ACTIVE VIBRATION ISOLATION AND EXCITATION BY PIEZOELECTRIC SLAB WITH CONSTANT FEEDBACK GAINS

A theoretical and experimental study of an active vibration isolation technique for high-precision position control involving use of a piezoelectric slab via the converse piezoelectric effect is presented. A theory of the piezoelectric isolation/excitation is first derived. A physical model made of polyvinylidene fluoride (PVDF) polymer slab is prepared to study its vibration excitation and to evaluate its active vibration isolation by injecting a processed feedback voltage at constant gains. The model is subjected to various amplitudes of base excitation at different frequencies, and the isolation characteristics of the piezoelectric slab are observed. Analytical solutions are in satisfactory agreement with the experimental results. The study shows that the vibration isolation is constant for different voltages at any given frequency, and a linear variation with frequency at constant feedback gains. The piezoelectric excitation is a linear function of excitation voltage for constant frequency and a quadratic function of frequency for constant excitation voltage. © 1990.