Experimental study on rolling stabilization of sphere detector for subsea pipelines

Spherical detector (SD) is promising in the field of subsea pipeline defect detection because of low risk of blocking and being convenient to use. Rolling stability of the SD has a great influence on the detection quality. This paper proposes and experimentally demonstrates that the factors affecting SD rolling stability include the weight, size and mass distribution of the detector. SDs with different parameters equipped with a triaxial accelerometer are used to experimentally study these factors in a steel pipe containing air flow inside. The results show that heavier SD has stronger anti-interference ability; the SD size has little effect on the rolling stability; when the mass of the SD is concentrated on one plane, SD can roll steadily around a fixed axis; when the SD can rotate stably around one certain axis of the accelerometer, the vibration of the pipeline can be accurately detected by the acceleration component.