Synthesis of trajectories in piezoelectric attitude control devices for nanosatellites

Abstract

Multi-degrees-of-freedom piezoelectric actuators can with be successfully used for nanosatellite’s attitude control. Piezoelectric actuators enable to increase resolution of the system and to reduce a number of components. Therefore accuracy and reliability of the control system increases, while cost decreases. There is several attitude control devices developed till now, where piezoelectric rings or cylinders are used. Actuator consisting of piezoelectric cylinder and the solid sphere was proposed to use for 3D attitude control device [1]. Axial traveling waves of the cylinder together with 3D oscillations in the contact points cylinder – sphere were employed to achieve 3D rotation of the sphere. However trajectory control problem of the contact points was faced, so detail investigation of that problem is given in this paper. Numerical modelling of piezoelectric actuator was performed to validate actuator design and operating principle through the modal and harmonic response analysis. Prototype piezoelectric actuator was build and experimental measurements of contact point trajectories were performed. The results of numerical modelling and experimental study are compared and discussed.