High-Speed On/Off Position Control of a Low-Pressure Water Hydraulic Cylinder Drive

The high-speed but accurate on/off positioning of a low-pressure water hydraulic cylinder is realized by connecting a large 4/3 on/off valve in parallel with four small 2/2 on/off valves. Design rules for the dimensioning of the valves are given based on the required position accuracy and maximum allowed pressure peaks. Experimental results with a 100 kg load mass show that 400 mm/s velocity and 0.3 mm position accuracy can be achieved despite of variations in load force, piston position or stroke length.