Study On Stability Of Steering Movement Process Of The Compound Driving Articulated In-pipe Robot

The application of pipelines has penetrated into all aspects of production and life since the beginning of the industrial age.AS an electromechanical integrated system performing a series of operations in the pipeline,the in-pipe robot reduces the risk of manual operations and labor intensity,and increases the operation reliability within the pipe.At present,though most of the in-pipe robot driving methods are relatively single,it is difficult to meet the needs of complex pipeline environments.On this basis,the concept of a compound-driving in-pipe robot was proposed,which may satisfies the performance requirements of strong endurance ability,diversified functions and high stability.Aiming at the compound driving in-pipe robot,the stability of steering movement process is studied in this paper.Based on the principle of "compound(driving)",this paper establishes a general physical model of the compound-driving in-pipe robot.First of all,taking it as the research object,static analysis including the composite driving force and the resistance in the pipe are performed on the model.Considering the space constraints,spatial motion equation and dynamic modeling aiming at the steering movement process are obtained.The stability and steering movement process of the compound driving in-pipe robot are described.The concept of ZMP and the stability analysis method of ZMP are introduced.The steering movement process of the in-pipe robot is described by the pose matrix.The gap changing trend between the traveling wheel of the robot with different postures angles and the pipe wall are calculated by MATLAB simulation.Based on the virtual prototyping technology,the single-unit body,double-unit body,and robots with different posture angles passing through the 90° bend pipe are simulated by ADAMS.The movement characteristics of single-unit body,double-unit body and the influences concerning stability of the in-pipe robot with different pose angles passing through bends are contrasted and analyzed.Based on the CFD algorithm,the velocity vector and pressure distribution of the flow field when changing the position of the leather bowl and the gap between the leather bowl and the pipe wall are described by the fluid computation model.In the light of the four different working conditions of robot,the kinematics characteristics under the coupling effect of motor drive and fluid drive in steering movement process are numerically described and analyzed.The experiment platform was built and the experiment of the simple principle prototype in water filled pipe was completed.The correctness of the theoretical analysis and the movement characteristics of the compound driving are verified by the experiments of the traction force and the steering movement process of the in-pipe robot under different working conditions,which lay a foundation for the further research of the compound driving in-pipe robot technology.