| The robot joint system is the basic unit to control the movement of the robot.The robot controls the coordinated movement of multiple joints to drive the robot to move flexibly like a human arm.Therefore,the quality of the robot joint servo system is directly related to the working performance of the robot.PID control has the advantages of simple structure,few control parameters and convenient parameter setting,and is often used as a traditional joint servo controller.The robot joint is a nonlinear system,which is easily affected by unknown loads,changes in the internal parameters of the joint motor,and complex external interference.The PID control has poor anti-interference ability and is difficult to control efficiently..For this reason,this paper uses the active disturbance rejection control with strong antiinterference ability to replace the traditional PID control to design the robot joint servo controller,and the inertia of the joint system is identified,and the obtained accurate inertia value is compensated to the controller,so as to improve the joint performance as much as possible.The main research contents of the control system are as follows.1.This paper introduces the main components of the robot joint system in detail.The key control unit,the frameless torque motor,is mathematically modeled.The mathematical model of the joint torque motor in the threephase rotating coordinate system is established,and the coordinate transformation,Analysis and research of key technologies such as vector control and space voltage vector modulation.2.In order to improve the anti-disturbance capability of the joint module servo control system,a nonlinear active disturbance rejection controller is designed to replace the traditional PID control.The active disturbance rejection controller includes a state observer,which can observe the internal and external disturbances of the system in advance,and compensate for it through the feedforward link,which has a strong anti-disturbance capability.In addition,the active disturbance rejection controller can be flexibly designed according to the order of the controlled object,and can perform compound control on two or more objects.For the difficult problem of parameter tuning in the nonlinear active disturbance rejection controller,the article discusses the parameters of each parameter.Tuning is detailed to make it more practical.In order to verify the control strategy designed in this paper,the simulation model of the joint servo control system is established.The simulation experiments prove that the control strategy has better performance in anti-interference ability,response speed and stability than the traditional PID servo control method.outstanding.3.Considering the different load states of the robot during the handling process,the moment of inertia of the joint system also changes all the time.In order to avoid the influence of the drastic change of inertia on the performance of the controller,this paper uses the Landau discrete recursive identification algorithm to identify the rotational inertia of the joint system online,and compensates the accurate inertia of the identification to the controller,so that the active disturbance rejection controller and the parameters related to inertia can be adjusted automatically according to the change of inertia,which further improves the anti-disturbance capability of the system.By building the joint module experimental platform,in the joint module speed loop control mode,the performance of the controller designed in this paper is verified,and the performance of the traditional PI controller,the nonlinear active disturbance rejection controller performance,and the inertia identification of the joint motor are verified respectively.,The performance of the ADRC controller after inertia compensation,the experimental results show that the ADRC control has a faster response to load disturbance than the PI control,and the control performance after inertia compensation has been improved. |
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