Included are an electromagnetic actuator which includes an electric motor configured to generate drive forces for a damping operation and a telescopic operation; an information acquirer which acquires a stroke velocity of the electromagnetic actuator; a drive force arithmetic part which includes a damping force calculator configured to calculate a target damping force and a telescopic force calculator configured to calculate a target telescopic force, and which obtains a target drive force based on the target damping force and the target telescopic force; and a drive controller which controls drive of the electric motor using the target drive force. The drive force arithmetic part includes an adjuster which performs an adjustment to reduce a telescopic control amount for the target telescopic force based on the stroke velocity acquired by the information acquirer.

A method of controlling a vehicle when the vehicle passes over a speed bump, may include: dividing sections of the road into a first section within a first time period before the front wheel of the vehicle collides with the speed bump, a second section while the front wheel collides with the speed bump, a third section within a second time period before the rear wheel collides with the speed bump, and a fourth section while the rear wheel collides with the speed bump; and controlling and distributing at least one of suspension damping force, driving power and braking force to the front wheel and the rear wheel for each of the first section, the second section, the third section and the fourth section to reduce the amount of impact to be applied when the vehicle collides with the speed bump and to reduce a vertical motion of the vehicle that occurs while the vehicle goes over the speed bump.

An active suspension device includes: a preview sensor that detects a height of a road surface in front of a wheel; and an ECU that controls a stroke of a suspension to perform a preview control. The ECU includes: a front wheel preview control part that performs a preview control; a preview control success determination part that determines whether the preview control is successful; and a rear wheel control part that controls a stroke of a suspension of a rear wheel. When the preview control of the front wheel is successful, the rear wheel control part performs a preview control and a skyhook control of a rear wheel to control the stroke of the suspension of the rear wheel. When the preview control of the front wheel is unsuccessful, the rear wheel control part cancels the preview control of the rear wheel and perform the skyhook control of the rear wheel.

A suspension device includes an actuator capable of generating a thrust force and a controller. The controller includes a first vibration suppression force computation unit configured to obtain a first vibration suppression force from a vertical velocity of a sprung member, a second vibration suppression force computation unit configured to obtain a second vibration suppression force from a vertical velocity of the unsprung member or a relative velocity between the sprung member and the unsprung member, a low-pass filter having a breakpoint frequency between a sprung resonance frequency and an unsprung resonance frequency and processing a signal in the course of obtaining the second vibration suppression force using the second vibration suppression force computation unit, and a target thrust force computation unit configured to obtain a target thrust force of the actuator on the basis of the first vibration suppression force and the second vibration suppression force.

Left and right stabilizer bars are provided between left and right wheels of a vehicle. A control unit controls an actuator to control a rotation angle of the right stabilizer bar with respect to the left stabilizer bar. The control unit determines whether the vehicle is moving, whether a vehicle speed is less than a first threshold value, and whether a vehicle state is in transition from a moving state to a stopped state. A detection unit detects a control amount of the actuator. When the vehicle is moving, the vehicle speed is less than the first threshold value, the vehicle state is in transition from the moving state to the stopped state, and the control amount of the actuator is greater than zero, the control unit decreases the control amount of the actuator such that the control amount of the actuator becomes zero before the vehicle speed becomes zero.

A damping force control device for controlling damping forces of shock absorbers by a control device, which is configured to to estimate first vertical speeds at the positions of wheels based on the vertical accelerations of a vehicle body at the positions of the wheels, to estimate second vertical speeds of the vehicle body caused by driver's driving operation based on driving operation amount of the driver, to calculate target damping forces by subtracting products of damping coefficients of the ride comfort control and second vertical speeds from the sums of products of the damping coefficients of the ride comfort control and first vertical speeds and products of damping coefficients for controlling posture change of the vehicle body and the second vertical speeds, and to control damping coefficients of the shock absorbers based on the target damping forces.

An active chassis control for a motor vehicle with an adaptive control circuit for reducing body vibrations (A.sub.actual) of the motor vehicle, in which a control unit is integrated, which, depending on a current body vibration (A.sub.actual) or a parameter correlating therewith (a), controls a chassis actuator. The control unit is followed by an adaptive unit which adapts an actuating signal (S) generated by the control unit with a driving speed-dependent scaling factor (f(v)), in particular by generating an adapted actuating signal (S′) with which the chassis actuator can be controlled. Depending on the situation, a factor allowance (Δf) can be added to the driving speed-dependent scaling factor (f(v)) in the event of a significantly greater body vibration (A.sub.o) in order to effectively dampen the significantly greater body vibration (A.sub.o).

In a suspension controlling apparatus for a vehicle including a suspension whose damping force is variably settable and a control unit capable of controlling the damping force of the suspension, for appropriately obtaining a pitch behavior. When a vibration state of a vehicle in a vertical direction exceeds a given vibration state, a control unit controls damping force of suspensions on the basis of a target damping force in order to execute a skyhook control. However, when acceleration in a forward and rearward direction of the vehicle is outside a given range, a decision condition for the given vibration state is changed to a condition on the side on which the skyhook controlling damping force control of the suspensions is less likely to be started.

A method for controlling the damping characteristic of a shock absorber of a vehicle, particularly for compensating the variation of the operating temperature of the shock absorber, in an active or semi-active suspension system. The compensation of the variation of the operating temperature of the shock absorber takes place by: estimating a mechanical power dissipated in heat by the shock absorber; estimating a thermal power exchanged by the shock absorber with the environment; evaluating the current operating temperature of the shock absorber as a function of the dissipated mechanical power and of the thermal power exchanged with the environment; and controlling the driving current of the control valve of the shock absorber according to a shock absorber reference model indicating a relationship between the damping force of the shock absorber, the operating temperature of the shock absorber and the driving current of the control valve.

To improve off-road travel performance, ECU is configured to: set one of front left and right wheels and rear left and right wheels as roll stiffness decrease subject wheels and set another as non-roll stiffness decrease subject wheels; bring a spring switching valve and a leveling valve into an open state for each of the roll stiffness decrease subject wheels, causing left and right hydraulic cylinders to communicate to each other for the roll stiffness decrease subject wheels; and bring the spring switching valve and the leveling valve into a closed state and bring a bypass valve into the open state for one of the left and right wheels of the non-roll stiffness decrease subject wheels, to cause a second gas spring for one of the left and right wheels of the non-roll stiffness decrease subject wheels to communicate to the hydraulic cylinders of the roll stiffness decrease subject wheels.