The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
High altitude platforms, also known as pseudo-satellites, are envisioned as unmanned aircraft flying at altitudes above 15 km to provide observation, remote sensing or communication services. A challenging yet recurring requirement for such aicraft is to be able to perform long-endurance missions over multiple days or even weeks. A sophisticated onboard energy management system including solar panels...
In this paper, we investigate the problem of the dynamics of a quadrotor unmanned aerial vehicle undergoing impact with its environment. This work is motivated by the fact that operation of UAVs (manual or autonomous) carries with it a significant risk of collision with surrounding objects, particularly in unknown, unstructured environments. To make small UAVs more viable and expand their autonomy,...
The sole means for conventional multirotor UAVs to achieve horizontal translation motion is by inducing changes in vehicle attitude. The lack of horizontal force control not only disallows full controllability in all 6 Degrees of Freedom (DoFs), but also limits the set of possible control solutions. One way of achieving horizontal force control is by mounting the rotors of a UAV under a fixed amount...
This paper describes a control approach for transitioning VTOL UAVs controlled by differential thrust, allowing to fly in all flight phases spanning a continuous transition between hover and cruise flight. A quaternion based attitude controller makes use of an additional reference frame that is rotated by the transition angle with respect to the body-fixed frame. This approach allows intuitive control...
In this paper a fractional-order (or alternatively known as a non-integer) FOPID type controller (that gives better performance than classical, integer-order PID type) was proposed for tracking of the rotational speed reference signal of propeller in electric propulsion system used in multirotor flying robots and platforms. For propulsion system (electronic speed controller, brushless direct current...
Multirotor aerial vehicles are extensively employed in applications requiring a stationary surveillance platform to monitor a situation on the ground for a specific duration. In most cases, these systems are small in size and weigh < 10Kgs. This paper presents a design methodology employed to develop a multirotor system exceeding the conventional size and weight category. The study includes modelling...
An optimization problem based on discrete-integer and continuous variables in order to design a multirotor for a specific application (maximum thrust-to-weight and maximum flight time) is developed. We considered the length and the diameter of the rods as continuous variables and the selection of the motors, propellers, and battery as discrete-integer variables, the components selected are available...
The increasing civilian demand for autonomous aerial vehicle in the professional markets led to an abundance of inexpensive navigational hardware platforms and vehicle prototypes. Current photogrammetry-based applications require crisp and precise positioning of images so that the process does not fails. Also systems adaptable to the circumstances for better effectiveness, vehicles capable of vertical...
Conventional quadrotor UAVs have crucial underactuation limitations. This appears in the coupling between the roll angle and the movement in y-direction, and between the pitch angle and the movement in x-direction. The quadrotor capability of hovering with either roll or pitch angle is restricted due to these limitations. In this paper, a novel design modification is proposed in order to increase...
The versatility of the quadcopter as one of the most flexible aerial vehicle has earned its spot as a favourite for drones and hobby projects. Conventional quadcopters are in use today, which consists of four propellers attached to four motors on the quadcopter body. The propellers are paired such that the opposite pairs rotate in the same direction whereas the adjacent pairs rotate in the opposite...
Multi-rotor Unmanned Aerial Vehicles make use of multiple propellers, mounted on arms, to produce the required lift. This article investigates the influence on propulsion system efficiency in hover due to the configuration of these propellers. Influence of pusher or puller configuration of the propeller, number of blades, shape and dimensions of the arm, coaxial and overlapping propellers, is presented...
This paper presents the design of an adaptive augmentation for cascaded outer-loop path and inner-loop acceleration tracking controllers. The adaptive augmentation is based on a nonlinear design plant and uses model reference adaptive control (MRAC). The outer-loop position controller is a nonlinear model predictive controller (NMPC) with velocity adjustment which incorporates the states and control...
In light of recent U.S. Federal Aviation Administration (FAA) notices, there is a surge in the research and development of the ‘micro’ class sUAS for commercial purposes. Natural gas production and distribution companies in particular are making an effort to develop aerial leak detection methods with sUAS. These efforts require a comprehensive evaluation of sUAS capabilities and the environmental...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.