Disclosed herein are hydraulic actuators and methods for the operation of actuators having variable relative pressure ratios. Further disclosed are methods for designing and/or operating a hydraulic actuator such that the actuator exhibits a variable relative pressure ratio. In certain embodiments, the relative pressure ratio of the hydraulic actuator may be dependent on one or more characteristics (such as, for example, frequency or rate of change) of an oscillating input to the hydraulic actuator.

An electrically powered suspension system includes: an actuator that is provided between a vehicle body and a wheel of a vehicle and generates a load for damping vibration of the vehicle body; an information acquisition part that acquires information on a sprung state amount and a road surface state; a target load calculation part that calculates a first target load related to skyhook control based on the sprung state amount and calculates a second target load related to preview control based on the road surface state; and a load control part. The target load calculation part calculates a third target load related to pitch generation control based on a target pitch angle and calculates a combined target load into which the first target load, second target load, and third target load have been combined. The load control part performs load control of the actuator using the combined target load.

Provided is an electric suspension device including an electromagnetic actuator that is provided between a body and wheel of a vehicle and generates damping force for damping vibration of the body. It includes: an information acquisition unit that acquires information on a sprung speed and sprung acceleration of the vehicle; a bounce target value computation unit that computes a bounce target value for controlling the vehicle's bounce orientation based on the sprung speed; and a driving control unit that controls driving of the actuator with a control target load which is based on the bounce target value. The bounce target value computation unit has a bounce target load map in which the bounce target value is associated with the sprung speed. The bounce target value computation unit adjusts a width of a dead zone set in the map based on the information on the sprung speed and sprung acceleration.

A method for adjusting the damper hardness of a vibration damper of a wheel of a transportation vehicle, wherein the transportation vehicle body movement signal is generated by a control device of the transportation vehicle from a first sensor signal of the first sensor unit connected fixedly in to a transportation vehicle body, a wheel movement signal is generated from a second sensor signal of a second sensor unit which detects a wheel position of the wheel with respect to the body, a speed signal which describes a speed of the transportation vehicle body is generated based on the transportation vehicle body movement signal, and the wheel movement signal and an actuation signal for setting the damper hardness is generated based on the speed signal. The transportation vehicle body movement signal is filtered by a first filter unit and/or the wheel movement signal is filtered by a second filter unit.

A regenerative shock absorber that include a housing and a piston that moves at least partially through the housing when the shock is compressed or extended from a rest position. When the piston moves, hydraulic fluid is pressurized and drives a hydraulic motor. The hydraulic motor, in turn, drives an electric generator that produced electric energy. The electric energy may be provided to a vehicle, among other things. The regenerative shock absorber may also provide ride performance that comparable to or exceeds that of conventional shock absorbers.

System and method for improving braking efficiency by increasing the magnitude of a frictional force between a tire of a vehicle wheel and a road surface. Braking efficiency may be improved by controlling the normal force applied on the wheel, with an active suspension actuator, based on the wheel's slip ratio.

A regenerative shock absorber that include a housing and a piston that moves at least partially through the housing when the shock is compressed or extended from a rest position. When the piston moves, hydraulic fluid is pressurized and drives a hydraulic motor. The hydraulic motor, in turn, drives an electric generator that produced electric energy. The electric energy may be provided to a vehicle, among other things. The regenerative shock absorber may also provide ride performance that comparable to or exceeds that of conventional shock absorbers.

Disclosed herein are hydraulic actuators and methods for the operation of actuators having variable relative pressure ratios. Further disclosed are methods for designing and/or operating a hydraulic actuator such that the actuator exhibits a variable relative pressure ratio. In certain embodiments, the relative pressure ratio of the hydraulic actuator may be dependent on one or more characteristics (such as, for example, frequency or rate of change) of an oscillating input to the hydraulic actuator.

Provided is an electric suspension device including an electromagnetic actuator that is provided between a body and wheel of a vehicle and generates damping force for damping vibration of the body. It includes: an information acquisition unit that acquires information on the vehicle's sprung speed, pitch rate, and roll rate; a bounce target value computation unit that computes a bounce target value for controlling the vehicle's bounce orientation based on the sprung speed; a pitch target value computation unit that computes a pitch target value for controlling the vehicle's pitch orientation based on the pitch rate; a roll target value computation unit that computes a roll target value for controlling the vehicle's roll orientation based on the roll rate; and a driving control unit that controls driving of the actuator with a control target load which is based on a sum of the bounce, pitch, and roll target values.

Provided is an electric suspension device including an electromagnetic actuator that is provided between a body and wheel of a vehicle and generates damping force for damping vibration of the body. It includes: an information acquisition unit that acquires information on a sprung speed and sprung acceleration of the vehicle; a bounce target value computation unit that computes a bounce target value for controlling the vehicle's bounce orientation based on the sprung speed; and a driving control unit that controls driving of the actuator with a control target load which is based on the bounce target value. The bounce target value computation unit has a bounce target load map in which the bounce target value is associated with the sprung speed. The bounce target value computation unit adjusts a width of a dead zone set in the map based on the information on the sprung speed and sprung acceleration.