Research On Several Key Technologies Of Agricultural Picking Robot With Double Manipulators Cooperation

Fruit yield in China accounts for a larger proportion of that in the world,but compared with the western developed countries,the harvesting automation level of our country is low.Compared with single-arm robots,the dual-arm cooperative robots have advantages in the complex work environment and the operation tasks.In this paper,two 5-DOF manipulators are taken as an example to study somekey technologies aboutagricultural picking with dual-arm cooperative robot,such as collision avoidance path planning,coordinated motion analysis,time-optimal trajectory planning,coordination control ofdouble manipulators,etc.The research provides technical accumulation for the actual picking in the later period.Firstly,in this paperthe link coordinate system of manipulator is established and the D-H parameters of each link are determined,the forward and inverse kinematics of the manipulator is analyzed by analytical method.Then the trajectory planning in joint space,the position interpolation and the orientation interpolation in Cartesian space are respectively studied.Incollision avoidance path planning,single manipulator is studied,the corresponding collision avoidance detection method and path search method are proposed,and the collision avoidance path planning is carried out by simulation.The results show that the manipulator can reach the target point from the starting point along the planning path without collision with obstacles.Incoordinated motion analysis,firstly in this paper the Monte Carlo method is used to solve the workspace of dual-arm robot,and the cloud figure of workspace is obtained.Then the cooperative motion constraint of dual-arm robot is analyzed,and the fit between hole and shaft with double manipulators is taken as an example to be studied.For the use of dual-arm robot in agricultural picking,in this paper the pursuit movement between double manipulators is analyzed and simulated,the cooperative picking task is decomposed and the corresponding simulation is carried out.Intime-optimal trajectory planning,firstly,PSO algorithm is used to realize time-optimal trajectory planning for single manipulator under the specified velocity constraint,the simulation results show that each joint of the manipulator can move at a higher velocity close to the limit value,and verify the validity of 3-5-3 order polynomial interpolation based on PSO algorithm.Next,the general problem about time-optimal trajectory planning of the dual-arm robot is studied in this paper by using multi-segment spline polynomial interpolation,and the 4-3-3-4 polynomial interpolation is taken as an example to carry out time-optimal trajectory planning for the dual-arm robot,the simulation results show the motion of each joint of the dual-arm robot is smooth and the velocity constraint is satisfied.In coordination control ofdouble manipulators,firstly in this paper,the hardware platformof dual-arm robot control systembased on Arduino is built,thenthesoftware solutions for real-time control of dual-arm robot areproposed.Then through the upper computer programming,some examples which using Matlab/GUI interface to manipulate the manipulator are realized.Finally we carry out the cooperation experiment on the dual-arm robot by respectively taking the fit between hole and shaft with double manipulators and the pursuit movement between double manipulators as an example,and the results obtained are close to the simulation results in the previous chapter.