Research On Design And Control Of Interplant Weeding Manipulator In Orchard

The large-scale planting of orchards has brought about the rapid development of orchard mechanization.In the daily planting management of orchards,weeding of orchards is the most important part.Under the background of the increase in the scale of orchards and the decrease in the labor force,the development of orchard weeding machinery will help reduce labor intensity and improve planting efficiency.Aiming at the problem that the orchard weeding machinery currently on the market can only complete the weeding between the rows of fruit trees and the weeds between the fruit trees need to be removed manually.After comprehensive analysis of the research status of domestic and foreign scholars in the direction of orchard weeding machinery,the robotic arm is combined with orchard weeding.It designs a kind of orchard weeding robotic arm and its control ways.The main research contents of this thesis are as follows:(1)The design of the weeding robot arm.According to the operation requirements of weeding between plants in the orchard,some main design indexes of the robotic arm are determined.Determine the structural plan of the robot arm according to the design index of the robot arm and explain the operation process of the weeding robot arm.The DH method is used to establish its kinematics model and analyzes the motion work space.Based on the flexibility index,the genetic algorithm is used to optimize the length of each member with the goal of optimal operability.Using inverse motion to test the rationality of the optimized bar size.(2)The trajectory planning of the weeding manipulator between plants in the orchard.According to the difference in the working space of the manipulator,it chooses cubic and fifth degree polynomial interpolation in the joint space,as well as the circular interpolation method and the linear interpolation method in the Cartesian space are studied.To realize the smooth operation of the manipulator,the method of segmented polynomial interpolationwith inverse kinematics is used to complete the trajectory planning of the manipulator in the joint space.(3)The establishment of the dynamic model of the manipulator system.The dynamics of the weeding manipulator is analyzed,and the Lagrange method is used to establish the system dynamics model of the weeding manipulator.(4)Research on trajectory tracking algorithm of robotic arm.It introduces PID algorithm control and introduce fuzzy PID,designs fuzzy rules,fuzzy reasoning,fuzzification of fuzzy PID,etc.At the same time,genetic algorithm is proposed to optimize fuzzy rules and membership functions to improve the trajectory tracking performance of the system.The fuzzy rules and membership functions are optimized and calculated to complete the design of the fuzzy controller of the manipulator.To compare the control effects of the three control methods,the planned trajectory is taken as the ideal input and the trajectory tracking accuracy of the three different control methods are simulated.The results show that the designed fuzzy control system is effective and accurate.