Gm Global Technolgoy Operations, Inc.

Deron C Littlejohn

Bryan Peter Riddiford

Scott A Stacey

John F Hoying

Richard Charles Swortzel

Hsiao Hsiou Chang

G Donald Denney

An improved cold temperature compensation control method for an EH braking system in which cold temperature operation is detected without requiring a temperature sensor. An electronic controller monitors the pressure developed by one or more electrically operated boost units for a characteristic pressure profile that occurs in cold temperature operation of the braking system, and adjusts the control strategy when the characteristic pressure profile is detected. The characteristic pressure profile is deemed by its frequency and amplitude parameters; specifically, a frequency above a threshold frequency, and an amplitude above a threshold amplitude. In a first mechanization, the controller responds to a detected cold temperature operation by reducing the gain of a closed-loop pressure control, while in a second mechanization, the controller responds by switching from the closed-loop pressure control to a closed-loop position control.

Electro-hydraulic braking system having cold temperature detection and

A brake system control apparatus comprising: a sensor providing an output signal indicative of operator foot force on a brake pedal; an actuator coupled to wheel brake and controlling a wheel brake force applied by the wheel brake responsive to a control signal; a controller coupled to the sensor and the actuator and including a differentiator (60) receiving the output signal and determining a rate of change of the operator foot force on the brake pedal, a comparator (62) for comparing the rate of change to a predetermined minimum, wherein a rate of change above the predetermined minimum indicates a quick application of brake pedal force by the vehicle driver, a brake gain adjuster (64) for increasing a gain of the brake system when the rate of change is above the predetermined minimum, a brake command generator (72, 74) determining a control signal in response to the increased gain when the rate of change of brake force is above the predetermined minimum and responsive to a base gain when the rate of change of brake pedal force is not above the predetermined minimum, wherein, when a rate of change of brake force above the predetermined minimum is detected, the vehicle brake system has an effective gain higher than the base gain

Brake system control method and apparatus

In a vehicle with a right front wheel brake, a right rear wheel brake, a left front wheel brake and a left rear wheel brake, a brake control system method for distributing a commanded yaw force to the wheel brakes according to the step of distributing the yaw force to the vehicle wheel brakes according to a priority hierarchy wherein each successive vehicle wheel brake in the priority hierarchy is commanded only if a sum of all previous vehicle wheel brakes in the priority hierarchy have not achieved transfer of the commanded yaw force to the vehicle body.

Brake control system

A method of brake system control, and apparatus for performing same, comprising the steps of (i) determining a brake command for right and left wheel brakes; (ii) monitoring right and left wheel speeds; (iii) comparing the right and left wheel speeds to determine a speed difference; (iv) if the right wheel speed is greater than the left wheel speed, adjusting a left gain of the of a left brake command to reduce torque provided by the left wheel brake; (v) if the left wheel speed is greater than the right wheel speed, adjusting a right gain of a right brake command to reduce torque provided by the right wheel brake.

Brake control system method and apparatus

In a motor vehicle braking system wherein a first brake device has a first mode of operation in which power-assisted braking is provided and a second mode of operation in which manual braking is provided, wherein the second braking system has a second brake device controlled by a control command, a method of controlling the braking system comprising the steps of receiving a signal indicative of an operator brake request, determining the control command in response to the signal and a first gain factor if the first brake device is in the first mode of operation, determining the control command in response to the signal and a second gain factor if the first brake device is in the second mode of operation, wherein the second gain factor is less than the first gain factor, applying the control command to the second brake device.

Brake system with brake gain shifting

A method of controlling an electric brake having an actuator controllable for moving brake pads against and away from a friction brake surface comprising the steps of (i) retracting a brake actuator after a braking operation; (ii) measuring a parameter indicative of work during the retraction; and (iii) moving the brake actuator to a position at which the brake actuator is ready for a next brake operation, wherein step (iii) is responsive to the measured parameter, wherein the brakes are rehomed adaptively to compensate for brake wear.

Method of adaptively homing brake actuators

A method of controlling a brake system comprising the steps of: (i) receiving a brake command from a brake pedal; (ii) responsive to the received command, applying full power to the brake actuator for a first time period after the brake command is received; (iii) after the first time period, applying power to the brake actuator responsive to the brake command and a first gain factor for a second time period; (iv) after the second time period, applying power to the brake actuator responsive to the brake command and a second gain factor, wherein the second gain factor is less than the first gain factor, wherein the brake actuator is initialized responsive to the brake command.

Method of initializing a brake actuator

In a vehicle brake system having braking control responsive to a pressure signal from a pressure transducer in a hydraulic brake line, a method of operation comprising the steps of: (a) determining whether a brake pedal is depressed; (b) when the brake pedal is determined to be depressed: (i) controlling the brake system responsive to the pressure signal and a stored offset value for the pressure transducer, and (ii) resetting a timer; (c) when the brake pedal is determined to be not depressed: (i) cycling the timer, (ii) determining whether the timer has timed out, and (iii) if the timer has timed out, (iii.i) receiving the pressure signal from the pressure transducer, (iii.ii) comparing the pressure signal to a predetermined limit value indicative of an acceptable maximum sensor output when the pedal is not depressed, and (iii.iii) updating the stored offset value responsive to the pressure signal.

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Middletown, OH, United States of America

Deron C Littlejohn