Hydraulic Switching Control - Objectives, Concepts, Challenges and Potential Applications

Hydraulic switching control operates via the switching of valves. Numerous principles exist, some of which are already routinely applied, some others have been studied, but many more are possible. A successful realization of many switching techniques requires fairly advanced hydraulic components, foremost fast switching valves, fast check valves and compact accumulators which can resist high load cycles, and a sound understanding of the relevant processes by advanced modelling, simulation, and experimental analysis. Switching control can bring the following advantages: lower costs, higher robustness, better standardization, easier control due to better repeatability and less hysteresis; better energetic efficiency by the application of energy saving converter principles; generation of very fast motion for relatively high loads. Some elementary switching principles and switching converter principles are described in this paper. The authors expect an early industrial application of novel switching techniques in heavy duty and in agricultural machines.