Precise measurement method of carrier motion state in microgravity environment

•A measurement platform is constructed to provide high-precision time and space references.•A circular cooperative target is designed, and the center of the circle is fitted with high precision.•A joint camera self-calibration model is constructed to solve the camera parameters.•The absolute pose of the moving carrier relative to the center of the earth is measured by combining stereo vision and IMU. In the field of aerospace and planetary science, precise measurement of the motion state of a moving carrier represents an important part of scientific exploration missions. the paper presents a fusion of the stereo vision and IMU to measure the velocity, angle, and angular velocity of a moving carrier precisely. First, a stereo camera self-calibration model with additional geometric constraints is developed, whichaccuracy of better than 0.379 pixels is achieved. Then, a three-dimensional reconstruction with accuracy of better than 0.727 pixels is achieved. Finally, the spatial relationship between the carrier, the stereo camera, and the IMU is used to determine the absolute pose change of the moving carrier relative to the center of the Earth. The proposed method ensures high measurement accuracy of the velocity, angle, and angular velocity of the moving carrier of better than 0.19 mm/s, 0.09°, and 0.127°/s, respectively, which can provide reliable technical support for the motion state estimation of deep space moving vehicles.