A suspension control apparatus includes a variable damping coefficient type shock absorber disposed between sprung mass and unsprung mass of a vehicle and an actuator for setting and adjusting a damping coefficient of the variable damping coefficient type shock absorber on the basis of a control signal. An upward and downward absolute velocity detector for detecting an upward absolute velocity and a downward absolute velocity of the vehicle is provided. A control unit changes a signal from the upward and downward absolute velocity detector in accordance with a running condition of the vehicle to obtain a control target signal. A control signal generator outputs the control signal for the actuator on the basis of the control target signal from the control unit. A signal representative of the roughness of a road surface on which the vehicle is running is generated and a feature of the control unit is adjusted for changing the control signal on the basis of the signal representative of the road surface roughness.

Suspension control apparatus

An electric power steering apparatus has a steering mechanism SM having universal joints 4, 6 in a torque transmitting system, a steering toque detecting unit 14, a steering angle detecting, unit 18, a torque fluctuation detecting unit 43 for detecting a torque fluctuation due to the crossing angle α in the universal joints 4, 6 on the basis of the steering angle θ detected by the steering angle detecting unit 18 and any one of the steering torque T detected by the steering torque detecting unit, a current command value It and self-aligning torque SAT; and a current command value correcting unit 44 for correcting the current command value on the basis of the torque fluctuation detected by the torque fluctuation detecting unit 43 and the steering angle θ detected by the steering angle detecting unit 18.

Electric Power Steering Apparatus

Improved methods of controlling the stability of a vehicle are provided via the cooperative operation of vehicle stability control systems such as an Active Yaw Control system, Antilock Braking System, and Traction Control System. These methods use recognition of road surface information including the road friction coefficient (mu), wheel slippage, and yaw deviations. The methods then modify the settings of the active damping system and/or the distribution of drive torque, as necessary, to increase/reduce damping in the suspension and shift torque application at the wheels, thus preventing a significant shift of load in the vehicle and/or improving vehicle drivability and comfort. The adjustments of the active damping system or torque distribution temporarily override any characteristics that were pre-selected by the driver.

Vehicle systems control for improving stability

In a stabilizer control apparatus for a vehicle, a stabilizer includes a pair of stabilizer bars disposed between a right wheel and a left wheel of the vehicle, and an actuator having an electric motor disposed between the stabilizer bars. A turning determination device is provided for determining a turning operation of the vehicle. And, a controller is provided for controlling the electric motor in response to the result determined by the turning determination device. The electric motor is substantially prohibited from being fed with electric current, when the turning operation of the vehicle is being decreased.

Stabilizer control apparatus

A system for influencing the travel dynamics of an automobile includes at least two sensor units (S1, S2, S3) for capturing the movements of the vehicle. First evaluation units (A1) evaluate the signals of the sensor units, these first evaluation units being spatially combined with the aforementioned sensor units to a sensor module (10). Connected with the first evaluation units by linkage mans (11), second evaluation units (A21, A22, A23, A24) process the signals processed in the first evaluation units, dependent on a regulation and/or control objective, to activation signals for actuators which influence the vehicle movements.

System for influencing the travel dynamics of an automobile

A pressure control system for suspension delivers a pressure which is proportional to a current level chosen to energize a solenoid of a pressure control valve to a shock absorber of a suspension. A change in the pressure of a return path which supplies a low pressure to the pressure control valve causes the pressure which is applied to the suspension to change. In order to suppress such change, a junction of the pressure control valve with the return path has an orifice interposed therein or is connected to a low pressure accumulator. On the other hand, in the event a depression occurs in the output of the high pressure piping, a cut valve which functions to isolate the suspension from the pressure control valve may be temporarily cut off in response to a pressure fluctuation in the high pressure piping. In order to prevent this, an orifice is interposed between the high pressure piping and a pilot chamber of the cut valve.

Pressure control system for suspension

A system for controlling a steering angle of a vehicle, such as a steering angle of a rear steering wheel, the system having a yaw rate sensor for detecting a yaw rate of the vehicle, an actuator electrically controlled to change the steering angle of the vehicle, and a controller for controlling the actuator to control the steering angle on the basis of an input which includes at least a component derived from the detected yaw rate The controller includes a detector for detecting an abnormality of a value of the yaw rate detected by the yaw rate sensor, and a limiter for limiting an amount of change in the steering angle to within a predetermined tolerable range when the abnormality is detected

Vehicle steering control system wherein steering angle change is limited to within a predetermined range upon occurrence of abnormality in detected vehicle yaw rate

In a hydraulic suspension system, a plurality of actuators having working fluid chambers are provided. Each actuator is adapted to increase and decrease vehicle height as the results of the supply and the discharge of working fluid to and from its working fluid chamber, respectively. Working fluid supply passages supply working fluid at supply pressure to the working fluid chambers and working fluid discharge passages discharge working fluid from the working fluid chambers. Cut-off valves and pressure control devices are provided in the supply passages and the discharge passages. Each cut-off valve is adapted to remain in its closed position whenever the supply pressure is not more than a predetermined value. Each pressure control device is adapted to control the supply of the working fluid to and the discharge from the associated working fluid chamber to adjust the pressure within the chamber. The system further comprises devices for detecting the pressures within the working fluid chambers and a device for determining the supply pressure. The pressure control devices are controlled so that their controlling pressures may substantially be equal to the pressures within the associated working fluid chambers determined by the pressure determining devices at least until the cut-off valves are opened.

Hydraulic suspension system for a vehicle with less abrupt change in vehicle height when started

In order to prevent an inverse rolling or an unnatural rolling of a vehicle body during a turning of the vehicle on a low friction road, in an active suspension having an actuator adapted to increase or decrease vehicle height at the corresponding portion so that the rolling of the vehicle body is suppressed by a control of the actuator carried out in response to a control amount based upon an actual transverse acceleration of the vehicle body and a control amount based upon an estimated transverse acceleration deduced from a steering angle and vehicle speed, the control amount based upon the estimated transverse acceleration is reduced relative to the control amount based upon the actual transverse acceleration when a discrepancy between the estimated transverse acceleration and the actual transverse acceleration increases beyond a predetermined limit of relationship.

Active suspension with roll control by reducibly modified estimated transverse acceleration

A fluid pressure type active suspension in a vehicle such as an automobile having a four wheel steering means, including fluid pressure type actuators (1FR,1FL,1RR,1RL) each provided between a vehicle body and each wheel, working fluid supply (18) and exhaust (48) means for supplying and exhausting a working fluid to and from each actuator, vehicle height detection means (144) for detecting vehicle height of a portion of the vehicle body corresponding to each wheel relative to the wheel, and a control means for controlling the working fluid supply and exhaust means according to control parameters including a vehicle height detected by the vehicle height detection means, wherein the control means is adapted to modify the control of the working fluid supply and exhaust means in accordance with whether a front to rear wheel steering angle ratio of the four wheel steering means is in a same phase region or an opposite phase region so that the vehicle height is controlled to be higher or lower or the rolling control is suppressed less or more according to whether the front to rear wheel steering angle ratio is in the opposite phase region or in the same phase region, respectively.

Shinichi Tagawa

Papers

Pressure control system for suspension

Vehicle steering control system wherein steering angle change is limited to within a predetermined range upon occurrence of abnormality in detected vehicle yaw rate

Hydraulic suspension system for a vehicle with less abrupt change in vehicle height when started

Active suspension with roll control by reducibly modified estimated transverse acceleration

Fluid pressure type active suspension having variable performance responsive to front to rear wheel steering angle ratio