Gm Global Technolgoy Operations, Inc.

William Keith Adams

Ian Y Hwa

Kenneth L Oblizajek

John D Sopoci

Gregory K Peterson

Roderick L Lemmer

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 test apparatus for eliciting a gear rattle from a gear-train employed in a device includes a fixture configured to support the device in a fixed starting position. The test apparatus also includes a tie-rod operatively connected to the device. Additionally, the test apparatus includes a controller configured to command the tie-rod to apply to the device at the starting position a force event defined by a mathematical function continuous in time. The force event is configured to elicit the gear-train rattle from the gear-train. A method for eliciting a gear rattle from a gear-train employed in a device is also disclosed.

Method and apparatus for excitation of gear rattle

Methods and systems are provided for evaluating a steering system of a vehicle, in which the steering system includes a steering column, steering rack, and pinion. The rack is manipulated as the steering system is mounted to a testing system. The steering column is also manipulated as the steering system is mounted to the testing system. Data is collected from the manipulating of the rack and the dithering of the steering column for use in evaluating the steering system.

Methods and systems for evaluating vehicle steering systems

A method for characterizing steering gear reversal clunk noise in a steering system having a rack and a pinion gear, and electric power steering assist via a steering assist motor, includes transmitting a steering input angle control signal to a rotary actuator to rotate a steering shaft to a fixed steering angle with assist active. A linear actuator applies an axial force at a constant rate along a longitudinal axis of the rack. Axial rack acceleration is measured after imparting the axial force. A control action is executed when peak amplitude of the axial acceleration value exceeds a calibrated threshold axial acceleration value indicative of the clunk noise. A system includes the rotary actuator and steering system, a linear actuator for providing a calibrated axial apply force along the rack axis, an accelerometer for measuring an axial acceleration value of the rack, and the controller noted above.

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Brighton, MI, United States of America

William Keith Adams