Patent ID: 7353743

Claim:
An apparatus for controlling a position of a fluid operated cylinder having at least one fluid chamber defined by a piston located within a housing for movement between first and second end limits of travel, the apparatus comprising: at least one electrically actuated proportional flow control valve connected in fluid communication with each inlet port and each outlet port of the fluid operated cylinder to be controlled for selectively and proportionally controlling fluid flow into and out of the at least one fluid chamber of the fluid operated cylinder to be controlled; at least one pressure sensor for measuring fluid pressure with respect to each chamber of the fluid operated cylinder to be controlled; at least one discrete position sensor associated with the fluid operated cylinder to be controlled for sensing a discrete predetermined position of the piston within the cylinder to be controlled; and a control program executable by a control device operably connectible to the at least one valve, the at least one pressure sensor, and the at least one position sensor for controlling actuation of the at least one valve, the control program configured to calculate a pressure in the at least one fluid chamber required to move the piston a selected distance from a predetermined position within the housing, and for controlling the at least one electrically actuated proportional flow valve to obtain the calculated pressure within the at least one fluid chamber corresponding to the selected distance of movement for the piston within the cylinder to be controlled.