3-DoF zero power micro vibration isolation via linear matrix inequalities based on H_∞ and H_2 control approaches

摘要

Zero-power micro vibration isolators based on hybrid electromagnets, consisting of coils and permanent magnets, have potential usage in many industrial and academic fields, such as space laboratory operations in orbit, micro-nano assembly, clean room design, bio-engineering, Stewart platforms, transportation, semiconductor manufacturing, suspension system design, and robotic surgery platforms etc. due to providing mechanical contact free micro vibration isolation with comparatively low energy consumption. Classical controllers optimized in time-domain do not show satisfying disturbance rejection performance for multi-directional mechanical disturbances varying at different frequencies. To tackle this problem, optimization techniques in frequency-domain are needed. In recent years, linear matrix inequality (LMI) based controllers have received lots of attention and become very popular due to their ability to satisfy multi-objective frequency-domain requirements. However, an experimental research including LMI based H_∞ and H_2 feedback controllers for a zero-power 3-DoF micro vibration isolator has not been conducted so far. In this study, H_∞ and H_2 controller types are employed to minimize the H_∞ and H_2 norms of both ground and direct disturbances for 3-DoF micro-scale vibration isolation with zero-power objective. Moreover, the experimental setup has been designed and manufactured to meet aforementioned goals. The design parameters of the experimental setup are explicitly given. The effectiveness of the proposed LMI structures for 3-DoF micro vibration isolation with zero-power problem is shown with the experimental results.