Hydraulic Switching Control - Principles and State of the Art

Today, switching control is the common method to control electrical drives and replaced former drive control technologies nearly totally. Several researchers orally report about their trials to apply switching principles in hydraulics and that they gave up due to several hard problems encountered, such as great noise. In the work of the authors’ research group it turned out that switching control can be applied to hydraulics as well with a substantial improvement of efficiency, the possibility of energy recuperation, and a cost reduction compared to proportional valve techniques. Numerous converter principles are conceivable. But whatever principle is realized it requires fast switching- and check- valves, fast response and compact accumulators, a compact arrangement of all components affected by the switching processes, and a sound understanding of fast hydraulic processes.