Research On The Movementmechanism Of The Pipeline Robotwith The Omni-directional Wheelin Surface

The pipeline has brought great economic benefits to the country and great convenience to the people,that is a transport channel of important material,such as natural gas,water and so on.However,the pipeline is often affected by the internal fluid and external environment in the use of the process,so that there is some hidden dangers: aging,leakage.Therefore,it is necessary to inspect the pipeline regularly to improve the reliability and prolong the service life.With the development of robot technology,the detection technology of robot gradually replaces the traditional detection methods,because of the advantages of high efficiency and accuracy.Moreover,the ability of robots to work in a small space is improved by using the omnidirectional mobile platform.So,the pipeline inspection robot has been widely research and application.But facing with the complex pipeline environment,there are still some problems needing to solve.In order to solve these problems,the pipeline robot is designed based on the omnidirectional moving gear train and its movement mechanism is studied in this paper.The main content of this paper are as follows:1.Based on the theory of TRIZ,a kind of omnidirectional wheel in surface is designed using the conversion method of "harmful to good".The omnidirectional wheel is developed by knifing the sphere surface and increasing the free rotation roller.The relationship is established between the wheel slip and passive obstacle motion,and the sliding friction can be transformed into the rolling friction through this wheel.Then,the kinematic condition of the omnidirectional wheel on the uneven surface is analyzed using the contact surface kinematics analysis method,and the equation of motion of the wheel on the pipe surface is analyzed.At last,its performance is simulated under different working conditions in ADAMS.2.The relationship between the closing force and the contraction angle of the wheel leg and the self-adaptability capacity to pipe diameter are established by means of the principle of virtual displacement,describing the trend of the change in Matlab.In order to ensure the stability of the closing force and improve the adaptability to the pipe diameter,the evaluation function is established through the weighting coefficient transformationmethod in the genetic algorithm,and the multi-dimensional unrestricted optimization method is used to optimize the design parameters.At last,when the pipeline robot passes through the varying diameters of the pipe,the charge of its closing force is simulated in ADAMS.3.Studying the movement performance of the pipeline robot,the motion of the pipeline robot through the curve and the T-shaped pipe is analyzed,and the capacity of the position adjustment is also given.The simulation model is established by ADAMS software,and the simulation results are given to demonstrate its capability of turning and position adjustment.4.The restraint is analyzed to pipeline robot from elbow and obstacle by the simplified mathematical model.According to the advantage and disadvantage of different travel mechanism,the walking way of the pipeline robot is determined.Designing the mechanism with a passive self-adapting capacity to the pipe diameter,researching the turning scheme and the passive obstacle wheel,the model of the pipeline robot is preliminarily established by adopting the modular combination structure.