基于二型模糊遗传控制器的冗余自由度机械臂运动控制的研究

Research on motion control of redundant degree of freedom manipulator based on two type fuzzy genetic controller

对冗余自由度机械臂的运动轨迹进行准确的控制,有助于提高工作效率以及工作质量。在对5自由度冗余机械臂结构分析的基础上,设计了一种二型模糊遗传控制器,可用于控制冗余自由度机械臂按照既定轨迹进行运动。首先,对冗余机械臂的结构进行分析,并借助拉格朗日函数冗余度机械臂扭矩与连杆位置关系的动力学模型。然后,通过二型隶属函数定义二型模糊集及区间二型模糊集。对区间二型模糊逻辑系统主要模块的功能进行分析,以其为核心部分设计区间二型模糊PID控制器,并制定区间二型模糊PID控制器的规则库,采用遗传算法对区间二型模糊PID控制器的参数进行选择,以对机械臂的运动轨迹进行控制。最后,采用二型模糊遗传控制器对锯齿及正弦目标轨迹进行跟踪测试,测试结果显示:与PID控制器相比,本文设计的二型模糊遗传控制器,在对锯齿及正弦目标轨迹跟踪时,最大跟踪误差分别减少5.97 mm和3.66 mm。说明本文设计的二型模糊遗传控制器,能够控制冗余度机械臂较为准确地按照目标轨迹运动。

It is helpful to improve the work efficiency and work quality to control the motion track of redundant manipulator accurately.In this paper,based on the analysis of the structure of 5-DOF redundant manipulator,a two type fuzzy genetic controller is designed,which can be used to control the redundant manipulator to move according to the given trajectory.Firstly,the structure of the redundant manipulator is analyzed,and the dynamic model of the relationship between the torque of the redundant manipulator and the position of the connecting rod is established with the help of Lagrange function.Then,two types of fuzzy sets and interval two types of fuzzy sets are defined by two types of membership functions.This paper analyzes the functions of the main modules of the interval two type fuzzy logic system,designs the interval two type fuzzy PID controller with it as the core part,and formulates the rule base of the interval two type fuzzy PID controller,and selects the parameters of the interval two type fuzzy PID controller by using genetic algorithm to control the motion track of the manipulator.Finally,the tracking test of the zigzag and sinusoidal target track is carried out by using the two fuzzy genetic controller.The test results show that the maximum tracking error of the two fuzzy genetic controller designed in this paper is reduced by 5.97 mm and 3.66 mm respectively when tracking the zigzag and sinusoidal target track compared with PID controller.It shows that the two fuzzy genetic controller designed in this paper can control the redundant manipulator accurately according to the target trajectory.