Name: autopilot sensors for uav flight control
Uploaded: 2023-04-30T07:05:02.000Z
Duration: 8 min 36 s
Channel: JoVE

本流程将演示惯性测量单元（IMU）和大气数据系统（ADS）传感器的校准及其与飞控计算机的集成，并展示在户外飞行设施中如何使用集成的惯性导航系统（INS）和大气数据系统进行数据采集与处理。实验在密歇根大学的M-Air网状飞行测试设施中进行，展示了四旋翼飞行器端到端的飞行控制。
1. 传感器校准：惯性测量单元（IMU）
当使用高质量测试设备进行支持时，传感器校准效果最佳。对于三轴惯性测量单元（IMU），应使用精密速率转台分别对每个轴的陀螺仪和加速度计进行校准（图6）。该速率转台可精确地以用户设定的角速度旋转。用户发出一系列速率指令，在此过程中，IMU采集传感器校准所需的数据。因此，下述单轴校准实验需重复三次，分别对应IMU传感器的三个轴（x, y, z）。
<ol>
	<li>将IMU安装在转台上，使待校准的传感器轴线沿径向向内或向外。</li>
	<li>测量转台中心到IMU中心的距离。该距离即为圆周运动的参考半径。</li>
	<li>将数据采集（DAQ）计算机、IMU和电池直接安装在转台上，并将所有组件直接连接。</li>
	<li>设置软件以采集IMU的角速率和加速度数据。</li>
	<li>在转台静止时，记录陀螺仪和加速度计的零偏值。</li>
	<li>进行一系列实验，采用不同正负恒定的转台旋转速率。传感器校准预期呈线性关系。采集0（基准值）、±15、±30和±60度/秒角速度下的数据。转台可运行于更高速率，但所选数值已足以覆盖典型无人机飞行操作中预期的信号范围。</li>
	<li>针对上述每个角速度值，采集待校准陀螺仪和加速度计的数据。在开始采集数据前，应确保已稳定达到目标旋转速率，以维持恒定转速。假设数据采集频率至少为30–100 Hz，持续采集10–15秒的数据，以便在最终校准值中滤除干扰信号。</li>
	<li>断开连接并从转台上取下IMU，将其调整至待校准的加速度计方向朝下。</li>
	<li>通过计算机系统采集+1g数据。</li>
	<li>翻转IMU，使待校准的加速度计方向朝上，通过计算机系统采集-1g数据。这些额外数据点易于获取，可用于验证由转台数据在±1g处获得的每条线性校准曲线。准确校准1g值尤为重要，因为线性加速度数据用于确定相对于四旋翼飞行器本体的“向下”方向。</li>
	<li>处理数据。对陀螺仪和加速度计的数据点建立线性拟合关系，将采集到的电压值转换为国际单位制（MKS）下的旋转速率（陀螺仪）和线性加速度（加速度计）。确认校准误差足够低。需注意，转台可直接控制角速度以进行陀螺仪校准。由圆周运动向心力引起的相应加速度a可根据设定的角速度ω和IMU相对于转台中心的半径r计算得出： 
	<img src="/files/ftp_upload/10470/10470eq17.jpg" alt="角加速度方程 \( a = \omega^2 r \)；圆周运动的物理公式。" data-altupdatedat="1761830439000">    (9)</li>
</ol>
2. 四旋翼飞行实验
在最后一组实验中，我们将惯性测量单元（IMU）和皮托管系统安装在四旋翼飞行器上（如图7所示），并在密歇根大学的M-Air网状飞行设施中进行飞行。该飞行器通过将Ardupilot开源自动驾驶仪软件包移植到Beaglebone Blue（未使用微处理器）上实现稳定，并通过Mission Planner地面站软件在飞行前完成配置。无线电遥控发射机/接收机接口使飞行员能够向Ardupilot的“内环”飞行控制律发送“外环”指令，以调节四旋翼的滚转角、俯仰角、偏航角（航向）和高度。[14]
由于四旋翼飞行器无需空速反馈即可实现稳定，Ardupilot 仅依赖惯性测量单元（IMU）数据以及用于测量高度的气压传感器，该传感器在程序初始化时相对于起飞点的气压进行校准，从而根据飞行员输入实现飞行稳定。Ardupilot 的完全自主飞行功能需要来自全球定位系统（GPS）或其他感知系统（例如高速运动捕捉系统）的惯性位置数据。由于我们的实验是在受限环境中使用四旋翼飞行器进行的，因此无需皮托管大气数据系统。然而，在不确定的强风环境中执行精确飞行路径的固定翼飞机和多旋翼飞行器，皮托管系统则是必不可少的。[15, 16] 飞行测试程序分为三个阶段：飞行前、飞行测试和飞行后。这种划分方式类似于有人驾驶飞机飞行员所遵循的标准驾驶舱检查单程序。[17]
飞行前
<ol>
	<li>在安装前对电池进行充电并测试。</li>
	<li>建立明确的测试环境（室内或室外），并标记区域，确保无关人员远离。</li>
	<li>确保飞行测试团队已接受简报并具备执行计划测试的资质（经过培训）。</li>
	<li>若在室外飞行，须确保航空器和飞行员已根据美国联邦航空管理局（FAA）规定完成注册和认证。开放空间测试至少需要三人：指挥飞行员（PIC）、目视观察员（VO）和地面站操作员。在我们的测试中，四旋翼飞行器将在室外的网状设施内飞行。对于室内测试，将配备两名系留操作员，以确保飞行器无法飞离。请注意，由于无人机未占用开放的室外空间，因此无特定的FAA规定适用于网状飞行测试。</li>
	<li>开启飞行计算机和地面站笔记本电脑。</li>
	<li>采集初步数据，以确保传感器正常工作。飞行员及支持团队必须充分理解飞行计划，并制定中止/恢复程序。</li>
</ol>
飞行测试
<ol start="6">
	<li>在地面站启动数据采集。</li>
	<li>确认飞行区域已清空/安全。 </li>
	<li>臂部推进器/电机</li>
	<li>启动飞行测试序列。</li>
	<li>进行飞行测试，由飞行员逐项喊出每个步骤，至少包括： 
	起飞（发射）、飞行模式切换、已知航点目标或机动动作，以及降落。确保所有人员各司其职，并根据需要执行应急程序（飞行终止）。航点与飞行轨迹针对每次飞行具体设定。在四旋翼实验中，我们按照中等强度的十字形和矩形航线飞行，保持恒定高度和航向，随后进行爬升/下降，再执行偏航序列。此次飞行中的角速度与线加速度在数据中清晰可辨，证实惯性测量单元（IMU）与飞控系统工作正常。</li>
</ol>
飞行后
<ol start="11">
	<li>解除电机锁定，以确保电机不会意外启动。</li>
	<li>保存并下载飞行数据至归档存储设备。</li>
	<li>根据飞行员、目视观察员（VO）和地面站操作员的反馈，以文字形式记录飞行日志。</li>
	<li>检查电池，并根据需要进行充电。</li>
	<li>回收设备，并清理现场，为下一位使用者做好准备。</li>
</ol>

本文介绍了实现固定翼和旋翼航空器实时飞行控制所需的传感器系统、数据采集以及信号滤波过程。该数据处理流程是所有有人驾驶和无人驾驶航空器自动驾驶系统的关键组成部分。多旋翼飞行器需要自动驾驶系统来维持稳定，而各类航空器在执行飞行任务时，均高度依赖实时数据采集与飞行控制，尤其是在日益自主化的航空系统中，这些系统承担着空中数据采集和载荷运输等任务。尽管可直接使用现成的传感器组件进行集成，但在不同环境中充分了解传感器的性能及其局限性对于确保系统可靠性至关重要。例如，强降水或结冰可能堵塞皮托管，城市峡谷结构可能遮挡全球定位系统（GPS）信号。
此外，异常姿态可能需要对依赖欧拉角姿态表示的状态估计计算进行扩展。通过集成额外传感器所获得的鲁棒性，与支持冗余传感器所需的额外成本和重量之间，存在固有的权衡。最低成本的小型无人机很可能将继续采用本文所述的用于飞行控制的基本传感器组合。尽管最可靠的飞机（如商用运输机和战斗机）的状态估计也基于与本文所述相似的传感器，但它们依靠三重冗余和传感器多样性，以确保飞机飞行控制器能够在传感器故障或极端恶劣环境条件下依然依赖准确的状态估计。
<p class="j...

实时飞行控制：嵌入式传感器校准与数据采集

来源： Ella M. Atkins，密歇根大学安娜堡分校航空航天工程系，密歇根州，美国
概述
自动驾驶系统利用机载传感器采集的数据来稳定飞机，这些传感器用于测量飞机的姿态、角速度和空速。自动驾驶系统可调节这些参数，使飞机从起飞（发射）到降落（回收）全程自动执行飞行计划。类似类型的传感器数据也被用于控制各种飞机，从大型固定翼商用运输机到小型多旋翼直升机（例如具有四个推进单元的四旋翼飞行器）均适用。
通过全球定位系统（GPS）等传感器获取惯性位置和速度信息后，自动驾驶实时飞行控制系统可使多旋翼或固定翼飞行器稳定其姿态和空速，从而沿预定轨迹飞行。传感器集成、校准、数据采集和信号滤波是开展飞行控制实验的前提条件。
本文介绍了一种传感器套件，可为飞行控制提供必要的数据。文中描述了两种不同嵌入式计算机平台上的信号接口与数据采集方法，并总结了传感器校准过程。针对每个数据通道，分别应用了单通道移动平均滤波器和中值滤波器，以降低高频信号噪声并消除异常值。
本实验展示了用于实时飞行控制的数据采集与传感器校准。已有若干已发表的论文阐述了传感器数据采集与控制的原理，且近期研究主要集中于小型无人机（UAV）所用的传感器[1-3]。

传感器校准
速率陀螺仪校准图的一个示例如图8所示。在此情况下，速率陀螺仪发出的标称（零速）读数为2.38 V。针对以度每秒为单位测量的六个不同旋转速度，采集了速率陀螺仪的电压数据，并对这些数据进行了线性拟合。如图所示，该线性拟合对所有采集到的数据点提供了非常好的近似。
飞行测试结果
图9展示了四旋翼飞行器在室内环境中飞行时，30秒横向加速度数据集的原始数据与滤波后数据。滤波参数d和n取值相对较大，以清晰地展示滤波过程的影响。如图所示，原始数据中的噪声得到了抑制。然而，滤波后的数据存在明显的时间延迟，例如在t=5 s前不久出现的（被衰减的）正向加速度趋势。在本图中，整体加速度趋势显示出轻微的负向偏差；这可能是由于惯性测量单元（IMU）安装时相对于四旋翼推力平面存在轻微俯仰角度，导致重力加速度的一个微小分量被反映在<em...

来源：密歇根大学安娜堡分校航空航天工程系 Ella M. Atkins

概述  
自动驾驶仪可使飞机在飞行中保持稳定……

固定翼飞机通过平衡四种力实现稳定飞行：空气动力升力、空气动力阻力、推进系统推力以及重力。为了实现稳定飞行，飞机还必须在三个轴（滚转轴、俯仰轴和偏航轴）上平衡力矩。所有旋转均定义为围绕这些轴的角度变化：滚转轴的变化引起侧向摆动，俯仰轴的变化引起前后倾斜运动，偏航轴的变化引起航向改变。为了在遇到阵风等突发情况时稳定飞机，飞行控制系统会实时发出电机和操纵面指令。因此，控制系统利用多种传感器，精确测量当前飞行高度、滚转角、俯仰角、偏航角以及空速。传感器获取数据后，需对信号进行滤波处理，以降低噪声和异常值对处理后数据质量的影响。随后，将数据整合为对飞机状态的完整估计，并用于飞行控制。固定翼飞机和多旋翼飞行器均依赖该控制系统来监测和控制飞行器的高度。两者也都使用一种称为惯性测量单元（IMU）的传感器扫描系统。惯性测量单元（IMU）通常由三种传感器组成：加速度计用于测量线性加速度，角速度陀螺仪用于测量角速度，磁场传感器用于测量局部磁场的方向和强度。IMU 通常与 GPS 系统结合使用，并安装在飞机重心附近，其传感器轴与飞机机体轴对齐。在本实验中，我们将演示使用精密转台对一个简单的惯性测量单元（IMU）进行校准。随后，我们将校准后的IMU安装到多旋翼飞行器上，并进行飞行测试，以查看实时数据和滤波数据。在实验的第一部分，我们将使用精密速率转台对包含各轴速率陀螺仪和加速度计的惯性测量单元（IMU）进行校准。该速率转台可根据一系列速率指令，以用户设定的精确速度旋转。这使我们能够确定电压读数与速度之间的关系。首先，使用螺丝将惯性测量单元（IMU）安装在转速转台上，并调整其方向，使当前待校准的传感器轴（本例中为X轴）沿径向向内或向外对准。测量转台中心到IMU中心的距离，并将该测量值作为圆周运动的参考半径。IMU已安装在数据采集板上，将各组件直接连接即可。现在，设置软件以采集惯性测量单元（IMU）的角速率和加速度数据。进行一系列实验，采用不同的正负恒定转台转速，以零转速作为基准测量值。当转台静止时，记录速率陀螺仪和加速度计的S值。然后启动测试并采集数据。完成该方向的所有角速度测试后，取下惯性测量单元（IMU），重新放置使其加速度计朝上。重新固定后，启动测试以采集-1 G数据。随后，翻转IMU，使加速度计朝下，采集+1 G数据。完成 x 轴校准后，重新放置 IMU，使 z 轴传感器方向径向朝外，并重复所有测试，注意将 IMU 分别朝上和朝下放置以校准加速度计。对 y 轴传感器执行相同的步骤。在实验的下一部分中，我们将把惯性测量单元（IMU）安装在四旋翼飞行器上，并在带有防护网的飞行实验室内进行飞行。通过径向控制发射接收接口，操作员可以发送高度、航向、横滚角、俯仰角和偏航角的控制指令。开始之前，请为所有电池充电，并在将组件安装到四旋翼飞行器上之前进行测试。然后准备飞行，确保至少有三人——指挥飞行员、目视观察员和地面站操作员——均已了解飞行计划。将四旋翼飞行器带入带防护网的飞行场地，并将其放置在平坦的着陆板上。飞行测试从起点起飞并爬升至1.5米高度开始。随后，我们将以0.5 m/s的参考速度执行一个边长为两米的方形飞行轨迹。四旋翼飞行器在每次位置变换前会暂停。接着，我们将以0.5、1和1.5 m/s的速度进行若干段更高速度的飞行，以展示速度对超调量的影响。开始飞行测试时，先在地面站启动数据采集。确认飞行区域无障碍后，启动电机。随后，由飞行员在执行每一步操作前逐一喊出指令，开始飞行测试流程，首先从起飞开始。务必通报所有飞行模式的切换、已知的航路点目标或飞行动作。飞行计划执行完毕后，通知飞行团队其余成员四轴飞行器即将最终下降并着陆。随后，解除四轴飞行器的电机启动状态。保存并下载所有飞行数据，并在飞行日志本中记录本次飞行。最后，回收所有设备，并清理现场以便下一位使用者使用。现在让我们解读结果。首先从IMU的校准数据开始，我们展示一个速率转台的旋转速度与陀螺仪电压关系的图表。请注意，速率转台可直接控制角速度，用于陀螺仪校准。通过对数据进行线性拟合，可实现从陀螺电压计算速度。在本例中，速率陀螺仪在零速度时的标称输出电压为2.38伏特。最后，让我们来看一下飞行数据。此处展示了使用我们校准后的惯性测量单元（IMU）获取的四旋翼飞行器30秒内的侧向加速度数据集。该图显示了IMU测得的原始加速度与滤波后加速度随时间的变化情况。数据经过滤波处理以去除测量中的噪声。可以看出，原始数据中的噪声已被衰减。然而，滤波后的数据存在一定的时延。总之，我们学习了飞机控制系统如何利用多种传感器在飞行过程中测量当前的高度和空速。随后，我们对一个角速度陀螺仪和加速度计进行了校准，并将它们安装在四旋翼飞行器上，然后开展了飞行实验。

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Real-time Flight Control: Embedded Sensor Calibration and Data Acquisition

实时飞行控制:嵌入式传感器校准和数据采集

autopilot sensors for uav flight control

Autopilot flight control depends on onboard sensors that measure an aircraft’s orientation, angular velocity, and airspeed. These measurements let the system stabilize the aircraft and help it follow a flight plan from takeoff through landing.

The same kind of sensor data is used in many aircraft, including large fixed-wing transport planes and small multirotor helicopters such as quadcopters with four thruster units. When inertial position and velocity are captured with a sensor such as the Global Positioning System (GPS), the autopilot can help a multicopter or fixed-wing aircraft hold its attitude and airspeed while following a set trajectory.

Accurate flight control experiments also require sensor integration, calibration, data acquisition, and signal filtering. The sensor suite in this work provides the data needed for flight control, and the signal interfaces and data acquisition methods are shown on two different embedded computer platforms.

Sensor calibration is summarized as part of the setup. To clean the data, single-channel moving average and median filters are applied to each channel. These filters reduce high-frequency noise and remove outliers, which helps prepare the measurements for real-time flight control.

Autopilot Sensors for UAV Flight Control

aerodynamic performance of a model aircraft: the dc-6b

aerodynamic-performance-of-a-model-aircraft-the-dc-6b

Wind Tunnel Testing of a DC-6B Model

A low-speed wind tunnel can be used to study the aerodynamics of a DC-6B model aircraft. It helps measure how the airplane performs and how stable it is in flight. This type of testing is useful for understanding aircraft behavior under controlled airflow. The model used here has a removable tail and a 6-component external aerodynamic force balance. That setup lets researchers measure lift coefficient (CL), drag coefficient (CD), pitching moment coefficient (CM), and yaw moment coefficient...

propeller characterization: variations in pitch, diameter, and blade number on performance

propeller-characterization-variations-pitch-diameter-blade-number-on

Propeller Slip and Blade Design Effects

Propellers are twisted airfoils used to move aircraft and watercraft. The chord angle changes along the radial station of the propeller, which affects how the blade pushes air. Because propellers are important in propulsion systems, engineers study them to help design high-performance vehicles. A key propeller feature is pitch, or twist. Pitch is usually measured as a length and describes the theoretical distance a propeller would move through the air in one full revolution. In real...

airfoil behavior: pressure distribution over a clark y-14 wing

airfoil-behavior-pressure-distribution-over-a-clark-y-14-wing

Measuring Lift with a Clark Y-14 Airfoil

A Clark Y-14 airfoil is used to measure pressure distribution and estimate lift. An airfoil is a 2-dimensional wing section that helps show key wing performance features. In this demonstration, the pressure distribution around the airfoil is measured with a wind tunnel. Pressure distribution is closely related to the lift generated by an airfoil. The Clark Y-14 model used here has a thickness of 14% and a flat lower surface from 30% of the chord length to the back. The model also includes 19...

clark y-14 wing performance: deployment of high-lift devices (flaps and slats)

clark-y-14-wing-performance-deployment-high-lift-devices-flaps

Wing Lift Control with Flaps and Slats

The Clark Y-14 wing shows how flaps and slats can change airplane lift during takeoff and landing. A wing is the main part of an airplane that generates lift, and high-lift devices help improve its performance when extra lift is needed. Flaps are located on the trailing edge of the wing. Slats are located on the leading edge. In this experiment, both devices are added to a Clark Y-14 wing so their aerodynamic effects can be studied in a wind tunnel. The wind tunnel creates set airspeeds for...

turbulence sphere method: evaluating wind tunnel flow quality

turbulence-sphere-method-evaluating-wind-tunnel-flow-quality

Measuring Wind Tunnel Turbulence with a Sphere

Wind tunnel turbulence can be measured with a smooth sphere as a test model. Wind tunnel tests help engineers design vehicles and structures that will face airflow during use. The air flows are applied in a controlled way, and the model is usually a smaller version of the full-sized object. For low-speed wind tunnel tests, the flow around the model must match the flow around the real object as closely as possible. This is called dynamic similarity, and it depends on the Reynolds number. The...

cross cylindrical flow: measuring pressure distribution and estimating drag coefficients

cross-cylindrical-flow-measuring-pressure-distribution-estimating

Cylinder Flow in a Wind Tunnel: Pressure Drag

Cylinder flow in a wind tunnel shows how pressure changes around a circular object and how those changes relate to drag. The lesson focuses on cross cylindrical flow, where air moves across a cylinder and the pressure on its surface is measured. It also compares real fluid behavior with the simpler results predicted by ideal inviscid potential flow theory. For an ideal fluid, the pressure around a cylinder is vertically symmetric. The pressure upstream and downstream of the cylinder is also...

nozzle analysis: variations in mach number and pressure along a converging and a converging-diverging nozzle

nozzle-analysis-variations-mach-number-pressure-along-converging

Nozzle Flow Regimes in Converging Nozzles

Nozzle flow changes as the nozzle cross-section changes. A nozzle can accelerate or slow a fluid by shaping the flow path. In aerospace propulsion, nozzles are widely used to help produce thrust. In rockets, propellant leaves the chamber and passes through a nozzle. The nozzle speeds up the propellant and creates a reaction force that moves the system forward. In jet engines, a nozzle converts energy from a high-pressure source into kinetic energy in the exhaust. The flow in a nozzle is...

schlieren imaging: a technique to visualize supersonic flow features

schlieren-imaging-a-technique-to-visualize-supersonic-flow-features

Supersonic Shock Waves with Schlieren Imaging

Schlieren imaging is used to show shock waves and compression waves in supersonic flow. It helps make air motion visible when the flow becomes compressible. In this demonstration, a Mach 2.0 flow over a cone is examined with a Schlieren system. Military jet fighters and projectiles can travel faster than the speed of sound. The speed of sound is the rate at which a sound wave moves through a medium, and it is 343 m/s. Mach number compares an object’s speed to the speed of sound. An object at...

flow visualization in a water tunnel: observing the leading-edge vortex over a delta wing

flow-visualization-water-tunnel-observing-leading-edge-vortex-over

Delta Wing Vortex Flow in a Water Tunnel

Delta wing vortex flow can be studied with a water tunnel and dye visualization. A delta wing is a common wing shape for high-speed airplanes because it performs well in transonic and supersonic flight. It has a small aspect ratio, which means the wing span is short compared with the average chord, and a high sweep angle. These features help reduce drag at high subsonic, transonic, and supersonic speeds. A delta wing also has a high stall angle. Stall happens later than it does for a high...

surface dye flow visualization: a qualitative method to observe streakline patterns in supersonic flow

surface-dye-flow-visualization-qualitative-method-to-observe

Supersonic Surface Flow Patterns with Dye

Supersonic surface flow patterns can be studied with dye flow visualization. This method uses dye on the surface of a body to show how gas moves across it. The resulting streakline patterns help reveal flow paths and surface behavior. Flow visualization is a key tool in aerodynamics research. It helps researchers study flow structure and check ideas about fluid motion. Visualization methods are often grouped into off-the-surface and surface flow techniques. Off-the-surface methods look at the...

pitot-static tube: a device to measure air flow speed

pitot-static-tube-a-device-to-measure-air-flow-speed

Measuring Airspeed with Pressure Differences

A Pitot-static tube measures airspeed by comparing air pressure differences. It is widely used to find unknown speeds in airflow, including airplane airspeed. The method relies on Bernoulli's principle, which links changes in pressure to changes in airflow speed. The tube senses stagnation pressure and static pressure. Stagnation pressure is the pressure where the air is brought to rest, and static pressure is the pressure of the moving air around it. The tube connects to a manometer or a...

constant temperature anemometry: a tool to study turbulent boundary layer flow

constant-temperature-anemometry-tool-to-study-turbulent-boundary

Measuring Skin Friction in a Turbulent Boundary Layer

A turbulent boundary layer forms near a solid surface when fluid flow becomes irregular and mixed. In this region, viscous effects and viscous shear stress dominate because friction between the fluid and the surface slows the flow. Outside the boundary layer, the flow is inviscid, which means friction, thermal conduction, and mass diffusion do not create dissipative effects. The boundary layer idea, first introduced by Ludwig Prandtl in 1904, helps simplify the Navier-Stokes equation for flow...

pressure transducer: calibration using a pitot-static tube

pressure-transducer-calibration-using-a-pitot-static-tube

Pitot-Static Pressure Measurement Calibration

Pitot-static pressure measurement calibration uses a wind tunnel, a manometer, and a pressure transducer to link flow pressure to an electrical signal. Fluid pressure is an important flow property for understanding the aerodynamics of a system. In this setup, a pitot-static probe measures stagnation and static pressure during subsonic flow. A U-tube manometer is one of the oldest pressure measurement systems still used today. It is a U-shaped glass tube partly filled with liquid. Because it...

real-time flight control: embedded sensor calibration and data acquisition

Autopilot flight control depends on onboard sensors that measure an aircraft’s orientation, angular velocity, and airspeed. These measurements let the system stabilize the aircraft and help it follow a flight plan from takeoff through landing. The same kind of sensor data is used in many aircraft, including large fixed-wing transport planes and small multirotor helicopters such as quadcopters with four thruster units. When inertial position and velocity are captured with a sensor such as the...

multicopter aerodynamics: characterizing thrust on a hexacopter

multicopter-aerodynamics-characterizing-thrust-on-a-hexacopter

Hexacopter Thrust Testing in a Wind Tunnel

Hexacopter thrust testing shows how a six-rotor drone produces lift and drag. Multicopters are popular for hobby and commercial use. They are commonly built as quadcopters, hexacopters, or octocopters, depending on whether they use four, six, or eight thrusters. This study uses a small modular hexacopter platform with propulsion unit redundancy. Redundancy means the vehicle has backup capability if one motor fails. The team first measured static motor thrust with a dynamometer while changing...

aeronautical engineering

本系列介绍了航空工程的基本概念，重点是评估空气动力学性能的方法、可视化亚音速和超音速流模式的技术，以及校准测量系统的程序。实时飞行控制。

See how onboard sensors, GPS, calibration, and filtering support autopilot flight control for fixed-wing aircraft and quadcopters in real time.

Autopilot Sensors for UAV Flight Control

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