Most of the spherical unmanned aerial vehicles (SUAVs) use control surfaces, which are functions of aileron and an elevator, to generate control torque. The work proposes a new conceptual design of an SUAV system controlled through center-of-gravity (CG) variations with its path-tracking control law designed for the system. Compared to the one using control surfaces, the concept suggested is beneficial in the aspect of the expandability of building lighter and smaller SUAVs, especially. A CG variation principle by actuating a pendulum type of a moving part is considered as a methodology for both translational and rotational motion control of an SUAV. Since variations of the moment-of-inertia (MOI) elements which resulted from the motion of the moving part affect the performance of the suggested method, the variations of MOI analysis are performed for all angular ranges of the moving part. As a result, certain angular ranges for the moving part to prevent the degradation of the path-tracking performance by the effect of the MOI changes are found. By considering the findings, numerical studies are performed for hovering, ascent, descent, and horizontal tracking missions. The applicability of the proposed SUAV system and the corresponding controller to achieve the path-tracking missions is demonstrated through the numerical simulation.

中文翻译：

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重心变化驱动球形无人机系统及其控制律

大多数球形无人飞行器（SUAV）使用控制表面来产生控制扭矩，这些表面是副翼和电梯的功能。这项工作提出了一种通过重心（CG）变化控制的SUAV系统的新概念设计，并为此系统设计了路径跟踪控制律。与使用控制面的飞机相比，建议的概念在制造更轻，更小的SUAV的可扩展性方面特别有益。通过致动活动部件的摆类型来改变CG的原理被认为是用于SUAV的平移和旋转运动控制的方法。由于运动部件的运动引起的惯性矩（MOI）元素的变化会影响建议方法的性能，MOI分析的变化是针对运动部件的所有角度范围进行的。结果，找到了用于运动部分的特定角度范围，以防止由于MOI改变的影响而导致的路径跟踪性能的下降。通过考虑这些发现，对悬停，上升，下降和水平跟踪任务进行了数值研究。通过数值仿真证明了所提出的SUAV系统及其相应的控制器实现路径跟踪任务的适用性。和水平跟踪任务。通过数值仿真证明了所提出的SUAV系统及其相应的控制器实现路径跟踪任务的适用性。和水平跟踪任务。通过数值仿真证明了所提出的SUAV系统及其相应的控制器实现路径跟踪任务的适用性。