Trajectory Tracking Control Of 6-DOF Manipulator

The illusion of robots has been around for a long time.In ancient times,there were skilled craftsmen who could make simple robots,but due to various constraints,robotics did not develop.In the 1960 s,the United States created the beginning of industrial robots,which opened the door to the robot world.More and more experts and scholars are actively involved in the research of this emerging robot technology,which leads to the rapid development of the robot technology,and with the accumulation of time,more and more kinds of robots are developed for practical application.At present,the most widely used robots are industrial robots,and most industrial robots are arm robots,namely,mechanical arms.The operations of mechanical arm in industrial production are mainly divided into point-to-point operations and operations along specific trajectories,namely,point-to-point operations and tracking operations.Both of these operations need to ensure the stability of each joint in the operation process of the manipulator,that is,the smooth transition of joint position,speed and acceleration.The mechanical arm can replace human beings to do heavy and dangerous work on the premise that the precision of the robot arm in production meets the requirements.The research object of this paper is the existing manipulator in the laboratory.The manipulator has the characteristics of complexity,strong coupling and nonlinearity.In order to achieve the high precision control of the robot arm,it is necessary to study the trajectory planning and trajectory tracking control.The main work of this paper has the following aspects:(1)The forward kinematics modeling is carried out for the manipulator studied in this paper,the inverse kinematics is solved by analytical method,the workspace is analyzed by Monte Carlo method,and the rationality of the model is verified.(2)Trajectory planning is studied.According to the difference of working space,it is divided into the trajectory planning of cartesian space and the trajectory planning of joint space,they are studied that spatial linear interpolation method and the spatial circular interpolation method of cartesian space,and the cubic polynomial interpolation and quintic polynomial interpolation based on boundary conditions in joint space.And apply it to the established robot arm model for simulation,the curve of joint Angle,angular velocity and angular acceleration varying with time is obtained,and the smoothness of motion of the six joints is verified.(3)The tracking control algorithm is studied.To complete high-precision and repetitive tracking operations,it is not enough to only conduct trajectory planning research,because the manipulator will be subject to various disturbances during operation,which will make the manipulator deviate from the original trajectory.Therefore,it is still needed to reseach trajectory tracking control.Firstly,the dynamics modeling of the manipulator is simplified.There are always various uncertain factors in the modeling of the mechanical arm,which are inevitable.Therefore,it is difficult to accurately establish the dynamic model of the mechanical arm.The control algorithm adopted in this paper is adaptive fuzzy inversion control and adaptive iterative learning control,and its advantage is that it does not need an accurate model.The two control algorithms are simulated respectively,and the tracking accuracy of the two algorithms are analyzed.The results show that the adaptive iterative learning control has a better accuracy with a tracking error of 0.01 and the control accuracy can be maintained without repeated disturbance.