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 damper bumper cap for covering the rod side end of the damper tube containing a piston rod seal and for retaining a dust cover on the damper tube. The cap includes a side wall positioned in contact with the damper tube, an end wall that extends radially inwardly over the piston rod seal, and an annular skirt that is spaced radially outward of the side wall. First and second groups of connection wall segments extend radially between the side wall and the annular skirt at different heights to define vent openings in the spaces between the connection wall segments in the first and second groups of connection wall segments. The vent openings thus provide a plurality of tortuous airflow paths through the cap at circumferentially spaced locations.

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).

An air filter for an air suspension. A housing part is mounted on a vehicle body, connected to a height control part that controls the height of a vehicle, and allows fluid to pass therethrough. A filter part is disposed inside the housing part to remove foreign matter from the fluid. One or more noise reducing parts are disposed inside the housing part to reduce a movement speed of the fluid and reduce noise.

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 damper bumper cap for covering the rod side end of the damper tube containing a piston rod seal and for retaining a dust cover on the damper tube. The cap includes a side wall positioned in contact with the damper tube, an end wall that extends radially inwardly over the piston rod seal, and an annular skirt that is spaced radially outward of the side wall. First and second groups of connection wall segments extend radially between the side wall and the annular skirt at different heights to define vent openings in the spaces between the connection wall segments in the first and second groups of connection wall segments. The vent openings thus provide a plurality of tortuous airflow paths through the cap at circumferentially spaced locations.

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 method for changing a ride height position of a motor vehicle comprises measuring a respective relative distance of a vehicle superstructure from corresponding wheels, with spring travel sensors and transmitting a respective spring travel signal to an electronic open-loop and closed-loop control device of the motor vehicle. The spring travel signals pass through a frequency filtering in the electronic open-loop and closed-loop control device The frequency filtering initially comprising a bandpass filtering which splits the spring travel signal into a signal component excited by the wheel and a signal component excited by the vehicle superstructure. The signal component excited by the vehicle superstructure is filtered out, the frequency filtering then comprising an absolute value conversion of the bandpass-filtered spring travel signal and subsequently a low-pass filtering.

A wheel suspension for a vehicle with a supporting vehicle element includes at least one pair of single-sided swing arms. Each single-sided swing arm is associated with a hydraulic cylinder, which is linked to the single-sided swing arm and/or the supporting vehicle element. Each hydraulic cylinder is subdivided in a fluid-tight manner into two chambers.

A system for determining a displacement velocity signal for controlling an active wheel suspension of a land vehicle by open-loop and/or closed-loop control includes at least one Kalman filter, and at least one acceleration sensor arranged on a sprung mass of the land vehicle to sense a vertical acceleration of the sprung mass and to generate a corresponding acceleration signal supplied to the Kalman filter. The Kalman filter includes a mathematical motion model of the sprung mass, and input states of the Kalman filter include a vertical acceleration of the sprung mass, a vertical displacement velocity of the sprung mass, and a vertical displacement distance of the sprung mass. A displacement measurement signal having a value 0 is supplied continuously to the Kalman filter to determine the displacement velocity signal. Constant noise variance values of a measurement noise covariance matrix of the Kalman filter that are assigned to the displacement measurement signal are, in each case, set at one half of a maximum vertical displacement distance of the sprung mass.