This paper presents an accurate solution of finite-time Cartesian trajectory tracking control problem of a quadrotor system by designing and implementing a novel robust flight-control algorithm. The quadrotor is subject to nonlinearities, unmodeled dynamics, parameters’ uncertainties, and external time-varying disturbances. To reject the disturbances and enhance the control system’s robustness, a terminal sliding mode-based active antidisturbance control (TSMBAADC) approach is proposed for rotational and translational subsystems. To improve the tracking performance, a nonlinear continuous terminal sliding manifold and a fast reaching law are proposed in this work to quickly drive the systems’ states to the equilibrium point even in the presence of lumped disturbances. The convergence time of the states can be pretuned based on the parameters of the sliding manifold and the reaching law. Lyapunov theorem is used to provide a rigorous stability proof for the feedback control system. Numerical simulations and processor-in-the-loop (PIL) experiments are conducted to validate and implement the designed flight control algorithm on real autopilot hardware. The novelty of the proposed research lies in hardware implementation of a sophisticated version of modern control technique that exhibits a multitude of distinguishing features including but not limited to (i) finite-time tracking stability featuring fast convergence is ensured, (ii) chattering and singularity problems in sliding mode control (SMC) are avoided, and (iii) null steady-state error is achieved along with enhanced robustness. Finally, the proposed control law is compared with two recently reported research works. Results of performance comparison in term of the integral of square error (ISE) and the absolute value of the derivative of the input (IADU) dictate that the proposed technique overperforms by precision and chattering alleviation.

中文翻译：

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基于终端滑模的主动抗干扰方法对四旋翼飞机的鲁棒有限时间轨迹跟踪控制：PIL实验

通过设计和实现一种新颖的鲁棒飞行控制算法，提出了一种四旋翼系统有限时间笛卡尔轨迹跟踪控制问题的精确解决方案。四旋翼受到非线性，非建模动力学，参数不确定性和外部时变干扰的影响。为了消除干扰并增强控制系统的鲁棒性，针对旋转和平移子系统提出了一种基于终端滑模的主动抗干扰控制（TSMBAADC）方法。为了提高跟踪性能，在这项工作中提出了一种非线性连续终端滑动流形和一个快速到达定律，即使在存在集总扰动的情况下，也能快速将系统的状态驱动到平衡点。状态的收敛时间可以根据滑动歧管的参数和到达定律进行预调节。李雅普诺夫定理用于为反馈控制系统提供严格的稳定性证明。进行了数值模拟和在环处理器（PIL）实验，以在实际的自动驾驶仪硬件上验证并实现设计的飞行控制算法。提出的研究的新颖性在于现代控制技术的复杂版本的硬件实现，该技术具有多种独特的功能，包括但不限于（i）确保具有快速收敛性的有限时间跟踪稳定性，（ii）颤动和奇异性避免了滑模控制（SMC）中的问题，并且（iii）实现了零稳态误差以及增强的鲁棒性。最后，拟议的控制法则与最近报道的两项研究工作进行了比较。根据平方误差（ISE）的积分和输入的导数的绝对值进行性能比较的结果 （IADU）指出，所提出的技术在精确度和颤抖缓解方面均胜过其表现。