Hitachi Automotive Systems, Ltd.

Hitachi Astemo Ltd.

Norikazu Matsuzaki

Toshiyuki Innami

Kimio Nishino

Masayuki Kikawa

Ayumu Miyajima

Toshiyuki Ajima

Daisuke Goto

Makoto Yamakado

Masatsugu Arai

Hiroaki Sato

Kentaro Ueno

Shingo Nasu

Takayuki Ohno

Takuya Obata

Masaru Sakuma

Takaya Tsukagoshi

Naoki Takahashi

Daisuke Kojima

Shuji Ohshita

Minoru Kishi

Suguru Saotome

An ESCincreases distribution of a braking force to rear wheels according to a reduction in a speed of a vehicle due to braking, and distributes the braking force so as to allow the vehicle to be kept stopped due to braking forces applied to the rear wheels when the vehicle stopped. Then, a second ECU holds the braking force by driving a parking mechanism with the vehicle kept stopped due to the braking forces applied to the rear wheels.

Brake system, braking force distribution apparatus, and electric brake apparatus

A parking brake control device is configured to, when releasing a hold on a braking force, energize an electric motor, and change a drive time of the electric motor based on a current change amount in a predetermined interval after a predetermined time has elapsed since a current value of the electric motor starts to decrease after increasing and a current value at which the current change amount of the electric motor converges to a predetermined value or less.

Electric brake device and electric brake control device

An electric booster including an input member that is advanceably/retractably moved according to a brake pedal operation. An electric motor of an electric actuator advanceably/retractably moves a power piston. A master pressure control unit sets a target movement amount of the power piston according to an amount of a movement of the input member that is caused by the brake pedal, and controls the electric motor to move the power piston so as to achieve the target movement amount, thereby causing a brake hydraulic pressure to be generated in a master cylinder. The master pressure control unit includes a reaction force generation portion, which changes a characteristic of a hydraulic reaction force applied to the brake pedal. The reaction force generation portion corrects the target movement amount of the power piston according to a temporal change in the movement amount of the input member.

Electric booster

Even when downstream stiffness in a brake hydraulic circuit changes due to variation in a caliper forming a part of a wheel cylinder, temperature, wear degree, and deterioration of a frictional pad, and/or the like, a brake control apparatus performs calculation processing for calculating a switching reference operation amount, switching operation amount deviation calculation processing for calculating a deviation from the switching reference operation amount, operation amount offset processing for offsetting a pedal operation amount detected by an operation amount detection unit, target hydraulic pressure calculation processing for calculating the target hydraulic pressure with use of the offset operation amount and a reference hydraulic characteristic, and control of the electric motor () according to the target hydraulic pressure. By this configuration, the brake control apparatus limits an excessive movement amount of a primary piston by changing the reference hydraulic characteristic according to the change in the downstream stiffness.

Brake control apparatus

A brake control device capable of suppressing a sense of discomfort felt by a driver. The brake control device () includes a braking command addition part (A) for adding an automatic-brake braking command value (B) output from an automatic-brake braking command calculation part () and a pedal operation braking command value (A) output from a pedal operation braking command calculation part (B). The pedal operation braking command calculation part includes a pedal operation braking command selection part (B), a normal brake characteristic part (B) for holding a normal brake characteristic, and an automatic brake characteristic part (B) for holding an automatic brake characteristic. The pedal operation braking command selection part selects a braking command value output from the automatic brake characteristic part when the automatic-brake braking command value is more than 0, and outputs the selection result to the braking command addition part as the pedal operation braking command value.

Brake control device

A brake control system which can maintain the behavior of a vehicle stable when wheels slip. A slip amount detector (), configured to detect an amount of slip at the front and rear wheels, is connected to a second ECU (). A first ECU () has a regenerative slip control unit which executes repeatedly a slip restricting control in which, while the front wheels are being detected as slipping based on a detection value of the slip amount detector during the execution of regenerative braking by a motor-generator (), the amount of regenerative braking by the motor-generator is reduced by a predetermined amount, and thereafter, the resulting reduced amount of regenerative braking is held for a predetermined period of time. The regenerative slip control unit sets the predetermined reduction amount larger than a predetermined reduction amount by which the amount of regenerative braking is reduced in the slip restricting control.

Brake control system

According to the present invention, limited electric power is consumed so as to achieve long-lasting use of electric power during brake control with the use of an auxiliary power supply source when there is a malfunction of a vehicle power supply source. In addition, a brake control device for ensuring responsiveness at the beginning of braking or when emergency braking is necessary is provided. The brake control device of the present invention is a brake control device for detecting electric signals generated depending on the degree of brake-pedal operation and calculating the driver's demanded braking force based on the electric signals so as to generate the demanded braking force, which comprises an auxiliary power supply source for supplying electric power to the brake control device when there is a malfunction of a vehicle power supply source and controls braking depending on the charged capacity of the auxiliary power supply source.

A motor drive device inputs two detection signals from a rotation position sensor thereby to detect a rotation position, and controls a voltage to be applied to a motor according to the detected rotation position. The motor drive device has a control unit for outputting a first voltage in a first state in which the square sum of sampling values sampled from the two detection signals is a predetermined value, and outputting a second voltage in a second state in which the square sum is not the predetermined value.

Motor drive device

A brake system which can secure quietness in a passenger compartment is provided. A vehicle brake systemincludes a brake assist devicewhich boosts a pressing force on a brake pedalby drive of a motor, and an assist control unitwhich controls the motor. The assist control unitchanges responsiveness of the motorin accordance with a vehicle speed, and sets a dead zone amount and a filtering value to large values in a region with a low vehicle speed. Thereby, responsiveness of a boosting operation of the motorto the operation of the brake pedal is made low, and a rotational variation and a vibration are prevented from occurring to the motorby a minute variation of a detection signal of a stroke sensorduring low-speed traveling or stoppage of traveling.

Vehicle brake system

Provided is a brake control apparatus for a vehicle which detects an amount of brake-pedal operation by means of an electric signal, and then calculates a braking force demanded by a driver from the electric signal, and thereby generates the demanded braking force. A control mode for a braking force is switched from a normal control mode to a stationary-vehicle control mode, if a determination that the vehicle is in a stationary state is followed by another determination that an electric signal corresponding to an actual braking force exceeds a command value for a stationary-vehicle braking force while the vehicle is in the stationary state. The control mode for a braking force is switched from the stationary-vehicle control mode to the normal control mode, if it is determined that the demanded braking force becomes smaller than the command value for the stationary-vehicle braking force. In addition, in the stationary-vehicle control mode, a braking force generated by a means for braking is equal to the command value for the stationary-vehicle braking force, whereas, in the normal control mode, the braking force generated by the means for braking is equal to the braking force demanded by the driver.

Disclosed is a brake control apparatus which includes a brake booster for augmenting deceleration, and which addresses the problem in conventional brake control apparatuses that deceleration and pedal reaction force depend on driver brake pedal input, and thus the pedal response and the ride comfort from the feeling of deceleration are affected by the manner in which the brake pedal is actuated by the driver. The brake control apparatus comprises a pedal reaction force generation unit for generating a pedal reaction force on the brake pedal, and a brake control unit for controlling the brake force in such a way as to suppress driver brake input fluctuations, wherein the pedal reaction force generation unit suppresses pedal reaction force fluctuations in accordance with specific deceleration and pedal reaction force characteristics. The brake control apparatus further comprises a calculation unit for calculating a target deceleration on the basis of lateral jerk information in the left-to-right direction of the vehicle, wherein the brake control unit suppresses the brake force in such a way that the target deceleration is produced and, when the amount by which the brake pedal is depressed reaches a specific amount in respect of the target deceleration, the pedal reaction force generated by the pedal reaction force generation unit may be increased.

A brake control system that enables accurate brake control is provided that precisely detects a master-cylinder pressure and includes a back-up function. The brake control system includes a master-cylinder operated by a brake operation of a driver; a first mechanism that regulates a pressure inside the master-cylinder according to the brake operation amount; a first control apparatus that controls operation of the first mechanism; a second mechanism that regulates communication of the pressure inside the master-cylinder to a wheel-cylinder; and a second control apparatus that controls operation of the second mechanism and operation of a pump apparatus that increases a pressure communicated to the wheel-cylinder. The first and second control apparatuses each have a power supply circuit and CPU. The brake control system further includes a first hydraulic pressure sensor that measures a pressure inside the master-cylinder and is electrically connected to the first control apparatus, and a second hydraulic pressure sensor that measures a pressure inside the master-cylinder and is electrically connected to the second control apparatus.

Disclosed is a brake control system including a plurality of control apparatuses using a brake operation amount detection apparatus and one brake operation amount detection apparatus. The brake control system includes: a master-cylinder pressure control apparatus that controls a master-cylinder pressure based on a brake operation amount; a wheel-cylinder pressure control apparatus that controls a wheel-cylinder pressure of each wheel; and a master-cylinder pressure detection apparatus that detects a signal for calculating the master-cylinder pressure, the master-cylinder pressure control apparatus controls the master-cylinder pressure based on a detection result detected by the master-cylinder pressure detection apparatus, and the wheel-cylinder pressure control apparatus controls the wheel-cylinder pressure based on the detection result detected by the master-cylinder pressure detection apparatus.

In a brake controller, a slope climbing vehicle stop detecting means determines when the vehicle is stopped while climbing a slope, and a pedal release detecting means determines that the pedal is released. An assist control unit interpolates a decrement in brake fluid pressure in the master cylinder due to an input piston movement caused by a release of a brake pedal. An assist piston is controlled by an electric motor to restore and maintain the fluid pressure within the master cylinder.

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Minami-Alps, Japan

Norikazu Matsuzaki