Vibration Analysis of an In-Pipe Inspection Robot Considering Fluid-Structure Coupling

Abstract

A fluid drive in-pipe inspection robot is an essential device for the inner inspection of long-distance oil and gas pipelines. Obstacles such as dents and welds can significantly affect the operation stability of the robot as well as the accuracy of inspection. In this paper, a dynamic model is created to investigate the vibrational response of an in-pipe inspection robot moving through a dented pipe. A mechanical model of the polyurethane sealing disc is established based on the Kelvin spring damping model to simulate its bending deformation. Using the simplified model of the in-pipe inspection robot, the axial vibration equation of the robot is analyzed in detail. Furthermore, a dynamic simulation of the virtual prototype of the in-pipe inspection robot is conducted using the MSC/ADAMS software, considering the interaction between the fluid and the structure. Then, the effects of the robot’s speed, sealing disc interval, and dent height on the vibration response during the pigging are examined. The results indicate that the faster the in-pipe inspection robot passes over the pipe dents, the higher the axial vibration generated by the robot, while the time needed for returning to the stable state is shorter. The pitch vibration caused by the dent substantially intensifies with an increase in the sealing disc interval. The axial and pitch vibration caused by the dent intensify significantly with increasing the dent height. The results obtained herein should prove useful to the optimization of the structural design and precise positioning of the in-pipe inspection robot.