Browsing by Author "Espinoza, Albert"

Now showing 1 - 2 of 2

The Effects of UAV Quadcopter Propeller Tilt Angle on Flight Stability
(LACCEI Inc., 2020-07) Espinoza, Albert; Carrasquillo, Katherine; Pérez, José; Fernández, Yamil; Martínez, Renier
Unmanned Aerial vehicles (UAVs) have captivated the interest of many researchers in recent years and are currently used in a wide range of applications such as: geographic mapping, weather forecasting, aerial photography, law enforcement, and search and rescue. Many of these applications require a multirotor UAV in order to maintain a stationary position in mid-air, and thus UAVs must be designed to be as stable as possible to reduce the need for excessive flight controller corrections and positioning errors, particularly under windy conditions. This research focuses on performing an empirical study on the effects of adding an inward propeller tilt angle, a design feature commonly used to improve stability in fixed-wing aircraft, on the flight stability of a quadrotor UAV. A ready-to-fly quadrotor UAV kit was assembled, and its propellers were tilted inward at various fixed angles of 0o, 5o and 10o, and the planar motion of the UAV was computed using object visual tracking software. The results demonstrate that adding a propeller tilt angle improves quadrotor UAV flight stability.
Unmanned Autonomous Aerial Navigation in GPS-Denied Environments
(LACCEI Inc., 2020-07) Habib, Noshin; Martínez-Martínez, Josué; Flores-Abad, Angel; Aponte-Roa, Diego; Espinoza, Albert
This work focuses on enhancing existing technology to support unmanned aerial vehicle navigation for the inspection of power plants. These inspections are a vital component of a power plant’s capability to function but can be costly and dangerous to do by humans. Therefore, it has been proposed to utilize a small, unmanned quadcopter integrated with autonomous navigation by using an alternate signal in place of GPS. The quadcopter can gain the ability to navigate to desired coordinates without the need for GPS, which can often be unavailable within these structures. The UAV uses an optical flow sensor to determine the ground velocity and x-y position, and sonar for measuring the altitude. Using ROS and MAVLink, the communication can be modified to use “fake GPS” data, instead of the actual GPS signal, to be published in the appropriate ROS topics to avoid GPS failures. The optical flow and fake GPS are filtered by an Extended Kalman Filter to get a better position estimation during navigation. Through this process, autonomous flight was successfully achieved without GPS.