论文部分内容阅读
基于模型降阶的控制器由于忽略了高频未建模动态的影响,有可能产生溢出问题从而导致闭环系统不稳定,难以保证振动控制的效果,考虑高频未建模动态等不确定性问题影响,克服传统控制策略在振动主动控制中的不足,研究了柔性悬臂梁结构振动系统的H_∞鲁棒主动控制策略。基于ANSYS软件数值模拟得到压电柔性悬臂梁结构的模态振型,避免了试验建模的繁琐性、复杂性及较高的成本投入,通过与理论结果的比较,验证了ANSYS软件分析结果的正确性。通过模态分析提取了压电柔性悬臂梁结构的前3阶模态振型,剩余模态作为模型的不确定性加以考虑,通过分析系统存在的模型不确定性以及选取适当的权函数,最终完成了柔性悬臂梁结构振动系统的鲁棒控制器设计。通过从频率域上分析闭环传递函数的奇异值,表明权函数有较强的抑制外部干扰的能力,通过从时域上分析开环和闭环振动系统的单位阶跃响应,表明闭环振动系统的振幅很快趋于稳定且在较长时间内没有出现溢出不稳定现象,仿真结果表明,基于H_∞控制理论的混合灵敏度分析方法的鲁棒控制器能有效抑制悬臂梁的振动,振动系统的动态性能及鲁棒性能均得到了极大改善。
Based on model reduction, ignoring the influence of high-frequency unmodeled dynamics, it is possible to generate overflow problems that lead to instability of the closed-loop system, to ensure the effect of vibration control and to consider uncertainties such as high-frequency unmodeled dynamics , Overcomes the shortcoming of the traditional control strategy in the active vibration control, and studies the H_∞ robust active control strategy of the flexible cantilever vibration system. Based on the numerical simulation of ANSYS software, the modal vibration modes of the piezoelectric flexible cantilever beam structure are obtained, which avoids the cumbersomeness, complexity and high cost of experimental modeling. By comparing with the theoretical results, the results of ANSYS software analysis Correctness Through the modal analysis, the first 3 modes of piezoelectric cantilever beam structure are extracted and the remaining modes are considered as the uncertainty of the model. By analyzing the model uncertainty and selecting the appropriate weight function, the final The robust controller design of flexible cantilever structure vibration system is completed. By analyzing the singular values of the closed-loop transfer function from the frequency domain, it is shown that the weight function has a strong ability of suppressing external disturbances. By analyzing the unit step responses of the open-loop and closed-loop vibration systems in time domain, it is shown that the amplitude of the closed-loop vibration system The simulation results show that the robust controller based on hybrid sensitivity analysis of H_∞control theory can effectively restrain the vibration of cantilever beam and the dynamic performance of vibration system And robust performance have been greatly improved.