Kelsey-hayes Company

Danny R Milot

Richard J Barron

Yuhong Zheng

Kenneth A Doll

Mark S Luckevich

Gregory J Krawczyk

Mark D Lubbers

S Ben Choi

Steven Dale Keen

Wenwei Song

A system for and a method of controlling the stability of a vehicle includes an electronic control system controlling a vehicle stability control subsystem based at least in part on static tire data received by the electronic control unit.

Vehicle stability control utilizing static tire data

A method is provided for detecting a rollover event of a vehicle. A lateral kinetic energy of the vehicle is determined in response to vehicle longitudinal velocity and vehicle side slip angle. A lateral acceleration of the vehicle is measured. A tire normal force is measured. A rollover potentiality index is determined in response to the lateral kinetic energy and the lateral acceleration. A rollover index is determined by weighting the rollover potentiality index by a factor of the lateral acceleration and by a factor of the tire normal force. A comparison is made to determine if the rollover index is above a predetermined threshold.

Method and apparatus for vehicle rollover mitigation

A method of controlling an advanced chassis control system of a vehicle such as an anti-lock brake system, traction control system, vehicle stability control system, or roll control system affecting the vehicle dynamic performance and safety is disclosed. A control unit controls the operation of the advanced chassis control system based at least in part upon predictions of force generating characteristics of tires of the vehicle and driver input signals. The advanced chassis control system of the vehicle is controlled in one manner if the tire is determined to be inflated, controlled in another, different manner if the tire is determined to be deflated. During normal driving, the chassis control systems can operate to control the vehicle according to the desires of the driver while accounting for at least one tire being deflated. During braking the controller can act to distribute braking forces in order to divert forces from the deflated tire to the inflated tires.

Vehicle stability control enhancement using tire force characteristics

An anti-lock brake controller that is operable, upon detecting a potential wheel lock-up situation during a vehicle braking cycle, to cycle apply and dump valves associated with vehicle rear wheels continuously between apply and dump modes to determine an estimated maximum friction wheel slip. The controller then is further operable to utilize the estimated maximum friction wheel slip to determine reference velocities that are used to continuously control apply and dump valves associated with the vehicle front wheels to optimize vehicle braking.

Anti-lock brake system with continuous wheel slip control

An electrohydraulic brake system where brake pressure is controlled by the combined action of an apply valve and a dump valve by the implementation of a method of controlling the voltage applied to the apply and dump valve. The EHB pressure control system receives a desired wheel pressure command and, with a caliper pressure feedback signal, implements an algorithm to compute one voltage command for the apply valve and another for the dump valve, corresponding to a requested flow from the hydraulics. The voltage command drives current control electronics. The electronics in turn power the solenoids of the proportional apply and dump poppet valves to control flow in or out of the brakes and modulate wheel pressure as required. Use of the algorithm to control the electromagnetic poppet valves achieves the commanded pressure at a vehicle's brakes reliably and with good control in all states of flow through the valve. The algorithm is a function of the existing pressure within the system and whether there is bulk or leakage flow through the valves.

Vehicle braking system with proportional poppet valve pressure control strategy

An apparatus and control method for a motor vehicle having steerable front and rear wheels and an associated wheel brake for each wheel. The apparatus and control method includes a sensor for generating a vehicle dynamic state signal based upon a sensed vehicle dynamic state of the vehicle. A vehicle stability control system is provided to control the selective braking of the wheel brakes of the vehicle based, at least in part, upon the vehicle dynamic state signal. A rear wheel steering system for controlling steering of the rear wheels based, at least in part, upon the vehicle dynamic state signal is also provided.

Control architecture and method for integrating vehicle stability control functions with rear wheel steering control functions in a motor vehicle

A system for real-time signal processing for vehicle monitoring, including a first device disposed in a tire of a vehicle and producing a signal that is a function of a tire contact time period, during which a point at the tire circumference stays in contact with the ground, and a second device operative to repetitively perform a first task of processing the signal to calculate the tire contact time period at a first predetermined rate, and to repetitively perform a second task of calculating a tire load based at least in part upon the calculated tire contact time period at a second predetermined rate, wherein said second predetermined rate is less than said first predetermined rate.

Real-time signal processing for vehicle tire load monitoring

Direct sensing of rough road conditions are used to modify operation of a wheel slip control system. At least one suspension sensor () senses an operating parameter of the suspension system. A road surface classifier is responsive to the suspension pension sensor () for generating a road surface signal representing a roughness of a road surface over which the vehicle travels. A braking system includes a wheel speed sensor and a brake actuator. An active braking control detector wheel slip in response to the wheel speed sensor () during at least one of braking or accelerating of the vehicle and modulates the brake actuator in response to the detected wheel slip. The active braking control is responsive to the road surface signal for modifying modulation f the brake actuator as a function of the road surface signal.

Rough road detection using suspension system information

The present invention determines a longitudinal wheel speed of an individual wheel from an angular rate signal from a wheel rotation sensor. Vehicle suspension information or operating characteristics are input to a suspension system mathematical model to determine instantaneous rolling radius, taking into account changes in tire rolling radius resulting from vertical motion of the road surface. Improved accuracy of wheel speed permits less severe filtering of wheel speeds in detecting wheel slip and/or modified speed and acceleration thresholds in slip control.

Advanced wheel slip detection using suspension system information

An electrohydraulic brake system where brake pressure is controlled by the combined action of an apply valve and a dump valve by the implementation of a method of controlling the voltage applied to the apply and dump valve. The EHB pressure control system receives a desired wheel pressure command and, with a caliper pressure feedback signal, implements an algorithm to compute one voltage command for the apply valve and another for the dump valve. The solenoids of the proportional apply and dump poppet valves are operated to control flow in or out of the brakes and modulate wheel pressure as required. The algorithm is used to control the electromagnetic poppet valves in all states of flow through the valve. The algorithm is a function of the existing pressure within the system and whether there is bulk or leakage flow through the valves.

A control system for controlling braking and ACC functions of a vehicle includes a braking algorithm. A first signal processor receives input signals from at least one sensor and transmits transfer signals to the braking algorithm. The control system also includes an ACC algorithm. A second signal processor receives input signals from at least one sensor and transmits transfer signals to the ACC algorithm. Transfer signals are generated by the braking algorithm and transmitted to the ACC algorithm. Transfer signals are generated by the ACC algorithm and transmitted to the braking algorithm. Output signals are generated by the braking algorithm and transmitted to a hydraulic control unit to control vehicular braking. Output signals are generated by the ACC algorithm and transmitted to ACC actuators.

Enhanced active brake control system functionality through system integration with adaptive cruise control

A brake control system determines when a wheel is unstable or stable during a braking condition. An unstable wheel is determined when the wheel speed is different from the estimated vehicle speed by greater than a fixed amount. When the wheel is determined to be unstable, an amount of brake pressure reduction is determined according to a proportional-plus-integral compensation. The proportional-plus-integral compensation is a function of the difference between the wheel speed and the estimated vehicle speed, as well as a wheel deceleration value. When the wheel is determined to be stable, brake pressure is applied according to an exponential rate. A hold mode is entered when the wheel is determined to be no longer decelerating during a dump cycle.

Brake control using proportional plus integral slip regulation and

A method of controlling the operation of an electrohydraulic brake booster to achieve a desired pedal feel. The method includes sensing brake pedal movement from a fully retracted rest position before a significant resistance to travel of the brake pedal is developed. The method further includes generating a command pulse that results in application of pressurized hydraulic fluid to the boost piston assembly sufficient to overcome preloaded spring forces and seal friction in the boost piston assembly that would otherwise tend to resist further brake pedal travel. The method further includes providing a control signal override when a brake pedal 'bounce' condition is detected to avoid undesired vehicle braking. A brake pedal bounce condition may occur if the brake pedal is released suddenly so that the brake pedal returns to the fully retracted rest position rapidly enough to bounce off of a mechanical stop at that position and move in the brake apply direction.

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Ann Arbor, MI, United States of America

Danny R Milot