| It is tedious, dangerous and difficult to inspect power transmission lines. So far, most of the inspections are completed by workers. Obviously, manual inspection have many disadvantages: low efficiency, high cost, etal. Now as the development of robot technology, it is necessary to develop line-inspecting robot, which can inspect the power transmission lines automatically.Inspection robot for power lines is a kind of special robot which is a highly efficient robot system to complete the inspection tasks with high quality, high efficiency and low cost. The robot can not only move on the line, but also it can observe the power lines and transmit the video signal to supervision station automatically. Then, these images are converted to provide the status of power lines and relative devices from which people can detect the damages of power transmission line.Many researchers have introduced various design of inspection robot. However, the practical applications of them are limited and many problems of technique are required to be solved. This article research goal is to develop the robot so that automatical inspection on the entire transmission line becomes the reality.In this dissertation, the working environment of power transmission lines and the key technologies of inspection robot are discussed in detail. The mechanical structure of inspection robot is proposed which includes the wheel and claw mechanism, arm mechanism, guide and support mechanism and control box. The structure of the robot is designed to be capable of navigating on the lines and surmounting obstacles. The robot can choose rolling or crawling way according to line's situation. When meeting the obstacle, robot can cross obstacle, and continue to march forward. Inspection robot for power transmission lines must plan its behaviors to negotiate obstacles according to obstacle when it is crawling along the power transmission line. For this purpose, based on the structure of transmission lines, two arms are designed to be suspended on the same side of the wire which can avoid the inference of the affiliated facilities like the towers.The locomotion mode and steps of the robot on the power line are analyzed when robot is working on the line. Then the typical tasks are discussed and presented by kinetics analysis. The discussion results show that each step can be divided into several basic movement of the robot. And the feasibility of the mechanical configuration is validated simultaneously.The control system is an important part of the inspection robot system. A three-layers control system is proposed, which includes supervision and management system on the ground station,robot control,actuations directly controlled by microprocessors. The roles of the upper layer are to receive the inspection images in real-time, conduct the fault detection, monitor the operations of the robot and remotely control robot operations. Based on the embedded computer (PC104), the middle layer plays the role of analyzing, distributing and coordinating. It receives and analyses the commands from the upper layer, then distributes the tasks to individual lower level actuator controllers. Under the auto-operation mode, it makes its own decisions for planning the sequence of operations according to knowledge data base without the upper layer's involvement. The remote ground system is installed on the ground station based on a portable computer. Embedded computer correspond with remote ground system through the wireless network. From the human-machine interface on the ground system, the operator on the ground can monitor the states of the robot and remote control the robot if necessary.Robot servo system is the use of motor torque generated by motor directly or indirectly to drive robot for the implementation of the various sports bodies to achieve the set or track position. In this design, three loops of control strategy are adopted, that is, torque control, speed control loop and position control loop. Robot joint is required to satisfy the measures of performance of fast response speed,running stably and high accuracy. Torque control of the motor is the main issue of the high accuracy servo drive systems. In this paper, relationship of duty cycle value, back EMF and torque is analyzed. A way based on PWM duty cycle is introduced to eliminate torque ripple. Experimental results: based on a single-chip microcomputer XC167CI, control system is presented to illustrate the effectiveness of the proposed method for the control. Finally, the general controller is applied in the inspection robot used for power transmission line,which can achieve satisfactory performances.A series of experiments are completed, including module unit experiments, laboratory overall system debugging and the 500KV field experiment for inspection task.The experiment and test results show that the inspection robot system has possessed the capabilities of navigation and inspection tasks on the power lines. The project has fulfilled the technical requirement of power transmission system and has a good application prospect.
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