Research On Trajectory Planning Of Fruit-vegetable Harvesting Based On 5 Order B-spline

Robot joints trajectory planning is the basis of robot motion control.According to the requirements of the robot's task,in order to improve the efficiency of the robot and ensure that the task can be completed smoothly,it is necessary to do some search about robot joints trajectory.Besides the robot working life can be improved if the motion trajectory of robot is enough smooth.In order to improve the working efficiency of the fruit-vegetable harvesting robot and reduce the impact during the operation process,5 order B-spline was proposed to interpolate the motion trajectory in this paper based on the time-jerk,and the 5 order B-spline interpolation trajectory was optimized.The main contents of this paper is following:1.The mathematical model of the robot was established based on the designing parameters.The kinematics equation of the robot was obtained according to the DH parameters on the basis of the DH coordinate theory.At the same time,the inverse kinematics of the robot was carried out in detail so as to verify the correctness of the motion equation.In addition,the robot simulation model was established by using the MATLAB robot toolbox according to the DH parameters,and the movement of the robot was demonstrated in the Cartesian space(work space).2.According to the idea of artificial potential field,the motion space of robot was abstracted into virtual potential field and the obstacle avoidance algorithm of robot was designed in dynamic operation environment based on the mathematical model of the potential field.The virtual initial point,path obstacle and target point was designed by using MATLAB GUI.The use of simulation interface was introduced briefly.Single barrier and multi-barrier virtual environment was built respectively to simulate.The experimental results show the barrier could be avoided effectively to prove correctness of the algorithm.3.The construction methods of 5 order B-splines was studied emphatically,and the similarities and differences of the 5 order B-spline and 7 order spline interpolation trajectories were analyzed by using the robot toolbox function.According to the position points that must be passed during the movement of the robot,the optimized 5 order B-spline interpolation trajectory was obtained by GA algorithm,and the motion trajectory of the robot after optimization wassimulated by MATLAB.Compared with the previous non-optimal trajectory,the optimized trajectory was shortened 6.62 s,and the jerk of each joint was reduced in some degree during the process of movement.