| Overgrowth of trees under high-voltage transmission lines can pose a safety hazard to the operation of the lines,so the power sector needs to regularly prune the obstructed branches,which is called tree barrier clearing.The traditional way of cleaning tree barriers is to use manual hand tools or chain saws to climb the heights.This way is inefficient and labor-intensive,and there are also risks of people falling from heights and electric shock.The above problems can be avoided by using mechanical clearing instead of manual clearing.After analyzing and summarizing the research status of tree-pruning machinery for transmission lines at home and abroad,this paper designs a structure of tree barrier cleaning manipulator,and studies the kinematics,dynamics,trajectory planning and control system of the manipulator,as follows:(1)Structure design of tree barrier cleaning manipulatorAccording to the working environment and characteristics of the tree obstacle cleaning robot arm,its structural design is divided into three parts:the design of the shear fork lifting mechanism,the design of the robot arm body,and the design of the end operation tool.The end operation tool can realize the functions of sawing,cutting and clamping.Firstly,the working principles and structures of these three mechanisms are analyzed respectively,and then their three-dimensional models are established.Finally,the statics characteristics of the lifting mechanism and the manipulator are simulated and analyzed to verify whether the structural design meets the working requirements.(2)Kinematics research of tree barrier cleaning manipulatorFirst,the D-H method is used to establish the forward kinematics model of the manipulator,and the correctness of the forward kinematics model is verified through simulation analysis.Then,the analytical method is used to solve the inverse kinematics model of the manipulator,and on this basis,the correctness of the inverse kinematics model is verified through algebraic method.The Monte Carlo method is applied to solve the workspace of the tree barrier cleaning robotic arm,and the differential transformation method is used to construct a Jacobian matrix to analyze the singular shape and position of the robotic arm.(3)Research on dynamics and trajectory planning of tree barrier cleaning manipulatorFirstly,the Newton Euler method method is applied to establish the dynamic model of the tree barrier cleaning manipulator,and the joint motion curve is simulated to verify the correctness of the dynamic model;Secondly,the joint space trajectory planning of the robotic arm is carried out,and the displacement,velocity,and acceleration function curves of each joint under cubic and quintic polynomial interpolation methods are drawn.The trajectory planning method of the robotic arm is determined by comparing the function curves.(4)Design of the control system of tree barrier cleaning manipulatorFirstly,design the control system scheme for the tree barrier cleaning robotic arm,and then determine the use of a microcontroller to control the robotic arm according to work requirements.Secondly,select and design the hardware components and circuits of the control system.Based on this,determine the programming language and environment for the control system software design,design the system initialization process and motor control process to facilitate the compilation of control programs.In this paper,a multifunctional transmission line tree barrier cleaning manipulator based on scissors lifting mechanism is designed.Through theoretical analysis and simulation verification,the kinematics,dynamics and trajectory planning of the manipulator are studied,and the control system design of the manipulator is completed,which lays the foundation for the follow-up research of the tree obstacle cleaning manipulator,and has certain practical value. |
