Patent ID: 6341552
Filing Date: 2002-01-29
Classification: F15B,F16D,F16H,G05D

Abstract:
A method for automatically calibrating a hydraulic control system comprising the steps of:(a) providing a source of hydraulic fluid pressure; (b) supplying said hydraulic fluid pressure to an inlet of an electrically operated pressure control valve; (c) connecting an outlet of said pressure control valve to a hydraulically operated actuator; (d) providing a controller with a control logic and a memory; (e) connecting said controller to said pressure control valve; (f) energizing said pressure control valve with a control signal from said controller and providing a controlled hydraulic fluid pressure through said valve outlet to said hydraulically operated actuator; and (g) sensing the pressure of said controlled hydraulic fluid pressure and at a set point level providing a signal indicative thereof to said memory of said controller and storing the same in memory; (h) measuring an amount of current to said pressure control valve required for said hydraulic fluid pressure to reach said set point level; (i) comparing said measured current with a preset value of said current as a function of pressure; and, (j) adjusting said control signal based upon a comparison of the measured current with the preset value of current for automatically calibrating the hydraulic control system.