【作者】 刘子旭；

【导师】 赵劲松； 张辉；

【作者基本信息】 燕山大学 ， 机械工程（专业学位）， 2023， 硕士

【摘要】 下肢外骨骼机器人是一种结合了仿生技术与机器人技术的装置。如今,这类机器人在工业生产和医疗康复中得以广泛应用。然而,机器人具有复杂的非线性模型,各关节间存在动力耦合,使得机器人各关节难以实现独立控制,并且人机之间存在相互作用干扰,两者均严重影响外骨骼跟踪精度。因此,本文以下肢外骨骼为研究对象,以提高外骨骼跟踪性能为目标,提出模态解耦控制消除各关节间动力耦合,提出虚拟力矩控制以降低人机之间相互作用力矩。本文主要研究内容如下:(1)根据几何关系建立下肢外骨骼系统运动学模型,根据拉格朗日方程建立下肢外骨骼系统动力学模型,基于电液伺服理论建立液压动力元件模型,从而建立液驱下肢外骨骼系统整体模型,为研究模态解耦奠定基础。(2)分析各关节通道产生动力耦合原因,基于振动理论构建下肢外骨骼系统模态空间,得到模态变换矩阵,分析液驱下肢外骨骼模态通道独立特性,最终设计出模态解耦PI控制器。(3)研究虚拟力矩控制以抑制人机相互作用力矩影响,采用递推最小二乘法辨识外骨骼名义模型,利用零相差跟踪控制理论得到外骨骼名义逆模型,基于卡尔曼滤波算法进行下肢外骨骼运动预测,为实现虚拟力矩控制结构中滤波器设计,以使该结构的鲁棒性能接近最优,采用混合灵敏度控制对滤波器进行优化。(4)制定基于快速原型技术的液驱下肢外骨骼系统实验方案,验证液驱下肢外骨骼模态解耦控制效果,基于模态控制器验证利用虚拟力矩控制消除人机作用力矩干扰的有效性。更多还原

【Abstract】 Lower limb exoskeleton robot is a device that combines bionic technology and robot technology.Today,such robots are widely used in industrial production and medical rehabilitation.However,because of the complex nonlinear model of the robot and the dynamic coupling between the joints,it is difficult to realize independent control of each joint,and there is interaction interference between human and robot,both of which seriously affect the trajectory tracking accuracy of the exoskeleton.Therefore,this paper takes the lower limb exoskeleton as the research object,aiming at improving the tracking performance of the exoskeleton.The modal decoupling control is used for eliminating the dynamic coupling between joints,and the virtual torque control is used for reducing the interaction force between man-robot.The main research contents of this paper is as follows:(1)The lower limb exoskeleton kinematics model is established based on geometric relations.The dynamic model of lower limb exoskeleton is established according to Lagrange method.The hydraulic power element model is established based on the electrohydraulic servo theory.Finally,the overall model of lower limb exoskeleton system is established,which laid a foundation for the study of modal decoupling.(2)The reasons for dynamic coupling of each joint channel are analyzed,the modal space of lower limb exoskeleton system is constructed based on vibration theory,and the modal transformation matrix is obtained.The independent characteristics of each modal channel in lower extremity exoskeleton are analyzed.The physical space decoupling condition and the performance relationship between modal space and physical space are derived.Finally,the modal decoupling PI controller is designed.(3)Virtual torque control is studied to suppress the influence of human-robot interaction torque.Using Recursive Least Square method to identify the nominal model of exoskeleton.The nominal inverse model of exoskeleton is obtained by using zero-phase tracking technology.Lower limb exoskeleton motion prediction based on Kalman filter algorithm.In order to realize the design of the filter and make the robustness of the structure close to the optimal,the filter is optimized by using mixed sensitivity control.(4)Make an experimental plan for electro-hydraulic driven lower limb exoskeleton based on rapid prototyping technology.Verify the effect of modal decoupling control on electro-hydraulic driven lower limb exoskeleton.Based on modal controller to verify the virtual torque control to eliminate the effectiveness of man-machine function disturbance torque.更多还原