【作者】 王亮；

【导师】 殷时蓉；

【作者基本信息】 重庆交通大学 ， 机械工程（专业学位）， 2024， 硕士

【摘要】 随着中国人口老龄化日益严重,加之意外事故频发,下肢功能受损的患者比例逐年攀升。下肢康复外骨骼机器人作为一种前沿的可穿戴智能系统,正逐渐成为辅助下肢功能缺失患者完成康复训练的重要工具。为了提高下肢外骨骼机器人的柔性,一些学者采用气动人工肌肉做驱动源,但是气动人工肌肉的强非线性和迟滞性会引起系统的抖动甚至不稳定。为了减少气动肌肉驱动的下肢外骨骼机器人的抖动,本文设计了一种气动人工肌肉(PAM)与磁流变阻尼器(MRB)相结合的下肢外骨骼机器人,用磁流变阻尼器的阻尼力来减少系统的抖动,并对机器人的控制策略进行研究,本文主要研究内容如下:(1)柔性下肢外骨骼机器人结构设计。首先依据人体下肢的基本情况,得到下肢机器人相应的关节自由度和步态运动等数据,设计了一款气动人工肌肉(PAM)和磁流变阻尼器(MRB)相结合的柔性下肢外骨骼机器人。该机器人的膝关节采用交叉四连杆结构,其瞬心和人体膝关节的瞬心变化一致,保证人体行走的平衡性和安全性;为了适应不同身高的穿戴者需要,本设计采用可变长度的连杆结构,论文对PAM和MRB进行了选型和安装方式的设计并对下肢外骨骼机器人进行了运动学分析。(2)下肢外骨骼机器人动力学分析。首先对气动人工肌肉进行力学性能分析,搭建了气动人工肌肉的等压、等张以及等长的实验平台得到了气动人工肌肉的精确数学模型;然后通过数据的拟合得到了磁流变阻尼器的力学模型;最后对下肢外骨骼机器人进行了动力学的分析。(3)柔性下肢外骨骼机器人控制策略研究。针对复合关节的多输入单输出系统,设计RBF滑模控制和PD迭代控制相结合的控制策略从而完成对下肢外骨骼机器人的控制。通过Matlab仿真结果表明,在只有PAM驱动时仿真结果出现了较高的振荡且收敛效果差,在引入PD迭代控制的MRB以后系统的稳定性得到了改善,验证了加入磁流变阻尼器后对气动人工肌肉驱动的柔性下肢外骨骼机器人柔顺性和稳定性的改善。(4)柔性下肢外骨骼机器人关节物理实验验证。设计柔性下肢外骨骼机器人的控制系统搭建实验硬件平台以及软件平台,与加入磁流变阻尼器的实验作对比实验,分别对其进行轨迹跟踪及人体膝关节轨迹跟踪实验,通过实验对比,验证了加入磁流变阻尼器以后柔性下肢外骨骼机器人有比之前较好的柔顺性及稳定性,证明引入磁流变阻尼器的有效性。更多还原

【Abstract】 With the increasing trend of aging in China and the frequent occurrence of accidents,the number of patients with lower limb dysfunction is showing an increasing trend year by year.The lower limb rehabilitation exoskeleton robot,as a cutting-edge wearable intelligent system,is gradually becoming an important tool to assist patients with lower limb dysfunction in completing rehabilitation training.In order to improve the flexibility of lower limb exoskeleton robots,some scholars use pneumatic artificial muscles as the driving source.However,the strong nonlinearity and hysteresis of pneumatic artificial muscles can cause system shaking or even instability.In order to reduce the shaking of lower limb exoskeleton robots driven by pneumatic muscles,this paper designs a lower limb exoskeleton robot that combines pneumatic artificial muscles(PAM)and magneto rheological dampers(MRB).The damping force of the magneto rheological damper is used to reduce system shaking,and the control strategy of the robot is studied.The specific research content mainly includes:(1)The structure of flexible lower limb exoskeleton robot is designed.Firstly,based on the basic situation of the human lower limbs,the corresponding joint degrees of freedom and gait motion data of the lower limb robot were obtained.A flexible lower limb exoskeleton robot combining pneumatic artificial muscles(PAM)and magnetorheological dampers(MRB)was designed.The knee joint of the robot adopts a cross four link structure,and its instantaneous center changes consistent with the instantaneous center of the human knee joint,ensuring the balance and safety of human walking;In order to meet the needs of wearers of different heights,this design adopts a variable length linkage structure.The paper selects and installs PAM and MRB,and conducts kinematic analysis on the lower limb exoskeleton robot.(2)Dynamic analysis of lower limb exoskeleton robots.Firstly,the mechanical properties of pneumatic artificial muscles were analyzed,and an experimental platform of equal pressure,equal tension,and equal length was constructed to obtain an accurate mathematical model of pneumatic artificial muscles;Then,the mechanical model of the magnetorheological damper was obtained through data fitting;Finally,a dynamic analysis was conducted on the lower limb exoskeleton robot.(3)Research on control strategies for flexible lower limb exoskeleton robots.A control strategy combining RBF sliding mode control and PD iterative control is designed for a multi input single output system of composite joints to achieve control of lower limb exoskeleton robots.The simulation results using Matlab show that there is high oscillation and poor convergence in the simulation results when only PAM is driven.After introducing the MRB with PD iterative control,the stability of the system has been improved.Verified the improvement of flexibility and stability of a flexible lower limb exoskeleton robot driven by pneumatic artificial muscles after the addition of magnetorheological dampers.(4)Experimental verification of joint physics for flexible lower limb exoskeleton robots.Design a control system for a flexible lower limb exoskeleton robot and build an experimental hardware and software platform.Conduct comparative experiments with the addition of magneto rheological dampers,and conduct trajectory tracking and human knee joint trajectory tracking experiments.Through experimental comparison,verify that the flexible lower limb exoskeleton robot with the addition of magneto rheological dampers has better flexibility and stability than before,and prove the effectiveness of introducing magneto rheological dampers.更多还原