Research On Trajectory Planning Of 6-DOF Robot

The greatest advantage of industrial robots is their ability to perform repetitive tasks accurately over a long period of time,which makes them widely used in production lines in a variety of industries.In recent years,with the introduction of intelligent technology,industrial robots have developed rapidly.Robot trajectory planning is the basic part of robot control system.The primary purpose of robot trajectory planning is to meet the requirements of the task,so that it can complete the task assigned by the user accurately.Under this premise,the trajectory planning also needs to satisfy the kinematics and dynamics constraints of the robot,so that the robot can operate smoothly without vibration and impact,and in different applications,different indicators of motion performance are optimized accordingly.In this thesis,the method of solving the inverse kinematics of 6-DOF robots is studied,and the trajectory of 6-DOF industrial robots is planned in cartesian space by using an interpolation method based on NURBS(Non-Uniform Rational Basic Spline)curve.The main contents of this thesis are as follows:Firstly,RBF(Radical Basis Function)neural network is used to construct the prediction model of inverse solution for 6-DOF robots,and FGA(Fluid Genetic Algorithm)is used to optimize the parameters of the neural network,including node center vectors,width vectors and output layer weights,so as to improve the solution accuracy.Then sample data is collected from the Kawasaki RA010 N robot to train the network.Finally,the performance of the network is tested with test sample,and the accuracy of the solution is analyzed.Secondly,based on NURBS curve theory,trajectory for 6-DOF industrial robots is planned in cartesian space.First,the 5th-order B-spline basis functions are obtained,and then the calculation method of reverse 5th-order NURBS curve is analyzed.In this thesis,an interpolation method based on 5th-order NUBRS curve is used for trajectory planning to ensure that the velocity,acceleration and jerk of the end-effector of the robot are continuous,taking into account the constraints of the velocity and acceleration at the beginning and ending point of the trajectory.After calculating the interpolation points of the trajectory by using the above method,the corresponding joint angles of each interpolation point are calculated according to the inverse kinematics of the robot.Finally,an experiment is implemented on a platform of Kawasaki robot to achieve the planned trajectory.