Toyota Jidosha Kabushiki Kaisha

Aisin Seiki Kabushiki Kaisha

Nippon Soken, Inc.

Nippondenso Co., Ltd.

Aisin Seiki K.k.

Toyota Jidosha Kogyo Kabushiki Kaisha

Advics Co., Ltd.

Toyota Jidosha K.k.

Toyoto Jidosha Kabushiki Kaisha

Tatsuo Sugitani

Hiroyuki Ichikawa

Nobuyasu Nakanishi

Kazutaka Kuwana

Kiyoyuki Uchida

Tsuyoshi Yoshida

Kazunori Sakai

Hideo Inoue

Masaru Kamikado

Kuniaki Okamoto

Kenji Ito

Takashi Kondo

Naoto Kushi

Takaharu Idogaki

Shinsuke Sakane

Ikuo Hayashi

Yoshinori Kadowaki

Toshihisa Ishihara

Hiroaki Tanaka

Kenji Tozu

Shigeyuki Akita

Satoshi Ishida

Ken Asami

Takeshi Goto

Kazuya Maki

Akira Sakai

Kouichi Yamanoue

Masahiro Matsuura

Masaaki Uechi

Hiroshi Ueno

Hiromi Tanaka

Ryuichi Kurosawa

Masashi Kishimoto

Syouichi Masaki

Shouichi Masaki

Toshiyuki Mikida

Hiromi Maehata

Masashi Ohta

Kouji Yotsuya

Hirohide Iwase

Yukio Maeda

Koyoyuki Uchida

A master cylinder device including: a housing whose front side is closed and which has a separation wall for separating the inside of the housing into a front side chamber and a rear side chamber; a pressurizing piston disposed in the front side chamber so as to define a pressurizing chamber for pressurizing the brake fluid and an input chamber into which a brake fluid from a high pressure source is introduced; an input piston disposed in the rear side chamber and moving forward by an operation force; and a transmission rod which is through the separation wall, whose proximal end portion is fixed in one of the pressurizing and input pistons, and whose distal end portion is apart from the other of the pressurizing and input pistons in a state of no forward movement.

Master cylinder device

In a vehicle steering apparatus, front wheels are controlled to be turned by a computer program processing. A displacement/torque conversion sectionconverts a steering angle &#x3b8; into a steering torque Td that is in relation of exponential function. A torque/lateral-acceleration conversion section, torque/yaw-rate conversion sectionand torque/curvature conversion sectionconvert into an anticipated lateral acceleration Gd, anticipated yaw rate &#x3b3;d and anticipated turning curvature &#x3c1;d based upon the steering torque Td. Turning angle conversion sectionsandcalculate target turning angles &#x3b4;g, &#x3b4;&#x3b3; and &#x3b4;&#x3c1;. A turning angle deciding sectiondecides a target turning angle &#x3b4;d among the target turning angles &#x3b4;g, &#x3b4;&#x3b3; and &#x3b4;&#x3c1; according to the detected vehicle speed V. A turning control sectioncontrols the steered wheels to be turned into the target turning angle &#x3b4;d. Herewith, the vehicle steering apparatus of the present invention can turn the vehicle so as to be adapted to a man's perception characteristic in all speed areas with respect to an operation on a steering handle by a driver. Therefore, the driver can easily drive the vehicle in all speed areas.

Vehicle steering apparatus

A braking force control device and method performs brake assist control. A timer CT begins to count the elapsed time, for example, from when the elevation gradient &Dgr;P,of a master cylinder pressure P,becomes equal to or greater than a first threshold value TH,. It is determined that an emergency brake operation is executed, when the master cylinder pressure P,becomes equal to or greater than a second threshold value TH,before a predetermined time has passed, and then the brake assist control starts.

Braking force control device and braking force control method

A braking system for braking a motor vehicle by the front and rear brakes of the vehicle's front and rear wheels, respectively, including a distribution control device for controlling a distribution of front and rear wheel braking force produced by the respective front and rear brakes, according to a selected one of a first and a second distribution pattern, each of which represents the front and rear wheel braking forces in relation to each other wherein the rear wheel braking force defined by the second distribution pattern is larger than that defined by the first distribution pattern at least when the front and rear wheel braking forces are smaller than respective predetermined values. The selection of the two distribution patterns may be dependent on vehicle load.

Vehicle braking system adapted to optimize distribution of braking forces

Vehicle braking system distribution of front and rear braking forces is

A vehicle anti-lock braking system having X-crossed two pressure application sub-systems connected to respective independent chambers of a master cylinder, each sub-system including a normally-open first shut-off valve in a front brake cylinder passage between the master cylinder and a front wheel brake cylinder, a series connection of a normally-open second shut-off valve and a proportioning valve disposed in a portion of a rear brake cylinder passage connected to the front brake cylinder passage and a rear wheel brake cylinder, a normally-closed third shut-off valve in a reservoir passage connected to the rear brake cylinder passage and a reservoir, a pump in a pump passage which is connected at one end to the reservoir and the other end to a portion of the rear brake cylinder passage between the proportioning valve and the rear wheel brake cylinder, and a controller for controlling the three shut-off valves.

Vehicle anti-lock braking system wherein output end of pump passage is

An anti-skid apparatus for installation in a vehicle braking system includes an electrically operated actuator arranged to control hydraulic brake pressure applied to each wheel brake cylinder of road wheels of the vehicle and an electronic control device for applying an electric control signal to the actuator in response to electric signals indicative of each rotational speed of the road wheels so that the actuator is operated to decrease or increase the brake pressure when the rotational speed of the road wheels in braking operation becomes lower than a reference speed the value of which is defined on a basis of a travel, speed of the vehicle. The electronic control device is designed to detect a step on a travel road of the vehicle in braking operation and to compare the rotational speed of the road wheels with a subtracted value of the reference speed when the step on the travel road has been detected within a predetermined time thereby to maintain the actuator in its deactivated condition when the rotational speed of the road wheels is larger than the subtracted value of the reference speed.

Anti-skid apparatus for automotive vehicle

The anti-skid control system is capable of performing highly reliable anti-skid control through its accurate estimation of the vehicle speed and proper compensatory control even when sharp braking occurs or in the brake fluid pressure control on road surfaces with a low coefficient of friction likely to cause considerable fluctuations in wheel acceleration. The anti-skid control system is provided with a fluid pressure generating device, a fluid pressure controlling device, a wheel velocity detecting device, a standard speed setting device, a fluid pressure controlling mode setting device which sets either the pressure decrease mode or the pressure hold mode when the wheel velocity declines to a level lower than the standard speed and sets the pressure increase mode when the wheel velocity is equal to or higher than the standard speed. A maximum inflection point detecting device detects the maximum inflection point indicating the maximum value for the shift of the wheel velocity mentioned above from an increase to a decrease when the wheel velocity is not any lower than the standard speed. A fluid pressure controlling mode correcting device switches from the pressure increase mode mentioned above to either the pressure hold mode or the pressure decrease mode when the wheel velocity becomes equal to or higher than the standard speed and also becomes equal to or higher than the wheel velocity at the maximum inflection point.

Anti-skid control system

An anti-skid control system for use in a motor vehicle which controls a braking pressure for a wheel of the motor vehicle to keep a slip of the wheel to an appropriate state by alternately performing a pressure-increasing operation and a pressure-maintaining operation in accordance with a slipping state of the wheel. The system first detects a slipping state of the wheel before performing the pressure-increasing operation on the basis of a vehicle speed and a wheel speed and then detects a slipping state of the wheel when a predetermined time period is elapsed from the pressure-increasing operation in a state that the braking pressure is maintained after the completion of the pressure-increasing operation so as to calculate a variation of the slipping state of the wheel on the basis of the detection results. Further, the system adjusts the ratio of a time period for the pressure-increasing operation to a time period for the pressure-maintaining operation so that the ratio becomes smaller as the variation of the slipping state becomes greater. This arrangement allows the wheel slipping state to be accurately detected without including errors due to the braking pressure increasing operation, thereby quickly increasing the braking pressure to an appropriate value.

Anti-skid control system for motor vehicle

The anti-skid control system is constructed with a brake fluid pressure source for generating brake fluid pressure at high and low levers, a switching valve feeding either high pressure or low pressure to the wheel cylinders, a wheel velocity detecting device sensing the driving wheel rotating speed, an acceleration detecting device detecting the vehicle acceleration and a first arithmetic operation device for finding the estimated vehicle speed and the wheel rotating acceleration based on the wheel velocity detected by the wheel velocity detecting device and the vehicle body acceleration detected by the acceleration detecting device. A brake fluid pressure controlling device is provided for increasing, decreasing or maintaining the brake fluid pressure in the wheel cylinders, controlling the switching valve on the basis of wheel velocity, estimated vehicle speed, and wheel rotating acceleration. A second arithmetic operation device marks the minimum and maximum values in the wheel velocity after a brake fluid pressure reduction based on the wheel velocity detected by the wheel velocity detecting device calculates the recovery acceleration in the wheel velocity in the shift from the minimum value to the maximum value and compares the recovery acceleration with the set value. A vehicle acceleration correcting device corrects the vehicle body acceleration detected by the acceleration detecting device so as to set the vehicle body acceleration at a smaller value in case the recovery acceleration is less than the set value.

Anti-skid brake control system based on acceleration detection

An anti-skid control system for an automotive vehicle is provided with an actuator which is disposed in a hydraulic circuit between a pressure generator and a wheel brake cylinder. The actuator is arranged to control the hydraulic braking pressure applied to the wheel brake cylinder. In response to a wheel speed detected by a wheel speed detector, it is determined in an electronic control unit whether a condition for decreasing the braking pressure is effected. When this condition is effected, the decrease mode is provided in the control unit. When a predetermined period of time lapses after the decrease mode is initiated, the decrease mode is turned to a pressure control mode for applying the braking pressure to prevent the road wheel from being locked. When the condition is not effected during the predetermined period of time after the decrease mode is initiated, the decrease mode is turned to a direct supply mode for directly communicating the pressure generator with the wheel brake cylinder. Consequently, the lack of braking force caused by the delay of timing for decreasing the hydraulic braking pressure due to an erroneous detection of a locking condition of the road wheel on a rough road is effectively prevented.

Anti-skid control system for an automotive vehicle

The anti-skid control system is provided with wheel velocity sensors only for the driving wheels and yet is capable of performing the anti-skid control through its accurate estimation of the vehicle speed and proper compensatory control even when sharp braking occurs immediately upon the release of the accelerator after the occurrence of acceleration slip. The anti-skid control system is capable of starting the anti-skid control with certainty even when the braking operation is not detected because of a failure in the operation of the brake switch. The system is provided with a fluid pressure generating device, a fluid pressure controlling device, a brake operation detecting device, an acceleration detecting device, a wheel velocity detecting device, a braking force controlling device, a brake force correcting device and an acceleration slip detecting device.

The invention is directed to an arrangement for monitoring a road condition which determines the coefficient of friction of the road surface on the basis of a signal corresponding to an acceleration of a vehicle detected by an acceleration sensor. The signal is converted into one of at least two predetermined values by conversion means in response to a magnitude of the acceleration every cycle of a predetermined time period. The converted value is summed up by summing means by a predetermined number of consecutive cycles to provide a total value in the last cycle thereof which is stored in memory means. Then, in determination means, one of at least two standard values is selected in response to the condition of increase or decrease of the total value in the present cycle provided by the summing means as compared with the total value in the previous cycle stored in the memory means. And, the total value in the present cycle is compared with the above one of at least two standard values to produce a road condition signal corresponding to a result of comparison which represents the coefficient of friction of the road surface. The present system is applicable to an anti-skid control system for an automotive vehicle.

Road condition monitoring system

The anti-skid control system is provided with wheel velocity sensors only for the driving wheels and is capable of performing the anti-skid control through its accurate estimation of the vehicle speed and proper compensatory control even when sharp braking occurs immediately upon the release of the accelerator after the occurrence of acceleration slip. The anti-skid control system is capable of starting the anti-skid control with certainty even when the braking operation is not detected because of a failure in the operation of the brake switch. The system is provided with a fluid pressure generating device, a fluid pressure controlling device, a brake operation detecting device, an acceleration detecting device, a wheel velocity detecting device, a braking force controlling device, a first estimated vehicle speed setting device and a second estimated vehicle speed setting device.

Sensors detect rotational speeds of respective vehicle wheels. A slip detection reference value is calculated from the detected rotational speeds of the vehicle wheels. Acceptable slip ranges for the respective vehicle wheels are determined in accordance with the calculated slip detection reference value. The rotational speeds of the vehicle wheels are compared with the corresponding acceptable slip ranges respectively. Slip controls of the respective vehicle wheels are performed when the rotational speeds of the vehicle wheels reside outside the corresponding acceptable slip ranges respectively. The highest of at least two of the rotational speeds of the vehicle wheels is selected. Differences between the respective rotational speeds of the vehicle wheels and the selected highest vehicle wheel rotational speed are calculated. The slip detection reference value is corrected in accordance with the respective calculated differences.

Vehicle wheel slip control system

Growing community of inventors

Mishima, Japan

Tatsuo Sugitani