TRACKED VEHICLE STEERING SYSTEM WITH STEERING PUMP MONITORING

摘要

A control system is provided for a tracked vehicle drive/steering system having an engine driven hydraulic steering pump which drives a hydraulic steering moto r. The steering pump is responsive to steering control signals representing a status of an operator manipulated steering wheel. The steering motor provides an input to a differential track drive mechanism which responds to manipulation of the steering wheel and drives le ft and right tracks to turn the vehicle. The control system includes a control unit which receives signals from an engine speed sensor, a steering motor rotation speed and direction sensor, and the steering control signals. The control unit calculates a motor speed threshol d value as a function of sensed engine speed and steering control signals, and generates a fault signal as a function of a relationship between the steering motor speed signal and a motor speed threshold value. The control unit generates an overspeed fault signal when t he steering motor speed signal is greater than the motor speed threshold value or less than a negative motor speed threshold value, and generates a data conflict fault signal when the steering motor speed signal is less than a negative minimum motor speed threshold val ue or greater than a minimum motor speed threshold value. The controlunit, when the vehicl e is not being commanded to turn by the steering control signals, generates a minimum threshold value, and generates an overspeed fault signal when the motor speed signal i s greater than the minimum threshold value or is less than a negative minimum threshold value.