Analysis of a three-extensible-rod tracker based on 3-RPS parallel manipulator for space large deployable paraboloid structure with power and communication integration. (April 2020)

• Record Type: Journal Article
• Authors: Zheng, Tao; Zheng, Fei; Rui, Xi; Yan, Lide; Niu, Kui; Zhang, Fengbin
• Is Part Of: Acta astronautica. Volume 169(2020)
• Page Start: 1
• Page End: 22
• Publication Date: 2020-04
• Subjects: Space large deployable paraboloid structure -- Power and communication integration -- Three-extensible-rod tracker -- Parallel mechanism -- Dynamic analysis; Astronautics -- Periodicals; Outer space -- Exploration -- Periodicals; Astronautics; Periodicals; 629.405
• DOI: 10.1016/j.actaastro.2019.12.021
• Languages: English
• ISSNs: 0094-5765

Abstract

Abstract: The combination of a solar array and a communication antenna can reduce the entire mass, physical size, and cost in space applications. Currently, related studies mainly focus on the combination of the two structures on one flat plate structure (FPS). Compared with the FPS, a paraboloid structure has lower surface density and higher conversion efficiency. Therefore, the novel design of a space large deployable paraboloid structure with power and communication integration (SSPCI) is proposed for spacecraft on a sun synchronous earth orbit. A novel three-extensible-rod (TER) tracker is studied in detail for the SSPCI to track the sun for power in the sunshine region or turn to face the ground station for communication in the earth's shadow region. The proposed TER tracker includes three extensible rods, where one end of each rod is connected to the base platform by a rotary joint, and the other end is connected to the mobile platform by a smart compound joint as a substitute for a spherical joint; this is known in the literature as a 3-RPS parallel mechanism. In contrast to existing serial mechanisms, it provides a simple and lightweight structure, high structural stiffness, low inertia, and more accurate positioning and pointing of the mobile platform. Meanwhile, the linear extensible rods used in the TER tracker help to reduce energy consumption, and do not require the use of large and heavy speed reducers. A kinematic model of the TER tracker is also established. Based on this kinematic model, a dynamic model is then derived by using Newton–Euler formulation. The motion trajectory of the TER tracker is planned for the SSPCI to track the sun or turn to face the ground station. By setting related parameters, the workspace and pointing accuracy of the TER tracker are analyzed and found to be satisfactory for the SSPCI, and the motion process of tracking the sun or turning to face the ground station is simulated to test the theoretical analysis. The driving force and consumed energy of the TER tracker are obtained; the results shows that the TER tracker is able to drive the SSPCI to track the sun or turn to face the ground station with the aforementioned advantages and small energy consumption. By using finite element analysis, the SSPCI supported by the TER tracker is found to have satisfactory structural performance at different orientations in a zero gravity state. Meanwhile, the TER tracker has a satisfactory operation life and can adapt well to the space thermal environment. Finally, preliminary sun tracking experiments on the TER tracker are performed on the ground successfully, indirectly proving its feasibility of the TER tracker from the mechanism principle and control mode in space applications. Highlights: Space large deployable paraboloid structure with power and communication integration (SSPCI). Novel space tracker based on three-extensible-rod (TER) mechanism/kinematics. Dynamic modeling of TER tracker. Numerical simulation for TER tracker to track the sun or to communicate with ground station. Experimental validation of TER tracker for sun tracking on the ground.