Research On Optical Axis Consistency Detection Technology Based On Connected Domain Discrimination

In the field of detection,detection and national defence,such as aerospace,military weapons with guidance,infrared imaging and radar detection as their main functions are equipped with photoelectric systems rich in far infrared,laser,near infrared and other bands,such as semiconductor laser emitters,visible imaging instruments.The better the parallelism of each optical axis of the weapon system,the more active advantage it will have in the modern and future all-digital wars that may break out,and the faster it can grasp the wartime intelligence and realize the precision strike and flexible maneuver.Due to the special performance requirements of some photoelectric weapons,a variety of photoelectric units are equipped for them,making the overall size of the weapon equipment larger,resulting in a larger span between photoelectric units,which is not only difficult to install,but also the optical axis precision of each photoelectric unit can not be guaranteed.When weapons and equipment are actually used for investigation,if the optical axis of each photoelectric equipment is not consistent,the position of the tracking object will be deviated,and innocent people may be injured by mistake in actual attack.Therefore,multi-axis consistency detection and improving the accuracy of optical axis parallelism are always a key research area.There are many factors that affect the parallelism accuracy of optical axes of photoelectric equipment,such as the actual machining error,the use in bad environment,the long use time and so on,which will result in the reduction of the parallelism accuracy of optical axes.Therefore,before the use of optoelectronic equipment and in all stages of use,it is necessary to periodically carry out precision detection and adjustment,according to the actual situation of the specific equipment itself,to adjust the optical axis deflection within the scope of work permit.In this paper,a set of optical axis consistency detection system which is easy to assemble,easy to operate and high precision is developed according to the photoelectric unit of an airborne radar weapon system of avic.With the off-axis parabolic reflector structure,the internal optical path is folded and reflected for many times to meet the requirements of field of view,which greatly reduces the volume of the equipment itself.The system is equipped with infrared,laser and visible light source generating devices in three different bands,and the optical axis position acquisition is realized by machine vision.In this paper,the mathematical model of optical path propagation is established,and the conclusion that the position of light source is consistent with that of spot is obtained.Image processing and target recognition algorithm are used to locate the centroid of light spot.In this paper,the spot location method based on connected domain discrimination is proposed by analyzing the spot characteristics of airborne radar system.The improved adaptive threshold algorithm is used to narrow the target region,and the connected domain markers are used to identify all the prospects.Simulation results show that the improved adaptive threshold method combined with the connected domain discrimination method can effectively suppress the background noise of laser spot in airborne radar system and locate the laser spot energy center rapidly.The system can be applied to indoor and outdoor environment,can detect in situ or off-site equipment.The uncertainty of the system is less than 10 seconds.The deflection Angle of each optical axis in the initial state of the system is measured by experiments.At the same time,the maximum adjustment range of laser axis is 21 points.