| The inspection robot for power transmission line is capable of doing the high intense and risk inspection work instead of the inspection technicists,and is being a research hotspot recently.As the carrier of inspection and electrical equipment,the obstacle-crossing ability of the inspection robot mechanism has become the basic indicator of robot performance.In recent years,the domestic and international researchers have proposed many robot mechanisms,the multi-unit serial configuration has great capabilities of gravity balance and adaption to the obstacle surroundings with horizontal angle,but has never got enough attentions for its complicated mechanism comparing with other configurations.Regarding to the 500kV overhead ground wire environment,based on the transmission line typical obstacles' categories,parameters,combinations and the existing robot mechanism characteristics,the following four works are mainly completed:a)the robot mechanism is designed,the robot dynamic and energy consumption characteristics are analyzed,b)the robot obstacle-crossing flows are planned,the mechanism parameters are optimized,c)the characteristic of the robot gravity balance is analyzed,d)the prototype experiments are performed.The concrete research contents are as follows:(1)A novel multi-unit serial inspection robot structure for power transmission line based on parallelogram unit mechanism is proposed,which unit based on parallelogram mechanism is driven by diagonal mode to do the pitching motion.The concrete architectures separately driven by electric cylinder and cables are designed.A novel single-motor cable-diagonal-driven principle(SMCDDP)for the robot unit based on parallelogram mechanism is proposed to meet the requirements of light weight,few driving motors,having the abilities of switching the supporting stands.The switching method is presented,the prototype is established.The kinematic,dynamic characteristics and the practicability of the units based on every driving principles are separately analyzed,the results show that the electric cylinder driving principle has the advantage of simple control mode and certain practical value,but the mass of electric cylinder is large and the existing electric cylinder technology is incapable of meeting the cylinder extending stroke requirement,the SMCDDP has the advantage of small mass,comparatively simple control mode,few driving motors and better practicality.The energy consumption characteristics of the novel serial robot unit based on SMCDDP and the conventional serial robot unit are analyzed contrastively,the results show that the robot based on the novel unit has lower energy consumption and better long endurance capability.(2)The obstacle-crossing flows of the robot based on the unit driven by SMCDDP are presented oriented to different obstacles.The accurate mathematic model considering the cable guide pulley size of the unit is established.The robot geometric parameters are optimally designed based on the obstacle-crossing flows and obstacle parameters.The restrictions are that the robot has the ability to adapt to the pitching angle of transmission line with no obstacle when moving forward,to cross vibration damper from upside directly,to meet the screw stroke requirement,to cross the typical obstacle combinations.The optimization objects are that the robot vertical size is minimum,the cable suspending length is minimum,the robot length is minimum,the robot overall dimensions are minimum.Then a couple of robot geometric parameters are solved out with the multi-objective optimization tool.The workspace analysis results of the robot obstacle-crossing arm shows that the robot with the optimized geometric parameters has the ability to cross the typical obstacles installed on the transmission line.The crossing flow of the robot oriented to typical obstacle combination is presented.(3)The gravity balance condition of the proposed robot is presented.The steering obstacle-crossing algorithm flow under the gravity balance condition of the 3-arm and 4-unit inspection robot proposed in this thesis is presented.A kind of cylindrical coordinate transform method is proposed to reduce the inverse kinematic unknown variables,the bisection-interpolation approach algorithm is used to search for the gravity balance posture,and the changing curves of the robot joint angles are presented.The steering obstacle-crossing method under the gravity balance condition of the 5-arm 8-unit configuration proposed in this thesis is presented under the same obstacle environment.The comparing analysis results show that the proposed 3-arm mechanism has the ability to cross the obstacles on the transmission line with horizontal angle,but the crossing path and posture are limited.The arm of the proposed 5-arm mechanism is capable of crossing the obstacles through arbitrary path without interference in its workspace,the 5-arm mechanism has a better gravity balance capability.(4)The prototype based on the unit driven by SMCDDP and the experimental transmission line environments are established.The experiments of unit pitching motion,supporting stand switching and energy consumption are executed,the practicality of the novel robot unit,the accuracy of the unit mathematic model and the analysis result of the energy consumption are verified.The prototype experiments of moving straightly,crossing single typical obstacle,crossing combined obstacles,crossing the obstacles on the steering line are performed.The experimental results show that the robot has the capability of crossing the obstacles on the transmission line,the proposed robot mechanism meets the obstacle-crossing requirements.A novel multi-unit serial inspection robot mechanism for power transmission line is proposed in this thesis,the kinematic,dynamic,gravity balance,obstacle-crossing principle analysis and the prototype experiments are executed.The experimental results show that the novel robot mechanism meets the moving,crossing obstacle,steering requirements,the robot mechanism has the capability of operating on the power transmission line. |
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