Gm Global Technolgoy Operations, Inc.

Allen John Walenty

Kevin Gerard Leppek

David Alan Thatcher

Alexander Kade

George N Villec

Robert A Rimkus

Alex Kade

Scott R Kloess

Anthony Luke Simon

J David Rosa

Calvin E Wolf

Shahram Zarei

Onno R Van Eikema Hommes

John G Maxgay

David M Ford

Cary Walter Brooks

Alfred Russell Robertson

John Andrew Weber

A tire pressure monitoring system for a vehicle having a plurality of inflatable tires includes a plurality of rotation sensors that generate rotation signals based on a rotation of each of the tires and a pressure sensor that is responsive to a pressure within one of the tires and that generates a pressure signal based on the pressure. A control module receives the pulse signals and the pressure signal and that detects a low pressure condition of at least one of the tires based on the pressure signal and the pulse signals.

Hybrid tire pressure monitoring system

The present invention provides an apparatus and method for characterizing tire pressure on the four tires of a conventional passenger automobile. The method uses an apparatus disposed on a key fob. The key fob includes a tire valve stem interface that is capable of taking manual measurements of tire pressure. The fob further includes a pressure transducer that translates tire pressure into electronic form where it can be displayed on an LCD screen and transmitted by RF to an automobile computer. The automobile computer further includes a program that provides for the measurement of tire pressure in a sequential method thereby assuring that the tires are at placarded pressure or more. The method includes steps of using the key fob to measure the tire pressure and transmitting the tire pressure to the computer for processing.

Tire pressure characterization method and key fob

An improved ABS control method incorporates entry criteria for initiating ABS control based on brake pedal position and rate of depression, adaptively adjusted by a reference pedal position corresponding to a predefined vehicle deceleration. A periodically-updated characterization of the relationship between brake pedal position and vehicle deceleration is used to establish the reference brake pedal position, and when insipient wheel lock is detected, the initiation of ABS control is delayed by an entry delay period that decreases with increasing rate of pedal depression and with the degree to which the pedal position exceeds the reference pedal position. In this way, the entry conditions are predicated primarily on the manner of brake pedal depression, with adaptive adjustment for variations in braking effectiveness.

Anti-lock brake control method having adaptive entry criteria

A method and apparatus of characterizing for tire pressure imbalances in a set of tires of vehicle, the vehicle having four wheels, and each wheel having a sensor generating a pulse for a predetermined amount of distance traveled by the wheel including entering a first characterization mode, accumulating a number of pulses from each sensor and adding the number of pulses from each sensor to generate a first record total pulse count in the characterization mode, generating a second record total pulse count in the characterization mode, determining if the first record is similar to the second record, and discarding at least one of the first and second records if the first and second records do not meet a criteria.

Method and apparatus for detecting tire pressure

An improved anti-lock control method for a vehicle brake system identifies various factors that degrade the effectiveness of the brake system and adaptively adjusts a brake apply rate during anti-lock brake control to compensate for the identified degradation so that the optimal tractive force during anti-lock brake control is more nearly realized. The identified factors include fading due to brake heating, hydraulic leakage, mis-adjusted and non-releasing rear brakes, brake wear and excessive vehicle weight.

Adaptive compensation method for an anti-lock brake control

The present invention relates to methods of torque transfer, torque transfer units, and vehicles incorporating the same. According to the method, a delta signal indicative of a rotational condition of the first driveline is generated and a torque transfer unit is controlled as a function of a torque transfer control algorithm. The control algorithm commands a transfer torque representing an amount of torque to transfer from the source of power to one of the first and second drivelines. The torque transfer control algorithm is a function of the delta signal and is substantially independent of any rotational condition of the second driveline over a primary operational range of the algorithm. Reference values may comprise a desired vehicle acceleration value, an actual vehicle acceleration value, a vehicle ground speed value, temporally displaced first driveline acceleration values, temporally displaced first driveline speed values, and combinations thereof.

Drive torque transfer scheme

Apparatus and methods are provided for controlling movement of an automobile in a pitched position. The apparatus has an attitude sensor that is configured to determine a pitch of the automobile and a speed sensor that is configured to determine a speed of the automobile. In addition, the apparatus has a braking mechanism that is configured to inhibit movement of the automobile and a controller that is configured to control the braking mechanism. The controller is configured to receive the pitch and the speed determined by the attitude sensor and the speed sensor, respectively, and control the braking mechanism based at least in part upon an evaluation of the pitch and the speed in order to inhibit movement of the automobile in the pitched position.

Methods and apparatus for inhibiting movement of an automobile in a pitched position

A method and apparatus for operating a vehicle anti-lock braking system includes a brake pedal and a brake modulator that reduces braking pressure by an initial pressure reduction after detecting insipient wheel lock. Vehicle deceleration is measured as a function of brake pedal position. A first table is updated with the vehicle deceleration and the brake pedal position. A coefficient of friction of a road surface is estimated based on the first table. A slip target for at least one wheel is estimated and is based on an estimated maximum slip of the at least one wheel before losing traction minus an estimated potential for vehicle rollover. A deceleration target for at least one wheel is estimated and is based on an estimated maximum deceleration of the at least one wheel before losing traction minus the estimated potential for vehicle rollover.

Anti-lock braking system controller for adjusting slip thresholds on inclines

A vehicle anti-lock braking system includes a brake pedal and a brake modulator. The brake system reduces braking pressure by an initial pressure reduction after detecting insipient wheel lock. Vehicle deceleration is measured as a function of brake pedal position. A first table is updated with the vehicle deceleration and the brake pedal position. A coefficient of friction of a road surface is estimated based on the first table. Wheel slip and deceleration target thresholds are determined based on the coefficient of friction. The wheel slip and deceleration target thresholds are used to populate a command table for the anti-lock braking system. Brake heat, brake torque, vehicle weight and grade are estimated. Release and apply pressures are calculated from an adjusted coefficient of friction, a coefficient of friction and the grade.

Method for determining optimal ABS slip and deceleration thresholds

An improved anti-lock rear brake yaw control method utilizes a measure of braking intensity to regulate both the initiation of yaw control and the anti-lock braking control parameters once yaw control is initiated. The brake torque and the rate of brake pedal depression provide measures of braking intensity, and are used to develop variable slip and deceleration thresholds to which the rear wheel differential slip and deceleration are compared. The variable thresholds permit initiation of yaw control at relatively low levels of differential wheel slip or deceleration during panic braking, while requiring higher levels of differential wheel slip or deceleration to initiate yaw control during moderate braking. Once yaw control is initiated, the slip and deceleration thresholds are utilized to adaptively adjust the slip and deceleration targets, so that the targets are set in accordance with the slip and deceleration of the rear wheel with the lowest coefficient of friction during panic braking, and at higher levels during moderate braking.

Anti-lock brake yaw control method

An improved anti-lock brake control method in which the brake pressure reduction initiated upon detection of insipient wheel lock is adaptively determined based on a periodically updated characterization of the relationship between brake pedal position and vehicle deceleration. The brake torque and vehicle weight are estimated based on the characterization data, corrected for variation in brake heating, and used to compute the surface coefficient of friction, which in turn, is used to schedule the initial anti-lock brake pressure reduction for optimal braking system performance.

Anti-lock brake control method having adaptive initial brake pressure reduction

A brake system control method for use in a vehicle in which wheel speed normalization factors are iteratively updated, comprising the steps of: monitoring a plurality of wheel speed signals from a plurality of wheel speed sensors; determining for each wheel a wheel acceleration responsive to the wheel speed signal; determining an acceleration dead band for each wheel, wherein the acceleration dead band is proportional to a measure of vehicle acceleration; comparing the wheel acceleration to the dead band; and if the magnitude of the wheel acceleration is greater than the magnitude of the dead band, inhibiting update of the normalization factors.

Brake system control in which update of wheel speed normalization factors is selectively inhibited

An improved anti-lock brake control method adaptively determines exit criteria for terminating anti-lock brake control based on rate of brake pedal release and estimates of the brake torque and road surface coefficient of friction. The brake torque and road surface coefficient of friction are estimated based on a periodically updated characterization of the relationship between brake pedal position and vehicle deceleration.

Anti-lock brake control method having adaptive exit criteria

An improved method of diagnosing conditions of a vehicle braking system that degrade the braking effectiveness informs the driver of the condition so that repair or adjustment can be timely made. The relationship between brake pedal position and vehicle deceleration is determined during a calibration interval to construct a calibration table of brake effectiveness, and then periodically over the life of the braking system to develop a current brake effectiveness table. Braking system abnormalities that impair the braking effectiveness are diagnosed by analyzing the table values.

Method of diagnosing a vehicle brake system using brake pedal position and vehicle deceleration

A control for an automatic shifting power transmission employs an algorithm to determine the proper gear ratio during vehicle deceleration. The algorithm establishes downshift grade requirements based on the brake pressure and speed threshold targets based on brake pressure. A grade average is calculated from the operating parameters of acceleration, engine braking, aerodynamic drag, rolling resistance and brake torque deceleration. If the grade average is within downshifting range and the speed target is met, the control commands a downshift to the next lower gear ratio. The downshift grade requirements decrease as brake pressure increases and speed targets increase as brake pressure increases.

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Macomb, MI, United States of America

Allen John Walenty