Experimental demonstration of a method to actively stabilize satellite structures against random perturbations of thermal boundary conditions using a closed-loop filter and controller approach

Abstract

AbstractModern space travel requires increasingly stable support structures for optical instruments or antennas, which can hardly be realized with the traditional approaches. Therefore, an approach for active structural stabilization of thermal-induced distortions was developed, simulated, and patented within the framework of the Infrared Astronomy Satellite Swarm Interferometry (IRASSI) project. Based on this approach, the thermomechanical transfer functions between the change in heat flux and the change in displacement of the finite-element (FE) model of a structure have already been validated in their basic functionality. In an experimental setup, the FE model was extended to include a closed-loop filter and controller approach consisting of a Kalman filter processing the temperature measurements in conjunction with a Linear Quadratic Regulator (LQR). It was shown that this setup can compensate for predefined sinusoidally oscillating disturbance heat flows, with an improvement of 4 dB compared to the uncontrolled case. In this paper, an experimental setup revised with respect to the positioning of the sensors and control heating elements, in conjunction with an extension of the filter and controller approach, will demonstrate that the system can respond to reproducible, random fluctuations in the disturbance heat flux, as well as stepped changes, and that performance has improved due to the revision.