LPV Control for Active Vibration Mitigation in High Stability Space Missions: A Comparative Study

Robust microvibration mitigation and pointing performance analysis for high stability spacecraft

“…The goal, which is to establish stability and performance, bounds to drive the closed-loop system to the limits of achievable performance. This paper builds upon the previous work reported in other works [16][17][18][19][20] and introduces the following key contributions in modeling, performance specification, robust controller synthesis, and performance analysis:…”

“…The proposed microvibrations strategy is based on the previous work reported in other works. [16][17][18][19][20] The isolation architecture relies on passive elastomer isolators to mitigate high-frequency harmonics while a complementary active control strategy targets the low-frequency perturbations. The model of isolation setup is afterwards integrated with the simplified structural model of a flexible spacecraft driven by a reaction wheel.…”

“…In order to avoid placing contradictory requirements, consider the closed-loop transfer M d w →e p = W p (G pd −G pu S i KG d )W d from normalized wheel disturbances d w to pointing performance e p and assume that the weight W p has a high gain in a particular frequency region. In order to satisfy the requirements (32), the controller must shape the function S i K with sufficiently high gain in the same frequency range and decrease the open-loop disturbance contribution given by P d w →e p = W p G pd W d (see (18)). However, a high amplitude S i K will also cause an amplification of the noise contribution to the pointing errors M d n →e p and potentially conflict with the requirements on the robust stability and control effort performance.…”

“…The goal, which is to establish stability and performance, bounds to drive the closed‐loop system to the limits of achievable performance. This paper builds upon the previous work reported in other works and introduces the following key contributions in modeling, performance specification, robust controller synthesis, and performance analysis: a new disturbance model that is suitable for synthesis/analysis for the perturbations produced by a reaction wheel spinning at a particular rate; the uncertain and parameter varying model that is derived in this paper contains the dynamics of the satellite with its flexible attachment, the ACS, the microvibration mitigation unit including the reaction wheel. The resulting end‐to‐end model considers the coupling between all these various subcomponents; the control objectives are defined both in terms of pointing performance of the optical instrument and are guaranteed for the particular mission profile; a procedure is introduced to synthesize a low‐order robust linear parameter varying (LPV) controller for different levels of system uncertainty and the closed loop is afterwards analyzed for time‐varying parameters, saturations and time‐varying delays using μ and IQC analysis. …”

“…In line with these goals, the aim of this paper is to design a microvibration mitigation system for generic observation satellites equipped by flexible appendages, reaction wheels and an ACS, with the main objective to improve the pointing performance of the optical instrument, the final goal being the improvement of the image quality. The proposed microvibrations strategy is based on the previous work reported in other works . The isolation architecture relies on passive elastomer isolators to mitigate high‐frequency harmonics while a complementary active control strategy targets the low‐frequency perturbations.…”