Performance Improvement of Slowly Moving Fluid Power Drives Using Pulse-Width-Modulation
An experimental investigation was conducted to determine the effects of the dry friction, fluid compressibility and mechanical compliance on the output motion of a slowly moving fluid power drive. In these experiments, the characteristic of the stick-slip vibrations was determined.
In an attempt to attenuate, ultimately to supper the induced vibration, high frequency, low amplitude dithering technique was superimposed into the main motion of the load. Dither signal was generated by applying Pulse-Width-Modulation (PWM) technique as the input signal to the electro-hydraulic servomechanism. The load consists of fixed inertia, variable dry friction force and driven via variable mechanical compliance link. The effects of the dither signals on the quality of the output motion been investigated. As a result, the critical values of dither amplitudes and frequencies to suppress the stick-slip vibrations were determined.
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