Experimental Investigation of Deployment Process of Large Hoop Truss Antenna for Space

Large hoop truss antennas are locked into a stable structure during deployment in space. The key to characterizing the performance of each mechanism, and discovering problems in the deployment process, is the three-dimensional motion of the antenna. Therefore, it is important to measure antenna motion with high precision for antenna design. Contact measurement requires sensors to be attached to the object, affecting the motion of the antenna; thus, noncontact measurement is the preferred measurement method. For a large antenna, a large field of view and observation angle are required to measure the deployment process. Traditional binocular stereo vision measurement is not sufficiently accurate. In this paper, 36 cameras were combined into an array to measure antenna deployment. A high-precision triggering system was designed, a calibration method suitable for large-scale, multiangle measurement was developed, and a reconstruction method based on the geometric constraints was proposed, greatly improving measurement resolution. The camera array was used to measure the motion of a large hoop truss antenna with a diameter of 4 m during deployment. Based on the measured parameters, the angular velocity of each antenna mechanism was calculated, and the synchronization of the antenna structure was analyzed.