doi: 10.17586/2226-1494-2015-15-4-615-622

# TRACKING CONTROL FOR A HYDRAULIC DRIVE WITH A PRESSURE COMPENSATOR

S. V. Aranovskiy, A. A. Losenkov, C. Vazquez

Article in Russian

For citation: Aranovskiy S.V., Losenkov A.A., Vazquez C. Tracking control for a hydraulic drive with a pressure compensator. Scientific and Technical Journal of Information Technologies, Mechanics and Optics, 2015, vol.15, no. 4, pp. 615–622.

Abstract
A problem of tracking control is considered for a hydraulic drive with a pressure compensator that is widespread in the equipment of heavy-duty machines. Method. The control problem is solved by means of a switching sliding-mode controller coupled with static nonlinear compensation and desired velocity feedforward. Main Results. Mathematical model of a hydraulic drive is given in view of the pressure compensator presence. Traditional model of a hydraulic drive is formulated for a system with a spool valve; purpose and principles of operation of the pressure compensator in hydraulic systems are described, and the extended model is presented illustrating compensator contribution to overall system dynamics. It is shown that the obtained model has an input static nonlinearity; the nonlinearity cancellation method is proposed giving the possibility for injection of a desired velocity feedforward term. The control law is chosen as a switching one and two chattering attenuation methods are studied: equivalent control estimation via filtering and sign function integration. Experimental studies are performed at a forestry hydraulic crane prototype and illustrate high tracking accuracy achieved for typical crane motions. Practical Significance. The results are suitable for heavy-duty hydraulic machines automation in construction, road building and forestry.

Keywords: hydraulic drive, pressure compensator, nonlinear model, static nonlinearity compensation.

Acknowledgements. The authors express their gratitude for Applied Physics and Electronics Department of Umeå University, Umeå, Sweden for putting at their disposal equipment to carry out experiments. This work was financially supported by Government of Russian Federation, Grant 074-U01.

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