Micropositioning and microvibration isolation of a novel hybrid active–passive platform with two-axis actuator for optical payloads

Abstract

Space missions face developmental limitations in the endeavor to attenuate microvibration significantly while aiming to achieve high micropositioning accuracy. To overcome this issue, various passive, active, and hybrid approaches have been proposed. Regarding the tradeoff performance, the hybrid method may be the most suitable among these approaches. However, the significantly small mass ratio between the platform and service payload cannot be adapted to the recent and future space missions. Therefore, a novel modular-based three-leg supporting hybrid active–passive platform is proposed, which aims to improve the microvibration isolation and micropositioning performance of ultraprecision equipment in a dynamic environment. A Newton–Euler-based method was adopted to describe the system accurately. To achieve motion decoupling of the system, we synthesized a suitable location layout for the three modular units and modal decoupling control method. In addition, an innovative custom-made two-axis actuator with a large stroke and high thrust was employed to strengthen the operational accuracy and dynamic performance. To simultaneously determine the microvibration isolation and micropositioning performances, hybrid micropositioning and microvibration isolation controllers, which synthesize the velocity feedforward and feedback, are proposed. Experiments and actual application demonstrated the effectiveness of the proposed scheme in terms of microvibration attenuation and micropositioning.