Purpose

Aircraft pitch control is fundamental for the performance of micro aerial vehicles (MAVs). The purpose of this paper is to establish a simple experimental procedure to calibrate pitch instrumentation and classical control algorithms. This includes developing an efficient pitch angle observer with optimal estimation and evaluating controllers under uncertainty and external disturbances.

Design/methodology/approach

A wind tunnel test bench is designed to simulate fixed-wing aircraft dynamics. Key elements of the instrumentation commonly found in MAVs are characterized in a gyroscopic test bench. A data fusion algorithm is calibrated to match the gyroscopic test bench measurements and is then integrated into the autopilot platform. The elevator-angle to pitch-angle dynamic model is obtained experimentally. Two different control algorithms, based on model-free and model-based approaches, are designed. These controllers are analyzed in terms of parametric uncertainties due to wind speed variations and external perturbation because of sudden weight distribution changes. A series of experimental tests is performed in wind-tunnel facilities to highlight the main features of each control approach.

Findings

With regard to the instrumentation algorithms, a simple experimental methodology for the design of optimal pitch angle observer is presented and validated experimentally. In the context of the platform design and identification, the similitude among the theoretical and experimental responses shows that the platform is suitable for typical pitch control assessment. The wind tunnel experiments show that a fixed linear controller, designed using classical frequency domain concepts, is able to provide adequate responses in scenarios that approximate the operation of MAVs.

Research limitations/implications

The aircraft orientation observer can be used for both pitch and roll angles. However, for simultaneousyaw angle estimation the proposed design method requires further research. The model analysis considers a wind speed range of 6-18 m/s, with a nominal operation of 12 m/s. The maximum experimentally tested reference for the pitch angle controller was 20°. Further operating conditions may require more complex control approaches (e.g. scheduling, non-linear, etc.). However, this operating range is enough for typical MAV missions.

Originality/value

The study shows the design of an effective pitch angle observer, based on a simple experimental approach, which achieved locally optimum estimates at the test conditions. Additionally, the instrumentation and design of a test bench for typical pitch control assessment in wind tunnel facilities is presented. Finally, the study presents the development of a simple controller that provides adequate responses in scenarios that approximate the operation of MAVs, including perturbations that resemble package delivery and parametric uncertainty due to wind speed variations.

中文翻译：

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风洞中飞机俯仰控制和仪表的一种集成方法

目的

飞机俯仰控制对于微型飞行器（MAV）的性能至关重要。本文的目的是建立一个简单的实验程序来校准变桨仪器和经典控制算法。这包括开发具有最佳估计值的高效俯仰角观测器，并在不确定性和外部干扰下评估控制器。

设计/方法/方法

风洞试验台设计用于模拟固定翼飞机动力学。在陀螺仪测试台中对在MAV中常见的仪器的关键要素进行了表征。校准数据融合算法以匹配陀螺仪测试台的测量值，然后将其集成到自动驾驶仪平台中。实验得到了电梯角到俯仰角的动力学模型。基于无模型和基于模型的方法，设计了两种不同的控制算法。根据由于风速变化引起的参数不确定性和由于突然的重量分布变化而引起的外部扰动对这些控制器进行了分析。在风洞设施中进行了一系列实验测试，以突出每种控制方法的主要特征。

发现

关于仪器算法，提出了一种用于设计最佳俯仰角观测器的简单实验方法，并进行了实验验证。在平台设计和识别的背景下，理论和实验响应之间的相似性表明该平台适用于典型的俯仰控制评估。风洞实验表明，使用经典频域概念设计的固定线性控制器能够在近似MAV运行的情况下提供足够的响应。

研究局限/意义

飞机方位观察器可用于俯仰角和侧倾角。然而，对于同时偏航角估计，所提出的设计方法需要进一步的研究。模型分析考虑的风速范围为6-18 m / s，标称运行速度为12 m / s。俯仰角控制器的最大实验测试参考值为20°。进一步的运行条件可能需要更复杂的控制方法（例如，调度，非线性等）。但是，此操作范围足以完成典型的MAV任务。

创意/价值

研究显示了基于简单实验方法的有效俯仰角观测器的设计，该观测器在测试条件下实现了局部最佳估计。此外，还介绍了用于风洞设施中典型俯仰控制评估的测试台的仪器和设计。最后，该研究提出了一种简单控制器的开发，该控制器可在近似MAV操作的情况下提供适当的响应，包括类似于包裹递送的扰动和风速变化引起的参数不确定性。