Abstract:
A reduced control system suitable for control of an active suspension system as a controlled plant is described. The reduced control system is configured to use a reduced sensor set for controlling the suspension without significant loss of control quality (accuracy) as compared to an optimal control system with an optimum sensor set. The control system calculates the information content provided by the reduced sensor set as compared to the information content provided by the optimum set. The control system also calculates the difference between the entropy production rate of the plant and the entropy production rate of the controller. A genetic optimizer is used to tune a fuzzy neural network in the reduced controller. A fitness function for the genetic optimizer provides optimum control accuracy in the reduced control system by minimizing the difference in entropy production while maximizing the sensor information content.
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:
The method and apparatus of the present invention provide constant force suspension and near constant force Suspension and associated control algorithms, all of which may be utilized in vehicle suspension systems. By using the apparatus of the present invention, a vehicle may be isolated from the motion of a wheel as it follows rough terrain, thereby improving ride quality.
Abstract:
A damping coefficient control apparatus for a damper device in a suspension mechanism disposed between a sprung mass and an unsprung mass of a wheeled vehicle, wherein an absolute vertical movement velocity of the sprung mass is detected in an absolute space to adjust a damping coefficient of the damper device to a predetermined small value when vertical vibration of the sprung mass tends to be increased and to increase the damping coefficient of the damper device more than the predetermined small value in accordance with an increase of the absolute vertical movement velocity when vertical vibration of the sprung mass tends to be dampened, and wherein the magnitude of vertical vibration of the sprung mass is further detected to adjust a lower limit value of the damping coefficient of the damper device to a larger value than the predetermined small value when the magnitude of vertical vibration of the sprung mass increases.
Abstract:
A suspension control system for an automotive vehicle is disclosed in which a band pass filter is provided which passes only a frequency component of either of a vertical sprung mass acceleration signal derived from a vertical G sensor or a vertical sprung mass speed signal derived from an integrator which integrates the vertical sprung mass acceleration signal, both vertical acceleration sprung mass speed signal and vertical sprung mass speed signal falling in a predetermined frequency range (e.g., 0.5 Hz through 3.0 Hz). A control unit outputs a control signal to an actuator so to vary the position of an adjuster of each or any one of shock absorbers, thus a damping coefficient being set to a target damping coefficient position according to the vertical sprung mass speed.
Abstract:
A system for controlling damping force characteristics for respective shock absorbers of a vehicle in which each shock absorber is installed between sprung mass and unsprung mass at each tire wheel position, a front tire wheel side sprung mass vertical velocity and a front tire wheel side relative velocity between the sprung mass and unsprung mass are determined, the damping force characteristics of the shock absorbers located at the front tire wheels side are basically controlled on the basis of the control signal determined on the basis of the front tire wheel side sprung mass vertical velocity, and the damping force characteristics of the shock absorbers located at the rear tire wheels side are, on the other hand, controlled on the basis of the control signal determined on the basis of a front tire wheel side road surface input velocity determined on the basis of the front tire wheel side sprung mass vertical velocity and the front tire wheel side relative velocity determined from a front tire wheel side relative displacement and a rear tire wheel side vertical velocity determined from the rear tire wheel side relative velocity.
Abstract:
A system is for controlling a suspension performance detecting the road surface condition in front of an automotive vehicle. A road surface sensor generates an output corresponding to the size of roughness on a road surface located at a predetermined distance in front of the vehicle. A suspension damping coefficient is changed to a smaller value upon lapse of a delay time. The delay time is calculated on the basis of the output of a speed sensor, the delay time being the time required for the wheel to reach the detected rough roads surface. The changing of the suspension damping coefficient occurs on condition that the output of the road surface sensor falls within a control region defined by a lower threshold value and an upper threshold value. Accordingly, the change of the suspension damping coefficient to a smaller value is inhibited when an extremely rough road surface is detected in front of the vehicle, whereby a bottoming out of the suspension which may occur is prevented when the vehicle runs over the extremely rough road surface. Further, the ride feeling is improved when the vehicle runs over a moderately rough road surface.
Abstract:
A system for chassis control, specifically of passenger cars and trucks, where the control parameters of the controlled loop are varied for control of the chassis properties in contingence on the state of travel of the vehicle as determined by sensors. Specifically determined for recognition of the state of travel are parameters representing the vertical-dynamic state of movement of the vehicle and/or the individual driving style of the operator. This procedure is based upon the relative movements between the vehicle body and at least one wheel, captured by sensors.
Abstract:
A vehicle suspension device includes a shock absorber disposed between a sprung portion and an unsprung portion of a vehicle for each of the vehicle wheels, a damping force changing device for changing a damping characteristic of the shock absorber, a detecting device for detecting a difference in a damping force among the shock absorbers for respective wheels, and a control device for controlling the damping characteristic of the shock absorber so as to restrict the difference in the damping force among the wheels when the vehicle is in a specific running condition. Through the use of such a vehicle suspension device, diagonal vibration can be suppressed, improved running stability can be obtained and riding comfort can be improved.
Abstract:
An automotive activity control system controls vehicular driving activity, such as power distribution for delivering driving torque generated by prime mover of the vehicle to primary and secondary driving wheels, vehicular braking operation for preventing the road wheels from causing skidding during braking operation, vehicular attitude. The control system includes acceleration sensor, such as a longitudinal acceleration sensor, a lateral acceleration sensor, a vertical acceleration sensor for monitoring a vehicular driving behavior and providing control parameter for activity control. The control system detects faulty condition of the acceleration sensor for taking place fail-safe operation. Particularly, the control system detects faulty condition of the acceleration sensor to generate sensor signal representative of abnormal or impossible acceleration resulting in malfunction of activity control.