Optical method for position-attitude determination between spacecrafts based on computer vision

In order to realize autonomous control for formationflying spacecrafts, the relative state (relative position and attitude)between two space vehicles must be detected precisely. An optical method for determination of the relative position and attitude between spacecrafts is proposed, which is based on the computer vision and imaging theory. First, a quaternion method for measuring the relative position and attitude based on the coordinates of the feature points on the target body is deduced. Then the principle of the testing system and the calibrating technique is introduced. Finally, the experimenting prototype are established to confirm the validity of the testing principle and the algorithm, in which the APS(active pixel sensor) CMOS camera is used as image sensor. Since quaternion theory and the CMOS camera are used to testing the relative state, which make the system with a lot of the advantageous such as smaller volume, lighter weight, higher precision and lower power consumption etc, can be widely used in measuring the relative position and attitude between cooperative space targets.