Aisin Seiki Kabushiki Kaisha

Toyota Jidosha Kabushiki Kaisha

Toshiaki Hamada

Shuuichi Buma

Toshio Aburaya

Takashi Yonekawa

Kunihito Sato

Hiroyuki Ikemoto

Hiroshi Nakashima

Masaki Kawanishi

Toshio Onuma

Tadashi Terazawa

Hirofumi Nitta

Wataru Tanaka

Kaoru Ohashi

Shinichi Tagawa

Kouichi Kokubo

Yuichiro Sakakibara

Akihiro Yanaka

Shoichi Shono

Tsukasa Watanabe

Jun Mihara

Takami Sugiyama

Masaaki Tabata

Akihito Kusano

Hiroshi Toda

Nobuyasu Suzumura

Yoshikazu Tachiiri

Masahiro Inden

Tetsuya Kuno

Toshio Oonuma

Hitoshi Terada

A vehicular parking brake apparatus includes right and left-side brakes connected to an electric motor via a cable and an equalizer, so that the operating forces of the brakes become equal. In this case, the operating forces of the right and left brakes are commonly controlled based on one of the wheels that exhibits a greater rate of slip. Therefore, it is possible to avoid a rate of slip of the right and left wheels from becoming excessively great. The electric motor is controlled taking into account a transfer delay of the cable. Therefore, the slip rates of the right and left wheels can be quickly converged to a proper state. Thus, in a case where a parking brake is operated during the running of the vehicle, the operating force of the parking brake is controlled so that the state of slip of the wheels is a proper state.

Vehicular parking brake apparatus and control method thereof

A vehicle parking brake system having an AUTO selector for selectively establishing an automatic mode and a manual mode, parking brake units, and an electronic control unit operable in the automatic mode to automatically activate the parking brake units to apply a parking brake to vehicle rear left and right wheels (RW RW ) when the vehicle is in a parked state, and to automatically de-activate the parking brake units to remove the parking brake from the vehicle wheel, and in the manual mode to selectively apply and remove the parking brake to and from the vehicle wheels according to operations of a MANUAL MODE control switch. Where the MANUAL MODE control switch is operated in the automatic mode, data indicative of the operation of the control switch is kept stored in a memory until the memory is cleared when predetermined operating state of the vehicle is detected, so that the control of the parking brake units in the automatic mode is restricted to control the parking rake units according to the operations of the MANUAL MODE control switch in the manual mode.

Vehicle parking brake system, and method of controlling the same

A vehicle brake control device includes a brake member, a wheel brake cylinder mounted on a wheel, and a master cylinder. The master cylinder generates a master cylinder hydraulic pressure in response to an operating force applied to the brake member. The brake control device also includes an automatic pressure increasing control device, a braking force control device, a coefficient of friction detecting device that detects a coefficient of friction of the road, and an automatic pressure increasing restraining device. The automatic pressure increasing control device controls automatic pressure increasing operation of the master cylinder based on the operating force applied to the brake member. The braking force control device controls the increased master cylinder hydraulic pressure supplied to the wheel brake cylinder. The automatic pressure increasing restraining device restrains automatic pressure increasing operation of the master cylinder when anti-skid control is being performed with a low coefficient of friction.

Brake control device for a vehicle

A vehicular brake control device makes it possible to detect a failure or malfunction in closing an electromagnetic valve which is placed between a master cylinder and each of wheel cylinders. The vehicular brake control device includes a pressure application device which is capable of applying a hydraulic pressure automatically, i.e., regardless of a brake pedal depression, to each of wheel cylinders by way of a hydraulic pressure control device from a master cylinder and an ECU which drives the pressure application unit and the hydraulic pressure control device to adjust a braking force of each of wheels. The hydraulic pressure control device includes a set of pressure-maintaining and pressure-reducing valves for each wheel. The ECU has a pressure application check division which begins to check the pressure application at a predetermining timing.

Vehicular brake control device

A vehicle braking control apparatus carries out a pressure apply check to determine if the automatic pressure apply is calculated normally when the vehicle is started. The apparatus includes a fluid pressure generator that generates a master cylinder pressure in response to a pedal depression force, a fluid supplying device that supplies a braking fluid pressure to the wheel cylinders from the master cylinder, and a pressure apply device that introduces the fluid pressure to the pressure chamber of the fluid pressure generator. A controller controls the braking force of each wheel by driving the fluid pressure supplying device and controls pressurization of the master cylinder pressure by automatically controlling the pressure apply device. A pressure apply check device starts a pressure apply check to determine that the automatic pressure apply is calculated normally when the master cylinder pressure is increased up to a fixed value within a fixed time after the pressure apply check is started.

Braking control apparatus for vehicles

A braking control apparatus for vehicles which is capable of generating a braking force in response to a pedal depression force to non-controlled wheels while continuing vehicle stability control. The apparatus generates a brake fluid pressure including a pedal input pressure in response to the pedal depression force and a servo pressure in response to a fluid pressure introduced from a pressure apply unit. A fluid pressure control apparatus supplies brake fluid pressure, an electric control unit controls the braking force of each wheel by driving, and a pedal input pressure estimate portion estimates the pedal input pressure. The electric control unit controls the braking force of the non-controlled wheels during vehicle stability control based on the pedal input pressure estimated by the pedal input pressure estimate portion of the electric control unit.

The present invention is directed to a vehicle braking system having a stroke simulator and a servo device, which includes a pressure generator for generating a hydraulic braking pressure, a wheel brake cylinder operatively mounted on each wheel of the vehicle, a pressure control valve device which is disposed in a passage for communicating the pressure generator with the wheel brake cylinder, to control the hydraulic braking pressure supplied to the wheel brake cylinder, and an electronic controller for controlling at least in response to an amount of operation of the brake pedal. A master cylinder is provided for communicating with the wheel brake cylinder and supplying the hydraulic braking pressure into it in response to operation of the brake pedal, when at least one of the pressure generator, the pressure control valve device and the electronic controller is abnormal. A stroke simulator is connected to the master cylinder, and arranged to allow the brake pedal to advance in response to the amount of operation of the brake pedal. And, a servo device is provided for assisting the master cylinder to operate when at least one of the pressure generator, the pressure control valve device and the electronic controller is abnormal.

Vehicle braking system with a stroke simulator and a servo device

A vehicle motion control system for a vehicle for maintaining stability of a vehicle when the vehicle is in motion includes braking device for applying a braking force to each wheel of the vehicle. The system includes a lateral acceleration sensor for sensing a lateral acceleration of the vehicle and a yaw rate sensor for sensing a yaw rate of the vehicle. A vehicle slip angular velocity is calculated on the basis of output signals of the lateral acceleration sensor and the yaw rate sensor and then a vehicle motion condition is determined on the basis of the vehicle slip angular velocity. The braking device is actuated to apply a braking force to at least one of the wheels on the basis of the vehicle motion condition and irrespective of depression of the brake pedal in order to maintain the stability of the vehicle in motion. An abnormal condition of at least one of the lateral acceleration sensor and the yaw rate sensor is determined on the basis of the vehicle slip angular velocity.

Vehicle motion control system

The present invention is directed to a vehicle motion control system for maintaining vehicle stability, even in the case where the vehicle is tilted when the vehicle is in turning motion, wherein a braking force control unit is provided for controlling a braking force applied to each of front and rear wheels of the vehicle. The system includes a tilt detection unit which detects a tilt of a normal axis of the vehicle to its vertical axis, and a turn determination unit which determines a turning condition of the vehicle including a turning direction thereof. A yaw moment control unit is provided for controlling the braking force controlling unit to produce a yaw moment in a direction opposite to the turning direction of the vehicle in response to the tilt detected by the tilt detection unit when the turn determination unit determines that the vehicle is turning.

The invention is directed to a pressure supply system which has a fluid pump, an electric motor for driving the fluid pump to supply a hydraulic pressure in proportion to a current fed to the motor, and an accumulator for accumulating the hydraulic pressure supplied from the fluid pump. The pressure supply system includes a current detection device which detects the current fed to the motor, and a malfunction detection device which detects a malfunction of the pressure supply system on the basis of the output of the current detection device. The malfunction detection device is adapted to determine that the malfunction occurs when an increasing rate of the current fed to the motor is less than a predetermined rate, preferably after a predetermined time elapsed from the time when the current initially fed to the motor. The pressure supply system may further include such a warning device as a lamp or a buzzer, which will be activated when the malfunction detection device detects the malfunction of the system.

Pressure supply system having a malfunction detection device

The invention is directed to a pressure accumulating control system for use in a pressure supply apparatus which has a fluid pump, an electric motor for driving the fluid pump to supply a hydraulic pressure, and an accumulator for accumulating the hydraulic pressure supplied from the fluid pump. The system includes a pressure detection device for detecting the hydraulic pressure accumulated in the accumulator, and a continuous control device for feeding a current to the motor continuously. The continuous control device is adapted to feed the current to the motor continuously, when the pressure detected by the pressure detection device becomes less than a predetermined lower limit, and is adapted to terminate the continuous feeding of the current to the motor, when the pressure detected by the pressure detection device exceeds a predetermined upper limit. The system further includes an intermittent control device for feeding a current to the motor intermittently by a predetermined cycle of time. The intermittent control device is adapted to terminate the continuous feeding of the current to the motor, and is adapted to feed the current to the motor intermittently, when the current is continuously fed to the motor by the continuous control device for a period longer than a predetermined time.

Pressure accumulating control system

The present invention is directed to an anti-skid control system for controlling a braking force applied to road wheels including driven wheels of an electrically operated vehicle which has an electrical motor for driving the driven wheels. A hydraulic braking pressure is supplied to each wheel brake cylinder through an actuator. The actuator is controlled by a braking force controller into which output signals of wheel speed sensors are fed. A band-pass filter is provided for passing the wheel speeds of the driven wheels having an oscillation property within a predetermined band of frequencies, out of the wheel speeds detected by the wheel speed sensors. And, a coefficient of friction of a road is estimated to be relatively low when the output of the band-pass filter is in a predetermined range of frequencies. The hydraulic braking pressure in each wheel brake cylinder is controlled by the braking force controller in accordance with the estimated coefficient of friction and in response to the wheel speeds detected by the wheel speed sensors, thereby to control the braking force applied to each road wheel.

Anti-skid control system for an electrically operated vehicle

The invention is directed to a pressure monitoring system for monitoring a hydraulic pressure which is supplied from a fluid pump and accumulated in an accumulator. The pressure monitoring system includes an electric motor which drives the fluid pump to supply the hydraulic pressure in substantially linear proportion to a current fed to the motor, a current detection device which detects the current fed to the motor, and a pressure estimation device which estimates the hydraulic pressure accumulated in the accumulator in response to the current detected by the current detection device. A malfunction detection device may be provided for detecting a malfunction on the basis of the output of the pressure estimation device.

Pressure monitoring system

In an active suspension of a vehicle suspending a vehicle body on vehicle wheels by actuators in combination with a suspension mechanism which converts cornering forces acting at the vehicle wheels during a turn of the vehicle to a vertical force exerted to the vehicle body, the suspension force to be generated by the actuators is modified based upon an active suspension calculation taking the lateral acceleration due to the turn of the vehicle into consideration, so as to compensate for the vertical force, so that the active suspension control is not undesirably exaggerated by the effect of the cornering forces.

Active suspension of vehicle having system of compensation for cornering

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.

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Okazaki, Japan

Toshiaki Hamada