Ford Motor Company Limited

Lee-Fei Chen

Davorin David Hrovat

Anthony T Ander

Larry T Brown

Craig John Simonds

Andrew A Adamczyk

A technique for estimating a traction characteristic of a surface under a moving vehicle, such as the coefficient of friction of the surface. The traction characteristic can be estimated by generating a torque signal representative of at least an estimate of the amount of torque applied to the driven wheels of the vehicle. A load signal representative of at least an estimate of the load or weight applied to the driven wheels also is generated. The value of the torque signal is divided by the value of the load signal in order to generate a characteristic signal. Depending on the amount of slippage between the driven and non-driven wheels of the vehicle, the characteristic signal can be stored in order to provide an estimate of the traction characteristic of the surface in real time.

Vehicular surface traction characteristic estimation techniques

A method is provided, for use in controlling an apparatus or for use by a controller of apparatus, for estimating a single torque variable utilizing multiple models. In one embodiment, the apparatus is a vehicle. The method includes the steps of sensing operating parameters to obtain associated operating signals and obtaining estimates of the torque variable from at least two independent models. Each model generates a torque estimate signal based on the operating signals. The method also includes the steps of weighting the individual torque estimate signals according to a predefined accuracy of the associated torque model, to obtain a plurality of weighted individual torque estimate signals, and generating a final torque estimate signal based on the weighted individual torque estimate signals. Once the final torque estimate signal is obtained, the apparatus can be controlled based on the final torque estimate signal.

Robust torque estimation using multiple models

Techniques for controlling the spin of driven wheels of a vehicle also including non-driven wheels and an engine controlled by a spark angle and/or throttle position. The spark angle is controlled by a signal responsive to a slip error signal and a slip error derivative signal in order to alter the spark angle in a manner that controls the spin of the driven wheels. The throttle position is controlled by a throttle position control signal that is responsive to a slip error signal, a slip error derivative signal, and a slip error integration signal, in order to adjust the throttle position in a manner that controls the spin of the driven wheels. Wheel spin also can be controlled by the combination of a spark angle control signal and a throttle position control signal.

Vehicular wheel spin control techniques

Techniques for controlling the spin of driven wheels of a vehicle being driven over a surface, the vehicle also including nondriven wheels and an engine having a fuel system for varying engine torque. A characteristic signal representative of at least an estimate of the value of a traction characteristic of a surface under the vehicle is generated. A drive signal having a value dependent on the value of the characteristic signal is then generated. The engine torque is varied in response to the drive signal in order to control the spin of the driven wheels of the vehicle.

Method for vehicular wheel spin control that adapts to different road

In a powertrain including an engine controlled by the position of the throttle valve, a hydrodynamic torque converter and multiple ratio automatic transmission connected to the drive wheels of the vehicle, a solenoid-operated hydraulic valve supplies pressurized fluid to engage and release the clutch that controls torque transfer between an offgoing clutch and an oncoming clutch. The position of the throttle valve and the speed of the engine are applied as input to a mathematical model programmed in algorithmic form for execution by a digital microprocessor. The engine produces a signal representing net torque output by the engine and torque converter, which signal is applied as input to an inverse mathematical model of the solenoid-operated valve that supplies hydraulic fluid to the controlling clutch. The unique relationship of phase to gain, the frequency response of the solenoid valve, is inverted within the frequency range of interest to remove the effects of delay. Torque converter turbine speed error is determined as it is applied as input to a PID compensated feedback control, whose output is summed with the inverse of the solenoid valve frequency response to produce a duty cycle supplied to the solenoid that controls pressure in the transmission friction element.

Automatic transmission gearshift control having feedforward response of

A powertrain including an engine controlled by the position of a throttle valve, a hydrodynamic torque converter having a bypass clutch, multiple ratio automatic transmission connected to the drive wheels of the vehicle, a solenoid-operated hydraulic valve that supplies pressurized fluid to engage and release the bypass clutch, is controlled by operation of a feedforward control system. An engine math model produces a signal representing the net torque output by the engine, which signal is applied as input to an inverse mathematical model of the solenoid-operated valve that supplies hydraulic fluid to the bypass clutch. The unique relationship of phase to gain, the frequency response of the solenoid valve, is inverted to remove the effects of delay and transient rise time. Torque converter slip error determined as the difference between torque converter impeller speed and turbine speed, is applied as input to a PID compensated feedback control whose output is summed with the inverse of the solenoid valve frequency response to produce a duty cycle supplied to the solenoid of the bypass pressure hydraulic valve.

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Ann Arbor, MI, United States of America

Lee-Fei Chen