摘要 |
<p>A control system is provided for a tracked vehicle drive/steering system having an engine driven hydraulic steering pump (40) which drives a hydraulic steering motor (42). The steering pump (40) is responsive to steering control signals representing a status of an operator manipulated steering wheel (74). The steering motor (42) provides an input to a differential track drive mechanism which responds to manipulation of the steering wheel (74) and drives left and right tracks to turn the vehicle. The control system includes a control unit (70) which receives signals from an engine speed sensor (62), a steering motor rotation speed and direction sensor (80), and the steering control signals. The control unit (70), when the steering control signals indicate that the steering wheel (74) is turned in a direction opposite to a direction of rotation of the steering motor (42), generating and saving a first ratio value representing a ratio of the motor speed to the pump speed. Then, if the steering control signal is unchanged after a certain time duration, the control unit (70) generates and saves a second ratio value representing a later ratio of the motor speed to the pump speed. The control unit (70) then calculates a difference value representing a difference between the first and second ratio values, and generates a fault signal if the difference value has a magnitude which is less than a predetermined magnitude. Thus, the control system generates a fault signal when the sensed signals indicate that the steering pump swashplate position is not changing as it should in response to changes in steering wheel position. <IMAGE></p> |