Abstract: A hydraulic circuit controls a doubling acting cylinder of a vehicle suspension to provide load leveling and shock absorption functions. A set of solenoid valves control the application of pressurized hydraulic fluid from a supply line to the cylinder and from the cylinder to a tank return line to raise and lower the vehicle for load leveling. The chambers of the cylinder are interconnected by a parallel arrangement of a check valve, orifice and a relief valve. Another parallel arrangement of a check valve, orifice and a relief valve couples the cylinder to an accumulator. These parallel arranged components enable the doubling acting cylinder to function as a passive shock absorber. A lock-out valve is provided in the preferred embodiment a to defeat the shock absorber operation and provide a very stiff suspension.

Abstract: In a suspension control system according to the present invention, a controller previously stores damping force maps (an ordinary road map, a rough road map, and an extremely rough road map) corresponding to road surface conditions (an ordinary road, a rough road, and an extremely rough road) defined by the frequency and amplitude of the vertical acceleration. The frequency and amplitude of the vertical acceleration are detected, and a damping force map (the ordinary road map, the rough road map, or the extremely rough road map) corresponding to the detected information is selected. Damping force control is effected on the basis of the selected damping force map. Selection of a damping force map according to the frequency and amplitude of the vertical acceleration is also made when a change in the vertical acceleration, i.e. a change in the piston speed, is predicted during running on an ordinary road, a rough road or an extremely rough road.

Abstract: A vehicle suspension control derives demand force commands from relative velocities of the suspension dampers at the corners of the vehicle and applies the demand force commands only when a force corresponding to the demand force command can be effectively exerted by the damper. The control is also responsive to a sensed vehicle handling event to derive a body control enhancement damping commands for selected suspension dampers and apply the body control enhancement damping commands without regard for the direction of demand force for the suspension dampers. Each body control enhancement damping command is derived from one or more measured vehicle dynamic variables associated with the sensed vehicle handling event and modified in magnitude in response to the direction and/or magnitude of the sensed relative velocity of damper to which the body control enhancement damping command is to be applied.

Abstract: A damping force control device and method controls damping forces of dampers at locations of respective wheels. A first target damping force that inhibits vibrations of a vehicle body in the heave direction is calculated for each of the wheels, based on a single wheel model of the vehicle which employs the skyhook theory. A second target damping force that inhibits vibrations of the vehicle body in the pitch direction is calculated for each of the wheels, based on a model of front and rear wheels of the vehicle. A third target damping force that inhibits vibrations of the vehicle body in the roll direction is calculated for each of the wheels, based on a model of left and right wheels of the vehicle. One of the first through third target damping forces that has the greatest absolute value is selected for each of the wheels. The damping force exerted by the damper at the location of each wheel is set to the selected target damping force.

Abstract: A magneto-spring structure includes a lower frame and an upper frame vertically movably mounted on the lower frame via a link mechanism. The upper and lower frames have respective permanent magnets secured thereto, with like magnetic pole opposed to each other. The link mechanism includes a plurality of links and a connecting member for rotatably connecting them via a bearing. The links are made of non-magnetic material, while the bearing is made of ferromagnetic material.

Abstract: By passing the vertical acceleration through a phase adjusting filter and a gain adjusting filter, the phase of the vertical acceleration is advanced by 49 degrees so that the phase difference with respect to the actual relative velocity becomes 180 degrees in the neighborhood of the vehicle body resonance point, thereby making the phase of the vertical acceleration, in effect, coincident with the phase of the relative velocity. In the neighborhood of the vehicle body resonance point (1 Hz), the gain of the estimated relative velocity takes a small value. In frequency regions other than the neighborhood of the vehicle body resonance point, the gain of the estimated relative velocity is increased. Consequently, the controlled variable in the neighborhood of the vehicle body resonance point increases, and the controlled variable in higher frequency regions decreases. Damping force is adjusted in correspondence to the controlled variable.

Abstract: A motor vehicle has a body supported on a front pair of wheels and a rear pair of wheels with front suspension apparatus providing controllable vertical wheel constraint and roll stiffness and a rear pair of wheels with rear suspension apparatus providing controllable vertical wheel constraint and rear roll stiffness. Responsive to a commanded vehicle acceleration or braking, the driven wheel (acceleration) or front (braking) suspension apparatus is briefly altered to provide optimal tire patch traction for the one of the pair of wheels. The alteration may be further responsive to vehicle speed and/or lateral acceleration. The controllable part of the suspension apparatus may be dampers, springs or anti-sway apparatus such as torsion bars. If anti-sway apparatus, the front and/or rear roll stiffness may be controlled to promote oversteer at low vehicle speed and understeer at high vehicle speed.

Abstract: An air-suspension system has at least one air spring arranged between a chassis and a vehicle component mounted relative to said chassis for movement along an oscillatory path. A control valve is arranged inside the air spring and has control positions for feeding, blocking and discharging compressed air in the air spring. The control valve is activated via a control element also arranged inside the air spring. A guideway of the control element acts on one of an outer tube air-spring subassembly and a rolling tube air-spring subassembly which are movable relative to one another. The control valve is designed as a rotary-slide valve and is activated via the guideway and a rotary-slide valve body. The guideway of the control element is shorter than the stroke length of the air spring, the one of the subassemblies which actuates the control element being in releasable operative connection with the control element.

Abstract: When a hydraulic cylinder apparatus operates in a direction such that the same damping force as a skyhook damping force cannot be produced, a command signal is applied so as to operate an active system (a fluid supply/discharge valve) and supply or discharge a fluid relative to the hydraulic cylinder apparatus, to thereby provide compensation of the damping force and obtain a desired damping force (shock-absorbing function). It is unnecessary to continuously supply or discharge the fluid through the active system and energy consumption can be reduced as compared to a conventional active control.

Abstract: An automatic damper for an automobile automatic damper system which provides a compression valve operable to vary compressive damping characteristics of a damper, as well as a rebound valve operable to vary rebound damping characteristics of the damper. Use of the invention in cooperation with presently available electronic control modules and sensing algorithms provides a damper with either discrete valves or continuously variable valves for independently setting the rebound and compression damping characteristics of the damper.

Abstract: A control system for a resilient support mechanism such as a suspension mechanism of a wheeled vehicle including a damper disposed between an unsprung mass member and a sprung mass member of the vehicle, wherein a damping coefficient of the damper is divided into a linear portion and a nonlinear portion, and wherein the nonlinear portion of the damping coefficient is defined as a control input u and applied with a frequency weight Wu(s), while a vertical velocity of the sprung mass member, a relative velocity of the sprung mass member to the unsprung mass member and a vertical acceleration of the sprung mass member are defined as an evaluation output zp and applied with a frequency weight Ws(s).

Abstract: An Adaptive Off-state (AO) control method (55) for use in conjunction with a suspension system (10) including a controllable damper (22) interconnecting relatively moveable members (12, 14) to reduce the transmission of vibrational forces therebetween. Such suspension systems (10) are switchable between alternative on- and an off-state in accordance with a primary control method (53) and/or a secondary override control method (59). Sensors (48, 52) monitor the parameters of the suspension system (10), such as the displacement, velocity, and acceleration of the moveable members (12, 14). Damper command signals (107) are provided to the damper (22) in the on-state (116) to adjust the damping characteristics thereof. In the off-state, the damping signal in conventional systems is approximately zero or a constant relatively low magnitude.

Abstract: A device for controlling damping coefficients of shock absorbers (22FL, 22FR, 22RL, 22RR) of a four wheeled vehicle constructs a phantom damping system composed of a phantom side shock absorber (122, 122F, 122R) disposed vertically at a lateral inside of a turn running of the vehicle to have a lower end movable along a ground surface together with the vehicle and an upper end vertically movable relative to the lower end with a first phantom damping coefficient (Cg, Cgf, Cgr) therebetween, and a phantom angular shock absorber (124, 124F, 124R) arranged to act between the upper end of the phantom side shock absorber and the vehicle body with a second phantom damping coefficient (Ca, Caf, Car) therebetween, whereby, when the damping coefficients of the shock absorbers are controlled to substantially equalize the phantom damping system with the actual damping system of the actual shock absorbers with respect to damping vertical and rolling movements of the vehicle body, the mass center of the vehicle body is lowe

Abstract: A vehicle roll rigidity control device comprises a control unit and an actuator which can adjust an attenuation force installed between the vehicle front wheel and body. The control unit reduces the attenuation force of the actuator and increases the ability of the vehicle to turn around when the vehicle is in a turn transient state. When the sequential steering operation to the left and right is performed, the controller increases the attenuation force of the actuator and increase the roll rigidity of the front wheels.

Abstract: The disclosed suspension control system includes actuators for adjusting damping forces of front and rear variable-damping force shock absorbers. Also provided are front and rear vertical acceleration detectors. Usual control for the actuators are performed on the basis of the vertical accelerations detected by the vertical acceleration detectors. A control signal adjustor is provided to adjust a control signal to be sent to the actuator for the rear shock absorber such that the damping force of the rear shock absorber is reduced when the vertical acceleration detected by the front vertical acceleration detector or a rate of change thereof exceeds a preset reference value.

Abstract: A device for controlling damping coefficients of shock absorbers (22FL, 22FR, 22RL, 22RR) of a four wheeled vehicle constructs a phantom damping system composed of a phantom side shock absorber (122) disposed vertically at a lateral inside of a turn running of the vehicle and longitudinally shifted from a center of gravity of the vehicle body in a direction of a longitudinal acceleration or deceleration of the vehicle to have a lower end movable along a ground surface together with the vehicle and an upper end vertically movable relative to the lower end with a first phantom damping coefficient (Cg) therebetween, and a phantom angular shock absorber (124) arranged to act between the upper end of the phantom side shock absorber and the vehicle body with a second phantom damping coefficient (Ca) therebetween, whereby, when the damping coefficients of the shock absorbers are controlled to substantially equalize the phantom damping system with the actual damping system of the actual shock absorbers with respect t

Abstract: A damping force control device and method controls damping forces of dampers at locations of respective wheels. A first target damping force that inhibits vibrations of a vehicle body in the heave direction is calculated for each of the wheels, based on a single wheel model of the vehicle which employs the skyhook theory. A second target damping force that inhibits vibrations of the vehicle body in the pitch direction is calculated for each of the wheels, based on a model of front and rear wheels of the vehicle. A third target damping force that inhibits vibrations of the vehicle body in the roll direction is calculated for each of the wheels, based on a model of left and right wheels of the vehicle. One of the first through third target damping forces that has the greatest absolute value is selected for each of the wheels. The damping force exerted by the damper at the location of each wheel is set to the selected target damping force.

Abstract: A vehicle height adjust control apparatus and method prevents interference between a vehicle and a road surface due to a vehicle height reduction caused by an occupant or load added during a stop of the vehicle and minimizes unnecessary or ineffective operation of actuators while the vehicle is stopped with a brake pedal depressed. The apparatus has a vehicle sensor for detecting a vehicle speed, and a brake switch for detecting a brake pedal depressing operation. When the vehicle is stopped and the brake pedal is depressed, a microcomputer maintains a normal determination condition for starting a vehicle height adjustment to raise the vehicle body, but prevents a vehicle height reducing adjustment from lowering the vehicle body or uses a severe determination condition for starting a vehicle height reducing adjustment, thereby restricting the vehicle height adjustment only in the reducing direction.

Abstract: A method and system for providing variable load control and isolation in a vehicle suspension includes a variably flexible suspension element coupled between the frame of the vehicle and the wheel. The variably flexible suspension element comprises an electrically responsive material disposed therein that varies stiffness in response to electrical control signals applied thereto. The electrical control signals are generated by an electronic control unit and are representative of road conditions traveled by the vehicle as sensed by at least one sensor.

Abstract: A vehicle suspension control includes a vehicle body control responsive to body/wheel velocity at the corners of the vehicle body to derive a demand force command for dampers at each corner of the vehicle body for vehicle body control and applies each of the derived demand force commands to its respective damper only when a comparison of the direction of the demand force command with the sensed relative velocity of the damper indicates that a force corresponding to the demand force command can be effectively exerted by the damper. But the suspension control also includes a vehicle stability control responsive to an indicated vehicle lateral acceleration in a turn to determine, independently of the vehicle body control, a stability compression damping command for the suspension dampers on the side of the vehicle opposite the direction of the lateral acceleration and a stability rebound damping command for the suspension dampers on the side of the vehicle in the direction of the lateral acceleration.

Abstract: A vehicle suspension system is dynamically adjustable to minimize the effects of energy transfer on a driver, passenger or cargo within a vehicle. Each wheel preferably has a suspension module that includes a force absorbing device with an adjustable force absorbing capacity. A sensor is associated with each wheel that detects an amount of displacement and acceleration of the wheel in response to a force imposed on the vehicle as caused by variations in a road surface, for example. An electronic controller detects the amount of displacement and acceleration of one wheel and activates an electrically activated force imposing device at another wheel to effectively counteract the effect of the force on the one wheel within one millisecond. The force imposing device preferably is a piezoelectric actuator. The vehicle suspension system of this invention is dynamically adjustable and compensates for variations in a road surface, for example, while the vehicle is in transit.

Abstract: The present invention relates to an electronic suspension control system (ECS) not using a G sensor and a steering angle sensor but using an ECS control algorithm and an ABS wheel speed sensor in order to perform rough road detecting and roll controlling.

Abstract: A vehicle suspension system is responsive to an active brake signal from a brake system indicating the application of a greater braking force to one front corner brake than to the other front corner brake to affect vehicle yaw rate. The vehicle suspension system determines the relative velocities of the front corner suspension adjacent the front corner brake receiving the greater braking force and the diagonally opposed rear corner suspension and further determines a compression damping command for the front corner suspension and a rebound damping command for the rear corner suspension. While the active brake signal is present, the suspension control applies the compression damping command for the front corner suspension when its relative velocity indicates that it is in compression. While the active brake signal is present, the suspension control also applies the rebound damping command for the rear corner suspension when its relative indicates that it is in rebound.

Abstract: When a road surface is judged to be undulating and rough, a parameter for a bad road to attain “soft” damping force characteristics is set with priority to setting of a parameter for an undulating road to attain “hard” damping force characteristics. Consequently, “soft” damping force characteristics are obtained to improve the ride quality. This order of the priority is adopted especially when a vehicle speed is low. When the vehicle speed is high, the order of the priority is reversed.