基于故障观测器的机器人多关节手臂最优容错控制  

Optimal fault-tolerant control of robot multi-joint manipulator based on fault observer

作　　者：杨怀磊 姚云磊 YANG Huailei;YAO Yunlei(School of Information Engineering,Zhengzhou Tourism College,Zhengzhou 450009,China;School of Information Engineering,Kaifeng University,Kaifeng 475004,China)

机构地区：[1]郑州旅游职业学院信息工程学院,郑州450009 [2]开封大学信息工程学院,开封475004

出　　处：《现代制造工程》2024年第7期61-68,共8页Modern Manufacturing Engineering

基　　金：河南省科技攻关项目(232102220102)。

摘　　要：针对机器人多关节手臂容易出现卡死、饱和及损伤等故障影响控制精度的问题,利用设计的故障观测器提出了一种最优容错控制律。首先根据机器人多关节手臂末端的空间位置与各关节转动角度的关系,建立了机器人多关节手臂的故障模型;然后定义了多关节手臂的转角和接触力的跟踪误差,并设计了故障观测器,通过引入径向基函数(Radial Basis Function,RBF)神经网络估计出模型参数;最后根据动态规划的思想,建立了综合位置/接触力跟踪误差和故障的机器人多关节手臂性能指标矩阵,并设计了包含Hamiltonian方程的容错控制律,利用RBF神经网络求解出最优的性能指标,从而得到最优的容错控制律。仿真结果表明,设计的最优容错控制律能够克服各类故障带来的影响,故障估计的最大误差仅为0.09 N·m,位置跟踪的最大误差仅为0.14 cm,接触力控制的最大误差仅为0.18 N,验证了设计方法的可行性。六自由度多关节手臂测试结果表明,在8个空间坐标上定位的最大误差仅为0.17 cm,接触力的最大误差仅为0.22 N,从而验证了设计的最优容错控制律具有优越的工程实用性。Aimming at the issue of control accuracy affected by malfunctions such as jamming,saturation and damage that are prone to occur in robot multi-joint manipulator,an optimal fault-tolerant control law was proposed using the designed fault observer.Firstly,a fault model of the robot multi-joint manipulator was established based on the relationship between the spatial position of the end of the robot multi-joint manipulator and the rotation angle of each joint.Then,the tracking errors of the multi-joint manipulator rotation angle and contact force were defined,and the fault observer was designed.The model parameters were estimated by the introduced RBF neural network.Finally,performance index matrix of robot multi-joint manipulator with the tracking error of position/contact force and faults was established according to the idea of dynamic programming,and the fault-tolerant control law including Hamiltonian equation was designed.The RBF neural network was used to solve the optimal performance index,so as to obtain the optimal fault-tolerant control law.The simulation results show that the designed optimal fault-tolerant control law can overcome the influence of various faults,the maximum error of fault estimation is only 0.09 N·m,the maximum error of position tracking is only 0.14 cm,and the maximum error of contact force control is only 0.18 N,which verifies the feasibility of the designed method.The measured results of the six degrees of freedom multi-joint manipulator show that the maximum error of positioning on 8 spatial coordinates is only 0.17 cm,and the maximum error of the contact force is only 0.22 N,which verifies that the designed optimal fault-tolerant control law has superior engineering practicability.

关 键 词：机器人 多关节手臂 故障观测器 RBF神经网络 动态规划 最优容错控制 

分 类 号：TH39[机械工程—机械制造及自动化] TP273[自动化与计算机技术—检测技术与自动化装置]