Technology Of Line-of-sight (LOS) Stabilization For Ship-based Photoelectric Tracking

Compared with ground-based photoelectric tracking system, LOS stabilization ofship-based photoelectric tracking system is facing bigger difficulties and challenges. Onthe one hand, ships sailing in the water will be affected by a variety of complexinterference. The photoelectric tracking systems installed on the deck of ship will beinfluenced by these carrier coupling interference, which makes its visual axis deviatefrom the target to be measured. On the other hand, the swaying motion of ship due tothe interference has characteristics of low frequency and large amplitude. Ship-basedphotoelectric tracking system moving along with the carrier will do the same movement,which increases the difficulty of acquiring and tracking targets. So measures must betaken to guarantee the stabilization of LOS, only thus can the photoelectric trackingsystem track targets steadily and accurately.This paper firstly introduces the working principle of photoelectric tracking system,then analyzes the internal disturbance factors of system and the coupling interference ofcarrier which effects on the tracking servo system, emphasizing on how the motion ofship especially the swaying motion affect the tracking performance. Based on theanalysis, a method for isolating the impact of ship sway which is called ship-swayingfeedforward compensation control technology is presented in this paper, and therelational ship-swaying self-stabilization model is constructed by using the coordinatetransformation technology. Besides, it suggested that the active disturbance rejectioncontroller (ADRC) is applied to the speed-loop of the servo system of photoelectrictracking system for the purpose of overcoming the uncertain inside and outsidedisturbances and improving the disturbance rejection ability of system. This paperverifies the validity and feasibility of the above control algorithms by use of theMATLAB/Simulink simulation, then constructs a hardware platform based on PC/104and puts forward a real-time simulation scheme based on RTW and xPC Target which supports hardware in the loop and rapid control prototyping. By using this experimentalscheme, the experimental verification of the related LOS stability control algorithm inthis paper is completed on an electro-optical pod system.