A control unit that controls control currents supplied to shock absorbers that generate damping forces according to the control currents determines coefficients of two functions that functionally identify an equivalent damping coefficient and an equivalent spring constant of each suspension based on relationships between the control current supplied to each shock absorber and the coefficients of the two functions that change according to the control current and a frequency of a relative vibration between a sprung and an unsprung of a vehicle, and calculates a relative displacement or a relative velocity between the sprung and the unsprung based on a vertical acceleration detected by a detection device and the two functions in which the coefficients are determined.

A vehicle suspension control system includes a central suspension spring core, a first suspension spring surrounding an upper portion of the central suspension spring core, a second suspension spring surrounding a lower portion of the central suspension spring core, the first suspension spring and the second suspension spring coupled between a wheel and a fixed structure of a vehicle to inhibit movement of the wheel, a spring seat surrounding the central suspension spring core and coupled between the first and second suspension springs, the spring seat including an outer sleeve and multiple seals for retaining magnetorheological fluid between the outer sleeve and the central suspension spring core, one or more electromagnets adjacent the spring seat, and a suspension control module configured to energize the one or more electromagnets to selectively modify a viscosity of the magnetorheological fluid to inhibit movement of the first suspension spring or the second suspension spring.

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.

An absorber device for absorbing a force acting thereon includes an absorber housing which encloses an interior space and a hydraulic medium arranged in the interior space. An absorber piston rod has an absorber piston arranged thereon. The absorber piston divides the interior space into a first chamber and a second chamber. The absorber piston rod has a spring device for resiliently supporting the absorber piston relative to a quasi-static component. The absorber piston is mounted axially movably on the absorber piston rod. A first spring and a second spring of the spring device are arranged in each case on both sides of the absorber piston and resiliently connect the absorber piston rod to the absorber piston and counteract a movement of the absorber piston in the axial direction, relative to the absorber piston rod. The absorber device can be arranged in a hollow damper piston rod of a damper.

A suspension arrangement for a vehicle, in particular a utility vehicle having a base and a structure, is disclosed. This arrangement includes at least one first spring and at least one second spring, the at least one first spring and the at least one second spring having spring attachments which are connected to attachment apparatuses of the structure on one side and of the base on the other. The at least one second spring is fastened to the base by way of at least one adjustment device. An adjustable air spring suspension arrangement and methods for controlling the suspension arrangements are disclosed.

A suspension system includes: a variable damper configured to use a damping force variable actuator to adjust communication of working fluid generated in a passage by a relative movement between a vehicle body and a wheel, to thereby adjust a damping force over a range of a soft characteristic to a hard characteristic; and a controller configured to control the damping force variable actuator. The variable damper further includes a frequency response unit configured to reduce the damping force for vibration at a specific frequency. The controller is configured to increase a change rate from a soft side to a hard side at a time of controlling the damping force to reach a target damping force when a frequency of the relative movement between the vehicle body and the wheel is lower than a first frequency set to the frequency response unit.

An active damper system for damping high-frequency vibration excitation of the vehicle body, includes a damper bearing to support a vehicle chassis component on the vehicle body, wherein the damper bearing includes a first bearing element for fastening to the vehicle body and a second bearing element for fastening to the vehicle chassis component; an active actuating element connecting the first and second bearing elements; a first acceleration sensor for measuring an acceleration of the vehicle body; a control unit connected to the acceleration sensor and receiving a vertical acceleration of the vehicle body as input variable from the acceleration sensor, wherein the control unit influences the active actuation element. The active damper system includes a second acceleration sensor arranged on the second bearing element.

A spring assembly for mounting between a chassis and an unsprung mass of a vehicle, the spring assembly comprising a coil spring and a hydropneumatic spring acting in series, wherein the hydropneumatic spring is configured to be switchable between a compressible state and an incompressible state, such that when the hydropneumatic spring is in the compressible state, the equivalent spring rate of the spring assembly is a function of the spring rate of the coil spring and the hydropneumatic spring, and when the hydropneumatic spring is in the incompressible state, the equivalent spring rate of the spring assembly is a function of the spring rate of the coil spring.

A damping control system for a vehicle having a suspension located between a plurality of ground engaging members and a vehicle frame includes at least one adjustable shock absorber having an adjustable damping characteristic. The system also includes a controller coupled to each adjustable shock absorber to adjust the damping characteristic of each adjustable shock absorber, and a user interface coupled to the controller and accessible to a driver of the vehicle. The user interface includes at least one user input to permit manual adjustment of the damping characteristic of the at least one adjustable shock absorber during operation of the vehicle. Vehicle sensors are also be coupled to the controller to adjust the damping characteristic of the at least one adjustable shock absorber based vehicle conditions determined by sensor output signals.

A vehicle is provided which has a vehicle body, at least one hub of a wheel, and a suspension connecting the hub to the vehicle body. The suspension has a suspension arm hinged to the vehicle body and to the hub, a spring, and an electromechanical rotary actuator operable between an active adjustment condition and a damping condition of the motion of the suspension, via a leverage.