Patent ID: 7518523

Claim:
An actuator position control system comprising an actuator; at least one actuator position sensor mounted to the actuator; a flow control valve having at least one main stage spool, at least one spool position sensor that monitors the position of the main stage spool, a supply port, a tank port, a first control port, and a second control port wherein the flow control valve is in fluid communication with the actuator; a plurality of fluid pressure sensors for monitoring pressure of fluid at the supply port, the tank port, the first control port, and the second control port of the flow control valve; and a controller being in electrical communication with the flow control valve, wherein the controller is configured to: receive a desired actuator position input; receive fluid pressure data signals from the plurality of fluid pressure sensors; receive spool position signals from the spool position sensor; receive actuator position data signals from the actuator position sensor; determine corrected fluid flow rates to and from the actuator based on the fluid pressure data signals, the spool position signals, and an error-correction factor, wherein the error-correction factor is a function of the fluid pressure data signals and the spool position signals; determine estimated actuator position, wherein the estimated actuator position determination includes a kinematic component, which is a function of the corrected fluid flow rates to and from the actuator, and a dynamic component, which is a function of a pressure of a chamber of the actuator; apply adaptive gain factors to calibrate the estimated actuator position to the actuator position data signals from the actuator position sensor; compare the estimated actuator position to the desired actuator position input; and close the main stage spool valve to prevent fluid communication to the actuator.