Space Debris Detection And Location Method Based On Space-Based Visible Camera

With the rapid development of human space activities,the number of space debris in a sharp upward trend.In order to protect the safety of spacecraft in orbit,it is necessary to observe and locate the space debris.At present,the space debris observation,positioning methods can be divided into two methods:ground-based observation and space-based observation.Compared with ground observation,space-based observation has a wider range of detection and the SNR is higher Therefore,this paper uses space-based visible light camera and laser range finder to detect and locate space debris.In this paper,according to the characteristics of imaging trajectory of space debris,the feature extraction and matching method of debris trajectory is designed.The azimuth angle of the debris is calculated by combining the camera model,and the azimuth angle is filtered by Kalman filter.According to the filtering results,the laser range finder is guided to complete the ranging,and the relative position and velocity location of the debris are completed by the extended Kalman filter method.According to the geometric characteristics of the trajectory of debris,the debris trajectory is described by an ellipse which has an equivalent second order central moment to the debris trajectory.According to the characteristics of the ellipse's long axis,area,eccentricity and so on,the debris track inter-frame matching criterion is worked out,the one-to-one correspondence between the debris trajectories in different frame images is completed and the digital image coordinates at the end of exposure are calculated.In order to balance the accuracy and real-time requirement of debris trajectory extraction,ROI prediction method is designed in this paper,which can greatly improve the detection speed of debris trajectory and reduce the computational ability of on-board computer under the premise of guaranteeing the accuracy of debris trajectory extraction Claim.According to the results of the inter-frame matching,combined with the camera model,the debris azimuth angles are solved.In order to improve the accuracy of debris azimuth resolution,Kalman filter method is used to improve azimuth resolution of debris.According to the azimuth and azimuth angular velocity information,the laser range finder is guided to measure the space debris.Combining angle information and ranging information,we can calculate the relative position of the fragments.In order to obtain the relative position and velocity information of the debris,the extended Kalman filter is designed based on the relative dynamics of the debris,and the localization accuracy of the debris is improved.Finally,a simulation system of space debris compound detection and location is constructed.The system consists of two parts:feature extraction,matching and composite detection and localization.By changing the measurement accuracy of measuring equipment,the positioning accuracy of debris detection is compared.Simulation results show that the proposed method is effective.