부산대학교 도서관

This paper investigates the closed-loop positioning of a dielectric elastomer actuator (DEA) in which the high-voltage driving signal is generated by custom-developed electronics. The adopted driving circuit amplifies a 0 - 6 V input signal up to 0-3000 V at its output, but it introduces at the same time non-linearities and signal distortions which negatively affect the DEA actuation behaviour. A cascade control architecture is proposed to compensate for such effects and, in turn, achieve accurate motion control of the DEA. An inner voltage control loop is used to enhance the accuracy and bandwidth of the high-voltage circuit, while an outer position loop is designed by treating the controlled amplifier as a static gain. Three control architectures are then experimentally compared, in which the high-voltage command signal determined by the outer position controller is applied to the DEA via (i) the custom high-voltage circuit operating in open-loop; (ii) the custom high-voltage circuit operating with an inner voltage regulation loop; (iii) a commercially-available and bulky high-voltage amplifier. The obtained results show how the performance of (ii) is significantly closer to (iii) than to (i), thus demonstrating that our custom-developed electronic in combination with an inner voltage loop represents an effective means to develop accurate and cost-effective DEA motion control systems.