Estimation of Airspeed, Angle of Attack, and Sideslip for Small Unmanned Aerial Vehicles (UAVs) Using a Micro-Pitot Tube

Abstract

Fixed and rotary-wing unmanned aircraft systems (UASs), originally developed for military purposes, have widely spread in scientific, civilian, commercial, and recreational applications. Among the most interesting and challenging aspects of small UAS technology are endurance enhancement and autonomous flight; i.e., mission management and control. This paper proposes a practical method for estimation of true and calibrated airspeed, Angle of Attack (AOA), and Angle of Sideslip (AOS) for small unmanned aerial vehicles (UAVs, up to 20 kg mass, 1200 ft altitude above ground level, and airspeed of up to 100 knots) or light aircraft, for which weight, size, cost, and power-consumption requirements do not allow solutions used in large airplanes (typically, arrays of multi-hole Pitot probes). The sensors used in this research were a static and dynamic pressure sensor (“micro-Pitot tube” MPX2010DP differential pressure sensor) and a 10 degrees of freedom (DoF) inertial measurement unit (IMU) for attitude determination. Kalman and complementary filtering were applied for measurement noise removal and data fusion, respectively, achieving global exponential stability of the estimation error. The methodology was tested using experimental data from a prototype of the devised sensor suite, in various indoor-acquisition campaigns and laboratory tests under controlled conditions. AOA and AOS estimates were validated via correlation between the AOA measured by the micro-Pitot and vertical accelerometer measurements, since lift force can be modeled as a linear function of AOA in normal flight. The results confirmed the validity of the proposed approach, which could have interesting applications in energy-harvesting techniques.

Unmanned Aircraft Systems with Autonomous Navigation

“…Ariante G. et al [2] propose a practical method for the estimation of true and calibrated airspeed, angle of attack (AOA), and angle of sideslip (AOS) for small unmanned aerial vehicles (UAVs, up to 20 kg mass, 1200 ft altitude above ground level, and airspeed of up to 100 knots) or light aircraft, for which weight, cost, and power-consumption requirements do not allow solutions used in large airplanes (typically, arrays of multi-hole Pitot probes). The sensors used in this research were a static and dynamic pressure sensor ("micro-Pitot tube" MPX2010DP differential pressure sensor) and a 10 degrees of freedom (DoF) inertial measurement unit (IMU) for attitude determination.…”

Wind Speed Measurement via Visual Recognition of Wind-Induced Waving Light Stick Target

“…To better compare and validate the test results, two continuous curves are given for the proposed detection model by obtaining the imaging length X P from the discretized yaw angle α (0.5 • interval) based on Equation (5) as the dashed red line, and also by acquiring the yaw angle α from the above discretized imaging length X P based on Equation (6) as the blue solid line in Figure 19 below. Left and right limit angles are computed according to Equations ( 10) and (11), and depicted as the two horizontal lines; the top 77.6 • describes the left and the bottom −83.2 • denotes the right limit angle. The 13 detected yaw angles are illustrated as circular, blue-edge markers which go well with the detection model, while the red markers are the results beyond the limit.…”

“…This is because cup anemometers are less affected by turbulence and changes in wind direction than pitot tube anemometers, which can be affected by eddies and vortices in the flow [9,10]. On the other hand, pitot tube anemometers may be more suitable for measuring airspeed in aircraft, unmanned aerial vehicles (UAVs), or other fluid flows where the total velocity, including horizontal and vertical components, is of interest [11]. Therefore, computer vision hardware and algorithms similarly offer a strong alternative to other wind measurement systems, alongside the expected comparative application-specific merits.…”

A Review of Laboratory and Numerical Techniques to Simulate Turbulent Flows

“…Recently, Pitot tubes have been used to evaluate the trajectory and speed of hybrid unmanned aerial vehicles with vertical take-off and landing (Ariante et al [71]; Zhang et al [72]). Fixed-wing unmanned aerial systems are also used for the study of turbulence in the atmospheric boundary layer and in the proximity of wind turbines.…”