Hitachi Automotive Systems, Ltd.

Hitachi, Ltd.

Mazda Motor Corporation

Hitachi Astemo Ltd.

Kimio Nishino

Toshiyuki Innami

Kenichiro Matsubara

Norikazu Matsuzaki

Wataru Yokoyama

Toshiharu Sugawara

Toshimichi Minowa

Satoru Kuragaki

Yoshinori Endo

Tokuji Yoshikawa

Toshiyuki Ajima

Yuzo Kadomukai

Makoto Yamakado

Atsushi Yokoyama

Masayuki Kikawa

Ayumu Miyajima

Jiro Takezaki

Hirotaka Oikawa

Shingo Nasu

Tatsuro Kobune

Kenji Hashida

Shinji Seto

Masatsugu Arai

Yuki Tanaka

Shunsuke Aritomi

Takayasu Sakashita

Hitoshi Kobayashi

Takayuki Ohno

Takuya Obata

Shigeyuki Uehara

Hiroshi Chikuma

Michiharu Okada

Daisuke Kojima

Ryu Kai

Masayoshi Okamiya

Tomohiro Ohara

Provided fire an electric parking brake device and an electric parking brake control method that can apply an appropriate clamping force by accelerating data measurement and by suppressing influence of load fluctuation during idle running. For this end, the electric parking brake device of the present invention includes: a disc rotor; brake pads that are pressed to the disc rotor; an electric motor that imparts a thrust to the brake pads; a current detection unit that detects a motor current of the electric motor; and a brake control device that controls the electric motorbased on the motor current. The brake control device controls the electric motorbased on a current change amount of an electric current during a period from a point of time that the motor current becomes a peak current to a predetermined point of time.

Electric parking brake device and electric parking brake control method

A parking brake control apparatusdrives an electric motorB to advance a pistonaccording to an application request signal from a parking brake switch. The parking brake control apparatusincludes a running state detection portion that calculates a running state about whether a vehicle is running or stopped based on a wheel signal from a wheel speed sensor. When the running state cannot be calculated by the running state detection portion, the parking brake control apparatuscontrols the electric motorB in such a manner that the thrust force of the pistonchanges at a lower time rate of change than when the running state can be calculated.

Brake control apparatus

A parking brake controller () activates an electric actuator () in response to operation of a parking switch () to hold a disc brake () to serve as a parking brake. If a failure (fault) is detected in the parking switch (), the parking brake controller () activates the electric actuator () so as to hold the parking brake automatically upon detecting a condition that presumes the vehicle operator's intent not to drive any longer while the vehicle is at rest.

Brake system

Provided is a brake device capable of maintaining pads and a rotor in a desired positional relationship. When receiving a release request within a time period from start of execution of an application request to detection of contact between brake pad and a disc rotor, a parking brake control device inhibits execution of the release request, and executes the release request after detection of the contact between the brake pad and the disc rotor. Further, when receiving the application request within a time period from start of execution of the release request to detection of separation between the brake pad and the disc rotor, the parking brake control device inhibits execution of the application request, and executes the application request after detection of the separation between the brake pad and the disc rotor.

Brake device

A brake apparatus comprising: a caliper having a piston configured to move a brake pad to be pressed on a disc rotor rotating with a wheel; a thrust retaining mechanism located in the caliper to thrust the piston and maintain braking force exerted by the thrust piston; an electric motor mounted on the caliper to operate the thrust retaining mechanism; and a controller configured to apply electric current to the electric motor in response to an application command or a release command, thereby perform control according to the commands, wherein the controller, upon receiving a release command, configured to operate the electric motor to reduce braking force exerted by the piston by performing current maintenance control which continuously applies electric current to the electric motor and switching control which successively switches between a larger and a smaller amount of electric current applied to the electric motor.

Brake apparatus

A brake system includes a brake apparatus. This brake apparatus is configured to keep a vehicle braked by an electric mechanism in response to a parking brake request signal, and brake the vehicle by supply of a hydraulic pressure from a hydraulic source in response to an operation performed on a brake pedal. The brake system further includes a controller configured to drive the electric mechanism until a target pressing force is acquired to establish a brake holding state in response to the parking brake request signal. The controller is configured to change the target pressing force according to a change in a hydraulic pressure in the brake apparatus after starting driving the electric mechanism in response to the parking brake request signal.

When a controller () is restarted after system control has ended, a brake apparatus drives an electric motor () so as to achieve a corrected target thrust force calculated by setting a greater thrust force than a target thrust force set according to a temperature estimated value of a frictional member at this time, based on the temperature estimated value of the frictional member at the time of the end of the control, or drives the electric motor based on the temperature estimated value of the frictional member at the time of the end of the control.

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

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.

Brake control system

A brake control apparatus for a vehicle includes: a master cylinder for raising a wheel cylinder pressure according to operation of a brake pedal; a booster for raising the wheel cylinder pressure by operating the master cylinder independently of operation of the brake pedal; a pressure regulator provided with a hydraulic pump for raising the wheel cylinder pressure independently of operation of the master cylinder; and a control section including: a first controller for controlling the booster; and a second controller for controlling the pressure regulator. The control section detects that at least one of the booster and the first controller is in a state of malfunction; selects one of backup modes according to the state of malfunction, wherein the backup modes restrict operation of at least one of the booster and the pressure regulator in different manners; and controls the wheel cylinder pressure in the selected backup mode.

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.

A brake control system for a vehicle includes a first controller having a first brake operation quantity sensor and a second controller executing a different control from that of the first controller and having a second operation quantity sensor. The second controller may include a master pressure acquisition unit for acquiring a master pressure and a failure detection unit for detecting a failure of the first controller on the basis of the brake operation quantity detected by the second brake operation quantity sensor and the master pressure acquired by the master pressure acquisition unit.

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Hitachinaka, Japan

Kimio Nishino