Research on the proportional-integral-derivative synchronous control method of the marine spherical isolation plug in the rotation process

Abstract

The emergency pipeline repair technology is crucial to the maintenance and safety of pipelines under the emergency condition. In the offshore industry, the marine spherical isolation plug, a novel active plug device, is a significant emergency repair equipment of the hot tapping and line stop operation. In this article, the structure scheme and operation process of the marine spherical isolation plug are designed. A mathematic model is extracted from the proposed structure, and then the coordinates of the center of the spherical plug head is calculated using the D–H method. The displacements of the inserting hydraulic cylinder and the rotation hydraulic cylinder are investigated to provide the remote control data for the upper computer controller during the torsion process of the plug head. Moreover, a proportional-integral-derivative (PID) synchronous control method simulated by MATLAB is presented to reduce the rotation error of the plug head. To discuss the control strategy, a numerical model using ADAMS software is built. The results show that the error of the PID synchronous control method is more precise than that of the signal step-by-step control method; the number of steps of 90 is recommended in the actual operation. This article will provide theoretical guidance for the optimization design of the marine spherical isolation plug system.