Research On Deformation Error Measurement Of The Mounting Rod Of The Magnetic Sensor In Aerogeophysical Survey

In recent years, the surge in demand stimulated the rapid development of aerogeophysical technology. In practical applications, aeromagnetic measurement is a good method to improve the ability to detect in aerogeophysical survey. A magnetic sensor mounted on the outside of the body of the aircraft for measuring the geomagnetic field, in order to reduce magnetic interference of the body of the aircraft to the magnetic sensor, we use a length of the mounting rod to fixedly connect to the body of the aircraft and the magnetic sensor. Therefore, we need to measure the changes in relative gesture of the body of the aircraft and the magnetic sensor caused by the bending strain of the mounting rod in real time. In this paper, CCD marry as the core, a kind of optical methods is used to measure the small changes in the angle between two objects, mainly completing the work in the following aspects:1) In practical applications, the system is required to use the way of non-contact measurement to measure relative attitude, and can reach a certain measurement range and accuracy requirements. Based on the practical application of the requirements, the way of autocollimation is selected to measurement the relative attitude changes between two objects. What's more, based on the actual application environments, especially application of the “fold” rod, a small angle measurement system consisting of twin systems is designed.2) For the limitations of the simplified system model, a more comprehensive and rigorous mathematical model is presented. The paper builds an ideal model system for modeling analysis, obtaining the specific analytic relationship among the coordinates of the spot, position of the light and the deflection angle of the mirror. According to the restrictions and requirements of the measurement distance, measurement range, measurement accuracy and so on, parameters related to the devices are needed to be analyzed, and ultimately completing the work of selection of the system devices.3) According to the actual acquisition of the image effects, combined with the characteristics and application environme nts of various technologies, the appropriate image processing algorithms is selected due to results of the measurement accuracy and stability of different algorithms by the way of experiment.4) Configure appropriate mounting bases for all devices, and according to the size of the mounting base and device parameters, the fixed backplane of the system is to be designed. Upon completing the system assembly and commissioning, the absolutely zero calibration, repeatability and stability testing are being made. In the paper, there are two ways, experimental analysis and ideal model analysis, used for analysis and testing of the system measurement accuracy, and errors being analyzed.In the case of that the normal working distance is 2m and the measurement range is ?0.8? ? ?0.8?, the experimental results show that the system measurement accuracy is 3.5 ', the maximum repeatability error is 3.4 ', the stability drift is 8.2''/ 4h.