Research On The Detection Method Of Aeronautical Ground Light Intensity Based On Conjugate Imaging

Aeronautical Ground Light is an important facilities of visual navigation system,its photometric parameter is an important condition to judge the working state of lights.The usual detection method is offline detection that the lights are detecting in the laboratory after disassembly,and online detection that using the inspection vehicle to detect the lights.But there are some deficiencies that the testing cycle of the former is a little long,and the cost of the latter is high.To address the above issues,this paper proposes a detection system based on conjugate imaging and the main work is as follows:1)The spatial positioning system: it is used to locate the light outlets of lights on site.Firstly,shooting the lights by using the binocular camera and uploading the figures to PC.Secondly,determining the coordinates of the endpoints of the light outlets by using the corner detection.Finally,calculating the relative position between the light outlets and the sensors by using the parallax principle.2)The light intensity detection system: Firstly,using CCD to collect the illumination.Secondly,using the method based on illumination error feedback proposed in this paper,the surface light source is divide into several point light sources which are small enough and a group of light intensity distribution is preset for these point light sources.These values of preset light intensity distribution is used to calculate the illumination at each measuring point and the error between calculated illumination and actual measured illumination.Then the error feedback is used to update the preset light intensity distribution.After several iterations,the preset light intensity distribution is similar to the actual light intensity distribution of the lights.;3)After ensuring the detection method,the feasibility of this method has been verified by MATLAB simulation with LED array surface light source as an example.Then,some other cases of LED array,such as axis deviation or different distribution of light intensity,have been discussed and simulated to further verify the feasibility of this method.Finally,the compatibility between the approximate distribution of light intensity and the actual distribution of light intensity have been calculated,and the results are over 93%,which is acceptable in practice.In the end,takes the runway centerline light as an example,the light intensity distribution of the lamp has been tested under near-field condition.The light outlet location and light intensity distribution detection have been done.Finally,the compatibility has been calculated and the result is 94%.The requirements of practical application is met.