Structural Design And Path Planning Of String Tomato Picking Robot

String tomato is a new kind of tomato on the market,string harvest,deeply loved by the majority of consumers,its planting area is also increasing.The use of agricultural robots can improve the work efficiency and productivity of agriculture,reduce the labor intensity and work cost of workers,and also workers' labor comfort greatly improved.At present,no research has been found on the tomato picking robot in the greenhouse.The structure of the robot is designed and analyzed,and an end-effector for picking string tomato is developed.Finally,the path-avoidance path of the robot arm is carried out Planning.The main research contents are as follows:(1)The research status of agricultural picking robot at home and abroad is deeply understood,and a six-degree-of-freedom joint type of string tomato picking robot is designed with reference to the structure type of industrial robot and the picking environment of string tomato.3D model was built using SolidWorks software.Furthermore,the finite element analysis of the key components of the tomato picking robot is carried out using ANSYS Workbench software,and the simulation results show that its strength,stiffness and dynamic performance are good.(2)An end-effector for string tomato picking is designed,and the force sealing and the reliability of the clip finger are analyzed.At the same time,the two cutting methods of rotary cutting and shear cutting are compared.Finally,a physical prototype was made,and the load-bearing interference performance of the mother branch of the string tomato was tested.The minimum gripping weight under dynamic load-bearing interference is 1.015 kg,the test shows that the gripping ability of this end actuator fully meets the need of picking string tomato.(3)The kinematic model of string tomato picking robot is established,and the positive and inverse solutions and Jacobi matrix are solved.By using the MATLAB software,the correctness of the solution is verified,and the workspace of the picking robot is simulated to verify that the structure of the picking robot meets the requirements of picking.(4)The established three-dimensional model is imported into ADAMS software,and the inverse kinematics solution,angular velocity and velocity of each driving shaft are analyzed.and the variation of the torque of each rotating axis with time is also analyzed,which provides a theoretical basis for the following harvesting robot trajectory planning.(5)The spatial geometry envelope detection is carried out on the collision problem between the manipulator and the obstacle and its own entity.the spatial problem istransformed into the geometric position relationship in space and solved by analytic geometry knowledge.Combined with the improved step-by-step algorithm and collision model,the obstacle avoidance path of picking robot is planned.MATLAB simulation results show that the improved method has better effect.Finally,the motion is smoothed by the improved step-by-step method combined with cubic spline interpolation,and the smooth displacement,velocity and acceleration curves are obtained by MATLAB simulation.