Vehicle height adjustment device

1. A vehicle height adjustment device comprising:

an actuator configured to change a relative position of a body of a vehicle relative to an axle of a wheel of the vehicle;

a detector configured to detect the relative position of the body of the vehicle relative to the axle of the wheel of the vehicle;

a vehicle height controller configured to control the actuator based on a detection value detected by the detector to change the relative position to control a vehicle height, which is a height of the body; and

a malfunction detector configured to, when the detection value detected by the detector changes by a predetermined amount or more in a predetermined period of time, determine that there is a possibility of a malfunction occurring in the detector.

2. The vehicle height adjustment device according to claim 1 ,

wherein the detection value detected by the detector comprises a first detection value and a second detection value, and

wherein the malfunction detector is configured to:

immediately before the predetermined period of time, check the first detection values in a detection cycle that comprises a predetermined cycle length;

at a time of elapse of the predetermined period of time, check the second detection value in the detection cycle; and

determine that there is the possibility of the malfunction occurring in the detector when a difference between the first detection value and the second detection value exceeds a predetermined threshold.

3. The vehicle height adjustment device according to claim 1 ,

wherein the detection value detected by the detector comprises first detection values and a second detection value, and

wherein the malfunction detector is configured to:

immediately before the predetermined period of time, check the first detection values in a detection cycle that comprises a predetermined cycle length;

at a time of elapse of the predetermined period of time, check the second detection value in the detection cycle; and

determine that there is the possibility of the malfunction occurring in the detector when a difference between an average value of the first detection values and the second detection value exceeds a predetermined threshold.

4. The vehicle height adjustment device according to claim 1 , wherein after the detection value detected by the detector has changed by the predetermined amount or more in the predetermined period of time, and when the detection value is thus changed for a predetermined period of time or longer, the malfunction detector is configured to determine that the malfunction has occurred in the detector.

5. The vehicle height adjustment device according to claim 4 , wherein when the malfunction detector has detected the malfunction in the detector, the vehicle height controller is configured to control the actuator based on a predetermined detection value before the malfunction detector determines that there is the possibility of the malfunction occurring in the detector.

6. The vehicle height adjustment device according to claim 4 , wherein when the malfunction detector has detected the malfunction in the detector, the vehicle height controller is configured to control the actuator in accordance with a speed of the vehicle irrespective of the detection value detected by the detector.

7. The vehicle height adjustment device according to claim 2 , wherein after the detection value detected by the detector has changed by the predetermined amount or more in the predetermined period of time, and when the detection value is thus changed for a predetermined period of time or longer, the malfunction detector is configured to determine that the malfunction has occurred in the detector.

8. The vehicle height adjustment device according to claim 3 , wherein after the detection value detected by the detector has changed by the predetermined amount or more in the predetermined period of time, and when the detection value is thus changed for a predetermined period of time or longer, the malfunction detector is configured to determine that the malfunction has occurred in the detector.

9. The vehicle height adjustment device according to claim 7 , wherein when the malfunction detector has detected the malfunction in the detector, the vehicle height controller is configured to control the actuator based on a predetermined detection value before the malfunction detector determines that there is the possibility of the malfunction occurring in the detector.

10. The vehicle height adjustment device according to claim 8 , wherein when the malfunction detector has detected the malfunction in the detector, the vehicle height controller is configured to control the actuator based on a predetermined detection value before the malfunction detector determines that there is the possibility of the malfunction occurring in the detector.

11. The vehicle height adjustment device according to claim 7 , wherein when the malfunction detector has detected the malfunction in the detector, the vehicle height controller is configured to control the actuator in accordance with a speed of the vehicle irrespective of the detection value detected by the detector.

12. The vehicle height adjustment device according to claim 8 , wherein when the malfunction detector has detected the malfunction in the detector, the vehicle height controller is configured to control the actuator in accordance with a speed of the vehicle irrespective of the detection value detected by the detector.