Gm Global Technolgoy Operations, Inc.

Gregory K Peterson

David T De Carteret

Ian Y Hwa

Larry G Gepfrey

Scott A Kolp

William Keith Adams

Roderick L Lemmer

Mark S Hogle

Embodiments discussed herein enable detection of traction steer using measured and expected values of steering system data, such as, for example and without limitation, motor current, motor torque, motor position, motor velocity, steering wheel angle, and steering column torque. In some embodiments, the measured steering system data is compared to expected signal values, based on vehicle operating conditions, to determine if the vehicle is experiencing a traction steer event. In some embodiments, using known relationships between two or more steering system signals, a traction steer event is identified if an unexpected relationship is determined.

Methods and systems for traction steer detection

A suspension system for a vehicle is provided. The vehicle comprises a pair of rear wheels and a prop-shaft. A rear drive unit is operably coupled between the prop-shaft and the pair of rear wheels, the rear drive unit being configured to transmit torque from the prop-shaft to the pair of rear wheels. A twist-beam structure is provided having a first trailing arm and a second trailing arm. Each of the trailing arms is operably coupled to one of the pair of rear wheels. The twist-beam structure further comprising a curved beam member extending between the trailing arms, the curved beam member having a center portion disposed offset from the prop-shaft. A Watt linkage includes a first link coupled to the first trailing arm and a second link coupled to the second trailing arm.

Twist beam with watt linkage for driven rear axle

A method for characterizing a stiction condition in a manual steering gear includes transmitting a steering input control signal to a rotary actuator, and rotating a steering shaft with constant acceleration, via the rotary actuator, in response to the steering input control signal. A steering output torque is determined while rotating the steering shaft with the constant acceleration, receiving the steering output torque via the controller, and executing a control action when a rate of the received steering output torque exceeds a threshold rate indicative of the stiction condition. A system includes a rotary actuator, a manual steering gear having a steering shaft connected to the rotary actuator, a torque transducer for measuring a steering output torque imparted to the steering shaft by the actuator, and a controller programmed as set forth above.

Characterization of stiction condition in a manual steering gear

A system, method, and computer program product for detecting and compensating for a traction steer event is provided. A first wheel speed of a first driven wheel is compared with a second wheel speed of a second driven wheel to determine whether a wheel slip condition has occurred. If a wheel slip condition is determined to have occurred, a current operating state of a vehicle is compared to an expected operating state of the vehicle to determine if a traction steer event has occurred. If a traction steer event is determined to have occurred, brake pressure is selectively applied to the first or second driven wheel to compensate for the traction steer event.

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South Lyon, MI, United States of America

Gregory K Peterson