Ground Verification System And Test Method For Semi Physical Simulation Of Space Non Cooperative Targets

With the rapid growth of the number of space spacecraft,space on orbit missions are gradually increasing.The acquisition of three-dimensional information of space non cooperative targets can provide operation guidance for on orbit missions.The fault target that needs to be repaired in space on orbit mission may be in a non cooperative state due to out of control attitude.Due to the limitation of the computing power and load of the service spacecraft and the difficulty of maintenance operation,the on orbit service technology is still in the stage of key technology ground research and verification.Linear array lidar has become the most advantageous space on orbit measurement load because of its strong anti-jamming ability,long measurement distance and small external influence factors.Aiming at the problems of high cost of on orbit verification test,complex space environment and difficult control in the process of imaging point cloud data acquisition of space non cooperative target linear array radar,based on the three-dimensional reconstruction numerical simulation of non cooperative target,this paper develops a semi physical simulation ground verification system to simulate the flying around acquisition process of space service spacecraft.The main research work of this paper is as follows:(1)Analysis of the working process of data acquisition of non cooperative target flying around by space service spacecraft based on linear array lidar.The working process of linear array laser imaging is analyzed,the corresponding coordinate system is established,the data conversion theorem under different coordinates is explained,and the outlier noise removal algorithm of point cloud is studied;The relationship between radar scanning cross market and data acquisition volume is analyzed,and the on orbit motion state of non cooperative target is modeled.(2)Design and construction of semi physical simulation ground verification system.3D printing technology is used to print the target model to ensure the size of non cooperative target model;The KUKA six axis industrial robot is used to carry a scaled satellite model to restore the motion state of non cooperative targets;The three-axis precision turntable is equipped with linear array scanning laser sensor to complete the construction of radar scanning system;Complete the connection and communication of all subsystems through the integrated control system;The causes of system error are analyzed,and the scale and experimental environment are determined according to the semi physical simulation theory.(3)Quality evaluation criteria and systematic error analysis of target scanning results.It includes point cloud accuracy analysis,coincidence evaluation and error analysis criteria between actual motion and control motion;Point cloud accuracy analysis includes vertical,horizontal and distance resolution analysis;The evaluation of coincidence degree includes the evaluation of coincidence degree of typical size,the evaluation of parallelism and perpendicularity between typical edge lines and the evaluation of perpendicularity between typical adjacent surfaces;The error analysis criteria of actual motion and control motion include the accuracy evaluation of spin motion and nutation motion.Through the target scanning result quality evaluation criteria,the effectiveness of the scanning result data can be analyzed.(4)Data acquisition experiment and scanning result validity analysis experiment.The target extraction algorithm of scanning results is established to collect the flight around test data under standard operating conditions.Verifying the motion reduction of the attitude simulation system and the effectiveness of the scanning system.The experimental results show that the test system can effectively obtain the point cloud data of non cooperative targets in the multi view state.The mean value of the parallel fitting degree of the geometric features of the targets measured and calculated by the point cloud data is more than 98.5%,and the errors of nutation motion,spin motion angle and the real motion angle of the targets are less than 4% and 6% respectively,which can provide a real data reference for the space on orbit service and configuration reconstruction technology in the future.