AI 中文总结
本研究针对可倾转多旋翼飞行器，设计并提出以 effector 为中心的 NMPC 框架，整合构型优化、奇异处理与扰动补偿，通过真实实验验证其可实现无偏移全向空中操作的可行性。
AI 中文摘要
空中操作将机器人作业扩展至此前难以到达的空中环境。与配备机械臂的空中系统不同，可倾转多旋翼飞行器可通过其飞行基座直接生成六自由度力/力矩，通过倾转推力方向实现高效运动与全向操作。本研究针对可倾转多旋翼飞行器的空中操作，开展设计分析并提出基于力/力矩的控制框架。研究表明，四旋翼可倾转构型在无干扰的螺旋桨尺寸选择与不同姿态下的悬停效率间实现了平衡，其零空间冗余对在物理约束下穿越奇异构型至关重要；向上布置末端执行器则在几何间隙与可用力/力矩间取得良好平衡。为应对扰动，提出一种双策略：针对模型误差的改进积分项，以及用于外部力/力矩的基于加速度的估计器。基于上述见解，开发了以 effector 为中心的非线性模型预测控制（NMPC）框架，将设计选择、奇异构型处理与扰动补偿整合为统一公式。该框架在定制的可倾转四旋翼上以100Hz频率完全机载运行。真实实验包括90度阶翻旋转、白板推动及连续360度阀门转动，证明了该单臂自由度可倾转四旋翼在穿越奇异构型的同时实现基于力/力矩的全向操作的可行性。
英文摘要
Aerial manipulation extends robotic operations to previously inaccessible aerial environments. Unlike arm-equipped aerial systems, tiltable-multirotors can directly generate six-degree-of-freedom wrenches through their flight bases, enabling both efficient movement and omnidirectional operation by tilting the thrust direction. This work presents a design analysis and a wrench-based control framework for tiltable-multirotors in aerial manipulation. We show that a four-rotor tiltable configuration provides a balance between interference-free propeller sizing and hovering efficiency across different attitudes, and its null-space redundancy is crucial for traversing singular configurations under physical constraints. We further show that an upward end-effector placement yields a favorable trade-off between geometric clearance and available wrench. To address disturbances, we propose a dual strategy consisting of a modified integral term for model error and an acceleration-based estimator for external wrenches. Building on these insights, we develop an effector-centric nonlinear model predictive control (NMPC) framework that integrates design choices, singularity handling, and disturbance compensation into a unified formulation. The proposed framework runs fully onboard at 100 Hz on a custom-built tiltable-quadrotor. Real-world experiments, including a 90-deg step cartwheel rotation, whiteboard pushing, and continuous 360-deg valve turning, demonstrate the feasibility of wrench-based omnidirectional manipulation with singularity traversal on a one-DoF-per-arm tiltable-quadrotor.
Comments22 pages, 26 figures. Accepted to IEEE Transactions on Robotics (T-RO). This arXiv version includes a two-page appendix with additional implementation details
