Relative navigation of spacecraft based on the combination of inertial navigation and TOF camera

Based on the background of space station inspection, a relative navigation of spacecraft based on the combination of inertial navigation and Time of Flight (TOF) camera is proposed. Firstly, the acceleration under the system of the inspection device is measured by an accelerometer, and the relative position motion model between the centroids of the two spacecraft is obtained by combining with the Hill equation. Then, the angular velocity of the inspection detector is measured by the gyro, with the removal of angular velocity of the trajectory, the attitude motion model of the inspection device relative to the navigation system is derived. Finally, the point cloud data of the surface structure of the space station is measured by the TOF camera, and the extended Kalman filter is designed with the registration value as the observation. The relative position, velocity and attitude of the inspection detector and the space station are determined, and the drift error of the inertial measurement unit is estimated. Simulation results show that the estimation accuracy of the relative position is better than 0.01m, and accuracy of the relative attitude is better than 0.03°, which validate the effectiveness of the proposed algorithm.