Abstract: A toe angle changing control ECU for controlling a toe angle of wheels of a vehicle. The toe angle changing control ECU includes: a straight traveling state judging section for judging whether or not the vehicle is in a; a memory for storing the toe angle of the wheels while the vehicle is in the straight traveling state; and a toe angle setting section for setting the wheels to the toe angle stored in the memory (44) when the straight traveling state judging section judges that the vehicle is in the straight traveling state. While in the straight traveling state, the wheels are set to a toe angle at which the wheels are substantially parallel to the longitudinal direction of the vehicle, reducing the rolling resistance of the wheels, and improving fuel consumption.

Abstract: A suspension ECU 13 calculates a target characteristic changing coefficient a_new for changing a target characteristic, which is represented by a quadratic function, by use of the maximum actual roll angle ?_max generated in a vehicle body during the current turning state and a turning pitch angle ?_fy_max which is a fraction of an actual pitch angle ? generated as a result of turning, and changes the target characteristic by use of the coefficient a_new. Subsequently, the suspension ECU 13 calculates the difference ?? between the actual pitch angle ? and a target pitch angle ?h corresponding to the actual roll angle ? on the basis of the changed target characteristic, and calculates a total demanded damping force F to be cooperatively generated by the shock absorbers so as to reduce the difference ?? to zero.

Abstract: An actuating device for an active control suspension system which is provided at both ends of a sub-frame of a vehicle body and connected to one end of an assist link having the other end mounted at a knuckle and which changes a position of a mounting point of the assist link at the vehicle body, may include a member bracket fixedly mounted at each end of the sub-frame, provided with openings formed at both sides and an upper surface thereof, and formed of a pair of slide grooves having arc shape at the both ends thereof to slidably receive a pair of slide plates therein; an actuator connected to both slide plates through a pin-bolt unit; and a cam-bolt unit assembling a bush of the assist link with both slide plates and setting an initial position of the mounting point of the assist link at the vehicle body.

Abstract: A stabilizer system for a vehicle that includes a stabilizer bar and an actuator for changing stiffness of the stabilizer bar, an electric current to be supplied to an electric motor that is a drive source of the actuator is changed based on various parameters. The supply current is made smaller in a situation in which an operational direction of the actuator is toward a neutral position, than in another situation. Further, the supply current is made smaller with an increase in a distance of the operational position of the actuator from the neutral position. Moreover, the supply current is made larger with an increase in a steering speed. In detail, when the supply current is determined by multiplying a basic supply current by a control gain, the control gain is set to change depending upon the above-indicated parameter, whereby the supply current is changed based on the parameters.

Abstract: The invention relates to a wheel suspension for motor vehicles with level adjustment of the body, having a vertical adjusting device (22; 80) which is disposed between a wheel guide element and the superstructure of the motor vehicle and which is particularly designed as a ball screw mechanism driven by an electric motor and acts on an adjusting plate spring (34) of at least one support spring (14), wherein the vertical adjusting device (22; 80) is outwardly sealed by at least one enclosing rubber-elastic bellows (50, 52; 100). In order to prevent deformation of the at least one bellows and ingress of dirt or moisture into the vertical adjusting device, the invention proposes that the interior space (54, 56; 102) enclosed by the bellows (50, 52; 100) is connected directly or indirectly to an auxiliary volume (66; 108) positioned outside of the bellows (50, 52; 100).

Abstract: A vehicle (10) includes a control system (18) that is used to control a vehicle system. The control system determines a wheel normal loading in response to heave motion wheel loading, attitude-based wheel loading, and vertical motion induced wheel loading. The various wheel loadings may be indirectly determined from the sensors of the various dynamic control system outputs.

Abstract: An actuator includes a first rotary motor, a second rotary motor, and a transmission coupled to the first and second rotary motors. The transmission converts rotation of the first rotary motor in a first direction and simultaneous rotation of the second rotary motor in a second direction to linear motion of an output shaft in a single direction. The actuator is usable in an active automobile suspension.

Abstract: Herein, a particular vehicle suspension control arm in a suspension having multiple control arms is designed to create a range of available axial stiffness levels which relates to a range of toe change at the wheel under to lateral loading. In particular, a semi-active device is arranged on a given suspension control arm to allow a change in stiffness that produces a desirable amount of toe change under the presence of lateral loading. This suspension arrangement, when applied to the rear axle of an automobile, has significant merit in being able to enhance maneuverability and stability over a large range of operating conditions at a minimal level of control input energy and with robust failsafe operation.

Abstract: An axle-lifting device for lifting an axle of a vehicle. The axle-lifting device includes a function mechanism for generating a force component in an axle-lifting direction. The function mechanism is configured to generate a first force component for providing a first functionality and a second force component for lifting the axle in the axle-lifting direction.

Abstract: A method for actively suspending a real plant in a vehicle includes modifying a control signal on the basis of a difference between a property of the real plant, as indicated by the response of the real plant to the control signal, and a property of a nominal plant.

Abstract: A system and process for controlling vehicle loading on a multi-axle vehicle and improving maneuverability is disclosed. The system includes a reservoir of pressurized air and associated leveling valve that uses a relay valve to improve refill times when the vehicle returns from a dump mode operation to normal operation. The process reduces pressure in one or more of the axles when maneuvering the vehicle at predetermined slow speeds and maintaining that first predetermined pressure while the other axle(s) is at a greater pressure than the first axle. By preventing complete exhaustion of pressure from the suspension system, restoring air pressure is attained more quickly. Also, use of a relay valve enables higher flow rates to improve the refill time of the pneumatic suspension system after the dump operation.

Abstract: A vehicle control system estimates the vibration states of tires by using a vehicle vibration model that is separated into a vehicle body vibration model, a chassis vibration model, and a tire vibration model with high precision. The tire vibration model in the vehicle vibration model is formed of a rear wheel tire vibration model, a front wheel tire vibration model, and a virtual coupling element vibration model that virtually couples the rear wheel tire vibration model and the front wheel tire vibration model. Influence of the vibration state that is conducted between the front wheel tires and the rear wheel tires is considered while the tire vibration model and the chassis vibration model are separated from each other, thereby making it possible to estimate the vibrations that occur in the front wheel tires and the rear wheel tires.

Abstract: A method and an apparatus for controlling a semi-active suspension system (1) for motorcycles are described. According to the present invention, the damping forces applied to controllable force generators (2, 3), such as controllable shock absorbers, provided to the front and the rear semi-active suspensions of a motorcycle are jointly controlled. In particular, the pitch velocity (Vp) of the suspended mass (Ms) is taken into account so as to jointly control the front and rear suspension systems of a motorcycle. The present invention allows the optimization of the global adherence of the motorcycle to the road surface and of the driving and the travelling comfort of the vehicle.

Abstract: In some embodiments, the present systems include, consist of, or consist essentially of a roadarm having a first end, a second end, and an opening near the first end; where the second end is configured for attachment to a passive spring (e.g., an air spring, a coil spring, a compressible fluid spring, or a leaf spring), and the opening is configured for interchangeable use with any of: (a) a passive suspension system damping element, (b) a semi-active suspension system damping element, and (c) an active suspension system actuator. Other systems are included, such as those with common control systems for the active and semi-active suspension systems. Methods relating to such systems.

Abstract: In a configuration in which a control is performed for actuating the steering cylinder 17 so that the steering angle of the front wheel 11a (steering wheel), which is detected by the steering angle detector 62, becomes a target steering angle which is set in accordance with an operational state of the steering dial 42, the target steering angle of the front wheel 11a (steering wheel), which is set in accordance with an operational state of the steering dial 42, is compared with a detected steering angle of the front wheel 11a, which is detected by the steering detector 62, and when the difference between the target steering angle and the detected steering angle is a predetermined value or higher, the traveling speed of the vehicle 10 is regulated so that the traveling speed of the vehicle 10 becomes a predetermined speed or lower.

Abstract: The present embodiments relate to a semi-active suspension control system that utilizes controllable dampers for the purpose of improving maneuverability and vehicle hull stabilization. The disclosed semi-active control system can work in conjunction with a height management unit and on vehicles having variable ride heights, and hull stability and maneuverability can be achieved regardless of vehicle payload and ride height.

Abstract: A device for controlling the suspension of the body shell of a motor vehicle performs calculation of a relative modal body shell speed in relation to the mid-plane of the wheels, and calculation of the set modal stress of the damper as a function of the relative modal body shell speed in relation to the mid-plane of the wheels. The control value includes a determined shock absorption principle from among a plurality of different shock absorption principles that impose the force of the damper as a function of its travel speed.

Abstract: A tunable pneumatic suspension includes a piston and two opposed pneumatic chambers. The two champers apply opposed pneumatic pressures to opposite faces of the piston. The tunable pneumatic suspension also includes a pneumatic controller that independently controls the pressure in each of the chambers. The independent control of the two chambers allows the suspension to change the relative positions of the piston and the chambers by differing the pressures in each chamber, and allows the suspension to change its stiffness by increasing or decreasing the pressures in each of the chambers by equal amounts. If used in a vehicle, changing the relative positions of the piston and the chambers can change the ride height of the vehicle, and changing the stiffness of the suspension can change the stiffness of the vehicle's ride.

Abstract: A chassis system and a suspension module for vehicles having wheel subsystems incorporates a lateral torsion bar and a co-axial enveloping damper unit, featuring active-adaptive suspension characteristics. Pre-fabricated suspension modules are situated inside respective box-structures, connected via wheelbase and track members, allowing the storage of heavy elements (e.g., batteries or fuel-cells) at the chassis. The robust and self-carrying chassis is enhanced, using upper body members, in terms of structural rigidity, for a given wheelbase, achieving high impact-energy absorbtion. The suspension arms incorporate upper and lower members, articulation, connect internally or externally to the suspension module, and transmit drive and brake forces to the wheels.

Abstract: In a suspension system for a vehicle, a suspension spring, an absorber for controllably changing the damping coefficient becoming the reference of amount of its own generating damping force, a displacement force generator for controllably generating a displacement force are arranged in parallel between sprung and unsprung members. A vibration damping control is executed based on a so-called skyhook damper theory by utilizing the displacement force. In execution of the vibration damping control, when a sign of sprung-member absolute velocity Vu and a sign of sprung/unsprung-members velocity difference ?V are the same to each other, a damping-coefficient increasing control is executed to set a target damping coefficient C* of the absorber to a coefficient value C2 that is larger than a coefficient value C1 to which the target damping coefficient C* is set when the sign of sprung-member absolute velocity Vu and the sign of sprung/unsprung-members velocity difference ?V are different from each other.

Abstract: A method for operating a vehicle electronic stability control (“ESC”) system utilizing values for a variable obtained from a primary source and a redundant source includes the steps of receiving a first value for the variable from the primary source, receiving a second value for the variable from the redundant source, generating a normalized value as a function of the first value and the second value, determining whether the primary source is operating correctly, utilizing the first value for operation of the vehicle ESC system if the primary source is operating correctly, and utilizing the second value for operation of the vehicle ESC system if the primary source is not operating correctly and the second value is not greater in absolute value than the normalized value.

Abstract: The damper force in vehicles having a ride level control system is controlled by, when the leveling system is activated, a signal that is generated and transmitted to a damper force control device (5). When the level control system is activated, the damper force is adapted, and especially reduced for a rapid control.

Abstract: A lift truck includes a magneto-rheological damper coupled between the base frame and a frame holding a vertically sprung suspended wheel. The damper is electrically connected to a vehicle control system, which increases and decreases the damping force as a function of at least one of a weight of a load on the forks of the lift truck, a height of the mast of the lift truck, and a speed of the lift truck. As the weight of the load, height of the mast and speed of the vehicle increase, the damping force is increased. As the weight of the load, height of the mast, and speed of the vehicle decrease, the damping force is decreased. When the damper is activated to increase the damping force, the truck can maintain a four point stance, providing a larger footprint for the center of gravity, thereby limiting truck sway or oscillation.

Abstract: A method is provided for detecting a rollover event of a vehicle. A lateral kinetic energy of the vehicle is determined in response to vehicle longitudinal velocity and vehicle side slip angle. A lateral acceleration of the vehicle is measured. A tire normal force is measured. A rollover potentiality index is determined in response to the lateral kinetic energy and the lateral acceleration. A rollover index is determined by weighting the rollover potentiality index by a factor of the lateral acceleration and by a factor of the tire normal force. A comparison is made to determine if the rollover index is above a predetermined threshold.

Abstract: In a system in which an actuator force to be generated by an actuator is controlled based on a component sum that is a sum of a vibration damping component as the actuator force to be generated in a vibration damping control and a posture control component that is the actuator force to be generated in a body-posture control, a control in which the posture control component is limited so as to be not larger than a limit value is executable. The system ensures the actuator force that should be generated in the vibration damping control by limiting the posture control component, in a situation in which there is a limit in the actuator force that can be generated. Accordingly, a sufficient amount of a damping force can be generated, so that riding comfort of the vehicle and the like is prevented from being deteriorated.

Abstract: The objective of the present invention is to provide a vehicle motion control device capable of controlling the driving force distribution to the wheels with superior stability and response while effectively utilizing the tire grip.

Abstract: Upon searching control parameter used to adjust damping force of a damper from a map in accordance with damper speed and target damping force decided based on moving condition of the vehicle, the map sets the control parameter, which are relatively higher than the actual damping force characteristics, as map data in the area where the damper speed is less than a predetermined value, the area where the noise has the great influence on the sensor outputs. Therefore, it can be prevented that the control parameter of the damping force is varied largely or varied in a short period by the influence of noise, and the driving stability control of the vehicle can be executed exactly and the noise caused by switching the damping force of the damper can be reduced.

Abstract: A suspension system for a vehicle, including: an electromagnetic actuator configured to generate an actuator force and including a sprung-side unit supported by a sprung portion, an unsprung-side unit supported by an unsprung portion, a screw mechanism, and an electromagnetic motor; a connecting mechanism including a support spring for permitting one of the sprung-side and unsprung-side units to be floatingly supported as a floating unit by a unit-floatingly support portion that is one of the sprung and unsprung portions by which the floating unit is supported; and a controller including a sprung-vibration-damping control portion and a relative-vibration-damping control portion that is configured to execute a relative-vibration damping control for damping a vibration of the floating unit caused by the structure in which the floating unit is floatingly supported by the support spring.

Abstract: A predictive suspension system for a vehicle includes an imaging sensor, and energy source and a control. The imaging sensor is disposed at a vehicle and has a generally downward field of view, with the field of view encompassing an area forward of a tire of the vehicle. The energy source is operable to emit illumination in at least one linear pattern so that the linear pattern is projected onto a portion of the area forward of the tire of the vehicle that is encompassed by the field of view of the imaging sensor. The control processes image data captured by the imaging sensor and detects surface irregularities on a surface in front of the vehicle tire in response to the image processing.

Abstract: An apparatus and method using GPS for dynamically adjusting side-to-side positioning of a farm implement along a geographical path.

Abstract: A damping force control device (1) for a shock absorber (Dn) interposed between a sprung member (Bn) and an unsprung member (Wn) of a vehicle (A) comprises a damping force varying mechanism (3) which supplements a minimum damping force (Fdn) that can be generated by the shock absorber (Dn) with a variable damping force (Fcn). The device (1) comprises a control portion (2) which calculates a deviation (?n) between a damping force target value (Fsn) and the minimum damping force (Fdn) (S207), and open-loop controls the damping force varying mechanism (3) using a variable damping force (Fcn) calculated on the basis of the deviation (?n) such that the damping force generated by the shock absorber (Dn) coincide with the damping force target value (Fsn) (S208-S212), thereby optimizing damping force control of the shock absorber (Dn), which has a non-linear damping characteristic.

Abstract: A fitting for an active air suspension includes a housing with a central bore and a rigid tube having a first tube end inserted into the central bore with a second tube end extending outwardly of the housing. The first tube end includes a plastically deformed portion that prevents the rigid tube from being removed from the housing. A retention collar is used to secure a hose end to the second tube end.

Abstract: A system and process for controlling vehicle loading on a multi-axle vehicle and improving maneuverability is disclosed. The system includes a reservoir of pressurized air and associated leveling valve that uses a relay valve to improve refill times when the vehicle returns from a dump mode operation to normal operation. The process reduces pressure in one or more of the axles when maneuvering the vehicle at predetermined slow speeds and maintaining that first predetermined pressure while the other axle(s) is at a greater pressure than the first axle. By preventing complete exhaustion of pressure from the suspension system, restoring air pressure is attained more quickly. Also, use of a relay valve enables higher flow rates to improve the refill time of the pneumatic suspension system after the dump operation.

Abstract: An in-arm suspension (12) is provided for actively controlling a suspension arm (20) mounted to a vehicle frame (14). The suspension arm (20) has a housing (60) in which the a compressible fluid strut (32) and a fluid control section (90) are enclosed. The compressible fluid strut (32) includes a cylinder (134) and a piston rod (136) which is urged to extend from within the cylinder (134) in response to fluid pressure applied to compressible fluid disposed within the cylinder (134). A damper piston (174) is mounted to an interior portion of the piston rod (136), and moves with the piston rod (136) to pass the compressible fluid through the damper piston 174 and attenuate bounce and rebound of the piston rod (136) within the cylinder (134). A damper lock (210) is mounted to the piston rod (136) for selectively preventing the flow of compressible fluid through the damper piston (174).

Abstract: An adjuster device includes (a) a shaft held by a vehicle body; (b) an arm extending from the shaft in a direction intersecting an axial direction of the shaft; (c) an actuator causing one of rotation of the shaft and axial movement of the shaft in the axial direction; and (d) a motion converter converting the one of the rotation of the shaft and the axial movement of the shaft, into the other of the rotation of the shaft and the axial movement of the shaft. The arm is connected at a distal end portion thereof to one of at least one suspension arm, so as to enable the rotation of the shaft to cause change in a vertical distance between a wheel and the vehicle body. The shaft is connected to one of the at least one suspension arm or to an axle carrier, so as to enable the axial movement of the shaft to cause change in an alignment of the wheel. Also disclosed is an adjusting system including the adjuster device.

Abstract: The invention concerns a hydraulic spring support system including a double acting hydraulic cylinder with a piston chamber and a rod chamber, a first accumulator that is connected constantly with the piston chamber, and a second accumulator that is connected constantly with the rod chamber. The invention proposes that the piston chamber and the rod chamber are connected to each other by a variable flow resistance.

Abstract: A suspension system includes four electronically controlled actuators, one at each of the four wheels. The actuators are each controlled by an electronic control unit. The left front and right front actuators are mechanically connected with each other. The left rear and the right rear actuators are also mechanically connected with each other. The only connection between the front two actuators and the rear two actuators is an electronic communication through the electronic control unit.

Abstract: A vehicle includes a semi-active suspension including suspension dampers controllably adjustable in accordance with electronic stability control commands and ride and handling commands. Vehicle steering response states, turning direction states and vehicle dynamics states are binary coded in respective state variables and suspension control calibrations are binary coded in calibration words. Integrity and security of state variables and calibration words are ensured in efficient binary digit resource allocation schemes.

Abstract: A vehicle physical quantity estimating device including: a longitudinal vehicle body velocity estimating unit, estimating a longitudinal vehicle body velocity based on vehicle wheel velocities of each wheel; a longitudinal/lateral acceleration state value deviation computing unit, computing deviations in longitudinal and lateral acceleration state values based on output sensor signals corresponding to detected values of the vehicle motions of triaxial accelerations and triaxial angular velocities output from a sensor, and the estimated longitudinal vehicle body velocity; a low pass filter, letting only signals corresponding to motions that need attention pass through from the longitudinal/lateral acceleration state value deviation computing unit 14; and an attitude angle estimating unit, estimating the attitude angle based on the sensor signal(s), and signal(s) representing the deviations in longitudinal and lateral acceleration state values after low pass filter processing.

Abstract: A hydraulic cushion unit (1) is interposed between a frame and a rear wheel axle of a bicycle. A surplus hydraulic oil discharging passage (31a) discharges surplus hydraulic oil from the hydraulic cushion unit (1) to an accumulator (2) in contraction. A damping force generating valve (3) which maintains a closed state below a predetermined cracking pressure is disposed in the surplus hydraulic oil discharging passage (31a). A bypass passage (4) which bypasses the damping force generating valve (3) and a bypass valve (4) which opens and closes the bypass passage (L) are further provided. By closing the bypass valve (4) when pedaling of the bicycle is performed to start the bicycle, squatting of the bicycle is prevented while maintaining a shock absorbing function of the damping force generating valve (3).

Abstract: An active suspension system and method for controlling the height of a vehicle. In an exemplary embodiment, the active suspension system receives information from one or more input sources, including both internal and external vehicle inputs, and uses that information to actively control the vehicle height. By doing so, the active suspension system can reduce aerodynamic drag on the vehicle and improve the vehicle's fuel economy, ride comfort, handling, and other aspects of operation. Some examples of external vehicle inputs that may be used include: short-range road and vehicle information, as well as long-range traffic, road and route information.

Abstract: A vehicle suspension system (19) includes a suspension (47). A lateral acceleration sensor (32) generates a lateral acceleration signal. A roll rate sensor (34) generates a roll rate signal. A controller (26) detects an irregularity in the suspension in response to the lateral acceleration signal and the roll rate signal. A method of detecting suspension irregularities in a vehicle (10) includes the generating of a lateral acceleration signal and a roll rate signal. Roll angle is determined in response to the lateral acceleration signal and roll rate signal. A roll gradient, a roll acceleration coefficient, and a roll damping parameter are determined in response to at least the roll angle. The roll gradient, the roll acceleration coefficient, and the roll damping parameter are compared to associated nominal values. A suspension irregularity is indicated in response to the comparison.

Abstract: A method and system for coordinating a vehicle stability control system with a suspension damper control sub-system includes a plurality of dampers, each of which are controlled directly by the suspension damper control sub-system. A plurality of sensors sense a plurality of vehicle parameters. A supervisory controller generates vehicle damper commands based on the plurality of vehicle parameters for each of the dampers. A damper controller in electrical communication with the supervisory controller receives the vehicle damper commands and generates sub-system damper commands based on a portion of the plurality of vehicle parameters for each of the dampers. The damper controller also determines if any of the vehicle damper commands for any one of the dampers has authority over the corresponding sub-system damper command.

Abstract: The invention relates to a wheel suspension for motor vehicles, with at least one wheel-side support member which pivotally supports one vehicle wheel and at least one axle-side support member, between which at least one intermediate element is connected, in particular an actuator for setting the track angle and/or the camber angle (?, ?) of the vehicle wheel. According to the invention the wheel-side support member and the axle-side support member are pressed into contact with one another by a pretensioning means with a pretensioning force (FV).

Abstract: A vehicle includes a semi-active suspension including suspension dampers controllably adjustable in accordance with electronic stability control commands and ride and handling commands. Vehicle steering response states, turning direction states and vehicle dynamics states are binary coded in respective state variables and suspension control calibrations are binary coded in calibration words. Integrity and security of state variables and calibration words are ensured in efficient binary digit resource allocation schemes.

Abstract: A suspension control system and a suspension control method for a vehicle control the suspension based on the condition of the road surface traveled by the vehicle in addition to information pertaining to a corner obtained from a navigation device when the vehicle approaches the corner. A microprocessor controls damping forces of suspension devices on the basis of a degree of irregularity of the road surface detected immediately preceding entry of the automobile into a turn around the corner, and corner information from the navigation device.

Abstract: A system and method for providing a vehicle roll stability indicator that dynamically estimates the probability for vehicle rollover. The system determines vehicle kinematics from various vehicle sensors. From these kinematic values, the system estimates a roll angle of the vehicle and a bank angle of the vehicle. The estimated bank angle is used to correct the roll angle. The system determines a roll energy of the vehicle and a roll energy rate of the vehicle from the corrected roll angle. The system also calculates a tire lateral load transfer of the relative forces on the vehicle tires, and the duration that any of the tires have been off of the ground. From the roll energy, the roll energy rate, the tire lateral load transfer and the wheel airborne duration, the system calculates the roll stability indicator.

Abstract: An electromagnetic transducer including a stator and an armature, the armature defining a first axis and being driven to ride between first and second couplers back and forth relative to the stator along the first axis. The second coupler is configured to permit movement of the armature along a second axis orthogonal to the first axis.

Abstract: The present invention relates to a method for measuring a vertical acceleration and a velocity of a semi-active suspension system. Particularly, the present invention provides a method for obtaining a vertical acceleration from vertical accelerations measured from three vertical acceleration sensors of a semi-active suspension system of a vehicle, comprising the steps of: receiving first to third vertical accelerations measured from first to third vertical acceleration sensors; and obtaining a fourth vertical acceleration (Ad) by multiplying the first to third vertical accelerations by correction constants and subsequently summing up them.

Abstract: Upon searching control parameter used to adjust damping force of a damper from a map in accordance with damper speed and target damping force decided based on moving condition of the vehicle, the map sets the control parameter, which are relatively higher than the actual damping force characteristics, as map data in the area where the damper speed is less than a predetermined value, the area where the noise has the great influence on the sensor outputs. Therefore, it can be prevented that the control parameter of the damping force is varied largely or varied in a short period by the influence of noise, and the driving stability control of the vehicle can be executed exactly and the noise caused by switching the damping force of the damper can be reduced.