Research On Path Planning Method Of Distribution Network Live Working Manipulator

The live operation technology is a key technology to ensure the safe,reliable and continuous operation of the power distribution network,reduce the maintenance cost of the power grid and improve the quality of power supply.my country has built the world’s largest power grid,but at present,the live maintenance work of distribution network lines is still almost entirely done manually.Due to the complexity and danger of the power grid operating environment,the life safety of maintenance personnel cannot be effectively guaranteed,and the accident casualty rate is high.In the past two decades,domestic and foreign research institutions have developed a variety of live working robots for distribution networks,the lifting mechanism lifts the electric or hydraulic manipulator arm to the working scene,and the operator performs live maintenance work through remote operation in the high-altitude insulating bucket or on the ground,to a certain extent,the safety of operators is improved,and the realization of fully autonomous operation is the ultimate development goal of live working robots in distribution networks.There are electrical components such as phase lines,drainage lines,cross arms,drop switches,insulators and other electrical components in the live operation scene of the distribution network.The environment is complicated.When the manipulator is working,it is necessary to keep a sufficient safety distance from the phase line,and to avoid power distribution facilities and various hardware.The real-time motion planning of the robot arm is the key to realize automatic operation.Therefore,this paper studies the real-time path planning problem of the six-axis hydraulic manipulator in the distribution network operation environment.The main research contents are as follows:1.Kinematic modeling and workspace analysis of six-axis hydraulic manipulator.According to the equipment characteristics of the manipulator,this paper uses the D-H parameter method to establish the DH model of the manipulator,and completes the derivation of forward and inverse kinematics.Using MATLAB to model and analyze the manipulator to verify the correctness of the derived forward and inverse kinematics,and to analyze the work space of the manipulator.2.In order to solve the problems of long exploration time and too many path nodes in path planning for live working environment of distribution network,this paper proposes a Node Control-Bidirectional RRT(NC-BRRT)algorithm.First,in order to effectively improve the exploration speed,the strategy of gradually changing the sampling area is adopted to realize the path search;At the same time,in order to reduce the expansion of invalid nodes,a node control mechanism is used to constrain the expansion of the tree;Then,the node control strategy is used to search the path from the starting point and the target point respectively,so as to obtain a better path in a shorter time.3.Joint space smooth trajectory generation and time optimization.Unsmooth path planning will cause sudden changes in angular.velocity and angular acceleration during the operation of the manipulator,resulting in vibration and unstable motion of the manipulator.In this paper,the path post-processing algorithm,including trajectory smoothing and the optimization of the actual running time of the manipulator,uses the improved cubic spline algorithm to smooth the trajectory in the joint space of the manipulator,and the improved particle swarm algorithm is used to optimize the time of the joint traj ectory under the premise of satisfying the kinematic constraints of the manipulator,so as to obtain a trajectory-with a shorter duration.4.Motion planning experiment of hydraulic manipulator in distribution network scenario.The ROS system is used to build an experimental platform,and the performance of the node-based control-bidirectional RRT algorithm is experimentally verified based on the six-degree-of-freedom hydraulic manipulator independently developed by the laboratory.The experimental results show that the path exploration efficiency based on the node control-bidirectional RRT algorithm is relatively high,and the manipulator runs smoothly and the work efficiency is improved.