A vehicle suspension control device includes: an actuator configured to apply a control force in a vertical direction between an unsprung structure and a sprung structure; and an electronic control unit configured to control the actuator so as to generate the control force according to a required control amount for reducing vibration of the sprung structure. The required control amount includes at least two control terms of a displacement term, a velocity term, and an acceleration term related to displacement, velocity, and acceleration of the sprung structure. The electronic control unit calculates a magnitude of a frequency component of each of a plurality of frequency bands included in road surface vibration information, and determines a control gain of each of the at least two control terms so as to change based on the magnitude of the frequency component of each of the plurality of frequency bands.

A vehicle suspension control device includes: an actuator configured to apply a control force in a vertical direction between an unsprung structure and a sprung structure; and an electronic control unit configured to control the actuator so as to generate the control force according to a required control amount for reducing vibration of the sprung structure. The required control amount includes at least two control terms of a displacement term, a velocity term, and an acceleration term related to displacement, velocity, and acceleration of the sprung structure. The electronic control unit calculates a magnitude of a frequency component of each of a plurality of frequency bands included in road surface vibration information, and determines a control gain of each of the at least two control terms so as to change based on the magnitude of the frequency component of each of the plurality of frequency bands.

A method for controlling vehicle motion is described. The method includes accessing a set of control signals including a measured vehicle speed value associated with a movement of a vehicle. A control signal associated with user-induced input is also accessed. The method compares the measured vehicle speed value with a predetermined vehicle speed threshold value to achieve a speed value threshold approach status, and then compares the set of values to achieve a user-induced input threshold value approach status. The method monitors a state of a valve within the vehicle suspension damper, and determines a control mode for the vehicle suspension damper. The method also regulates damping forces within the vehicle suspension damper.

A method for controlling vehicle motion is described. The method includes accessing a set of control signals including a measured vehicle speed value associated with a movement of a vehicle. A control signal associated with user-induced input is also accessed. The method compares the measured vehicle speed value with a predetermined vehicle speed threshold value to achieve a speed value threshold approach status, and then compares the set of values to achieve a user-induced input threshold value approach status. The method monitors a state of a valve within the vehicle suspension damper, and determines a control mode for the vehicle suspension damper. The method also regulates damping forces within the vehicle suspension damper.

A roll vibration damping control system includes an electronic control unit configured to: compute a sum of a product of a roll moment of inertia and a roll angular acceleration of a vehicle body, a product of a roll damping coefficient and a first-order integral of the roll angular acceleration, and a product of an equivalent roll stiffness of the vehicle and a second-order integral of the roll angular acceleration, as a controlled roll moment to be applied to the vehicle body; compute a roll moment around a center of gravity of a sprung mass as a correction roll moment, the roll moment being generated by lateral force on wheels due to roll motion; and compute a target roll moment based on a value obtained by correcting the controlled roll moment with the correction roll moment.

A roll vibration damping control system includes an electronic control unit configured to: compute a sum of a product of a roll moment of inertia and a roll angular acceleration of a vehicle body, a product of a roll damping coefficient and a first-order integral of the roll angular acceleration, and a product of an equivalent roll stiffness of the vehicle and a second-order integral of the roll angular acceleration, as a controlled roll moment to be applied to the vehicle body; compute a roll moment around a center of gravity of a sprung mass as a correction roll moment, the roll moment being generated by lateral force on wheels due to roll motion; and compute a target roll moment based on a value obtained by correcting the controlled roll moment with the correction roll moment.

A system for filling a tank of a suspension system with hydraulic fluid includes: a module configured to turn on an external pump and pump hydraulic fluid into the suspension system, where the external pump is separate from the suspension system and is configured to pump hydraulic fluid into the suspension system via a port fluidly connected to a hydraulic line of the suspension system; and a fill module configured to, after operating the external pump, operate a pump of the suspension system and pump hydraulic fluid from the hydraulic line into the tank of the suspension system thereby filling the tank.

A road surface condition is determined appropriately. A road surface determining section (84) configured to determine a road surface state includes a threshold setting section (845) configured to set a threshold for determining the road surface state, so that a value of a desired control variable is multiplied by a coefficient determined in accordance with a result of the determination by the road surface determining section (84).

A road surface condition is determined appropriately. A road surface determining section (84) configured to determine a road surface state includes a threshold setting section (845) configured to set a threshold for determining the road surface state, so that a value of a desired control variable is multiplied by a coefficient determined in accordance with a result of the determination by the road surface determining section (84).

A system includes: a state module configured to selectively set a present state to a first state; a valve control module configured to determine first target open and closed states for valves of a suspension system based on the present state and to open and close the valves of the suspension system according to the first target open and closed states, respectively; a pump control module configured to, when the valves are in the first target open and closed states, respectively, selectively operate an electric pump of the suspension system in a first direction and increase a pressure of hydraulic fluid in a first portion of the suspension system including an accumulator, where the valve control module is configured to decrease the pressure in the first portion after the increase; and a diagnosis module configured to selectively diagnose a fault in the accumulator based on a pressure during the decrease.