The electromagnetic suspension apparatus includes: an electromagnetic actuator provided in parallel with a spring member between a vehicle body and a wheel of a vehicle and configured to generate driving force involving vibration damping of the vehicle body; an information acquisition unit configured to acquire, through a high-pass filter, time-series information about a stroke position of the electromagnetic actuator; and an ECU configured to calculate target driving force of the electromagnetic actuator and use the calculated target driving force to execute driving force control of the electromagnetic actuator. The ECU corrects the target driving force such that when the stroke position on the basis of the high-pass-filter-processed time-series information, from which low-frequency components (steady state deviation) have been removed, is present in a neutral region including a neutral position, spring force of the spring member is made weaker than when the stroke position is present in a non-neutral region.

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.

A control system (300) for controlling an active suspension system (104) of a vehicle (100), the control system comprising one or more controller (301), wherein the control system is configured to: obtain (908) information indicative of relative traction levels between different wheels (FL, FR, RL, RR) of the vehicle; and in dependence on the information, control (912) the active suspension system to increase normal force through a wheel (FR) of the vehicle having relatively high traction compared to one or more other wheels (FL, RL, RR) of the vehicle, and decrease normal force through a wheel (FL) of the vehicle having relatively low traction compared to one or more other wheels (FR, RL, RR) of the vehicle.

The invention relates to a method for compensating for vertically oriented movements of a superstructure of a vehicle. The vehicle is provided with the superstructure and with an active undercarriage having a plurality of wheels which are in contact with the carriageway, wherein each wheel is connected via an actuator adjustable over its length at a wheel assigned to a suspension point with the superstructure. Vertically oriented movements of the superstructure are caused by an inclination of the carriageway and by unevennesses of the carriageway, a first change of the length of at least one actuator is carried out for frequencies in a first, lower frequency range, and a second change of the length of the at least one actuator is carried out for frequencies in a second, higher frequency range.

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.

Integrated multiple actuator electro-hydraulic systems as well as their methods of use are described. Depending on the particular application, the integrated electro-hydraulic systems may exhibit different frequency responses and/or may be integrated into a single combined unit.

Integrated multiple actuator electro-hydraulic systems as well as their methods of use are described. Depending on the particular application, the integrated electro-hydraulic systems may exhibit different frequency responses and/or may be integrated into a single combined unit.

A characteristic is set to a first transmission force characteristic. A sensitivity is set to a first sensitivity. The maximum value of the square of a product of a value representing the first transmission force characteristic and a value representing the first sensitivity in a predetermined frequency range preset so as to include a frequency at which the value representing the first transmission force characteristic takes a peak value is set to an evaluation indication value. A complex spring constant in the vehicle longitudinal direction of the rear wheel suspension is set so that the evaluation indication value takes the minimum value out of values in a variable range of the evaluation indication value.

A vehicle integrated control method includes determining a road surface status, determining a vehicle status, determining an integrated control mode by determining a control status of an electronic control suspension and a motion of a sprung mass and an unsprung mass based on the determination results of the road surface status and the vehicle status, and controlling the electronic control suspension and an in-wheel system by determining a control amount based on the determined integrated control mode.

A method of optimizing a suspension system to avoid pitch resonance may include determining pitch characteristics of a vehicle for a terrain profile and speed range via a model associated with the vehicle, decoupling front and rear axles by removing pitch inertia from the model, and determining optimized damping for a main damper of a position sensitive damper over a linear range of wheel travel in a bounce control zone based on the pitch characteristics. The method may further include recoupling the front and rear axles by adding the pitch inertia back into the model, and selecting a secondary damper associated with a compression zone or a secondary damper associated with a rebound zone as a selected damper for adjustment based on which of the front and rear axles is limiting. The method may also include performing a damping adjustment to the selected damper and cyclically repeating selecting the secondary damper and performing the damping adjustment until pitch resonance is suppressed.