下肢携行外骨骼系统模糊自适应位置控制研究

Research on Fuzzy Adaptive Position Control of Carrying Lower Extreme Exoskeleton

研究下肢携行外骨骼系统稳定性控制问题。下肢携行外骨骼系统支撑行走阶段位置控制存在稳定性、实时性不足,提高位置控制的速度及精度,使具有适应性和鲁棒性,为了克服具有实时重力补偿的传统方法,提出固定重力补偿的位置控制方法,并利用模糊推理逻辑可逼近非线性函数的特点,将模糊控制算法与具有固定重力补偿的传统PD控制算法相结合,提出了具有固定重力补偿的模糊自适应位置控制算法,应用到下肢携行外骨骼支撑行走阶段的位置控制中。仿真结果表明控制方法能够使外骨骼准确迅速跟踪人体运动,并能够显著减小人所施加的力矩,系统鲁棒性较强,能够适应负载的变化,证明是一种行之有效的控制方法。

In order to overcome the disadvantages of conventional stance phase position control of lower extreme exoskeleton,improve the control precision and the speed,and increase the adaptability and robustness of the control system,a position control algorithm with fixed gravity compensation was presented.Using the characteristics of fuzzy reasoning logic as approaching nonlinear functions,the fuzzy adaptive position control algorithm with fixed gravity compensation was designed,which combines fuzzy control algorithm with the conventional PD control algorithm with fixed gravity compensation.Then the algorithm was applied to position control of lower extreme exoskeleton stance phase.The simulation results show that the algorithm can make the exoskeleton to trace the pilot＇s motion rapidly and accurately,as well as decrease the human-machine interaction force,and is robust to the variation of the load,which validates the feasibility of the presented control method.