Method and apparatus for suppressing vibration in vehicle a steering system

A power-assisted steering system for a wheeled vehicle comprising:

• a steering actuator movable along an axis to steer at least one wheel;
• a power boost system operative to urge the steering actuator;
• a housing enclosing at least a portion of the steering actuator and having an inner surface oriented toward the steering actuator;
• a damping member disposed between the steering actuator and the housing and having an outer surface oriented toward the housing;
• a clamping member disposed between the damping member and the housing, the clamping member movable parallel to the axis between a damping position wherein the clamping member is wedged between the inner surface of the housing and the outer surface of the damping member to urge the damping member against the steering actuator, and a released position wherein the clamping member does not urge the damping member against the steering actuator;
• and
• a control system operative to move the clamping member to the released position when the power boost system is urging the steering actuator along the axis, and to move the clamping member to the damping position when the power boost system is not urging the steering actuator along the axis.