Abstract: Generating powertrain torque versus throttle angle position data is done in order to, in effect, linearize the relationship between the two. The results improve pressure control through a reduction in slip during a dry road to ice transition, and other maneuvers where large surface friction coefficent changes are common and may be encountered.

Abstract: A method of controlling the driving wheels of a vehicle having an internal combustion engine wherein it is determined if a vehicle stuck or not and then, if stuck, the maximum permissible amount of wheel slip is increased with the intent of removing loose material, such as snow, underneath the tires. If the vehicle remains stuck and wheel slip continues, the amount of driving power and torque to the wheels is then reduced. Conversely, if the spin is not present at the subsequent gas pedal application (tip-in), and the vehicle is still stuck, the wheel torque limit is increased.

Abstract: Traction control for an internal combustion engine uses the gas pedal position, steering wheel position and velocity to set a wheel slip target during traction control operation.

Abstract: This invention uses cross-axis oscillation control of braking for traction control systems. Changing the amount of braking on each side of the vehicle reduces total wheel slip in a well-controlled, smooth and highly effective manner.

Abstract: A vehicle yaw control for a vehicle having wheel brakes wherein the wheel brakes complement driver controlled steering efforts by establishing a maximum steering angle that can be used for any given coefficient of friction at the wheel-road interface and for any given speed, thereby achieving optimum lateral control during turning maneuvers by compensating for under-steering and over-steering for each driving condition.

Abstract: A method for estimating hydraulic pressure in a control system that includes hydraulic pressure actuators (28,30) remotely situated with respect to a pressure source (14) wherein pressure at the remote location can be estimated thereby eliminating the need for using pressure transducers to obtain a pressure signal for use in an electronic controller (86,90,142) based on a calibratable relationship between estimated brake pressure and the difference in the volume of fluid flowing toward the pressure actuator and from the pressure actuator. An effective duty cycle for a solenoid operated fluid flow control valve (60,62) in the actuator circuit is determined in accordance with an empirical relationship between the difference between (i) the estimated brake pressure and the supply pressure and (ii) a commanded duty cycle.

Abstract: An electronic controller for automatically adjusting the position of a throttle valve in either a single valve or a series valve throttle mechanism. A primary controller (20) produces an output signal (18) suitable for directly operating the single throttle valve in a "drive by wire" throttle system. When used to position a valve (32) in a two-valve series throttle system, the other valve (34) being directly controlled by the accelerator pedal, a signal translation unit (30) is employed to modify the output signal (18) from the primary controller in response to the current setting of the accelerator-controlled valve (34) and values indicating the current air flow rate (Q.sub.1) and the intake manifold pressure (P.sub.m). The primary controller (20) and the signal translation unit are implemented using a conventional electronic engine control processor, with the signal translation being performed by table lookup operations (51-54).

Abstract: An electronic traction controller for a vehicle reduces oscillations between a pair of driving wheels which may occur when the the traction controller attempts to control wheel spin of the driving wheels on surfaces which have differing frictional resistances, such as roads partially covered by snow and ice. The traction controller estimates the coefficient of friction beneath each of the driving wheels, and if the frictional resistance of the surfaces beneath each of the driving wheels varies by more than a predetermined amount, or if only one wheel is spinning, a value indicative of the inertia torque of the driving wheel and powertrain combination is determined, and compared against a predetermined value. A slip error value for each of the driving wheels is generated, which is indicative of the difference between the actual rotational speed of the driving wheel and the desired rotational speed of the driving wheel.

Abstract: Method, for use in a vehicle including a four wheel steering system and an electronic control unit having memory, of controlling the four wheel steering system while at least one of the wheels is under a torque load such that the vehicle behaves like a front wheel steering vehicle under no torque load, or a four wheel steering vehicle under no torque load. The method includes determining at least one control gain for the four wheel steering system so that the torque loaded vehicle behaves like a front wheel steering vehicle under no torque load, and controlling the four wheel steering system according to the control gain, thereby improving directional stability of the vehicle travelling on a slippery road surface. Apparatus is provided for carrying out the method.