METHOD OF VALVE CALIBRATION

摘要

A method of calibrating an electrically actuated hydraulic valve in a system that controls the flow of hydraulic fluid to a hydraulic cylinder connected to a machine element operates automatically. The system includes an ultrasonic sensor providing an indication of the position of the machine element. The calibration method includes the step of automatically applying a command signal to the hydraulic valve while monitoring the ultrasonic sensor to determine the level of the command signal required to cause the hydraulic cylinder to begin to move. The calibration method includes the additional step of automatically applying in succession a plurality of command signals of increasing level to the hydraulic valve while monitoring the ultrasonic sensor to determine the speed of movement of the hydraulic cylinder resulting from each of the command signals. Finally, the calibration method includes the steps of storing the level of the command signal required to cause the hydraulic cylinder to begin to move, and storing the speed of movement of the hydraulic cylinder resulting from each of said plurality of command signals of increasing level.