Research On The Design And Motion Analysis Of A Multi-linked And Wheeled Piping Robot

With the popularization and application of pipeline in all walks of life,the pipeline has become one of the main tools to transport substances.At present,in order to find and remove foreign bodies in pipe,the adopted process is to stop the related equipment,and then open the valve or piping to detect the location of foreign bodies in the pipe in artificial way.However,most of the pipelines,at high altitude or buried deep in the ground,or at high temperature,high pressure,high poison,high radiation or other bad environment,bring great inconvenience to the artificial operation,which causes that the work efficiency is low.Therefore,in order to improve the level of maintenance and accident treatment efficiency,reduce the labor intensity of workers,and avoid the occurrence of industrial injury,it is practically significant to develop a robot that can take the place of human to detect and clear foreign matter in pipeline.Based on the analysis and summary of pipeline robot research status both at home and abroad,combining with pipeline environment and operating requirements,the structure of the robot body adopts the modular-joint-series design and the unit adopts the wheeled-closed design scheme;robot unit-drive module and unit-joint module are respectively designed,and the key parts are designed in detail and meanwhile the finite element software is used for key parts analysis.Based on D-H homogeneous coordinate transformation principle,the kinematics model of pipeline robot is established;and MATLAB software is used to solve the forward kinematics equations of the robot;a genetic algorithm is used to optimize the solution of inverse kinematics equations.Combined with the feature of the structure of the robot and pipeline structure,a kind of S vertical crawling motion strategy is proposed,and then vertical crawling motion action is planned.Based on the mechanism of action between driving wheels and pipe wall,the D'Alembert's principle is used to establish dynamic model of the robot unit walking in pipeline,and based on the dynamic model above,dynamics model of vertical crawling motion with the mutual constraints between the units is established in Newton-Euler dynamic analysis method,and matrix equation about driving force of each robot unit and drive moment of each joint is got.Based on the movement simulation of robot walking in straight pipe,it turns out the basic function and the rationality of structure design of pipeline robot,and it also turns out that the dynamic model of robot with the interaction between driving wheels and pipe wall is correct.Based on the simulation of robot walking through the curved pipe,the pose of unit and joint through the curved pipe is got,and it turns out that the pipeline robot is able to walk through the curved pipe.Based on the simulation of robot crawling in vertical pipeline,the pose of the pipeline robot in the vertical pipe is analyzed,and it turns out the feasibility of planning strategy of S motion in vertical pipeline;the dynamic characteristic curve of vertical crawling motion is analyzed,and it turns out the validity of the dynamics model of the vertical crawling motion,as well as the reliability and stability of the vertical crawling movement.Based on robot unit maximum speed test experiment,it turns out that the maximum speed of the robot in pipe can meet the requirements of 6m/min performance index;it also further validates that the ontology driving structure design and mobile way selection are reasonable,which can achieve expected goals.Based on the traction test experiment of robot unit,the traction of the unit walking in the pipe is measured,and it turns out that the traction provided by the designed robot unit can meet the demand of actual pipeline operation.Based on the test experiment of two robot units walking through the curved pipe,it turns out that the multi-linked pipeline robot can smoothly walk through the curved pipe,and meanwhile it verifies the credibility of the simulation results of the curved pipe,and further verifies the feasibility of the scheme design of the connection joint mechanism and the rationality of the set parameters of the overall structure size.