This paper presents an attitude tracking control law and control allocation strategy for quadrocopters which prioritizes the vehicle’s ability to achieve a desired translational acceleration. The quadrocopter’s attitude error is split into a reduced attitude error, which describes the misalignment of the thrust direction, and a yaw error, which describes the orientation error about the thrust direction. A model-based proportional–derivative control law is derived, where the proportional action is in terms of the reduced attitude and yaw errors, and the derivative action is in terms of the quadrocopter’s angular velocity error. Almost global asymptotic convergence of the reduced attitude error is established, and the convergence of the yaw error is proven. It is further shown that the attitude control law decouples the reduced attitude error dynamics from the yaw error dynamics. A control allocation strategy is derived which exploits the decoupling in order to prioritize the correction of the reduced attitude over the yaw error. The proposed control strategy is computationally lightweight and therefore well-suited to run on board quadrocopters at high rates. Experimental results demonstrate improved error recovery and position tracking performance.

中文翻译：

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倾斜优先的直升机姿态控制

本文提出了一种直升机姿态姿态控制律和控制分配策略，该策略优先考虑了车辆实现所需平移加速度的能力。直升机的姿态误差分为减小的姿态误差和偏航误差，前者描述了推力方向的不对准，后者则描述了关于推力方向的定向误差。推导了基于模型的比例-微分控制定律，其中比例作用以减小的姿态和偏航误差表示，而微分作用以直升机的角速度误差表示。建立了减小姿态误差的几乎全局渐近收敛，并证明了偏航误差的收敛。进一步表明，姿态控制定律将减小的姿态误差动力学与偏航误差动力学解耦。推导了一种控制分配策略，该策略利用去耦功能，以优先于减小的姿态的校正而不是偏航误差的校正。所提出的控制策略在计算上是轻量级的，因此非常适合以高速率在机载直升机上运行。实验结果证明了改进的错误恢复和位置跟踪性能。