Brake system fault pedal gain change method and system
AssigneeGM Global Technology Operations LLC
InventorsTimothy M. Karnjate, William K. Manosh
Life of this patent
Estimating the term…
Abstract
A brake system fault pedal gain change method and system for brake pedal simulator equipped vehicles such as hybrid electric vehicles is provided. In the event of a brake system booster fault, the method alerts the driver by way of tactile feedback. Additionally, the disclosed method provides a controlled means to gradually increase required brake pedal force during a brake system fault to avoid an abrupt change in brake pedal force when the brake system boost is depleted.
Claims17
A method of implementing a brake pedal gain change in a vehicle having a brake simulator, a brake pedal operable by a driver of the vehicle for commanding actuation of a brake system, and a pedal sensor, the method comprising:
- detecting a fault in the brake system using a fault sensor;
- detecting at least one of a brake pedal force and a brake pedal travel of the brake pedal using the pedal sensor;
- converting the at least one of a brake pedal force and a brake pedal travel to a driver intended brake torque using the brake simulator;
- calculating the brake pedal gain change using the brake simulator;
- and
- applying the brake pedal gain change to automatically reduce the driver intended brake torque;
- wherein applying the brake pedal gain change increases a required amount of the brake pedal force needed to achieve a desired rate of vehicle deceleration, thereby providing tactile feedback to the driver of said fault in the brake system.
A braking system for an electrically driven vehicle, comprising:
- a friction brake system including:
- at least one braking member operable to apply a friction braking torque to wheels of the vehicle;
- a brake boost system providing energy to actuate said at least one braking member, said brake boost system having an energy storage member;
- and
- at least one brake system fault sensor operable to detect a brake boost system fault;
- an electric vehicle drive system including:
- at least one motor/generator operable to apply a regenerative braking torque to at least one of said wheels of said vehicle by conversion of mechanical energy into electrical energy;
- and
- an electric drive control electrically coupled to said at least one motor/generator and regulating operation of said at least one motor/generator;
- a brake simulator electrically interfaced with said friction brake system and said electric drive control, and in electrical communication with said brake system fault sensor;
- a brake pedal operable by a driver of the vehicle;
- and
- a brake pedal sensor operatively coupled to said brake pedal, and adapted for providing sensor measurements describing at least one of an amount of force and travel of the brake pedal to said brake simulator;
- wherein said brake simulator determines an intended driver braking torque using said sensor measurements, and automatically applies a reduction calibration to reduce said intended driver braking torque when said brake boost system fault is detected.
An electronic brake system for a driver operated vehicle which has a pressure storage device providing a boosted state for decelerating the vehicle, and a pump and motor for generating said boosted state, wherein the pump is faultable for potentially causing the brake system to revert to an unboosted state, the system comprising:
- a brake pedal responsive to a driver requested brake torque suitable for initiating the deceleration of said vehicle, wherein the driver requested brake torque is calculated and provided by the brake simulator;
- and
- a brake simulator connected to said brake pedal and responsive to a fault in one of the pump and the motor, and operable to reduce to the driver requested brake torque to effect a sufficiently higher tactile feedback to the driver through said brake pedal, whereby to alert said driver to a potential loss of boosted brake operation.
Dependencies are inferred from the claim text.