Research on automatic docking control algorithm of LNG unloading arm based on moving target flange

Abstract

Aiming at the problem that the PID control algorithm can not meet the requirement of tracking and docking of moving flange due to its slow response speed when controlling the LNG unloading arm, which has strong nonlinearity and time-varying system, the fuzzy control theory is introduced, and the fuzzy control algorithm based on experience and the fuzzy PID control algorithm which is combined with PID control are proposed and implemented respectively, which does not depend on the dynamic model of the LNG unloading arm. The two intelligent control algorithms are respectively applied to the LNG unloading arm of the test site. Taking a single joint as the test object, the performance test and the tracking test of the simulated moving target flange are carried out. The test show that the algorithm designed by introducing the fuzzy control theory has significantly improved the comprehensive response speed compared with the PID control algorithm, and the fuzzy PID control algorithm can fully meet the docking requirements of moving target flange in practical application because of its strong resistance to time delay.

Keywords

• lng unloading arm|moving target flange|fuzzy control|joint control