Brake control apparatus
AssigneeAdvics Co., Ltd.
InventorMototsugu SAWADA
Life of this patent
Estimating the term…
Abstract
An object of the invention is to reduce an influence of deviation in pressure increasing performance, which would be caused by individual differences of pressure increase valves, so that a desired braking force may be obtained. A moderate pressure increasing operation is carried out for wheel cylinder pressure of a wheel, which is on a high μ-road, wherein a demand differential pressure for a pressure increase valve is set at a first target pressure for a first time period and then switched to a second target pressure for a second time period. The influence of the deviation may be absorbed during the moderate pressure increasing operation, so that a difference of wheel cylinder pressure between front left and front right wheels may be reduced.
Claims16
A brake control apparatus for a vehicle comprising:
- pressure increase valves connected between a master cylinder and wheel cylinders for controlling a differential pressure between an upstream and a downstream sides of the respective pressure increase valves when power supply amount to each of solenoids of the pressure increase valves is linearly controlled, so that wheel cylinder pressure of brake fluid applied to each of the wheel cylinders is increased during a braking operation;
- and
- an electronic control unit for controlling each of the pressure increase valves,
- wherein the electronic control unit comprises;
- a power supply amount control portion for controlling the power supply amount to the solenoid of the pressure increase valve, which corresponds to the wheel cylinder for which a pressure increasing operation is carried out, in such a manner that a demand differential pressure for such subject pressure increase valve is alternately set at a first target pressure and a second target pressure, wherein the second target pressure is higher than the first target pressure, and
- a first differential pressure setting portion for setting the first target pressure in such a manner that the first target pressure is decreased in a stepwise manner each time when the demand differential pressure is switched from the first target pressure to the second target pressure.
A brake control apparatus for a vehicle comprising:
- pressure increase valves connected between a master cylinder and wheel cylinders for controlling a differential pressure between an upstream and a downstream sides of the respective pressure increase valves when power supply amount to each of solenoids of the pressure increase valves is linearly controlled, so that wheel cylinder pressure of brake fluid applied to each of the wheel cylinders is increased during a braking operation;
- and
- an electronic control unit for controlling each of the pressure increase valves, wherein
- the electronic control unit controls distribution of braking force between front wheels and rear wheels, so that the wheel cylinder pressure for the rear wheels is controlled to be lower than the wheel cylinder pressure for the front wheels in order to prevent a locked condition for the rear wheels,
- the electronic control unit linearly changes the power supply amount to the solenoid of the pressure increase valve, which corresponds to the wheel cylinder of the rear wheels for which a pressure increasing operation of the braking force distribution control is carried out, to control the differential pressure of the subject pressure increase valve, so that the wheel cylinder pressure for the subject wheel cylinder is increased, and
- the electronic control unit comprises a power supply amount control portion for controlling the power supply amount to the solenoid of the subject pressure increase valve, in such a manner that a demand differential pressure for the subject pressure increase valve is alternately set at a first target pressure and a second target pressure, wherein the second target pressure is higher than the first target pressure.
Dependencies are inferred from the claim text.