Toyota Jidosha Kabushiki Kaisha

Advics Co., Ltd.

Hideyuki Aizawa

Nobuyasu Nakanishi

Masahiro Hara

Satoshi Shimizu

Akiyoshi Yamada

Kiyoyuki Uchida

Noboru Noguchi

Akira Nakamura

Shirou Monzaki

Shin Koike

Shiro Monzaki

Noritaka Yamada

Harumi Ohori

Yutaka Ohnuma

Masayuki Soga

Satoshi Udaka

Akifumi Doura

Masatoshi Yoneyama

Ryozo Saitoh

Shouji Ito

Kenzi Ito

A braking force control device can control braking forces of the respective wheels of a vehicle, suppresses an increase of the braking force of a first wheel that is a wheel having a relatively large slip amount in a pair of right/left wheels and increases the braking force of a second wheel that is a wheel having a relatively small slip amount. The braking force control device may suppress the increase of the braking force of the first wheel before the friction coefficient of a road surface to the first wheel reaches a peak and when the friction coefficient is in the vicinity of the peak. It is preferable to suppress the increase of the braking force of the first wheel by holding the braking force of the first wheel.

Braking force control device

A braking control apparatus for vehicles is provided with a braking control for performing such control that when deceleration d determined by a deceleration determining device is not less than a predetermined value f(v) according to vehicle speed v determined by a vehicle speed determining device, a braking force exerted on a rear wheel is limited as compared with a braking force exerted on a front wheel. This predetermined value f(v) is set so as to become smaller with increase in the vehicle speed v.

Braking control apparatus and method for vehicles

A brake force control apparatus which can always accurately generate a brake force confirming to a driver's intention is provided. The brake force control apparatus performs brake assist control for supplying an increased brake fluid pressure which is greater than that generated in a regular brake operation to a wheel cylinder of a vehicle when an emergency brake operation is performed by a driver. A deceleration of the vehicle is detected. Additionally, a difference between a target deceleration which is to be generated during execution of the brake assist control and the deceleration is detected. A brake fluid pressure which is supplied to the wheel cylinder during execution of the brake assist control is controlled based on the difference.

Braking force controller

In order to obtain the vehicle speed of an ordinary automobile operating with a pair of drive wheels and a pair of driven wheels, so as to provide the base of a due slipless rotation speed of the respective wheels for use in an ABS control, the rotation speed of each of the pairs of drive and driven wheels are detected. Then the data signals generated by the detection are low pass filtered and checked to determine if any of the rotation speeds detected with the driven wheels is larger than the largest of the filtered rotation speeds. Then the vehicle speed is determined from the filtered rotation speeds, excluding that or those of the driven wheel or wheels whose detected rotation speed is larger than the largest of the filtered rotation speeds.

Device for detecting vehicle speed of four-wheeled vehicles for use in ABS

An antiskid control apparatus has magnetic rotational speed sensors for the respective wheels and is adapted to control the brake force, based on a speed of a first wheel and a speed of a second wheel during braking of a vehicle. When an antiskid control computer detects a road surface under road heating during execution of the brake force control of the vehicle, the computer terminates the brake force control of the vehicle where it is assumed that the vehicle is in a state of a predetermined speed.

Antiskid control apparatus

A brake force control apparatus having a pump for pumping up brake fluid from a fluid pressure passage connecting a master cylinder and a wheel cylinder is provided which can accurately detect an amount of brake operation intended by a driver during execution of a brake assist control. The brake assist control is achieved by supplying the brake fluid delivered by the pump to the wheel cylinder when an emergency brake operation is performed by a driver. The brake force control apparatus has a control signal generator and a fluid pressure controller. The control signal generator generates a control signal by compensating a decrease generated in the output signal when the pump pumps up the brake fluid from the fluid pressure passage. The fluid pressure controller performs the brake assist control by using the control signal.

Brake force control apparatus accurately detecting an amount of brake operation intended by a vehicle operator

A brake force control apparatus performs both a brake assist control and an antilock brake control without interference therebetween. A master cylinder generates a brake fluid pressure corresponding to a magnitude of a brake operation. A pump has an inlet port and an outlet port, the inlet port being communicable with the master cylinder. An inlet control valve controls communication between the master cylinder and the inlet port of the pump. A wheel cylinder is communicable with each of the master cylinder and the outlet port of the pump. A supplementary reservoir is communicable with each of the wheel cylinder and the inlet port of the pump. The brake assist control is performed, when the emergency brake operation is performed by the driver, by opening the inlet control valve and actuating the pump. The antilock brake control is performed by controlling communication between said wheel cylinder and each of the master cylinder, the outlet port of the pump and the supplementary reservoir and actuating the pump. The inlet control valve is opened when both the brake assist control and the antilock brake control are performed concurrently.

Brake force control apparatus for properly performing both an ABS

The pressure increases of a hydraulic pressure control module for controlling the braking forces of wheels are decided on the basis of wheel speeds and a vehicle speed estimated from the maximum wheel speed. In this case, on condition that the incremental rate of the vehicle speed exceeds a predetermined threshold value, the vehicle speed exhibited before the incremental rate exceeds the threshold value is kept as an estimated vehicle speed, which is used for deciding the pressure increases. Thus, the pressure increases can be appropriately decided even in a situation where a motor vehicle passes through a very-low-.mu. road part or a drop in road level.

Braking control system for a motor vehicle

As illustrated in FIG. 1, the wheel accelerations of the respective wheels are calculated from the detected wheel speeds, variations in the wheel accelerations are calculated from these wheel accelerations, the cumulative sums of the variations in the wheel accelerations are calculated from these variations, and the presumptive vehicle deceleration is calculated from the cumulative sums, whereby the vehicle deceleration can be accurately presumed without employing an acceleration sensor or the like. Further, the presumptive vehicle speed is calculated accurately using the presumptive vehicle deceleration. Still further, the slip factors of the respective wheels are calculated from the differences between the presumptive vehicle speed and the wheel speeds so as to perform an antiskid brake control at low cost and at a high precision.

Vehicle deceleration and vehicle speed presumption systems for motor

A vehicle brake cylinder pressure control apparatus wherein an amount of fluid flow into a reservoir is estimated based on vehicle deceleration and a pressure reducing time of the brake cylinder, while an amount of fluid flow from the reservoir is estimated based on a pumping time during which the fluid is pumped up from the reservoir by a pump, and the vehicle deceleration or an operating speed of a pump motor, so that an amount of the fluid stored in the reservoir is estimated on the basis of the amounts of the flow flows into and from the reservoir. Various parameters may be used in place of the vehicle deceleration, pumping time and motor operating speed, for estimating the amounts of the fluid flow into and from the reservoir and the reservoir fluid amount.

Hydraulic pressure control apparatus having device for estimating amount

An anti-lock braking-pressure control apparatus for a vehicle having a plurality of wheels, including at least one wheel speed sensor which detects respective actual speeds of the wheels of the vehicle, at least one solenoid-operated valve which regulates respective braking pressures applied to the wheels, a ground-speed sensor which detects a ground-speed of the vehicle as a running speed thereof relative to a road surface, and a controller which electrically operates, for preventing locking of each of the wheels, a corresponding one of the one or more solenoid-operated valves at a controlled duty cycle, the controller selecting one of a plurality of duty-cycle determining rules, and determining the duty cycle of the corresponding one solenoid-operated valve according to the selected one duty-cycle determining rule, the plurality of duty-cycle determining rules comprising (A) a first determining rule wherein the duty cycle is determined based on both (a) a wheel speed error that is a deviation of the actual speed of the each wheel from a target wheel speed obtained based on the ground-speed of the vehicle, and (b) a time derivative of the wheel speed error, and (B) a second determining rule wherein the duty cycle is determined based on one of (a) the wheel speed error and (b) the time derivative of the wheel speed error.

Duty cycle controller for anti-lock braking-pressure regulating valve,

A pressure generating apparatus for a hydraulic brake system, including a master cylinder having a pressure piston which partially defines a pressure chamber and which is advanced to generate a fluid pressure in the pressure chamber in response to an operation of a brake operating member. The apparatus further includes inhibiting device having a non-operated state for allowing the pressure piston to be advanced, and an operated state for inhibiting the pressure piston from being advanced, and a pressure changing device having a pressure changing chamber communicating with the pressure chamber. The pressure changing device operates to change a volume of the pressure changing chamber and thereby change the pressure chamber pressure. A controller is provided for controlling the inhibiting device and the pressure changing device, to change the pressure in the pressure chamber while the inhibiting device is placed in the operated state.

Brake pressure generator having means for controlling pressure

A device for detecting a rotating speed of a wheel of a vehicle, including an axle hub having a shaft portion, and a flange portion which extends radially outwardly from one of opposite ends of the shaft portion such that the wheel is secured to the flange portion. The shaft portion has an intermediate section at which the axle hub is rotatably supported by a stationary member via a bearing. The detecting device further includes a rotor secured to a part of the shaft portion of the axle hub remote from the flange portion so that the rotor is rotatable with the wheel. The rotor has an externally toothed section which has a multiplicity of teeth spaced apart from each other in a circumferential direction of the rotor. A speed detector is supported by the stationary member, so as to detect the teeth of the toothed section of the rotor during rotation of the rotor. A covering member attached to the stationary member cooperates with the same to cover the rotor.

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Susono, Japan

Hideyuki Aizawa