Design and Kinematic Analysis of a Parallel Space Pointing Mechanism Driven by Ultrasonic Motors

Space pointing mechanisms are crucial for controlling the movement of solar arrays, which can significantly improve power generation. So the solar array drive assembly plays a key role in advancing space technology. However, most current solar array drive assemblies face challenges related to weight and size. Therefore, this paper presents a lightweight design solution: a solar array drive assembly powered by ultrasonic motors that meet the requirements for the lightweight design. Firstly, a coordinate transformation in geosynchronous orbit is established to analyze the design requirement of the mechanism’s degree of freedom. Next, the structural composition and working principle of the mechanism is introduced. To achieve precise pointing motion, forward and inverse kinematic models are developed, followed by an analysis of the mechanism’s workspace and error model. The solar array drive assembly proposed in this paper is expected to be applied in micro-satellites and special orbiting spacecraft in the future.