摘要
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。
The stability of instruments in spacecraft is of critical importance.The Stewart platform is a kind of parallel mechanism,which is widely used for the vibration control of instruments in aerospace at the advantage of carrying capacity,stability,rigidity and high accuracy.The piezoelectric ceramics as sensor and drive are employed in the cubic Stewart platform,and then are simplified as a single-degree linear system based on the above assumption.The active vibration control system under the white noise excitation is studied.Based on the LQR control algorithm,the results of numerical analysis are abstained when the effect of time lag is considered.The results show that the displacement response of the Stewart platform under vibration control is reduced distinctly and the control effect is weakened due to the time lag which is compensated well by prediction formula of Adams.
出处
《应用力学学报》
CAS
CSCD
北大核心
2011年第5期514-517,557,共4页
Chinese Journal of Applied Mechanics
基金
863高科技计划(2009AA03Z106)
国家自然科学基金项目(61004064)
江苏省科技支撑计划(BE2010069)
江苏省六大人才高峰项目
