Active cancellation of brake torque variation
AssigneeFord Global Technologies, LLC
InventorsBradley J. Johnson, Dale Scott Crombez, John P. Joyce, Eric M. Gamberg
Life of this patent
Estimating the term…
Abstract
Systems and methods for cancelling brake torque variation in a motor vehicle are disclosed. Signals indicative of brake torque variation are received at a controller. Based on the signals, a frequency associated with the indicated brake torque variation is determined. At least one of an output time and output volume of pressurized brake fluid is adjusted based on the frequency to cancel the indicated brake torque variation.
Claims20
A method for cancelling brake torque variation, comprising:
- controlling, via a controller, an antilock brake system (“ABS”) brake pedal valve fluidly coupled to a reservoir, the ABS brake pedal valve controlling delivery of pressurized brake fluid from a master cylinder to brake calipers;
- receiving, at the controller, signals indicative of brake torque variation;
- determining, based on the signals, a frequency of the brake torque variation;
- bypassing, via the controller, control of the ABS brake pedal valve, by controlling, via the controller, a brake valve and a pump motor;
- and
- in response to controlling the brake valve and pump motor, calculating an output volume of pressurized fluid to be applied to calipers of the brake system, and reducing the brake torque variation by delivering the calculated output volume of pressurized brake fluid from an accumulator fluidly coupled to a pump and the brake valve to the calipers of the brake system by controlling the pump motor based on the frequency.
A system for cancelling brake torque variation, comprising:
- a master cylinder;
- a pump;
- a motor configured to drive the pump;
- an accumulator fluidly coupled to the pump;
- a brake valve disposed between and in fluid connection with the master cylinder and the accumulator;
- antilock brake system (“ABS”) brake pedal valves coupled to and in fluid communication with the master cylinder and a reservoir;
- and
- a controller configured to:
- receive signals indicative of brake torque variation;
- determine, based on the signals, a frequency and a phase associated with the indicated brake torque variation;
- calculate an output volume of pressurized fluid to be applied to calipers;
- control the motor based on at least one of the frequency and the phase to deliver the calculated output volume of pressurized brake fluid from the accumulator to the calipers via the pump to move brake pads into contact with a disc brake rotor, thereby bypassing ABS brake pedal valves control of pressurized brake fluid from the master cylinder and reducing the brake torque variation.
A method for cancelling brake torque variation in a brake system, the method comprising:
- controlling the brake system via an antilock brake system (“ABS”) brake pedal valve fluidly coupled to a reservoir;
- receiving, at a controller, signals indicative of brake torque variation;
- determining, based on the signals, a frequency of the brake torque variation;
- calculating an output volume of pressurized fluid to be applied to calipers causing brake pads to apply a clamping force on a rotor of the brake system;
- and
- reducing the brake torque variation by delivering the calculated volume of pressurized brake fluid from an accumulator fluidly coupled to a pump and the brake valve to the calipers of the brake system, while bypassing the ABS brake pedal valve control of the brake system via the controller by opening a brake valve and controlling a pump motor, based on the frequency.
Dependencies are inferred from the claim text.