Toyota Jidosha Kabushiki Kaisha

Advics Co., Ltd.

Koichi Tomida

Tomohiro Kato

Masanobu Yamaguchi

Satoshi Suzuki

Toshio Onuma

Masahiro Murata

Yusuke Mizuguchi

A control device for a vehicle brake system includes first judgment value derivation and storage means for deriving and storing as first judgment value a boosting limit judgment pressure which, if predetermined conditions are satisfied during the driving of hydraulic pumps by boost control means, a boosting limit judgment pressure calculation means calculates at the time when the predetermined conditions are satisfied, and returning start judgment means for judging whether the returning of the brake manipulation member has been started or not. The boost control means executes the boost control using as the boosting limit judgment pressure the first judgment value stored in the first judgment value derivation and storage means when the returning start judgment means judges during the driving of the pumps that the returning of the brake manipulation member has been started.

Control device for vehicle brake system

An assistance-limit recognizing device for recognizing a limit of assistance made by a vacuum booster that is configured to assist an operating force applied to a brake operating member. A communication between a variable pressure chamber and a negative pressure chamber of the vacuum booster is established, when the operating force is not applied to the brake operating member. A communication between the variable pressure chamber and the atmosphere is established while the communication between the variable pressure chamber and the negative pressure chamber is cut off, when the operating force is applied to the brake operating member, whereby the operating force applied to the brake operating member is assisted based on a pressure difference between a pressure in the negative pressure chamber and a pressure in the variable pressure chamber. The assistance-limit recognizing device is configured, upon reduction of the variable-pressure chamber pressure in process of change of the variable-pressure chamber pressure toward the atmospheric pressure with application of the operating force to the brake operating member, to recognize the limit of the assistance made by the vacuum booster.

Assistance-limit recognizing device, assistance-limit recognizing method, and vehicle brake system including the assistance-limit recognizing device

The control device adapted to a vehicle brake apparatus includes a vacuum obtaining portion, a master cylinder pressure obtaining portion and a boosting control portion for executing a boosting control which controls supplying of a boosting pressure established by driving the hydraulic pressure pump and controlling the pressure differential control valve so that the boosting pressure agrees to a target boosting pressure obtained with a target boosting gain smaller than a basic boosting gain which indicates a servo-ratio of the vacuum booster up to the time, when the master cylinder pressure becomes equal to or more than a boosting limit pressure which is a master cylinder pressure corresponding to a boosting limit of the vacuum booster at the vacuum obtained by the vacuum pressure obtaining portion, in addition to the master cylinder pressure established in response to the operation of the brake operation member.

Control device for a brake apparatus

A damping force control apparatus for a vehicle includes adjustable-damping-force shock absorbers. When the vehicle turns, an electronic controller calculates an actual roll angle of the vehicle body in accordance with sprung accelerations detected by sprung acceleration sensors. The electronic controller also calculates a target roll angle of the vehicle body in accordance with a lateral acceleration detected by a lateral acceleration sensor. The target roll angle is set such that it increases with the lateral acceleration acting on the vehicle during turning and is uniquely determined by the lateral acceleration. The electronic controller sets target damping forces of the shock absorbers such that the actual roll angle coincides with the target roll angle, and controls the damping forces of the shock absorbers in accordance with the set target damping forces.

Damping force control apparatus for vehicle

A damping force control apparatus with adjustable shock absorbers is disclosed. An electronic control unit calculates estimated roll angle and estimated pitch angle of a vehicle body based on detected sprung accelerations, calculates a target pitch angle from the estimated roll angle, and determines target damping force required for front-wheel-side shock absorbers such that the stimulated pitch angle coincides with the target pitch angle; calculates rear-wheel-side jack-up force exerted on the rear-wheel-side vehicle body based on detected vehicle speed detected yaw rate and detected lateral acceleration, and determines the force in the direction for overcoming the calculated jack-up force as target damping force of rear-wheel-side shock absorbers; and controls the operation of each actuator based on the rear-wheel-side and front-wheel-side target damping forces.

Vehicle damping force control with roll angle and pitch angle

A device for controlling damping coefficients of shock absorbers (,FL,,FR,,RL,,RR) of a four wheeled vehicle constructs a phantom damping system composed of a phantom side shock absorber (,F,,R) disposed vertically at a lateral inside of a turn running of the vehicle to have a lower end movable along a ground surface together with the vehicle and an upper end vertically movable relative to the lower end with a first phantom damping coefficient (Cg, Cgf, Cgr) therebetween, and a phantom angular shock absorber (,F,,R) arranged to act between the upper end of the phantom side shock absorber and the vehicle body with a second phantom damping coefficient (Ca, Caf, Car) therebetween, whereby, when the damping coefficients of the shock absorbers are controlled to substantially equalize the phantom damping system with the actual damping system of the actual shock absorbers with respect to damping vertical and rolling movements of the vehicle body, the mass center of the vehicle body is lowered according to a rolling thereof during a turn running of the vehicle, as the vehicle body rolls around the upper end of the phantom side shock absorber located laterally inside of the turn running.

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Toyota, Japan

Koichi Tomida