A Study On Key Technology For Improve Tracking Accuracy Of Ship-based Optoelectronic Equipment

Ship-based optoelectronic equipment integrates technology of optics, machineand electronics, and it has lots of advantage and function including a good real-timevision, high tracking accuracy, clear image display and strong disturbance rejectionfunction. Ship-based optoelectronic equipment has been used widely in the maritimemilitary area such as precision striking of fire-control weapons, laser weaponscounterreconnaissance, warning and trajectory predicted of missile and ship-basedaircraft takeoff and landing. With the improvement of flight speed, maneuverabilityand striking precision of the aircraft and missile, forward higher requirements havebeen asked on the performance of ship-based optoelectronic equipment. Theproblem that study and improve the tracking accuracy of ship-based optoelectronicequipment needs to be solved urgently, and it has very important significance.This dissertation mainly focuses on how to improve tracking accuracy ofship-based optoelectronic equipment, conditionality factors of the design of thecontrol system were analysed and discusses from the point of isolation thedisturbance both within the system and created by the ship disturbance. Three keytechnologies concerning servo control system design were analyzed and researchedin depth: exactly building of a new line of sight disturbed model, precisionprediction filtering methods for attitude data measurement of GPS/SINS integrated navigation system and servo control methods with higher disturbance rejectionability.First, servo control system of ship-based optoelectronic equipment wasintroduced detailedly in this paper, and some comprehensive analysis andsummarization were made for the element evaluation of ship-based optoelectronicequipment. Based on the special ship-based environment, the main factors whichaffect the tracking accuracy and dynamic performance were analyzed, and three keytechnologies were proposed in order to improve tracking accuracy.Through the analysis of the disturbed effect of ship-based optoelectronicequipment on the sea, two line of sight disturbed models were established: one isestablished based on three freedom rotation movements of heading, rolling andpitching under TV tracking mode; the other one is established based on threefreedom rotation movements of heading, rolling and pitching and one beelinemovement of course under data guiding tracking mode. The traditional feedforwardcontrol system simulation model was built by SIMULINK which introduced the lineof sight disturbed model to compensate the disturbances caused by the ship shake. Asimulation experiment was made by using this model, and the results show that theline of sight disturbed model established in this paper is accurate and reliable.GPS/SINS integrated navigation system is chosen as the measuring equipmentof the ship shake attitude, and error analysis of its various components was made.According to the error characteristics, two prediction filtering methods wereresearched in order to improve the data accuracy of the attitude angle and angularvelocity: adaptive unscented Kalman prediction filtering and variable structure leastsquares prediction filtering methods. Through measured signal filtering experiments,it can be proved that both two prediction filtering methods have a good filteringeffect, and the final filtering scheme is determined based on the results.To be dead against the disturbance both within the system and created by theship disturbance, two kinds of control methods under different tracking modes wereresearched based on traditional feedforward control methods: disturbance estimate control based on reference model under TV tracking mode and compositedisturbance estimate control under data guiding tracking mode. The study provesthat using these control methods can overcome system internal disturbances betterand well isolate external disturbances from ship shaking. The system simulationexperiments were made under two kinds of tracking modes by differentenvironments with ship shaking and no ship shaking. The result shows that thecontrol methods studied in this dissertation can isolate system disturbanceseffectively, and improve both tracking accuracy and dynamic performance of thesystem.Finally, three key technologies are applied in the servo control system fully inthis dissertation. A triaxial swing table of large load is used to simulate the shipshaking disturbance, which was made for TV tracking and data self-guided trackingexperiments under dynamic carrier. Initial calibration was carried out for GPS/SINSintegrated navigation system to ensure the veracity of attitude data. Experimentresults show that using three key technologies researched in this dissertation canimprove the tracking accuracy of ship-based optoelectronic equipment effectively.