Hitachi Automotive Systems, Ltd.

Masayuki Kikawa

Toshiyuki Innami

Norikazu Matsuzaki

Kimio Nishino

Ayumu Miyajima

Toshiyuki Ajima

Makoto Yamakado

Daisuke Goto

Masatsugu Arai

Kentaro Ueno

Takayuki Ohno

Takuya Obata

Tatsuji Ohkubo

Shuji Ohshita

A second ECU determines whether or not there is an abnormality in a hydraulic-pressure sensor in a first cycle based on a detection value of the hydraulic-pressure sensor, and outputs a signal indicating a determination of an occurrence of the abnormality to a first ECU via a signal line when determining the occurrence of the abnormality in the hydraulic-pressure sensor. The first ECU receives the detection value of the hydraulic-pressure sensor through communication from the second ECU via the signal line to determine whether or not there is the abnormality in the hydraulic-pressure sensor in a second cycle that is shorter than the first cycle. When determining that the hydraulic-pressure sensor is abnormal, the first ECU controls driving of an electric actuator based on a braking command from an operation-amount detection sensor without using the detection value of the hydraulic-pressure sensor determined to be abnormal.

Vehicle control apparatus and brake control apparatus

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.

Brake control 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

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.

Brake control apparatus

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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Kai, Japan

Masayuki Kikawa