A Study of Large Flexible Space Structure Control Using γ-Passivity

本研究的目的是：1)发展基于伽玛无源概念的控制器设计方法；2)验证大型柔性空间结构振动的伽玛无源控制。该方法的特点是既能确定控制系统的增益和相位裕度，又能保证一般非结构化不确定性控制系统的鲁棒稳定性。指出h∞控制是鲁棒控制系统的一种标准设计方法，它不需要指定期望增益和相位裕度。因此，本研究提出的方法比h∞控制更灵活。对该方法进行了柔性结构控制实验验证。控制的目的是抑制振动和调节结构的角度位置。控制的难点在于角位置的移动会刺激结构的高频振动。因此，在位置沉降性能和振动性能之间存在权衡。针对这一困难，控制系统的设计应提高系统的调节性能，并保证对未建模的高频动态的鲁棒稳定性。伽马无源控制，更一般地说，是一种基于耗散率概念的控制，已被证明是有效的，理论上和实验上都能满足上述要求。

The purpose of this study is 1) to develop a controller design method based on the notion of gamma-passivity and 2) to validate the gamma-passivity control for the vibration of large flexible space structures. The feature of the method is to enable us to specify gain and phase margins of control systems as well as to guarantee the robust stability for usual unstructured uncertainty. The H-infinity control which is known as a standard design method for robust control systems is pointed out not to be specify desired gain and phase margins. Therefore, the method proposed in this study is more flexible than the H-infinity control. An experimental validation of the method has been made for a flexible structure control. The aim of the control is to suppress the vibration and to regulate the angular position of the structure. The difficulty of the control is that the movement of the angular position stimulates high-frequency vibrations of the structure. Consequently, there is a tradeoff between the performance of settlement of the position and vibration. Toward such difficulty, the control system should be designed to improve the regulation performance and to guarantee the robust stability for unmodelled high-frequency dynamics. The gamma-passivity control, more generally, a control based on the notion of dissipativity has been shown to be effective the requirement mentioned above, theoretically and experimentally.