Patent ID: 6615114
Filing Date: 2003-09-02
Classification: E02F,F15B,G01L

Abstract:
A calibration system for a work machine using an electro hydraulic valve to control the operation of a work element, the work machine for use in a location having an atmospheric pressure, the valve being connected to the work element via a hydraulic circuit which includes actuator means coupled to the work element for controlling the operation thereof, the calibration system comprising:a pressure sensor positioned in communication with the valve and adapted to sense a pressure being exerted against the work element, the pressure sensor outputting a pressure sensor signal having a pressure sensor signal value indicative of the sensed pressure; and a controller in communication with the pressure sensor and adapted to automatically and dynamically calibrate the pressure sensor signal value to the atmospheric pressure, the controller comprising: storage means for storing the atmospheric pressure; a comparator in communication with the pressure sensor and adapted to compare the stored atmospheric pressure to the pressure sensor signal value of the received pressure sensor signal at atmospheric pressure; a detector in communication with the comparator and adapted to detect a difference between the stored atmospheric pressure and the compared pressure sensor signal value at atmospheric pressure; and a calculator adapted to calculate an atmospheric pressure calibration factor representing the detected difference such that accurate control of the pressure sensor is achieved.