Toyota Jidosha Kabushiki Kaisha

Other

Tsukasa Fukasawa

Takahiro Okano

Daisuke Nakata

Eiji Nakamura

Akihiro Otomo

Junichi Sakamoto

Akira Sakai

Masayasu Ohkubo

Naoki Yabusaki

Shingo Urababa

Toshiyuki Sakai

Naoyasu Enomoto

Tomohiko Takeda

Hiroki Asada

Yoshinori Suzuki

A vehicle brake system including a regenerative cooperative control device configured to control a regenerative brake device that applies a regenerative braking force to one of front and rear wheels and/or a friction brake device that applies a friction braking force to the front and rear wheels. After the regenerative braking force reaches an allowable regenerative braking force, the friction braking force applied to the other of the front and rear wheels is increased by the friction brake device up to a first friction braking force less than a braking force on an actual braking-force distribution line determined by the regenerative braking force at a time when it reaches the allowable regenerative braking force, and the friction braking forces applied to the one and the other of the front and rear wheels are subsequently increased so as to bring the friction braking forces close to the actual braking-force distribution line.

Vehicle brake system

A vehicle system, including: a steering system; and a longitudinal-force application system including longitudinal-force application actuators configured to apply longitudinal forces respectively to one or more left-side wheels and one or more right-side wheels and a longitudinal-force controller configured to control the longitudinal-force application actuators to control the longitudinal forces applied respectively to the one or more left-side wheels and the one or more right-side wheels, and an onboard power source device including a main power source and a secondary power source. When the main power source fails to supply electric power to the longitudinal-force application system and the steering system, the longitudinal-force controller controls the longitudinal-force application actuators to control a difference between the longitudinal force applied to the one or more left-side wheels and the longitudinal force applied to the one or more right-side wheels, thereby turning the vehicle.

Vehicle system

In a brake apparatus, an activation current for opening a simulator cut valve from a closed state is applied, whereupon a steady-state current is applied continuously to maintain the open state. A brake control apparatus and a brake control method are employed to perform control in which a valve opening current, which is higher than the steady-state current, is applied to the simulator cut valve every time a brake pedal is depressed. Thus, in a brake apparatus including a switch valve that is driven steadily by applying the steady-state current thereto, favorable control responsiveness can be maintained in the switch valve at all times while achieving a reduction in power consumption.

Brake apparatus brake control apparatus, and brake control method

In a brake controlling device (), a separating valve () is provided in a main flow path () for interconnecting a first liquid pressure circuit and a second liquid pressure circuit. When an abnormality detecting section detects an abnormality relating to brake fluid pressure, a controlling section sets the separating valve () to a closed state. A leakage suppressing section performs leakage suppressing processing for suppressing entry of a brake fluid, which is in the first liquid pressure circuit, into the second liquid pressure circuit after the separating valve () is set to the closed state. A leakage suppressing section sets a master cut valve () to a closed state to perform the leakage suppressing processing.

Brake controlling device

A hydraulic brake unit is provided. The hydraulic brake unit includes a manual hydraulic pressure supply unit that pressurizes a hydraulic medium supplied from a reservoir and generates a hydraulic pressure corresponding to a brake operation amount; first and second hydraulic systems in which the manual hydraulic pressure supply unit communicates with first and second wheel cylinders; a separation valve provided between the first hydraulic system and the second hydraulic system; and a brake ECU having a separation valve control unit and a hydraulic medium amount detection unit. The separation valve control unit executes control to close the separation valve when the hydraulic medium amount detection unit detects that the hydraulic medium stored in the reservoir has decreased below a predetermined amount.

Hydraulic brake unit and control method for such a hydraulic brake unit

There is provide a brake control technology according to which a target hydraulic pressure is reliably achieved when a hydraulic pressure is decreased during hydraulic control and brake drag does not occur even when the target hydraulic pressure is zero. In a brake apparatus, a dead-band region is set for the target hydraulic pressure that is used in the hydraulic control. When braking control is switched from the hydraulic control to regenerative control in cooperative braking control, residual pressure reduction control is executed. In the residual pressure reduction control, the target hydraulic pressure is set to a value that is lower than zero to which the hydraulic pressure should be brought.

Brake apparatus, brake control unit, and brake control method

A brake control apparatus has first and second wheel cylinders; a master cylinder unit; first and second systems; a separation valve; a pressure control mechanism that controls the working fluid pressure transferred to at least one of the first and second wheel cylinders independently of the brake operation, and a brake ECU. The brake ECU generates a differential pressure across the separation valve by operating the pressure control mechanism when there is no brake operation while a running drive source of a vehicle is stopped to determine whether the separation valve has a leakage abnormality.

Brake control apparatus and control method thereof

In an electric parking brake system, a first position (Park) is tentatively determined and also finally determined before the initial check is completed. Even when a second position is tentatively determined before the initial check is completed, the second position is finally determined after the initial check is completed. Then, a determination that the shift position has been changed is made. When a release command is issued based on the determination that the shift position has been changed, an electric motor is operated to release parking brakes.

Electric parking brake system and method for controlling the electric parking brake system

A hydraulic brake unit applies braking force to a plurality of wheels of a vehicle according to the operation of a brake pedal. A pressure increase linear control valve supplies hydraulic fluid from an accumulator to wheel cylinders of disc brake units of the respective wheels. Pressure-sustaining valves are placed in passages that extend from a first passage to the rear wheel cylinders. A pressure-increase response-delay reduction section closes the pressure-sustaining valves for a predetermined period of time after starting the hydraulic pressure control to temporarily limit the inflow of hydraulic fluid into the wheel cylinders that communicate with the first passage. Thus, the amount of the hydraulic fluid that is supplied to the second passage is increased, and it is possible to reduce the hydraulic pressure response delay in the second passage.

A method and apparatus control target deceleration of a vehicle in response to a master cylinder pressure and the like. A controlled braking mode in which the pressure in each wheel cylinder is controlled based on the target deceleration, and a driver braking mode in which the pressure in each wheel cylinder is directly controlled by a master cylinder. When an abnormality in the braking control is detected, the ratio of the wheel braking force to the amount of driver's braking operation is gradually adjusted closer to the ratio set for the driver braking mode.

Vehicle braking control method and apparatus

A vehicle braking system including a frictional braking device for applying a frictional braking torque to each of a plurality of wheels of the vehicle, a regenerative braking device including at least one electric motor for applying a regenerative braking torque to at least one drive wheel of the vehicle, and a total braking torque control device for controlling a total braking torque including one or both of the regenerative braking torque and the frictional braking torque which are applied to each of the wheels. When the total braking torque of at least one of the wheels has exceeded an upper limit corresponding to a friction coefficient of a road surface on which the motor vehicle is running, the total braking torque control device operates to zero the regenerative braking torque of each of the above-indicated at least one wheel and control the frictional braking torque of this wheel while reducing an influence of the zeroing of the regenerative braking torque.

Vehicle braking system having frictional and regenerative braking devices

A braking torque control system has a regenerative braking torque generator and a frictional braking torque generator and can control a total braking torque when there is failure in exchanging data between the regenerative braking torque generator and the hydraulic braking torque generator. In particular, when there is an abnormality in the exchanging of data, the target regenerative braking torque is reduced.

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Nishikamo-gun, Japan

Tsukasa Fukasawa