Rainer Haas, Evgeny Lukachev,
"Optimal feedforward control of a digital hydraulic drive"
: Proceedings of the Seventh Workshop on Digital Fluid Power, Seite(n) 129-142, 2-2015, ISBN: 978-3-200-04014-4
Optimal feedforward control of a digital hydraulic drive
Sprache des Titels:
Proceedings of the Seventh Workshop on Digital Fluid Power
Digital control of hydraulic applications is usually done using pulse width or pulse frequency modulation. In the case of good natured hydraulic applications, these controllers can easily be tuned by well experienced technicians. But there are a lot of other cases where such controllers lead to unwanted pressure peaks, position oscillations or even cavitation right behind the actuated vales. With the use of optimal feedforward control it is possible to keep additional restrictions beside the desired fast change of state, e.g. the position or the pressure in a volume chamber. Such an additional constraint could be a limitation of the lower pressure in order to avoid cavitation. The goal of this paper is formulate an optimisation problem which leads to a switching (digital) behaviour of the valves. For implementation and numerical evaluation of the result a solution technique was chosen which can be easily parallelized. It shows good convergence behaviour even if the initial values of the optimisation are a crude guess. Obtained results are verified using a more complex simulation model of the hydraulic circuit. The sensitivity of the optimized result on variation of the feedforward control signal is studied.