Toyota Jidosha Kabushiki Kaisha

Toyota Central Research and Development Laboratories, Inc.

Nobutaka Oowa

Shunichi Doi

Hiroyuki Ikemoto

Yasutaka Hayashi

Osamu Yasuike

Yasuji Arai

In this vehicle height adjustment system, a plurality of actuator assemblies are provided, one corresponding to each one of the vehicle wheels and resiliently suspending it from the vehicle body. These actuator assemblies have pressure chambers, and each is adapted to increase or decrease the vehicle height at a location corresponding to its corresponding wheel as respective results of supplying or discharging of working fluid to or from its pressure chamber. Working fluid supply/discharge means are provided corresponding to the actuator assemblies and supply and discharge working fluid to and from their pressure chambers. Wheel loading detection means are provided for sensing parameters representative of the loadings imposed by the vehicle body on the wheels, and vehicle height detection means are provided for sensing the heights of the vehicle above the wheels. A means for computing and control controls the working fluid supply/discharge means, based on the deviations of the actual wheel heights from standard wheel heights, and carries out control adjustment of the actual wheel heights to the standard wheel heights by, at least when the vehicle speed is below a determinate value, carrying out a correction to the adjustment control of the working fluid supply/discharge means, based upon the deviations of the actual wheel loadings from standard wheel loadings, by an amount appropriate substantially to eliminate the loading deviations.

System for vehicle height adjustment with loading deviation correction

In this vehicle height adjustment system, a plurality of actuator assemblies are provided, one corresponding to each one of the vehicle wheels and resiliently suspending it from the vehicle body. These actuator assemblies have pressure chambers, and each is adapted to increase or decrease the vehicle height at a location corresponding to its corresponding wheel as respective results of supplying or discharging of working fluid to or from its pressure chamber. Working fluid supply/discharge means are provided corresponding to the actuator assemblies and supply and discharge working fluid to and from their pressure chambers. Vehicle height detection means are provided for sensing the heights of the vehicle above the wheels. A means detects the rate of change of the steering angle of the vehicle. And a means for computing and control controls the working fluid supply/discharge means, based on the deviations of the actual wheel heights from standard wheel heights, and carries out control adjustment of the actual wheel heights to the standard wheel heights, by performing a prediction calculation of the fluctuations in wheel heights caused by vehicle rolling from the rate of change of steering angle as detected by the means for detecting the rate of change of steering angle and from the vehicle speed as detected by the vehicle speed detecting means, and by carrying out a correction to the adjustment control of the working fluid supplying and discharging means, based upon the calculation result, by an amount appropriate substantially to eliminate the wheel height fluctuations.

System for vehicle height adjustment with steering angle change rate

In this system for vehicle roll control, a plurality of duty radio controlled actuator assemblies are provided, one corresponding to each one of the vehicle wheels, and resiliently suspended from the vehicle body. These actuator assemblies have pressure chambers, and each is adapted to increase or decrease the vehicle height at a location corresponding to its corresponding vehicle wheel as a result of the supplying or discharging of working fluid to or from its pressure chamber. Working fluid supplying and discharging means supply working fluid to and discharge working fluid from the pressure chambers of the actuator assemblies. The system further includes means for sensing the road speed of the vehicle, and means for sensing the steering angle of the vehicle. Vehicle height detection means are also provided for sensing the heights of the vehicle above the vehicle wheels. A means for computing and control calculates the deviations of the actual detected vehicle body heights from standard vehicle body heights; when a certain condition is satisfied, it controls the working fluid supplying and discharging means according to a first duty ratio according to the deviations of the actual vehicle body heights, so as to maintain the deviations of the actual vehicle body heights within predetermined ranges; and then it controls the working fluid supplying and discharging means in the reverse order according to a second duty ratio.

System for vehicle body roll control with overshoot prevention

In this roll control system, suspension means are provided for resiliently suspending the vehicle wheels with variable hardness/softness characteristics, each suspension means including an actuator with a pressure chamber which increases or decreases wheel suspension height according to the supply or discharge of working fluid. Working fluid supply/discharge means are provided for the actuators, to supply and discharge working fluid to and from actuator pressure chambers. The road speed, the steering angle, and the actual body roll angle are detected. Means for computing and control computes a steady state vehicle body roll angle .phi..sub..infin. from the vehicle speed and steering angle, advances the phase of a signal indicative of .phi..sub..infin. to compute a compensating roll angle value .PHI..sub..infin., and then computes a difference value .phi. based upon a desired roll angle .phi..sub.a, .PHI..sub..infin., and the actual roll angle .phi..sub.t, according to the equation:

System for vehicle body roll control performing suspension hardness

In this system for vehicle roll control, a suspension device or an actuator is provided corresponding to each wheel of a vehicle, and resiliently suspends it from the vehicle body. Each such suspension device can alter its hardness or softness characteristics according to a control signal, while similarly the actuators are adapted to alter the suspended height of their wheels. A vehicle speed detecting device senses road speed, a steering angle detecting device senses steering angle, and a device detects the total vehicle body weight. A computing control device computes a predictive roll angle of the vehicle body from road speed and steering angle, and: if suspension devices are provided, controls them to be relatively hard when the absolute value of the predictive roll angle is larger than a threshold value, while controlling them to be relatively soft when the absolute value of the predictive roll angle is less than this threshold value; while, if actuators are provided, when the absolute value of the predictive roll angle is larger than a threshold value, it controls them in accordance with this predictive roll angle. Particularly, this computing device varies the threshold roll angle value according to the total vehicle body weight as detected by the weight detector, so as to decrease the threshold roll angle value along with increase of the total vehicle body weight.

System for vehicle body roll control detecting and compensating for

In this system for vehicle roll control, a plurality of actuator assemblies are provided, one corresponding to each one of the vehicle wheels and resiliently suspending it from the vehicle body. These actuator assemblies have pressure chambers, and each is adapted to increase or decrease the vehicle height at a location corresponding to its corresponding vehicle wheel as respective results of supplying or discharging of working fluid to or from its pressure chamber. A plurality of working fluid supplying and discharging valves are provided corresponding to the actuator assemblies and serve to supply working fluid to the working fluid chambers and to discharge working fluid from the working fluid chambers. A vehicle speed detector senses the road speed of the vehicle, and a steering angle detector senses the steering angle of the vehicle. A control computer computes a steady state roll angle .phi..sub..infin. of the vehicle body from the vehicle speed sensed by the vehicle speed detector and the steering angle sensed by the steering angle detector, and computes a difference value .phi. based thereon, the control computer being adapted to control the working fluid supplying and discharging valves according to the difference value .phi. when the absolute value of the difference value .phi. is larger than a determinate value.

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Toyota, Japan

Nobutaka Oowa