XPBD method based modelling of rib-mesh antenna deployment process and dynamic simulation analysis
Abstract
<p indent="0mm">With the increasing requirements for operating frequency and gain of spaceborne antennas, large-aperture, deployable and high-accuracy rib-mesh antenna have become the key technology for the development of spaceborne antennas. Rib-mesh deployable antenna reflector has the advantages of simple form, stable structure and high deployment reliability, and is one of the main forms of satellite antenna reflectors. This article proposes a structural scheme for a 6-rib mesh reflector, which consists of a tensioned cable-net that forms the reflective surface and is supported by radial ribs. By combining the boundary cable design with a mixed shape-force-finding method, an approximately equal pre-tension distribution scheme under the boundary condition of six-support-point is obtained. To analyze the complex dynamics of the deployment process by rotating and expanding the radial ribs, the method for solving the rotational state has been extended based on the XPBD (Extended Position-based Dynamics) algorithm. The constraint function for establishing antenna dynamic models has been designed based on both the nonlinear cable model and the Cosserat rod model. Compared to algorithms established using quaternions, the algorithm in this paper, which is based on rotation vectors, is simpler and more efficient. The accuracy and reliability of the algorithm are verified by comparing the results of the flexible cable free swing example with those of the absolute nodal coordinate formulation (ANCF). In addition, a dynamic simulation of the antenna deployment process is conducted. The results show that the collision effects and nonlinear characteristics between structures conform to physical laws. The antenna deployment process is stable, and the surface accuracy of the cable mesh reflector after deployment meets the design requirements, verifying the rationality and effectiveness of the antenna structure and deployment mechanism scheme.</p>
