Multi-criteria optimization of the Dither current intensity in the case of proportional valve

The paper presents experimental studies of the impact of Dither current settings at: the hysteresis of proportional valves, pressure pulsations in hydraulic systems and vibration of the piston rod of hydraulic cylinders. Measurements were carried out for several parameter settings of the Dither current, including the manufacturer default settings and without the Dither control. On the basis of obtained results (using the multi-criteria optimization) optimal settings have been determined (frequency and amplitude). The optimum frequency of the Dither current intensity was compared with the value of the natural frequency of examined hydraulic cylinder (taking into account a hydraulic stiffness) and with the cut-off frequency of tested valve.