It is an object of the present invention to improve accuracy in estimation of a state of a vehicle in order to achieve excellent ride comfort. An ECU (600) includes a reference vehicle model computation section (1100), which is configured to calculate a reference output by carrying out computation with respect to at least one of a plurality of state amounts in a planar direction and at least one of a plurality of state amounts in an up-down direction in an inseparable manner.

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.

Methods are provided for controlling various systems in a vehicle based on input signals from at least one physical sensor and at least one model of a vehicle or a portion of the vehicle. The controller a rely preferentially on one or the other inputs based on the frequency of a motion of the vehicle and the state of the vehicle or one or mor portions of the vehicle.

A method for controlling the damping characteristic of a shock absorber of a vehicle, particularly for compensating the variation of the operating temperature of the shock absorber, in an active or semi-active suspension system. The compensation of the variation of the operating temperature of the shock absorber takes place by: estimating a mechanical power dissipated in heat by the shock absorber; estimating a thermal power exchanged by the shock absorber with the environment; evaluating the current operating temperature of the shock absorber as a function of the dissipated mechanical power and of the thermal power exchanged with the environment; and controlling the driving current of the control valve of the shock absorber according to a shock absorber reference model indicating a relationship between the damping force of the shock absorber, the operating temperature of the shock absorber and the driving current of the control valve.

An electrically powered suspension system includes: an electromagnetic actuator; an information acquisition unit configured to acquire time-series information related to stroke position of the electromagnetic actuator, information on stroke velocity, and an amount of change in stroke of the electromagnetic actuator and information on a stroke direction based on the time-series information; a damping force calculation unit configured to calculate target damping force based on the information on the stroke velocity; and a drive control unit configured to control driving of the electromagnetic actuator using target driving force obtained based on the target damping force. The damping force calculation unit calculates equivalent friction compensation force based on the amount of change in the stroke and the information on the stroke direction, and corrects the target damping force based on the calculated equivalent friction compensation force. The equivalent friction compensation force has elastic force component and dynamic friction force component.

An object of the present invention is to provide a vehicle motion state estimation device and method that can estimate the vertical motion state amount with high accuracy by taking into consideration vertical force in which the frictional force acting in the front-rear direction or lateral direction of the wheel acts on the vehicle body due to the geometry of suspension. A vehicle motion state estimation device in a vehicle in which a wheel and a vehicle body are coupled via a suspension, the vehicle motion state estimation device including: a vertical motion-caused wheel speed component estimation unit that estimates a wheel speed component caused by vertical motion of the vehicle; a vertical force estimation unit that calculates vertical force in which frictional force of the wheel caused by motion of the vehicle acts on the vehicle body by geometry of the suspension; and a vertical motion estimation unit that estimates a state amount of vertical motion of a vehicle, in which the vertical motion estimation unit estimates a state amount of vertical motion of the vehicle based on a wheel speed component from the vertical motion-caused wheel speed component estimation unit and vertical force acting on the vehicle body from the vertical force estimation unit.

Disclosed in the present invention are an inertial regulation method of active suspensions based on terrain ahead of a vehicle and a control system thereof. According to the scanned terrain ahead of the vehicle, a center of mass trajectory and attitude history are calculated when the vehicle passes through the terrain ahead of the vehicle with passive suspensions. After smoothing the trajectory, the active suspension is controlled to make the vehicle drives according to the smoothed trajectory. During this period, a smoothness coefficient is adjusted to make each suspension stroke be limited within a limit stroke, and according to the supporting force and stroke of each active suspension calculated from a dynamics model, the impedance control based on force-displacement is carried out on an actuator of the suspension. The present invention can significantly improve the driving comfort and handling stability of the vehicle driving on an uneven road surface.

An object of the present invention is to provide a vehicle motion state estimation device and method that can estimate the vertical motion state amount with high accuracy by taking into consideration vertical force in which the frictional force acting in the front-rear direction or lateral direction of the wheel acts on the vehicle body due to the geometry of suspension. A vehicle motion state estimation device in a vehicle in which a wheel and a vehicle body are coupled via a suspension, the vehicle motion state estimation device including: a vertical motion-caused wheel speed component estimation unit that estimates a wheel speed component caused by vertical motion of the vehicle; a vertical force estimation unit that calculates vertical force in which frictional force of the wheel caused by motion of the vehicle acts on the vehicle body by geometry of the suspension; and a vertical motion estimation unit that estimates a state amount of vertical motion of a vehicle, in which the vertical motion estimation unit estimates a state amount of vertical motion of the vehicle based on a wheel speed component from the vertical motion-caused wheel speed component estimation unit and vertical force acting on the vehicle body from the vertical force estimation unit.

Disclosed in the present invention are an inertial regulation method of active suspensions based on terrain ahead of a vehicle and a control system thereof. According to the scanned terrain ahead of the vehicle, a center of mass trajectory and attitude history are calculated when the vehicle passes through the terrain ahead of the vehicle with passive suspensions. After smoothing the trajectory, the active suspension is controlled to make the vehicle drives according to the smoothed trajectory. During this period, a smoothness coefficient is adjusted to make each suspension stroke be limited within a limit stroke, and according to the supporting force and stroke of each active suspension calculated from a dynamics model, the impedance control based on force-displacement is carried out on an actuator of the suspension. The present invention can significantly improve the driving comfort and handling stability of the vehicle driving on an uneven road surface.

An electrically powered suspension system includes: an electromagnetic actuator; an information acquisition unit configured to acquire time-series information related to stroke position of the electromagnetic actuator, information on stroke velocity, and an amount of change in stroke of the electromagnetic actuator and information on a stroke direction based on the time-series information; a damping force calculation unit configured to calculate target damping force based on the information on the stroke velocity; and a drive control unit configured to control driving of the electromagnetic actuator using target driving force obtained based on the target damping force. The damping force calculation unit calculates equivalent friction compensation force based on the amount of change in the stroke and the information on the stroke direction, and corrects the target damping force based on the calculated equivalent friction compensation force. The equivalent friction compensation force has elastic force component and dynamic friction force component.