Gm Global Technolgoy Operations, Inc.

Delco Electronics Corporation

Scott A Stacey

Kamal N Majeed

Deron C Littlejohn

Eric Lee Jensen

David Andrew Shal

Scott Wilson Badenoch

Albert Victor Fratini, Jr

Joan B Arwine

Hsiao Hsiou Chang

James W Hauser

Jay R Varner

Bernard Claude Veron

Xavier Marie Groult

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 control method for a manual back-up electro-hydraulic braking system in which the rear service brakes of the vehicle are intentionally operated in a manual back-up mode under specified non-failure operating conditions to conserve electrical energy. The manual back-up mode for the rear service brakes is initiated if braking is commenced while the vehicle speed is below a near-zero threshold speed. If braking is commenced above the threshold speed, the manual back-up mode for the rear service brakes is initiated when the vehicle speed falls below the threshold and the pressure command for the rear brakes has been substantially constant for at least a predetermined time. In this case, the rear manual back-up mode is initiated by reducing the rear brake pressure command to the rear boost units at a controlled rate until the rear brake pressure reaches the manually developed pressure, and then entering the manual back-up mode. Once the rear manual back-up mode is initiated, it remains in effect until the driver releases the brake pedal.

Rear manual brake control for an electro-hydraulic braking system

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

A method of controlling a vehicle suspension system comprising the steps of: determining a relative velocity between a wheel and the corner of a vehicle body; determining responsive to the relative velocity, according to a non-linear passive function, a raw wheel demand force; determining an average vertical velocity of the wheel; determining, responsive to the average vertical velocity of the wheel, a first scaling factor; multiplying the first scaling factor by the raw wheel demand force to determine a scaled wheel demand force; and controlling the vehicle suspension system responsive to the scaled wheel demand force.

Vehicle suspension control using a scaled wheel demand force

A suspension system control according to the steps of: measuring a set of parameters indicative of motion of a body of the vehicle and of motion of wheels of the vehicle; determining a body demand force responsive to the measured parameters; determining a set of wheel demand forces responsive to the measured parameters; for each wheel of the vehicle: comparing the body demand force and the corresponding wheel demand force to determine whether the body demand force and the corresponding wheel demand forces are in phase; if the body demand force and the corresponding wheel demand force are in phase, determining a damper command responsive to the greater of the body and corresponding wheel demand force; if the body demand force and the corresponding wheel demand force are out of phase, determining the damper command responsive to the sum of the body demand force and the corresponding wheel demand force; and applying the determined damper command to a controllable variable force damper, wherein wheel vertical velocity occurring after a suspension event is minimized without sacrifice to passenger isolation from the suspension event.

Vehicle suspension control with wheel and body demand force phase

A method of controlling a vehicle suspension system including a real time continuously variable damper comprising the steps of: (a) determining a present actuator command for controlling damping force of the damper; (b) comparing the present actuator command to a previous actuator command to determine a difference value of the actuator commands; (c) if the difference value is positive, limiting the difference value to a positive threshold; (d) if the difference value is negative, limiting the difference value to a negative threshold, wherein the negative threshold has a magnitude greater than a magnitude of the positive threshold; (e) determining an output actuator command responsive to the difference value; and (f) outputting the output actuator command to the damper to control damper force, wherein the limiting of the difference value to the positive threshold reduces suspension harshness and audible noise and wherein the limiting of the difference value to the negative threshold reduces suspension audible noise.

Continuously variable damping system

A vehicle has a real time suspension control which requires, as inputs, a set of absolute body modal velocity signals. Accurate estimates of these signals are derived from relative position sensors at the body suspension points by converting the relative vertical position signals from these sensors to relative body modal (e.g. heave, pitch and roll) velocity signals and passing each of these signals through a second order low pass filter including an additional phase inversion for compensation of the 180 degree filter phase lag. Thus, the necessity of absolute body accelerometers is eliminated, for a significant cost reduction. In a vehicle having significant front to rear flexing or flexing within the front or rear suspension that can affect the accuracy of the estimated absolute body roll velocity, the normal roll velocity transformation equation is modified to include only the front or the rear pair of relative velocity signals.

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Kettering, OH, United States of America

Scott A Stacey