摘要
针对冗余机械臂在任务空间中的轨迹跟踪控制精度差问题,提出了一种基于非线性扰动观测器的滑模控制算法。首先,将末端执行器位姿轨迹通过运动学逆解转换成关节空间内的关节角轨迹,降低运动学求解的计算量;其次,利用拉格朗日法获得机械臂的动力学模型,明确系统输入输出关系;进而,设计非线性扰动观测器来估计与补偿系统的集总干扰,并引入基于趋近律的滑模控制算法来加快系统状态量的收敛速度;再者,控制器的稳定性在李雅普诺夫框架下得以证明;最后,以7自由度冗余机械臂为例对该文所提方法的有效性进行了仿真验证。仿真结果表明:文中控制器的控制性能要优于LADRC与SMC-LESO,能保证关节角具有较高的轨迹跟踪精度;该文方法能够较好地解决冗余机器人的运动学逆解问题,将求解精度控制在0.1mm的量级内。
Aiming at the low trajectory tacking control of a redundant manipulator,a sliding mode control based on nonlinear disturbance observer has been proposed in this paper.Firstly,the pose of the end-effector is transformed into the joints in the joint space through the inverse kinematics,which can reduce the calculation of the solution.Then,the dynamical model of the manipulator is created through Lagrangian equation,which can obtain the relation of inputs and outputs.Meanwhile,a nonlinear disturbance observer is designed to estimate and compensate the lumped disturbances.And a sliding mode control algorithm based on reaching law is introduced to accelerate the convergence rate of system state variables.Furthermore,the stability analysis is conducted under Lyapunov theory.Lastly,the effectiveness of the proposed method is tested using a 7 degree-of-freedom redundant manipulator.The results show that the proposed controller performs better than that of LADRC and SMC-LESO,which can guarantee high trajectory tracking accuracy of joint angles.The method in this paper can better solve the inverse kinematics solution of redundant robots and limit the accuracy within the order of 0.1mm.
作者
吴晓燕
虞启凯
韩江义
WU Xiao-yan;YU Qi-kai;HAN Jiang-yi(School of Intelligent Manufacturing,Nanjing Polytechnic Institute,Nanjing 210048,China;School of Automotive and Traffic Engineering,Jiangsu University,Zhenjiang Jiangsu 212013,China)
出处
《组合机床与自动化加工技术》
北大核心
2020年第10期136-139,共4页
Modular Machine Tool & Automatic Manufacturing Technique
基金
南京科技职业学院2017科研项目(NHKY-2017-06)。
关键词
冗余机械臂
任务空间
非线性扰动观测器
滑模控制
industrial manipulator
task space
nonlinear disturbance observer
sliding mode control
