Relative Navigation Of Spacecraft Based On The Combination Of Inertial Navigation And Linear Laser Triangulation

Surface inspection of large spacecraft is a special space on orbit service.It is of great significance to protect space station and other large spacecraft in long-term safe and stable operation in space.Aerospace power is developing space robots with patrol function device to realize autonomous Orbit service for space station,in order to complete the task of detecting and maintaining large spacecraft such as space station.Relative navigation between large spacecraft such as patrol equipment and space station has become the key technology in this field.Based on the background of space station inspection,The relative navigation technology of Spacecraft Based on Inertial / linear laser triangulation is studied.The main contents are as follows:A new scheme of combination of linear laser triangulation system and inertial position and attitude estimation system is presented to obtain relative navigation parameters of inspection device and space station.Firstly,the overall navigation system based on Inertial / linear laser triangulation is studied.Then,linear laser triangulation model is established.Finally,the relative motion model of integrated navigation based on linear laser triangulation system is studied.Due to the inspection equipment in the space station near the surface inspection carried out in orbit inspection,this puts forward higher requirements for relative navigation accuracy.The beam produced by a line laser is projected onto the surface of the object to be measured,the reflected light is received by infrared camera.If the object moves along the direction of the laser beam,the line laser imaging on the camera imaging plane moves accordingly.The moving distance of the measured object can be detected by the moving distance of the image point.A calibration method of triangulation system based on distance difference is proposed,this method solves the problem that the distance between the laser port and the calibration object cannot be directly and accurately measured.It Improves the precision of point cloud data acquisition.Point cloud data registration algorithm is studied.The accurate registration between the point cloud data and the point cloud data acquired by the linear laser triangulation system is realized.So the relative position and attitude between the inspection device and the space station are obtained.The combination of linear laser triangulation system and inertial position attitude estimation system is proposed to calculate the relative navigation parameters of the inspection device and the space station.Point cloud registration to obtain relative pose parameters calculation time is long,Inertial position and attitude estimation system acquires relative navigation information though real-time,but the positioning error of inertial pose estimation system will increase with time.In order to solve this problem,the relative position and attitude information obtained by point cloud registration is calculated by the relative navigation information calculated from the inertial position attitude estimation system.The establishment of the inspection device relative to the space station orbit coordinate system of the dead reckoning system as the system state equation according to the gyro,accelerometer and Hill equation.The observation equation is established based on the linear laser triangulation system.Finally,an extended Kalman filter is designed to realize the relative pose estimation of two spacecrafts,the effectiveness of the method is verified by simulation.To verify the effectiveness of the relative navigation technique presented in this paper,a joint simulation verification platform based on STK(System Tool Kit)and MATLAB software is built.It can quickly and efficiently verify the relative navigation process of two spacecrafts.A relative navigation semi physical simulation experimental platform based on linear laser triangulation system is built.The line laser triangulation system is calibrated,and calibration error is studied experimentally.The relative navigation method based on Inertial / linear laser triangulation system is studied in this paper.It can use the surface structure information of large spacecraft such as space station to realize patrol navigation.At the same time,we can use the real-time point cloud data to check the integrity of spacecraft surface structure.It can effectively support the autonomous operation of inspection spacecraft.