleration sensor 9A). Therefore, the first determination unit 25 executes the sensor abnormality process described above.

[0044] On the other hand, when the fluctuation range (vibration level) of one sprung acceleration sensor value is larger than the first fluctuation range R11, or when the fluctuation range (vibration level) of one sprung acceleration sensor value is larger than the fluctuation range (vibration level) of the other sprung acceleration sensor value, an abnormality in one sprung acceleration sensor value cannot be detected. Therefore, in order to detect abnormalities in the remaining sprung acceleration sensor values, a similar comparison process is performed on the remaining sprung acceleration sensor values. If no abnormalities are detected in any of the sprung acceleration sensor values, the first determination unit 25 determines that the vibration levels of all of the sprung acceleration sensor values ​​are normal and returns.

[0045] The ECU 21 according to the first embodiment has the above-described configuration. Next, as an example of sensor abnormality detection by the ECU 21, an operation when an abnormality is detected in the sprung acceleration sensor will be described with reference to FIG.

[0046] As shown in FIG. 4, when the vehicle speed exceeds the first threshold value V11, the ECU 21 determines whether the vibration level of the sprung acceleration sensor values ​​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 increases as the vehicle speed increases and becomes larger than the first fluctuation range R11. Therefore, the sprung acceleration sensors 9B and 9C that output these two sprung acceleration sensor values ​​are considered to be 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 smaller than the vibration levels of the sprung acceleration sensor values ​​of the sprung acceleration sensors 9B and 9C. Therefore, the sprung acceleration sensor 9A that outputs this sprung acceleration sensor value is considered to be abnormal. Therefore, the ECU 21 increases the count value of the abnormality detection counter. When the count number of the abnormality detection counter reaches a predetermined value, the ECU 21 outputs an error signal to notify that an abnormality has occurred in the sprung acceleration sensor 9A.

[0047] Thus, the ECU 21 according to the first embodiment has a CAN input unit 22 (traveling speed input unit) to which the vehicle traveling speed is input, and sprung acceleration input units 23A-23C (first sensor input unit, second sensor input unit) to which the signal fluctuation ranges (vibration levels) of the sprung acceleration sensors 9A-9C are input. The ECU 21 has a first determination unit 25 that determines whether the traveling speed (vehicle speed) from the CAN input unit 22 is equal to or greater than a 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 (e.g., sprung acceleration input unit 23A) serving as the first sensor input unit or the sprung acceleration sensor value (second sensor input value) of the sprung acceleration input unit (e.g., sprung acceleration input unit 23B) serving as the second sensor input unit is smaller than the first fluctuation range R11 and is smaller than the signal fluctuation range of the other.

[0048] Therefore, for example, even when the sprung acceleration sensor value is stuck within the normal range, an abnormality in the sprung acceleration sensor value can be detected by comparing the vibration level (signal fluctuation range) between multiple sprung acceleration sensor values.

[0049] The ECU 21 also includes a first judgment unit 26 that judges whether the traveling speed (vehicle speed) from the CAN input unit 22 is equal to or greater than 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 other signal fluctuation range.

[0050] Therefore, for example, even when the unsprung acceleration sensor value is stuck within the normal range, an abnormality in the unsprung acceleration sensor value can be detected by comparing the vibration level (signal fluctuation range) between multiple unsprung acceleration sensor values.

[0051] 1, 5, and 6 show a second embodiment of the present invention. The second embodiment is characterized in that the ECU includes a second determination unit that determines whether the traveling speed is equal to or less than a second speed and whether the signal fluctuation range of one of the first sensor input value and the second sensor input value is greater than the second fluctuation range and is greater than the signal fluctuation range of the other. In the second embodiment, the same components as those in the first embodiment are denoted by the same reference numerals, and their description will be omitted.

[0052] The input side of the ECU 31 according to the second embodiment is connected to the CAN 8, the sprung acceleration sensors 9A-9C, the unsprung acceleration sensors 10A, 10B, etc., and the output side is connected to the variable damping force actuator 7 of the variable damper 6, etc. The ECU 31 is configured in the same manner as the ECU 21 according to the first embodiment. The ECU 31 includes a processor as a control unit and a storage unit (none of which are shown) including 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.

[0053] The ECU 31 reads vehicle driving information from the CAN 8 via serial communication. The ECU 31 reads sprung acceleration sensor values ​​(sprung acceleration) based on detection signals from the sprung acceleration sensors 9A to 9C. The ECU 31 reads unsprung acceleration sensor values ​​(unsprung acceleration) based on detection signals from the unsprung acceleration sensors 10A and 10B. The ECU 31 calculates a target damping force and the like based on the vehicle driving information, sprung acceleration, and unsprung acceleration. The ECU 31 outputs a control command based on the target damping force to the variable damper 6 to control the force (damping force) generated by the variable damper 6.

[0054] The ECU 31 constitutes a sensor abnormality detection device that detects abnormalities in the sprung acceleration sensors 9A to 9C and the unsprung acceleration sensors 10A and 10B. Similar to the ECU 21 according to the first embodiment, the ECU 31 includes a CAN input unit 22, sprung acceleration input units 23A to 23C, and unsprung acceleration input units 24A and 24B.

[0055] The ECU 31 executes a program stored in the storage unit to detect abnormalities in the sprung acceleration sensors 9A-9C and the unsprung acceleration sensors 10A, 10B. The ECU 31 acquires the vehicle speed included in the vehicle driving information from the CAN 8. The ECU 31 acquires each sprung acceleration sensor value (sprung acceleration) based on detection signals from the three sprung acceleration sensors 9A-9C. The ECU 31 acquires each unsprung acceleration sensor value (unsprung acceleration) based on detection signals from the two unsprung acceleration sensors 10A, 10B.

[0056] The ECU 31 compares the vibration levels of any two of the three sprung acceleration sensor values ​​when the vehicle speed is lower than a second threshold value V21, which is a second speed. The ECU 31 includes a second determination unit 32 that determines that the sprung acceleration sensor 9A is in an abnormal state and that the sprung acceleration sensor values ​​are vibrating abnormally when, for example, the vibration level of the sprung acceleration sensor value of the sprung acceleration sensor 9A is greater than the second fluctuation band R21 and greater than the vibration level of the sprung acceleration sensor value of the sprung acceleration sensor 9B.

[0057] The reason why vehicle speed is included in the criteria for determining sensor abnormality is that, since vibrations due to road surface inputs are detected by the sensor while the vehicle is moving, it is not possible to determine whether the vibrations in the sensor values ​​are due to road surface inputs or abnormal sensor vibrations. That is, the second determination unit 32 detects abnormalities in the sprung acceleration sensor values ​​using the vibrations in the sprung acceleration sensor values ​​when the vehicle is stopped or in a state close to that. For this reason, the second threshold value V21 is the speed at which the vehicle stops and the vibration level of the sprung acceleration sensor values ​​becomes sufficiently small. The second threshold value V21 is set to a value within a range of 0.5 km / h to 1 km / h, for example. Specifically, the second threshold value V21 is set as appropriate depending on, for example, the characteristics of the sprung acceleration sensors 9A to 9C, the circuit that outputs the detection signal, and the resolution of the wheel speed sensors.

[0058] The second fluctuation range R21 is set to a value that is, for example, larger than the vibration level of normal sprung acceleration sensor values ​​while the vehicle is stopped and smaller than the vibration level of abnormal sprung acceleration sensor values. Specifically, the second fluctuation range R21 is set to a value that is approximately two to three times the vibration level of normal sprung acceleration sensor values ​​while the vehicle is stopped. The second fluctuation range R21 is set appropriately taking into consideration the characteristics of the sprung acceleration sensors 9A to 9C, the signal level of noise, etc.

[0059] Similarly, the ECU 31 compares the vibration levels of the two unsprung acceleration sensor values ​​when the vehicle speed is lower than a second threshold value V22, which is a second speed. The ECU 31 includes a second determination unit 33 that determines that the unsprung acceleration sensor 10A is in an abnormal state and that the unsprung acceleration sensor value is vibrating abnormally, for example, when the vibration level of the unsprung acceleration sensor value of the unsprung acceleration sensor 10A is greater than the second fluctuation range R22 and greater than the vibration level of the unsprung acceleration sensor value of the unsprung acceleration sensor 10B.

[0060] At this time, the second threshold value V22 is the speed at which the vehicle stops and the vibration level of the sprung acceleration sensor value becomes sufficiently small. The second threshold value V22 is appropriately set depending on, for example, the characteristics of the unsprung acceleration sensors 10A and 10B, the circuit that outputs the detection signal, and the resolution of the wheel speed sensor. The second threshold value V22 may be the same value as the second threshold value V21, or may be a different value.

[0061] The second fluctuation range R22 is set to a value that is greater than the vibration level of the normal unsprung acceleration sensor value while the vehicle is stopped and less than the vibration level of the unsprung acceleration sensor value when the vehicle is abnormal. Specifically, the second fluctuation range R22 is set appropriately in consideration of the characteristics of the unsprung acceleration sensors 10A and 10B, the signal level of noise, etc. The second fluctuation range R22 may be the same value as the second fluctuation range R21, or may be a different value.

[0062] Here, the sensor abnormality detection process performed by the ECU 31 will be described with reference to FIG.

[0063] The ECU 31 reads out a program stored in the storage unit and executes the sensor abnormality detection process. Here, the second determination unit 32 that performs abnormality detection for the sprung acceleration sensors 9A to 9C will be described as an example, but the second determination unit 33 that performs abnormality detection for the unsprung acceleration sensors 10A and 10B also performs the same process.

[0064] The ECU 31 receives the CAN signal from the CAN 8 and reads the detection signals of the three sprung acceleration sensors 9A to 9C. The ECU 31 obtains the vehicle speed included in the vehicle driving information from the CAN signal. The ECU 31 obtains three sprung acceleration sensor values ​​(sprung acceleration) based on the detection signals of the three sprung acceleration sensors 9A to 9C.

[0065] The ECU 31 determines whether the sprung acceleration sensor values ​​(output voltage values) are within a normal range. If all three sprung acceleration sensor values ​​are within the normal range, the ECU 31 executes the processing of the second determination unit 32. On the other hand, if at least one sprung acceleration sensor value is outside the normal range, the ECU 31 executes sensor abnormality processing. In the sensor abnormality processing, for example, the ECU 31 determines that an abnormality exists in the sprung acceleration sensor (e.g., sprung acceleration sensor 9A) that output a sprung acceleration sensor value outside the normal range, and increments the count of an 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 an abnormality exists in the corresponding sprung acceleration sensor.

[0066] The second determination unit 32 determines whether the vehicle speed is lower than the second threshold value V21. If the vehicle speed is higher (greater) than the second threshold value V21, there is a possibility that vibrations due to road surface inputs while traveling are detected by the sensor, and the second determination unit 32 cannot detect an abnormality based on the vibration level. Therefore, if 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.

[0067] On the other hand, when the vehicle speed is equal to or less than the second threshold value V21, the second determination unit 32 determines whether the vibration level of the sprung acceleration sensor values ​​is normal. Specifically, the second determination unit 32 selects any two of the three sprung acceleration sensor values. The second determination unit 32 compares one of these sprung acceleration sensor values ​​with the other sprung acceleration sensor value. The second determination unit 32 performs this comparison process on all of the sprung acceleration sensor values.

[0068] At this time, the second determination unit 32 determines whether the fluctuation range (vibration level) of one sprung acceleration sensor value is greater than the second fluctuation range R21 and is greater than the fluctuation range (vibration level) of the other sprung acceleration sensor value.

[0069] When the fluctuation range (vibration level) of one sprung acceleration sensor value is greater than the second fluctuation range R21 and is greater than the fluctuation range (vibration level) of the other sprung acceleration sensor value, it is considered that there is an abnormality in the sprung acceleration sensor corresponding to the one sprung acceleration sensor value (for example, sprung acceleration sensor 9A). Therefore, the second determination unit 32 executes the sensor abnormality process described above.

[0070] On the other hand, when the fluctuation range (vibration level) of one sprung acceleration sensor value is smaller than the second fluctuation range R21, or when the fluctuation range (vibration level) of one sprung acceleration sensor value is smaller than the fluctuation range (vibration level) of the other sprung acceleration sensor value, an abnormality in one sprung acceleration sensor value cannot be detected. Therefore, in order to detect abnormalities in the remaining sprung acceleration sensor values, a similar comparison process is performed on the remaining sprung acceleration sensor values. If no abnormalities are detected in any of the sprung acceleration sensor values, the second determination unit 32 determines that the vibration levels of all sprung acceleration sensor values ​​are normal and returns.

[0071] The ECU 31 according to the second embodiment has the above-described configuration. Next, as an example of sensor abnormality detection by the ECU 31, an operation when an abnormality is detected in the sprung acceleration sensor will be described with reference to FIG.

[0072] As shown in FIG. 6, when the vehicle speed drops below the second threshold value V21, the ECU 31 determines whether the vibration level of the sprung acceleration sensor values ​​is within the normal range. At this time, the vibration levels of the sprung acceleration sensor values ​​of the sprung acceleration sensors 9B and 9C are approximately zero and smaller than the second fluctuation range R21. Therefore, the sprung acceleration sensors 9B and 9C that output these two sprung acceleration sensor values ​​are considered to be 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 fluctuation range R21. In addition, the vibration level of the sprung acceleration sensor value of the sprung acceleration sensor 9A is larger than the vibration levels of the sprung acceleration sensor values ​​of the sprung acceleration sensors 9B and 9C. Therefore, the sprung acceleration sensor 9A that outputs this sprung acceleration sensor value is considered to be abnormal. Therefore, the ECU 31 determines that the sprung acceleration sensor 9A is abnormal and increases the count of the abnormality detection counter. When the count number of the abnormality detection counter reaches a predetermined value, the ECU 31 outputs an error signal to notify that an abnormality has occurred in the sprung acceleration sensor 9A.

[0073] Thus, the second embodiment configured as described above can also achieve the same effects as those of the first embodiment. The ECU 31 according to the second embodiment includes a second determination unit 32 that determines whether or not the traveling speed (vehicle speed) from the CAN input unit 22 is equal to or less than the second threshold value V21 (second speed) and whether or not the signal fluctuation range of one of the sprung acceleration sensor value (first sensor input value) of the sprung acceleration input unit (e.g., sprung acceleration input unit 23A) serving as the first sensor input unit or the sprung acceleration sensor value (second sensor input value) of the sprung acceleration input unit (e.g., sprung acceleration input unit 23B) serving as the second sensor input unit is greater than the second fluctuation range R21 and is greater than the signal fluctuation range of the other.

[0074] Therefore, for example, even when the sprung acceleration sensor value vibrates abnormally within the normal range while the vehicle is stopped, an abnormality in the sprung acceleration sensor value can be detected by comparing the vibration levels (signal fluctuation range) between multiple sprung acceleration sensor values.

[0075] The ECU 31 also includes a second judgment unit 33 that judges whether the traveling speed (vehicle speed) according to the CAN input unit 22 is equal to or less than a second threshold value V22 (second 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 (e.g., 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 (e.g., unsprung acceleration input unit 24B) as the second sensor input unit is greater than the second fluctuation range R22 and greater than the other signal fluctuation range.

[0076] Therefore, for example, even when the unsprung acceleration sensor value vibrates abnormally within the normal range while the vehicle is stopped, an abnormality in the unsprung acceleration sensor value can be detected by comparing the vibration levels (signal fluctuation range) between multiple unsprung acceleration sensor values.

[0077] The second embodiment may be combined with the first embodiment, that is, the ECU 31 may include the first determination units 25 and 26 according to the first embodiment in addition to the second determination units 32 and 33.

[0078] 1 and 7 to 9 show a third embodiment of the present invention. The third embodiment is characterized in that the ECU has a model estimation value calculation unit that estimates vehicle behavior from vehicle model information to obtain a vehicle behavior estimation value, and a comparison / determination unit that compares the vehicle behavior estimation value with the first sensor input value or the second sensor input value. In the third embodiment, the same components as those in the first embodiment are designated by the same reference numerals, and their description will be omitted.

[0079] An ECU 41 according to the third embodiment has an input side connected to the CAN 8, sprung acceleration sensors 9A-9C, unsprung acceleration sensors 10A, 10B, etc., and an output side connected to the variable damping force actuator 7 of the variable damper 6, etc. The ECU 41 includes a processor as a control unit and a storage unit (none of which are shown) including 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.

[0080] The ECU 41 reads vehicle driving information from the CAN 8 via serial communication. The ECU 41 reads sprung acceleration sensor values ​​(sprung acceleration) based on detection signals from the sprung acceleration sensors 9A to 9C. The ECU 41 reads unsprung acceleration sensor values ​​(unsprung acceleration) based on detection signals from the unsprung acceleration sensors 10A and 10B. The ECU 41 calculates a target damping force and the like based on the vehicle driving information, sprung acceleration, and unsprung acceleration. The ECU 41 outputs a control command based on the target damping force to the variable damper 6 to control the force (damping force) generated by the variable damper 6.

[0081] The ECU 41 constitutes a sensor abnormality detection device that detects abnormalities in the sprung acceleration sensors 9A to 9C and the unsprung acceleration sensors 10A and 10B. The ECU 41 is configured in substantially the same manner as the ECU 21 according to 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.

[0082] The ECU 41 executes a program stored in the storage unit to detect abnormalities in the sprung acceleration sensors 9A-9C and the unsprung acceleration sensors 10A, 10B. The ECU 41 acquires the vehicle speed included in the vehicle driving information from the CAN 8. The ECU 41 acquires each sprung acceleration sensor value (sprung acceleration) based on detection signals from the three sprung acceleration sensors 9A-9C. The ECU 41 acquires each unsprung acceleration sensor value (unsprung acceleration) based on detection signals from the two unsprung acceleration sensors 10A, 10B.

[0083] The ECU 41 has a model estimation value calculation unit 42 that estimates vehicle behavior from vehicle model information to obtain a vehicle behavior estimation value, and a comparison and judgment unit 43 that compares the sprung acceleration estimation value included in the vehicle behavior estimation value with the three sprung acceleration sensor values.

[0084] The model estimation value calculation unit 42 estimates the sprung acceleration based on the unsprung acceleration of each wheel and the road surface input using, for example, a quarter-vehicle model with a single wheel. At this time, the ECU 41 acquires the unsprung acceleration of the front wheels based on, for example, the detection signals of the unsprung acceleration sensors 10A and 10B. The ECU 41 acquires the unsprung acceleration of the rear wheels based on, for example, the detection signals of the unsprung acceleration sensors 10A and 10B and the vehicle speed. The ECU 41 acquires the road surface input based on, for example, vehicle driving information from the CAN 8.

[0085] Furthermore, the model estimation 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 quarter-size vehicle model with a single wheel. Note that the vehicle model is not limited to the quarter-size vehicle model, and may be a two-wheel model consisting of a set of left and right wheels or a set of front and rear wheels, or may be a four-wheel vehicle model.

[0086] The comparison / determination unit 43 obtains the vibration levels of the sprung acceleration sensor values ​​of the sprung acceleration sensors 9A to 9C based on the maximum and minimum peak-to-peak values ​​of the sprung acceleration sensor values. The comparison / determination unit 43 calculates the difference between the vibration levels of the sprung acceleration sensor values ​​of the sprung acceleration sensors 9A to 9C and the vibration level based on the sprung acceleration estimated value of the model estimated value calculation unit 42. When the absolute value of the difference between these vibration levels remains equal to or greater than a predetermined value for a certain period of time, the comparison / determination unit 43 determines that there is an abnormality in the corresponding sprung acceleration sensor value.

[0087] As a result, the comparison and determination unit 43 determines that the sprung acceleration sensor value of the sprung acceleration sensor 9A is stuck, for example, when the difference between the sprung acceleration sensor value of the sprung acceleration sensor 9A and the sprung acceleration estimated value calculated by the model estimated value calculation unit 42 is large despite the vibration level of the sprung acceleration sensor values ​​of the sprung acceleration sensors 9B, 9C being larger than the first fluctuation band R11 (constant value). Also, the comparison and determination unit 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 calculated by the model estimated value calculation unit 42 is large despite the vibration level of the sprung acceleration sensor values ​​of the sprung acceleration sensors 9B, 9C being smaller than the second fluctuation band R21 (constant value).

[0088] At this time, the predetermined value for determining whether the vibration level is appropriate is set as appropriate to a value that takes into consideration a margin for noise, etc., with the vibration level based on the sprung acceleration estimated value by the model estimated value calculation unit 42 as a reference. Specifically, the predetermined value is set to a value that is about 1 / 3 of the vibration level based on the sprung acceleration estimated value. Furthermore, the certain period of time for determining whether the vibration level is appropriate is set as appropriate based on experiments using an actual vehicle, taking into consideration the effect of suppressing erroneous detection, etc.

[0089] In addition, the ECU 41 has a comparison / determination unit 44 that compares the unsprung acceleration estimation value included in the vehicle behavior estimation value with the two unsprung acceleration sensor values. The comparison / determination unit 44 obtains the vibration levels of the unsprung acceleration sensor values ​​of the unsprung acceleration sensors 10A and 10B based on the maximum and minimum peak-to-peak values ​​of the unsprung acceleration sensor values. The comparison / determination unit 44 calculates the difference between the vibration levels of the unsprung acceleration sensor values ​​of the unsprung acceleration sensors 10A and 10B and the vibration level based on the unsprung acceleration estimation value of the model estimation value calculation unit 42. When the absolute value of the difference between these vibration levels remains equal to or greater than a predetermined value for a certain period of time, the comparison / determination unit 44 determines that the corresponding unsprung acceleration sensor value has an abnormality.

[0090] As a result, the comparison and determination unit 44 determines that the unsprung acceleration sensor value of the unsprung acceleration sensor 10A is stuck, for example, when the difference between the unsprung acceleration sensor value of the unsprung acceleration sensor 10A and the unsprung acceleration estimated value calculated by the model estimation value calculation unit 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 band R12 (constant value).Also, the comparison and determination unit 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 calculated by the model estimation value calculation unit 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 band R22 (constant value).

[0091] The ECU 41 according to the third embodiment has the above-described configuration. Next, as an example of sensor abnormality detection by the ECU 41, an operation when an abnormality is detected in the sprung acceleration sensor will be described with reference to Figures 8 and 9.

[0092] As shown in Fig. 8, when the vibration level of the sprung acceleration sensor value of any one of the sprung acceleration sensors (e.g., sprung acceleration sensors 9B and 9C) becomes larger than first fluctuation band 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 by the model estimated value calculation unit 42. At this time, if the absolute value of the difference in the vibration level remains equal to or larger than a predetermined value for a certain period of time, the ECU 41 determines that the sprung acceleration sensor value of the sprung acceleration sensor corresponding to that sprung acceleration sensor value (e.g., sprung acceleration sensor 9A) is fixed, and increases the count of an abnormality detection counter. When the count of the abnormality detection counter reaches a predetermined value, the ECU 41 outputs an error signal to notify that an abnormality has occurred in the corresponding sprung acceleration sensor.

[0093] As shown in Fig. 9, when the vibration level of the sprung acceleration sensor value of any one of the sprung acceleration sensors (e.g., sprung acceleration sensors 9B and 9C) becomes smaller than second fluctuation band 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 by the model estimated value calculation unit 42. At this time, if the absolute value of the difference in the vibration level remains equal to or greater than a predetermined value for a certain period of time, the ECU 41 determines that the sprung acceleration sensor value of the sprung acceleration sensor corresponding to that sprung acceleration sensor value (e.g., sprung acceleration sensor 9A) is vibrating abnormally, and increases the count of an abnormality detection counter. When the count of the abnormality detection counter reaches a predetermined value, the ECU 41 outputs an error signal to notify that an abnormality has occurred in the corresponding sprung acceleration sensor.

[0094] Thus, the third embodiment configured as described above can also achieve the same effects as those of the first embodiment. Furthermore, when the vibration level of the sprung acceleration sensor value of one of the sprung acceleration sensors (for example, sprung acceleration sensors 9B and 9C) exceeds a certain value but there is a large 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, the ECU 41 according to the third embodiment can determine that the corresponding sprung acceleration sensor value is stuck.

[0095] In addition, if the vibration level of the sprung acceleration sensor value of one of the sprung acceleration sensors (e.g., sprung acceleration sensors 9B, 9C) is very small, but the difference between the output of another sprung acceleration sensor (e.g., sprung acceleration sensor 9A) and the output of the model estimated value calculation unit 42 is large, the ECU 41 can determine that the corresponding sprung acceleration sensor value is vibrating abnormally.

[0096] In addition, if the vibration level of the unsprung acceleration sensor value of one unsprung acceleration sensor (e.g., unsprung acceleration sensor 10B) exceeds a certain value, but there is a large difference between the output of the other unsprung acceleration sensor (e.g., unsprung acceleration sensor 10A) and the output of the model estimated value calculation unit 42, the ECU 41 can determine that the corresponding unsprung acceleration sensor value is stuck.

[0097] Furthermore, if the vibration level of the unsprung acceleration sensor value of one unsprung acceleration sensor (e.g., unsprung acceleration sensor 10B) is very small, but the difference between the output of the other unsprung acceleration sensor (e.g., unsprung acceleration sensor 10A) and the output of the model estimation value calculation unit 42 is large, the ECU 41 can determine that the corresponding unsprung acceleration sensor value is vibrating abnormally.

[0098] Although the comparison and determination unit 43 in the third embodiment determines 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, the present invention is not limited to this. Similar to the first determination unit 25 and the second determination unit 32 in the first and second embodiments, the comparison and 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. The same applies to the comparison and determination unit 44 in the third embodiment.

[0099] 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 according to the first embodiment, and the second determination units 32 and 33 according to the second embodiment, in addition to the model estimated value calculation unit 42 and the comparison determination units 43 and 44.

[0100] In the above-described embodiments, the ECUs 21, 31, and 41 are used to detect abnormalities in the sprung acceleration sensors 9A-9C and the unsprung acceleration sensors 10A and 10B, but the present invention is not limited to this. The sensors that the ECU detects abnormalities in may be at least two sensors mounted on the vehicle, such as various acceleration sensors, a vehicle height sensor, and a gyro sensor. Furthermore, the ECUs 21, 31, and 41 are used to control the variable damper 6, but the present invention is not limited to this. An ECU that detects abnormalities in various sensors may be provided separately from the ECU that controls the variable damper.

[0101] In each of the above embodiments, the vehicle speed is transmitted by a CAN signal and the traveling speed input unit is the CAN input unit 22. However, the present invention is not limited to this. For example, if a wheel speed sensor is directly connected to the ECU, the traveling speed input unit may be a wheel speed input unit that receives the wheel speed from the wheel speed sensor.

[0102] In the above-described embodiments, an example has been described in which a semi-active suspension is configured using a variable damper 6, which is a force generating mechanism. However, the present invention is not limited to this, and the force generating mechanism may be configured as an active suspension that generates a force in the vertical direction between the vehicle body and the wheel. Specifically, the actuator is configured by an electric actuator, a hydraulic actuator, or the like that generates a force in the expansion or contraction direction between the vehicle body and the wheel.

[0103] In the above-described embodiments, an example has been described in which the actuator (force generating mechanism) that generates an adjustable force between the vehicle body 1 and the wheel 2 is configured using a damping force adjustable variable damper 6. However, the present invention is not limited to this, and the actuator may be configured using, for example, an air suspension, a stabilizer (kinesus), an electromagnetic suspension, or the like, in addition to a hydraulic shock absorber.

[0104] In the above embodiments, the suspension system used in a four-wheeled vehicle has been described as an example. However, the present invention is not limited to this and can also be applied to, for example, two-wheeled and three-wheeled vehicles, or work vehicles and transport vehicles such as trucks and buses.

[0105] The above-described embodiments are merely examples, and partial substitution or combination of the configurations shown in different embodiments is possible.

[0106] The present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and are not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations.

[0107] This application claims priority to Japanese Patent Application No. 2022-199480, filed December 14, 2022. The entire disclosure of Japanese Patent Application No. 2022-199480, filed December 14, 2022, including the specification, claims, drawings, and abstract, is incorporated herein by reference in its entirety. [Explanation of symbols]

[0108] 1: vehicle body, 2: wheels, 4: suspension device, 6: variable damper (damping force adjustable shock absorber, force generating mechanism), 7: variable damping force actuator, 8: CAN, 9A to 9C: sprung acceleration sensors, 10A, 10B: unsprung acceleration sensors, 21, 31, 41: ECU (sensor abnormality detection device), 22: CAN input unit (travel speed input unit), 23A to 23C: sprung acceleration input unit (first sensor 24A, 24B: unsprung mass acceleration input section (first sensor input section, second sensor input section), 25, 26: first judgment section, 32, 33: second judgment section, 42: model estimated value calculation section, 43, 44: comparison judgment section, V11, V12: first threshold (first speed), V21, V22: second threshold (second speed), R11, R12: first fluctuation range, R21, R22: second fluctuation range

Claims

1. A sensor abnormality detection device that detects abnormalities in at least three or more sensors provided in a vehicle, a running speed input unit for inputting the running speed of the vehicle; a first sensor input unit to which a signal fluctuation range of the first sensor is input; a second sensor input unit to which a signal fluctuation range of the second sensor is input; a third sensor input unit to which a signal fluctuation range of the third sensor is input; When the travel speed according to the travel speed input unit is equal to or greater than a first speed and the signal fluctuation width of the first sensor input value of the first sensor input unit is larger than a first fluctuation width, or is larger than a signal fluctuation width of the second sensor input value of the second sensor input unit or a signal fluctuation width of the third sensor input value of the third sensor input unit, the first sensor input value is determined to be normal; and when the signal fluctuation width of the second sensor input value of the second sensor input unit is larger than the first fluctuation width, or is larger than a signal fluctuation width of the first sensor input value of the first sensor input unit or a signal fluctuation width of the third sensor input value of the third sensor input unit, the first sensor input value is determined to be normal. a first determination unit that determines the second sensor input value to be normal when the signal fluctuation range of the third sensor input value of the third sensor input unit is larger than the first fluctuation range, or is larger than the signal fluctuation range of the first sensor input value of the first sensor input unit or the signal fluctuation range of the second sensor input value of the second sensor input unit, and determines that a sensor input value smaller than the first fluctuation range is abnormal when any one of the first sensor input value, the second sensor input value, and the third sensor input value is smaller than the first fluctuation range; A sensor abnormality detection device having the same.

2. The sensor abnormality detection device according to claim 1, The sensor abnormality detection device further includes a second determination unit that determines whether the travel speed input by the travel speed input unit is equal to or less than a second speed, and whether a signal fluctuation 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 a second fluctuation range and is also greater than the signal fluctuation range of the other.

3. The sensor abnormality detection device according to claim 1, a model estimated value calculation unit that estimates a vehicle behavior from vehicle model information to obtain a vehicle behavior estimated value; a comparison / determination unit that compares the vehicle behavior estimated value with the first sensor input value or the second sensor input value; The sensor abnormality detection device further comprises:

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