Toyota Jidosha Kabushiki Kaisha

Aisin Seiki Kabushiki Kaisha

Kabushiki Kaisha Toyota Chuo Kenkyusho

Olympus Optical Company, Ltd.

Toyota Kabushiki Kaisha

Toshio Onuma

Shuuichi Buma

Kaoru Ohashi

Ken Asami

Takashi Yonekawa

Hiroyuki Ikemoto

Toshio Aburaya

Masami Itou

Kunihito Sato

Toshiaki Hamada

Tsukasa Watanabe

Katsuhiko Hattori

Osamu Komazawa

Masaaki Tabata

Hideki Ohashi

Masaki Kawanishi

Takenari Yamaguchi

Masaki Kanatani

Koutaro Okimura

Atsushi Mizuta

Satoshi Suzuki

Nobuyasu Suzumura

Shigetaka Isogai

Shinichi Tagawa

Kouichi Kokubo

Hiroshi Naito

Koichi Tomida

Masahiro Murata

Mutsumi Miyashiro

Masahiro Fukuta

Takami Sugiyama

Satoshi Naganawa

Hiroshi Kondou

Youitirou Arai

Sigetaka Isogai

Shinji Matsuda

Kinihito Sato

A height controlling apparatus for controlling at least one actual height as a relative position of (a) a body of a vehicle and (b) at least one wheel of the vehicle relative to each other, the apparatus including at least one height controlling actuator which changes the at least one actual height; and an actuator control device which controls the at least one height controlling actuator so that the at least one actual height approaches at least one target height. The actuator control device includes a possibility detecting device which detects, before an absolute value of a difference of the at least one target height and the at least one actual height exceeds a reference value, whether there is a possibility that an object may be present in a direction in which the body is moved to change the at least one actual height, and a movement restraining portion which controls, when the possibility detecting device detects that there is the possibility, the at least one height controlling actuator to restrain a movement of the body in the direction.

Height controlling apparatus

A device for controlling damping coefficients of shock absorbers (,FL,,FR,,RL,,RR) of a four wheeled vehicle constructs a phantom damping system composed of a phantom side shock absorber (,F,,R) disposed vertically at a lateral inside of a turn running of the vehicle to have a lower end movable along a ground surface together with the vehicle and an upper end vertically movable relative to the lower end with a first phantom damping coefficient (Cg, Cgf, Cgr) therebetween, and a phantom angular shock absorber (,F,,R) arranged to act between the upper end of the phantom side shock absorber and the vehicle body with a second phantom damping coefficient (Ca, Caf, Car) therebetween, whereby, when the damping coefficients of the shock absorbers are controlled to substantially equalize the phantom damping system with the actual damping system of the actual shock absorbers with respect to damping vertical and rolling movements of the vehicle body, the mass center of the vehicle body is lowered according to a rolling thereof during a turn running of the vehicle, as the vehicle body rolls around the upper end of the phantom side shock absorber located laterally inside of the turn running.

Device for controlling suspension shock absorbers of vehicles based upon phantom substitute therefor

In a hydraulic active suspension system, a plurality of actuators having working fluid chambers are provided corresponding to the vehicle wheels. Each actuator is adapted to increase and decrease vehicle height in response to the pressure within its working chamber, which is controlled by a pressure control device. Vehicle speed and vehicle heights at the locations corresponding to the vehicle wheels are detected by corresponding sensors. A control device is further provided for controlling the pressure control device so that the pressures within the working fluid chambers are driven to substantially the desired pressures, the desired pressures determined by, at least, the sum of the first control parameters corresponding to the differences between the actual vehicle heights detected and the associated desired vehicle heights and the second control parameters corresponding to the changing amounts of the vehicle height differences. The second control parameters are so set that the higher the vehicle speed is, the higher the second quantities are in magnitude, enhancing the controllability and stability of the vehicle under higher vehicle speed conditions and ensuring a greater comfortability level of the vehicle under lower vehicle speed conditions.

Hydraulic active suspension system for a vehicle performing vehicle

A suspension pressure control system applies a pressure which is proportional to a current level supplied to a solenoid of a pressure control valve to a shock absorber associated with a suspension from the valve. A height and a lateral acceleration of a car body as well as a steering angular velocity are detected. A deviation of the height from a target height is calculated. The suspension pressure is adjusted responding to the deviation and a change rate thereof. Also a correction value is calculated on the basis of the lateral acceleration for adjusting the suspension pressure responding to the correction value and a change rate thereof. Proportional coefficients for converting the change rate of the deviation and the change rate of the correction value to pressures to be corrected are corresponding to the steering angular velocity.

Pressure control system for suspension

In a hydraulic active suspension system, a plurality of actuators having working fluid chambers are provided corresponding to vehicle wheels. Each actuator is adapted to increase or decrease vehicle height in response to the hydraulic pressure within its working fluid chamber. The hydraulic pressures within the working fluid chambers are controlled to their desired pressure by associated pressure control devices. A desired pressure computing device is further provided. The computing device calculates the actual values of roll, pitch, heave and warp of a vehicle body from the vehicle heights detected by detecting devices and calculates the differences between the actual values and the associated values of roll, pitch, heave and warp determined by a desired attitude of the vehicle body to compute the desired pressures for the actuators. The degrees of the roll and/or pitch differences are set to be higher than that of the warp difference in contributing to the determination of the desired pressures.

Hydraulic active suspension system for a vehicle capable of enhancing

In a hydraulic active suspension system, a plurality of actuators having working fluid chambers are provided corresponding to vehicle wheels. Each actuator is adapted to increase and decrease vehicle height in response to the pressure within its working chamber, which is controlled by a pressure control device. Vehicle speed and lateral acceleration are detected by corresponding sensors. A control device is further provided for controlling the pressure control device by compensating values determined base upon the lateral acceleration detected. The control device is adapted to reduce the compensating values in magnitude when the vehicle speed is lower than a predetermined value under which the lateral acceleration sensor sometimes detects a false lateral acceleration, thereby reducing the possibility that the vehicle body may generate an unpleasant roll due to the erroneous control on the pressures within the working fluid chambers based upon a false lateral acceleration.

Hydraulic active suspension system for a vehicle for controlling the

A pressure vibration damping device in a liquid supply passage for supplying a liquid from a pump to a hydraulic device such as a fluid pressure type suspension of a vehicle, including a pressure pulse absorbing means adapted to be able to accept and return a small amount of the liquid from and to said liquid supply passage so as to absorb momentary changes in the flow rate of the liquid in the liquid supply passage, and a liquid column vibration damping means adapted to be able to apply a substantial flow resistance principally to a high velocity flow of the liquid in the liquid supply passage at a part thereof between the pump and the pressure pulse absorbing means, the high flow velocity being due to pulse flows of the liquid induced by a resonance of pulsating output of the pump and the pressure pulse absorbing means and substantially higher than a mean flow velocity of the liquid corresponding to a normal rate of supply of the liquid through the liquid supply passage.

Pressure vibration damping device in combination of liquid column

In a hydraulic active suspension system, a plurality of actuators having working fluid chambers are provided corresponding to vehicle wheels. 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. Supplying and discharging devices supply working fluid to and discharge from the working fluid chamber. Vehicle height sensors detect the vehicle heights at the locations corresponding to the vehicle wheels. A control device is further provided. The control device controls the supplying and discharging devices so that the pressure within the working fluid chamber in each actuator may be a value corresponding to the sum of a basic pressure determined according to the running conditions of the vehicle and a compensating pressure determined based upon the integral value of the difference between a standard vehicle height and an actual vehicle height. When the integral value of the difference is larger in magnitude than a predeterminate value, it is reduced in magnitude by the control device so as to prevent the control with the compensating pressure from overriding the control with the basic pressure.

Hydraulic active suspension system for a vehicle capable of positively

A pressure control valve delivers a pressure which is proportional to a current level chosen to energize a solenoid therein to a shock absorber of a suspension. A spool in the valve has an annular groove for communicating an output port to a high pressure port or a low pressure port selectively. There are conical surfaces or inclined surfaces at edges of lands adjacent to the groove, which incline from annular surfaces of the lands toward the bottom of the groove. The inclined surfaces slow down a change of the flow rate from the high pressure port to the output port and from the output port to the low pressure port when the annular groove communicates with the high pressure port and the low pressure port respectively.

Pressure control valve device

A suspension pressure control system applies a pressure which is proportional to a current level supplied to a solenoid of a pressure control valve to a shock absorber associated with a suspension from the valve. When a pressure in a high pressure line which feeds a high pressure to the pressure control valve falls (rises), the pressure applied to the suspension is decreased (increased). Accordingly, the pressure in the high pressure line is detected by a sensor, and if it is low (high), the current level of the pressure control valve is corrected to a high value (low value). In order to prevent an abnormal pressure rise in the suspension which may be caused by an excessive pressure rise in the high pressure line during an idling operation of an engine, a correction which responds to the pressure of the high pressure line is chosen large when a vehicle speed is equal to zero or very low. In order to prevent an abnormality from occurring in the correction of the pressure which is attributable to an errorneous detected value during a failure of operation of sensor, such detected value is determined to be faulty, and in the event a fault occurred, the correction is modified to a given volume (0) which is allocated to a standard pressure in the high pressure line.

In a system for controlling the US-OS characteristic of a vehicle having front and rear suspensions, a device for changing the US-OS characteristic is provided which is adapted to alter the roll stiffness distribution between the front and the rear suspensions. A turning state quantity is detected and the changing rate of a turning state quantity is determined. A control device is further provided which is adapted to respond to the turning state quantity and the changing rate of the turning state quantity, and to control the US-OS characteristic changing device so that the higher the changing rate of the turning state quantity is, the more the US-OS characteristic may be shifted toward higher over-steer, and for the same changing rate the higher the turning state quantity is, the more the US-OS characteristic may be shifted toward higher under-steer.

US-OS characteristic control system for a vehicle responding to turning

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 into and from its working fluid chamber, respectively. A plurality of accumulators are connected with associated working fluid chambers. Working fluid supply passages supply working fluid into the working fluid chambers and working fluid discharge passages discharge working fluid from the working fluid chambers. Pressure control devices are provided in the supply passages and the discharge passages. Each pressure control device means is adapted to control the supply of the working fluid into and the discharge from the associated working fluid chamber to adjust the pressure within the chamber. The suspension system further comprises flow resistance control devices. Each flow resistance control devices is adapted to adjust at least one of the first flow resistance between the associated working fluid chamber and the associated accumulator and the second flow resistance of the associated discharge passage in response to the flow rate of the working fluid discharging through the discharge passage so that the higher the discharging flow rate is, the higher the ratio of the second to the first flow resistances may be, not only to reduce the flow rate of the working fluid discharging from the working fluid chamber through the discharge passage but also to increase the flow rate of the working fluid flowing into the accumulator from the working fluid chamber.

Hydraulic suspension system for a vehicle

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.

Provided is a suspension controller which has a plurality of control sections in a control mechanism and which has the order of priority among the suspension controls when two or more different suspension controls are simultaneously instructed from the control sections, so as to optimally control the suspension characteristic according to both the road condition and the running condition of the vehicle. The suspension controller of the invention includes a preference mechanism or logic for preferentially altering the suspension characteristic to a harder state in order to reduce the vibration of the vehicle body and to prevent an abrupt change of the vehicle attitude, thus providing good control, high stability and riding comfort.

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Susono, Japan

Toshio Onuma