Due to motion coupling and increased model dependence, the use of nonlinear controllers in real-time applications for aircraft is extremely constrained. This explains why proportional, derivative, and integral (PID) controls are frequently used in practice. However, fast changes in the commanded path and the requirement for high accuracy and tracking performance limit use of PID in landing. This paper presents a design of a decoupled incremental nonlinear dynamic inversion (INDI) controller for performing autonomous landing of a fixed-wing aircraft. The investigation is carried out using the ground effect model and is compared without it. A carrot chasing guidance algorithm is implemented for waypoint navigation to generate the command for the proposed controller's outer loop. The navigational state estimate issue has been resolved using the Cubature Kalman Filter (CKF) approach. Two decoupled CKF algorithms named complementary Cubature Kalman Filter (CCKF) and Integrated Cubature Kalman Filter (I-CKF) are proposed to estimate aircraft navigational states comprised of attitudes, navigational position in terms of latitude, longitude altitudes, and North-East-down velocities. The mathematical model for flare and approach trajectory is designed and commanded to follow the same by the proposed INDI controller. The effectiveness of INDI have been evaluated in a simulation environment by landing the aircraft in the same runway position at arbitrary wind conditions. The performance of the proposed INDI controller is juxtaposed with a conventional proportional integrator and derivative (PID) based landing controller. The simulation findings demonstrate that the INDI has a competitive edge over traditional PID approaches due to its robust performance, less dependence on model dynamics, and fast command tracking capability required during the flare phase.

中文翻译：

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地面效应飞机自主着陆解耦增量非线性动态反演控制


由于运动耦合和模型依赖性增加，非线性控制器在飞机实时应用中的使用受到极大限制。这解释了为什么在实践中经常使用比例、微分和积分 (PID) 控制。然而，命令路径的快速变化以及对高精度和跟踪性能的要求限制了PID在着陆中的使用。本文提出了一种用于执行固定翼飞机自主着陆的解耦增量非线性动态反演（INDI）控制器的设计。调查是使用地面效应模型进行的，并在没有地面效应模型的情况下进行了比较。胡萝卜追逐制导算法被实现用于航路点导航，以生成所提出的控制器的外环的命令。导航状态估计问题已使用 Cuature 卡尔曼滤波器 (CKF) 方法得到解决。提出了两种解耦 CKF 算法，称为互补 Cuature Kalman 滤波器（CCKF）和集成 Cubature Kalman 滤波器（I-CKF）来估计飞机导航状态，包括姿态、纬度、经度高度和东北向下速度方面的导航位置。拉平和进场轨迹的数学模型经过设计并由所提出的 INDI 控制器命令遵循相同的数学模型。 INDI 的有效性已在模拟环境中通过将飞机在任意风力条件下降落在同一跑道位置进行了评估。所提出的 INDI 控制器的性能与基于传统比例积分器和微分 (PID) 的着陆控制器并列。 仿真结果表明，INDI 比传统 PID 方法具有竞争优势，因为它具有强大的性能、对模型动态的依赖性较小以及耀斑阶段所需的快速命令跟踪能力。