Motion Planning And Experimental Research Of Distribution Line Maintenance Robots

Power distribution line live working has extremely wide range of applications.The use of robots instead of manual for distribution line maintenance operations,enables workers to get rid of high-altitude,high pressure and strong magnetic dangerous operating fields and environment,to ensure the safety of workers,which has an important practical significance.This paper focuses on the research and development of a live-working robot,and studies the kinematics modeling,path planning,trajectory optimization and arm coordination of articulated robots to meet the requirements of accurate and stable motion,compliance and safety requirements of the robot in the distribution line maintenance.The main work is as follows:On the basis of introducing the whole structure of a distribution line maintenance robot system and analyzing line maintenance tasks to be fulfilled,this paper investigates the movement characteristics of the manipulator and plans its motion path.The kinematical model of UR5 manipulator is established by DH parameter method,and the inverse kinematics equation of the manipulator is given based on numerical analysis.The range of motion of the joint is calculated by using parameters of the manipulator.The workspace of the manipulator is analyzed by Monte Carlo simulation,and the working area of the manipulator is given.Based on the collision detection method of the ellipsoidal bounding box,the collision avoidance algorithm of the manipulator is designed.Aiming at the requirements of the smoothness and precision of the trajectory of the maintenance robot,the trajectory optimization of the manipulator is studied.The fifth-order polynomial interpolation and cubic B-spline interpolation were used to plan the trajectory of the manipulator in joint space.Furthermore,a minimum time-jerk speed optimization algorithm based on genetic algorithm is proposed to optimize the B-spline interpolation time,which helps improve the work efficiency.The solution to the problem of the singular point and the joint velocity which may occur in the task space trajectory planning is discussed briefly.In order to avoid colliding the obstacle in the maintenance operation of the distribution line,a corresponding trajectory planning algorithm is designed for the 8-shaped trajectory of the manipulator's distal end and realized on the platform of the manipulator moving programming software.The experimental results show that with the proposed trajectory planning algorithm the manipulator can move along a complex trajectory smoothly,and the repeatability is good as well.A simulation experiment of two-manipulator cooperation to screw cap was conducted and the ideal experimental results were obtained.To imitating the nuts installation and disassembly,which are the most frequency operation in the maintenance of transmission and distribution lines,the experiment of twisting nut with manipulators was designed,and experimental results show that the manipulator movement planning can achieve the basic action of twisting nut.