| Pipeline is a critical infrastructure for modern society.For various reasons,pipeline is susceptible to internal defects and obstructions that affect its safety and efficiency.Therefore,the pipeline needs to be tested,repaired and cleaned in a timely and effective manner.With the development and application of robotics,the use of robots to complete pipeline operations has become a new trend.Pipeline robot is a kind of special robot specially used to accomplish various tasks inside the pipeline,which has a wide range of application prospects in the fields of pipeline inspection,maintenance and rehabilitation.In this paper,a crawler type pipeline inspection robot with adaptive and active adaptive functions is designed for the problems and challenges in the inspection process of small and medium-sized oil and gas pipelines.The robot is capable of working in a range of pipe diameters from 235 to 280 mm,with strong climbing and obstacle-crossing capabilities,and can adapt to complex pipeline environments.The main research work and conclusions of this paper are as follows:(1)The design of the overall scheme and structure design of the pipeline robot were completed.By analyzing the common types of existing pipeline robots,advanced technologies and research methods,the functional requirements and technical specifications of the robot designed in this project were determined,and the design of the overall scheme of the robot and the selection and design of its main components were completed.On this basis,the 3D modeling and assembly simulation of each component of the pipeline robot were carried out by using Solid Works,and the rationality of the structural design was initially verified,and the structural characteristics and working principle of the robot were elaborated.(2)The design and simulation verification of the disc spring of the diameter-changing mechanism were completed.The force analysis of the crossing process of the pipeline robot was carried out to obtain the required compensation force provided by the disc spring during the crossing process,and the static simulation of the robot was carried out according to the compensation force.The parameters of the spring force,compression,and space dimension of the disc spring were obtained through the simulation.And the selection and design of the disc spring was completed by referring to the Spring Manual.Then the characteristic curve of the disc spring was obtained by fitting with MATLAB.The results show that the design of the disc spring meets the expected requirements.(3)Finite element analysis and optimal design of the main force transmission components of the robot were carried out.The finite element analysis of the diameterchanging mechanism of the pipeline robot was carried out using ANSYS Workbench,and the results showed that the maximum equivalent force and deformation of the diameterchanging mechanism were 22.212 MPa and 0.031593 mm,which were less than the permissible values.Second,the design of the variable diameter mechanism was optimized by taking the horizontal coordinates of the robot active crank and slave crank and large connecting rod connection points as the design variables,the deformation of the disc spring as the constraint,and the maximum value of the robot overpressure on the pipe wall as the optimization objective.The final power transmission performance of the robot was improved by 22.29%.(4)Simulation and analysis were carried out for the passability problems of the pipeline robot.The three-dimensional model of the robot is simplified into a form convenient for processing by the simulation software,and two simulation models are established for straight pipe crossing and pipe bending.ADAMS was used to investigate the robot’s displacement,velocity,contact force and rotational torque during the process of horizontal pipe crossing,vertical pipe crossing and bending,and to compare them with the theoretical values.The results show that the robot has good overrun capability and bending capability. |
PDF Full Text Request