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Stewart平台是一种并联减振机构,因其具有承载能力强、刚度大、结构稳定、精度高等优点,广泛应用于航天航空和精密仪器领域。采用Cubic构型Stewart平台并对压电陶瓷的力-位移关系线性化后,可简化成单自由度的线性主动控制系统,对六自由度的Stewart平台分散控制,在随机平稳白噪声的激励下考虑时滞影响,并对其解耦后的Stewart平台进行LQR数值分析,用Adams预测公式进行时滞补偿。分析结果表明:Stewart平台具有较好的减振性能,能有效减小平台在微重力干扰下引起的位移反应;时滞因素会降低LQR的控制作用;可通过Adams预测公式对时滞影响进行较好地补偿。
Stewart platform is a parallel damper mechanism, because of its bearing capacity, stiffness, structural stability, high accuracy, widely used in aerospace and precision instruments. Using the Cubic Stewart platform and linearizing the force-displacement relationship of the piezoelectric ceramics, the system can be simplified to a single-degree-of-freedom linear active control system. The six-degree-of-freedom Stewart platform is decentralized. Under the excitation of stochastic stationary white noise Considering the influence of the time lag, the LQR numerical analysis of the decoupled Stewart platform is carried out, and the Adams prediction formula is used to compensate the delay. The analysis results show that the Stewart platform has good vibration reduction performance, which can effectively reduce the displacement reaction caused by the platform under microgravity interference. The lag factor can reduce the control effect of LQR. The Adams prediction formula can be used to compare the influence of lag time Well compensated.