Abstract: A controller estimates a state of a vehicle based on a wheel speed sensor provided on the vehicle, and outputs a control signal to a shock absorber provided between a wheel and a vehicle body according to the estimated state of the vehicle. The controller uses information of a sensor of an in-vehicle apparatus other than an apparatus dedicated to the shock absorber as an observed value in the estimation of the state of the vehicle. In other words, the controller uses sensor information of a navigation apparatus corresponding to the in-vehicle apparatus other than the shock absorber, more specifically, gyro information meaning information of a gyro sensor mounted on the navigation apparatus as the observed value in the estimation of the state of the vehicle.

Abstract: When a vehicle's driving situation is a rolling state, a compressor is used to transfer compressed air between left and right air suspensions of front wheels, and a compressor is used to transfer compressed air between left and right air suspensions of rear wheels. The air suspensions of the left and right front wheels and the air suspensions of the left and rear wheels thus independently generate counter rolls. This makes it possible to concurrently perform vehicle height adjustment of the air suspensions of the left and right front wheels and vehicle height adjustment of the air suspensions of the left and right rear wheels, which improves responsiveness in counter roll control.

Abstract: A stopped vehicle height of an air suspension for a stop-side wheel on a side that stops first is determined in consideration of a vehicle height that changes in accordance with a vehicle height change of the air suspension for a supply/discharge-side wheel on another side after a stop. Thus, when vehicle height adjustment of the air suspension for the supply/discharge-side wheel is finished, the stopped vehicle height of the air suspension for the stop-side wheel can be adjusted to the vicinity of a target value and the precision in the vehicle height adjustment can be increased.

Abstract: When a vehicle's driving situation is a rolling state, a compressor is used to transfer compressed air between left and right air suspensions of front wheels, and a compressor is used to transfer compressed air between left and right air suspensions of rear wheels. The air suspensions of the left and right front wheels and the air suspensions of the left and rear wheels thus independently generate counter rolls. This makes it possible to concurrently perform vehicle height adjustment of the air suspensions of the left and right front wheels and vehicle height adjustment of the air suspensions of the left and right rear wheels, which improves responsiveness in counter roll control.

Abstract: A shock absorber includes an inner cylinder electrode sealingly containing electrorheological fluid therein, a piston slidably inserted in the inner cylinder electrode, and a relief valve provided on the piston and configured to relieve an actual damping force according to a desired value. The controller includes an instruction value calculation portion configured to determine a high-voltage instruction value to output to the shock absorber based on a detection value output from a sprung acceleration sensor and an unsprung acceleration sensor. The electrorheological fluid has such a characteristic that an actual damping force value output according to the instruction value output from the instruction value calculation portion increases when a temperature is low compared to when the temperature is high. The relief valve and the high-voltage instruction value are set based on the actual damping force value that output when the temperature is high.

Abstract: A shock absorber includes an inner cylinder electrode sealingly containing electrorheological fluid therein, a piston slidably inserted in the inner cylinder electrode, and a relief valve provided on the piston and configured to relieve an actual damping force according to a desired value. The controller includes an instruction value calculation portion configured to determine a high-voltage instruction value to output to the shock absorber based on a detection value output from a sprung acceleration sensor and an unsprung acceleration sensor. The electrorheological fluid has such a characteristic that an actual damping force value output according to the instruction value output from the instruction value calculation portion increases when a temperature is low compared to when the temperature is high. The relief valve and the high-voltage instruction value are set based on the actual damping force value that output when the temperature is high.