Rudolf Scheidl, Ingo Biedermann, Andreas Plöckinger,
"Stabilizing Rest Positions of the Linear Digital Hydraulic Amplifier"
, in Arto Laamanen and Matti Linjama: Proceedings of the Fifth Workshop on Digital Fluid Power - DFP12, Tampere Finland, Seite(n) 89-102, 10-2012, ISBN: 978-952-15-2941-2
Stabilizing Rest Positions of the Linear Digital Hydraulic Amplifier
Sprache des Titels:
Proceedings of the Fifth Workshop on Digital Fluid Power - DFP12, Tampere Finland
The Linear Digital Hydraulic Amplifier is a modification of the classical linear hydraulic amplifier. It employs a finite number of hydraulic cylinders which are connected to high or low pressure depending on the force requirements. The control is accomplished only by mechanical and hydraulic components. Since a digital cylinder drive without closed centre valves can only realize discrete force values, a load force between these discrete force levels cannot be compensated statically but requires a periodic switching of the system leading to oscillations around the intended rest position and permanent energetic losses. In this paper two concepts for stabilizing the rest position employing check valves are studied. With these a rest position can be held stably in principle. In combination with position control, however, a complex stability problem occurs with complex stability boundaries in the parameter space.