基于改进指数幂趋近律的机械臂轨迹跟踪控制  

Trajectory Tracking Control of Manipulator Based on Improved Exponential Power Approach Law

作　　者：金之帆 杨会君[1] 张建锋[1] JIN Zhi-fan;YANG Hui-jun;ZHANG Jian-feng(College of Information Engineering,Northwest A&F University,Yangling Shaanxi 712100,China)

机构地区：[1]西北农林科技大学信息工程学院,陕西杨凌712100

出　　处：《计算机仿真》2023年第12期476-480,491,共6页Computer Simulation

基　　金：陕西省重点研发计划(2023-YBNY-212)。

摘　　要：针对机械臂轨迹跟踪系统在指数趋近律控制下产生的响应不迅速以及控制过程中系统抖颤等问题,给出了一个改进指数幂趋近律。首先通过在传统指数趋近律的恒速率项中导入新型分段函数来改善控制系统的响应,接着再在指数项中引入系统状态变量来抑制系统的抖颤现象。为了降低模型偏差和不确定干扰而对机械臂系统的影响,采用趋近律结合机械臂动力学模型的方式设计滑模控制律,并使用模糊算法进行对模型偏差和不确定干扰的自适应预测和在线补偿。最后,根据李雅普诺夫定理,证明了闭环控制过程的可靠性。仿真结果表明:所提供的控制方式不仅完成了对机械臂轨迹的准确追踪控制,同时提高了控制系统的工作速度,并有效控制了抖颤现象。Aiming at the problems of slow response and system jitter in the control process of the robotic arm traj⁃ectory tracking system under the control of exponential reaching law,an improved exponential power reaching law is proposed.Firstly,a new piecewise function was introduced into the constant rate term of the traditional exponential reaching law to improve the response speed of the system,and then the system state variable was introduced into the exponential term to suppress the chattering phenomenon of the system.For the purpose of reducing the side effects of model errors and uncertain disturbances,the approach law combined with the kinetic model of the manipulator was used to design the sliding mode control law,and the fuzzy algorithm was used to realize the adaptive estimation and online compensation of the model errors and uncertain disturbance.Finally,according to the Lyapunov theorem,the reliability of the closed-loop control process was proved.The simulation results show that the proposed control method not only can accurately track the trajectory of the end of the manipulator,but also improve the response rate of the system and effectively inhibits the vibration phenomenon.

关 键 词：机械臂 轨迹跟踪 滑模控制 趋近律 模糊控制 

分 类 号：TP242[自动化与计算机技术—检测技术与自动化装置]