摘要
为提高人机物理交互的准确性和柔顺性,实现最优交互性能,针对基于迭代学习的阻抗控制方法需要多次重复同一任务的问题,借鉴迭代最优控制无需系统矩阵信息即可优化代价函数确定系统最优控制输入的机制,提出了基于迭代最优阻抗的人机物理交互控制方法。方法采用双环控制结构。面向任务的外环设计了迭代最优阻抗控制器(IOIC),将求取最优阻抗参数的问题描述成线性二次型调节器问题,利用迭代最优控制,求取最优反馈增益,使包括轨迹跟踪误差和交互力在内的代价函数最小化;同时引入软辅助函数,避免参数突变可能带来的机器人抖动问题。面向机器人的内环设计了非奇异终端滑模轨迹跟踪控制器(NTSMTC),使机器人实际轨迹跟踪外环输出的阻抗轨迹,通过饱和函数消减控制律的抖振。仿真结果证明:所提方法在人机协作任务中,仅利用一次任务初始阶段的交互信息即可求得最优阻抗参数,使任务过程中的轨迹跟踪误差和交互人所消耗的力最小化。
In order to improve the accuracy and compliance of human-robot physical interaction and achieve optimal interaction performance,a human-robot physical interaction control method based on iterative optimal impedance was proposed to solve the problem that iterative learning-based impedance control method needs to repeat the same task many times.The proposed method draws on the mechanism by which iterative optimal control can optimize cost function to determine optimal control input to the system without information of the system matrix.A double-loop control structure was used for the proposed control method.An iterative optimal impedance controller(IOIC)was designed for a task-oriented outer loop.The problem of determining optimal impedance parameters was described as a linear quadratic regulator problem,which utilized iterative optimal control to find optimal feedback gain and minimize cost function including tracking error and interaction force.Robot jitter caused by parameter mutations was avoided by introducing soft auxiliary functions.A nonsingular terminal sliding mode trajectory tracking controller(NTSMTC)was used in the inner loop of the robot to make the actual trajectory of the robot track impedance trajectory output by the outer loop,and the chattering of control law was eliminated by saturation function.Simulation results prove that the proposed method can obtain optimal impedance parameters only by using interactive information in the initial stage of the task once in a human-robot collaborative task,so as to minimize the trajectory tracking error and the force consumed by the human during the task.
作者
刘微容
魏子丰
晋振兵
孟家豪
王星琨
张浩琛
LIU Weirong;WEI Zifeng;JIN Zhenbing;MENG Jiahao;WANG Xingkun;ZHANG Haochen(College of Electrical and Information Engineering,Lanzhou University of Technology,Lanzhou 730050,China)
出处
《北京航空航天大学学报》
北大核心
2025年第6期1843-1851,共9页
Journal of Beijing University of Aeronautics and Astronautics
基金
国家自然科学基金(62261032)
中央引导地方科技发展资金项目(25ZYJA026)
甘肃省重点人才项目
甘肃省高等学校创新基金(2022A-021)。
关键词
人机物理交互
阻抗控制
轨迹跟踪控制
最优控制
滑模控制
human-robot physical interaction
impedance control
trajectory tracking control
optimal control
sliding mode control
