APPARATUS FOR ESTABLISHING STEERING FEEL

摘要

A steering apparatus for artificially establishing steering feel in a steering system not having a mechanical connection between the steering wheel and the steerable wheels. The apparatus includes a hydraulic steering motor connected to the steerable wheels. A steering wheel position sensor and a steerable wheel position sensor each produce an electrical signal respectively indicative of the steering wheel position and the position of the steerable wheels, An electronic control unit monitors the sensor signals and controls a solenoid operated directional control valve to steer the vehicle in a direction and at a steering rate in response to the monitored signals. An electromagnetic friction brake is connected to a support and to the input shaft and is controlled by the electronic control unit to provide steering feel. The friction brake includes an armature fixed to the support and a brake member secured for rotation with the input shaft via a spline connection. The brake member is movable toward the armature under the influence of the magnetic field generated by the armature. The degree of mechanical coupling between the armature and the brake member is proportional to the magnetic field strength. Steering feel is controlled by the electronic control unit in response to the difference between the desired steering direction, as determined from the steering wheel position sensor, and the actual steering direction, as determined from the steerable wheel position sensor.