摘要
并联机构由于非线性强、控制过程复杂,导致其控制困难,精度难以满足工作要求。建立了三自由度刚柔耦合并联机器人的空间结构简化模型和多体系统树模型,基于多体系统传递矩阵法(MSTMM)对其动力学和状态空间表示进行了分析,并对其状态空间进行了Hankel模型约简;以此为理论基础,设计了LQR控制和基于遗传算法(GA)优化的LQR控制,分别对机器人工作情况进行了仿真对比分析。结果表明:基于遗传算法优化的LQR控制下机器人只需用时1 s便进入稳态。在稳态情况下,优化后与优化前相比,机器人动平台x、y和z方向最大位移分别下降了24.34%、13.51%和1.03%;各支腿上最大加速度分别下降了26.92%、33.96%和35.71%;各支腿上最大控制力分别下降了8.96%、7.37%和9.01%。由此可见在该优化控制方法下机器人响应快、精度高、稳定性好,充分证明了该方法的合理性和优越性,为进一步对并联机器人动力学性能和控制方法的研究提供了一定的理论依据。
Parallel mechanism is difficult to be controlled,because of its strong nonlinearity and complex control process,and its accuracy can not meet the working requirements.This work took a three-degree-of-freedom rigid-flexible coupled parallel robot as the research object,established a simplified space structure model of a robot and the tree model of a multi-body system,used the transfer matrix method of the multi-body system to study the Kinetics and the state space of the robot,and used the Hankel model reduction for the state space.The LQR control and the genetic algorithm(GA)-optimized LQR control were designed,and the working conditions of the robot were simulated and compared.The results show that the LQR control robot based on genetic algorithms(GA)only needs 1 second to enter the steady state.In a steady state,after optimization compared with that before optimization,the maximum displacement of the robot moving platform x,y and z decreased by 24.34%,13.51%and 1.03%respectively;and the maximum acceleration on the three legs decreased by 26.92%,33.96%and 35.71%respectively;the maximum control force of each leg decreased by 8.96%,7.37%and 9.01%respectively.It can be seen that under the optimal control method,the robot has the advantages of fast response,high precision and good stability.Thus the rationality and superiority of the method are fully proved,which provides a theoretical basis for further study of Kinetics performance and control methods of Parallel robots.
作者
王林军
史宝周
张东
丁仕豪
刘建明
WANG Linjun;SHI Baozhou;ZHANG Dong;DING Shihao;LIU Jianming(Department of Electrical and Mechanical Engineering,Lanzhou University of Technology,Lanzhou 730050,China;Western China Energy and Environment Research Center,Lanzhou University of Technology,Lanzhou 730050,China)
出处
《振动与冲击》
EI
CSCD
北大核心
2020年第20期82-90,96,共10页
Journal of Vibration and Shock
基金
国家自然科学基金(51806093)
甘肃省自然科学基金(18JR3RA141)。
作者简介
第一作者:王林军,男,教授,硕士生导师,1963年生;通信作者:史宝周,男,硕士,1993年生。
