| The airborne electro-optical platform is widely used in the military field and the public security, fire protection and civil fields such as environmental monitoring. Boresight sway is inevitably produced because of moving carrier attitude change, vibration, air turbulence and other factors on photoelectric platform which cause the influence of the imaging quality of airborne infrared and visible light imaging system. To test the performance of airborne photoelectric platform, it is important to identify the main affecting factors of the aerial image fuzzy, improve the image quality of imaging systems, research an effective method to realize the plane flying under the condition of vibration measurement of airborne photoelectric platform, especially measure the characteristics of high-frequency angular vibration.Through the analysis of the vibration characteristics of airborne photoelectric platform, the micro vibration test method and test system meeting the function and index is established. The measurement with vibration benchmark is present which use the sun as reference point. Using the four quadrant detector array, the sun spot position is obtained. The relative vibration of airborne photoelectric platform angle is calculated due to the certain relationship between the center of sun spot and deflection angle of the sun beam relative to the line of sight.Based on the general, the high precision spot center algorithm is researched, which significantly improve the accuracy of measurement of micro vibration measurement system. This paper discusses the principle of general and high precision spot center calculation method and process of database establishment and query. Simulation and experiment results show that the accuracy the spot center is two orders of magnitude improved by high precision spot center calculation method compared with the common spot center calculation method.High precision micro vibration measurement system is designed and developed in this paper. The main technical indicators, structure, module, device selection of the high precision micro vibration measurement system are discussed. The micro vibration measurement system of high precision and can realize the function of system wide field view, collect the sun spot data, micro angular vibration calculation, high speed measurement and high accuracy measurement.Compensation and correction is made on high precision micro vibration measurement system, in order to ensure the accuracy of the physical experiment. Compensation and correction are included as follows,(1) Study the effect on spot center location test of the inhomogeneous system then compensate and correct inhomogeneity on the four quadrant detector array devices and systems.(2) Analysis the effect of background light on the spot center location test, details the effect removal of background light (including system noise) method.(3) Test the influence of optical signal photoelectric response on a photosensitive unit to its adjacent element of quadrant detector and correct the "crosstalk" phenomenon using the linear compensation method.Through the field experimental verification, QD detector array vibration measuring system for the sun spot trajectory measurement function and micro angular vibration measurement function are verified, at the same time, the range of the measuring angle, frequency measurement range and measurement uncertainty of three main indexes are verified.In this paper, the photoelectric platform mounting external of rescue helicopter is taken as the research object, taking the sun as a reference point, high precision micro vibration measurement method and system based on four quadrant detector is researched. The displacement measurement system has high accuracy, fast response, wide measurement range, and can be used in different types of the micro vibration measurement of dynamic vector. |
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