气动人工肌肉驱动的肘关节辅助机器人迟滞补偿  

Hysteresis Compensation of Pneumatic Artificial Muscle Actuated Assistive Robot for the Elbow Joint

作　　者：秦岩丁 徐圆凯[1,2] 韩建达 QIN Yanding;XU Yuankai;HAN Jianda(College of Artificial Intelligence,Nankai University,Tianjin 300350,China;Tianjin Key Laboratory of Intelligent Robotics,Nankai University,Tianjin 300350,China)

机构地区：[1]南开大学人工智能学院,天津300350 [2]南开大学天津市智能机器人技术重点实验室,天津300350

出　　处：《机器人》2021年第4期453-462,共10页Robot

基　　金：国家重点研发计划(2018YFB1307601);国家自然科学基金(61873133,61873135,U1913208)。

摘　　要：面向上肢康复与辅助运动,研制了一款基于气动人工肌肉(PAM)柔顺驱动的肘关节辅助机器人.气动人工肌肉的迟滞非线性极大降低了系统的运动精度.常见的基于离线辨识的迟滞补偿方法不能很好地适应系统状态的变化.本文提出了一种将直接逆模型法与改进的自适应投影(MAP)算法相结合的自适应迟滞补偿策略:基于直接逆模型法,使用Prandtl-Ishlinskii模型创建系统的逆迟滞模型,并以该模型为迟滞补偿器;使用MAP算法实现逆迟滞模型参数的在线辨识.这种方法无须离线建模与求逆,且无须针对不同的轨迹调节控制器参数.实验结果表明,与PID(比例-积分-微分)控制器与自适应投影(AP)算法相比,该方法有效地补偿了系统的迟滞,暂态过程的调节时间与超调量明显优于前面2种方法,闭环系统能够很好地跟踪阶跃与幅值衰减的正弦信号等不同类型的运动轨迹.For the upper limb rehabilitative and assisted movement, a pneumatic artificial muscle(PAM) compliantly actuated assistive robot for the elbow joint is developed. The hysteresis and nonlinearity of pneumatic artificial muscles significantly reduce the motion accuracy of the system. The robustness of common hysteresis compensation methods based on offline identification against the variation of the system configuration is low. Therefore, an adaptive hysteresis compensation method is proposed in this paper, which integrates the direct inverse modeling approach and the modified adaptive projection(MAP) algorithm. Based on the direct inverse modeling approach, the Prandtl-Ishlinskii model is utilized to construct the inverse hysteresis model, i.e., the hysteresis compensator. MAP algorithm is used to complete the online parameter identification of the inverse hysteresis model. By the proposed method, the offline modeling and inversion are avoided, and the on-site tuning of the controller parameters in tracking different trajectories is also eliminated. Experimental results demonstrate the effectiveness of the proposed method in hysteresis compensation compared with PID(proportional-integral-derivative) controller and adaptive projection(AP) algorithm. The setting time and overshoot of the transient process are significantly better comparing with the above mentioned methods. The closed-loop system can accurately track different types of trajectories,such as step trajectory and sinusoidal trajectory with a descending amplitude.

关 键 词：气动人工肌肉 外骨骼 辅助机器人 迟滞补偿 

分 类 号：TP242[自动化与计算机技术—检测技术与自动化装置]