Toyota Jidosha Kabushiki Kaisha

Masayuki Soga

Yutaka Ohnuma

Junichi Sakamoto

Kiyoyuki Uchida

Yoshikazu Hattori

Hideyuki Aizawa

Ryoichi Kurasako

In an electronic control brake system capable of controlling the braking force by adjusting the hydraulic pressure applied to each wheel cylinder through the use of a pressurization source and a hydraulic pressure adjusting portion, the hydraulic pressure applied to a wheel cylinder is increased by a pressurization source while the brake is not operated during a stop of the vehicle. After that, a master cutoff valve is opened so as to release the hydraulic pressure to a master cylinder. Changes in the master pressure are investigated via a master pressure sensor so as to determine whether there is an abnormality in a stroke simulator or a simulator cutoff valve.

Vehicular braking control apparatus and abnormality detection method for vehicular braking apparatus

A vehicular braking control apparatus and method controls frictional braking performed by a frictional braking device, controls regenerative braking performed by a regenerative braking device, and controls shifting between a cooperative braking mode, realized by the frictional braking and the regenerative braking, and a single braking mode, realized by only the frictional braking. A correction coefficient for one of a frictional braking control amount and a regenerative braking control amount is calculated on the basis of an actual degree of vehicle deceleration and a reference degree of vehicle deceleration based on an amount of braking operation performed by a driver during braking in the single braking mode. The control amount is corrected based on the correction coefficient.

Vehicular braking control apparatus and braking control method thereof

A brake control apparatus for a motor vehicle includes first and second pressure regulators that regulate a pressure of a hydraulic fluid supplied from a high-pressure fluid supply source to first and second wheel cylinders, and a communication control device that controls fluid communication between the first and second wheel cylinders. A controller of the apparatus includes first and second control units that control the first and second pressure regulators, respectively. The controller determines whether one of the first and second control units may be failing to operate normally, and places the communication control device in an operating position for communicating the first and second wheel cylinders with each other when it is determined that the first or second control unit may be failing to operate normally.

Brake control apparatus and method for a vehicle

A brake control system and method that includes high-pressure fluid supply sources and cutoff devices for cutting off communication between a master cylinder and wheel cylinders during a control process. A determination is made whether there is inconsistency between detection values of two pressure detectors for detecting a pressure in the master cylinder and a detection value of a stroke detector for detecting a stepping-on stroke of a brake pedal. A final target deceleration of the vehicle is calculated based on the detection values that are consistent with each other and braking force of each wheel is controlled based on the final target deceleration.

Vehicle brake control system and method

A vehicular brake apparatus includes a disc brake mechanism that brakes rotation of a wheel by pressing a friction member against a brake disc. The vehicular brake apparatus has a wall thickness detector that detects a state of wall thickness of the brake disc, and a controller that controls a state of contact between the brake disc and the friction member. Based on the state of wall thickness of the brake disc detected by the wall thickness detector, the controller controls the state of contact between the brake disc and the friction member so that the friction member contacts a relatively great wall thickness portion of the brake disc more strongly than the friction member contacts a relatively small wall thickness portion of the brake disc. The brake apparatus is able to eliminate the wall thickness variation of the brake disc or suppress occurrence of a wall thickness variation.

Vehicular brake apparatus and control method

A control device for controlling the running behavior of a four wheeled vehicle has a mathematical tire model of each wheel defining a relationship between longitudinal and lateral forces vs. slip ratio, synthesizes the mathematical tire model at zero slip and a control input from an outside running behavior controller such as a spin controller or a driftout controller to generate nominal values of longitudinal force, lateral force and yaw moment of the vehicle body, and controls the slip ratio of the wheels through cyclic adjustment so as to approach the differences between the nominal values and the actual values in the longitudinal force, lateral force and yaw moment of the vehicle body to the corresponding differences of those parameters due to differentiation thereof by the slip ratio based upon the mathematical tire model, wherein when an uncontrollable braking force is applied to any one of the wheels due to a malfunction of the brake system, the nominal values of the longitudinal force and the yaw moment are modified to be decreased as much as an additional longitudinal force and an additional yaw moment corresponding respectively to a longitudinal force and a yaw moment generated in the vehicle by a difference between the uncontrollable braking force and a braking force to be applied to the one wheel according to the slip control.

Device for controlling running behavior of vehicle by mathematical tire model with compensation for brake malfunction

A device for controlling an electro-hydraulic brake system of a vehicle checks if a battery forming an electric power source for the electric part of the brake system is in its normal operating condition, by taking a chance that thevehicle is substantially stopped with a brake pedal not being substantially depressed by a driver, wherein the checking is carried out if the outlet voltage of the battery is lower than a predetermined voltage in a substantially loaded condition by momentarily driving a motor-driven pump forming a pressurized brake fluid source for the hydraulic part of the brake system with at least one wheel being braked by the pressurized brake fluid.

Device for controlling brake system of vehicle with checking of battery condition

A device for controlling an electro-hydraulic brake system of a vehicle checks if the battery or the alternator forming an electric power source for the electric part of the brake system is in its normal operating condition, and when the battery or the alternator is not in its normal operating condition, lowers the load imposed on the battery, so as to care the battery against a too soon failure. The device may also check if the driver is pumping the brake pedal at a substantial standstill of the vehicle, and when the brake pedal is so pumped, also lowers the load imposed on the battery, so as to care the battery against a useless consumption of the battery.

Device for controlling brake system of vehicle with care for battery

An electrically controlled brake system for a vehicle, wherein an electric control device of the system has a device for detecting a changeover of an ignition switch from an on-state to an off-state. The electrically controlled brake system also includes a device for detecting a depression of a brake pedal beyond a predetermined depth. The brake system has a device for counting a predetermined time duration when the ignition switch changeover detection device detects a changeover of the ignition switch from the on-state to the off-state. Furthermore, the electrically controlled brake system includes a device for shutting down the electrically controlled brake system when the time count device has counted the predetermined time duration and the brake pedal depression detection device fails to detect the brake pedal depression beyond the predetermined depth.

Electrically controlled brake system shut down by turn off of ignition switch with delay time

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.

Growing community of inventors

Susono, Japan

Masayuki Soga