Research On Trajectory Optimization Control Method Of Six-axis Calligraphy And Painting Robot

With the wide application of industrial robots,the demand for robot control research is increasing.Trajectory planning,as the research focus of robots,plays an important role in reducing repetitive and tedious workload,improving operation accuracy and optimizing operation time.The traditional trajectory planning method has such problems as low precision,slow speed and unstable operation.If there is no comprehensive and reasonable trajectory planning,the robot may be impacted and cause vibration,which may affect the operation accuracy and even the robot's life.In this paper,Denso VP6242 robot is taken as the research object to perform calligraphy and painting tasks.The research on robot trajectory planning is mainly divided into two parts:curve path fitting and velocity planning.By improving trajectory accuracy and running speed,the effect of calligraphy and painting can be improved.The main research contents are as follows:Aiming at the problem that the traditional curve fitting method has a large amount of computation,and the fitting error is large,the improved curve fitting method is studied.Firstly,the interpolation points generated by cubic spline were screened by introducing the included angle constraint of adjacent interpolation points,and then the obtained interpolation points were used as control points of the NURBS curve and fitted.Through MATLAB simulation verification and analysis,compared with the traditional curve fitting method,the curve fitted by the improved method is smooth,more fitting with the expected curve trajectory,and the error is smaller,which improves the accuracy of curve fitting and can optimize the robot's motion trajectory.Aiming at the problem that the traditional s-type acceleration and deceleration method has too much computation and the acceleration is abrupt,an improved trig function acceleration and deceleration planning algorithm with continuous acceleration is studied.Firstly,the velocity extremum was obtained according to the curvature of the curve,and the curve was segmented.Then,the velocity was adjusted and planned according to the length of each track by usingthe trigonometric function acceleration and deceleration algorithm.The simulation results of MATLAB show that the acceleration of the algorithm in this paper has no sudden change,and the running time is reduced compared with the traditional s-type acceleration and deceleration method.Finally,the improved curve fitting method and acceleration and deceleration planning algorithm are applied to the experimental control platform of Denso robot for calligraphy and painting experiments and analysis.The experimental results show that the trajectory planning algorithm in this paper has good calligraphy and painting effect and high running efficiency.