Electro-Hydraulic Steering System with Spool-Based Steering Event Detection

摘要

An electro-hydraulic steering system for an articulated machine includes an electrical circuit and a hydraulic circuit. The electrical circuit includes a controller, an electro-hydraulic valve assembly, and a spool position system. The hydraulic circuit includes a pump, at least one cylinder in selective fluid communication with the pump, and the valve assembly. The controller includes a computer-readable storage medium storing a steering system monitoring application which performs several steps. A desired flow of pressurized fluid to each cylinder and a desired spool position for the spool of the electro-hydraulic valve assembly, based upon the desired flow of pressurized fluid, are determined. The desired spool position and an actual spool position are compared to determine a spool-based flow error, which is summed over a period of time to determine a cumulative spool-based flow error. An event warning is issued when the cumulative spool-based flow error exceeds a threshold.

主权项

1. An electro-hydraulic steering system for a machine, the electro-hydraulic steering system comprising:
a controller; an electro-hydraulic valve assembly in electrical communication with the controller, the electro-hydraulic valve assembly including a spool reciprocally movable over a range of travel between at least two flow positions, the electro-hydraulic valve assembly adapted such that the spool moves in response to a control signal received from the controller; a spool position system having a sensor adapted to detect a position of the spool of the electro-hydraulic valve assembly and to generate a spool position signal indicative of the position of the spool, the spool position system in electrical communication with the controller and adapted to send the spool position signal to the controller; a pump adapted to provide a source of pressurized fluid; and a first cylinder in selective fluid communication with the pump; wherein the electro-hydraulic valve assembly is adapted to selectively direct the source of pressurized fluid to the first cylinder in response to the control signal received from the controller; wherein the controller is adapted to:
determine a desired flow of pressurized fluid to the first cylinder based upon a particular steering signal received by the controller,determine a desired spool position for the spool of the electro-hydraulic valve assembly based upon the desired flow of pressurized fluid,determine an actual spool position based upon the spool position signal received from the spool position system,compare the desired spool position and the actual spool position to determine a spool-based flow error,sum the spool-based flow error over a predetermined period of time to calculate a cumulative spool-based flow error for the predetermined period of time, andissue an event warning when the cumulative spool-based flow error for the predetermined period of time is outside of a predetermined range.