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Advances in Unmanned Aerial Systems and Payload Technologies for Precision Agriculture
Published in Guangnan Chen, Advances in Agricultural Machinery and Technologies, 2018
Felipe Gonzalez, Aaron Mcfadyen, Eduard Puig
The UAV designs mostly used for commercial applications are fixed-wing and rotary-wing aircraft. Among rotary-wing designs, helicopter and multirotor configurations are the most common. Multirotors are the most popular and easiest UAV type to manually control using radio transmitters. There are a number of multirotor configurations generally named after the quantity of rotors that form the propulsion system, such as quadcopters (four-rotor), hexacopters (six-rotor), and octacopters (eight-rotor). Taking into consideration recent statistics on the UAV platforms used in the United States for commercial operations (AUVSI, 2016), Table 6.1 shows the approximate percentage of each type of platform. Across all applications, multirotors represent nearly 90% of the entire market, demonstrating UAV operators have a clear preference for multirotor over fixed-wing. For agriculture in particular, nearly one-third of UAV platforms are fixed and two-thirds are multirotor.
High-Resolution UAS Imagery in Agricultural Research Concepts, Issues, and Research Directions
Published in Yuhong He, Qihao Weng, High Spatial Resolution Remote Sensing, 2018
Michael P. Bishop, Muthukumar V. Bagavathiannan, Dale A. Cope, Da Huo, Seth C. Murray, Jeffrey A. Olsenholler, William L. Rooney, J. Alex Thomasson, John Valasek, Brennan W. Young, Anthony M. Filippi, Dirk B. Hays, Lonesome Malambo, Sorin C. Popescu, Nithya Rajan, Vijay P. Singh, Bill McCutchen, Bob Avant, Misty Vidrine
A multirotor UAV uses individual rotors, or propellers, to generate lift for the vehicle. The number of rotors typically varies from three to eight, depending on the size of the UAV. It typically flies at slower speeds (5–7 m/s) and lower altitudes (20–80 m), which provides high-resolution images of small areas. The multirotor UAV usually has short flight times and limited payload capacity. With its vertical takeoff and landing capability, it can be operated in confined areas near obstructions, such as power lines, towers, or buildings. The autonomous flight software used in multirotor UAVs provides ease of use for the operator, while also providing fail-safe features to ensure that the operator does not violate regulations for flying in the National Airspace System.
A backstepping disturbance observer control for multirotor UAVs: theory and experiment
Published in International Journal of Control, 2022
Amir Moeini, Alan F. Lynch, Qing Zhao
Multirotor Unmanned Aerial Vehicles (UAVs) are popular due to their simple robust electro-mechanical design, high manoeuvrability, and low-cost. They are used in environment monitoring, terrain mapping, emergency response, and other applications (Kendoul, 2012). Increased adoption depends on a high-performance motion controller which can track desired 3D position and yaw trajectories. There are a number of challenges involved in improving motion control given the system's under-actuated nonlinear dynamics, bounded input, unmeasured and time-delayed states, and external disturbances. These challenges have attracted significant interest from the research community. This paper focuses on improving the robustness of nonlinear motion control to external force and torque disturbances. This robustness is clearly important for improving the performance and safety in a range of environments. For example, in outdoor applications, the UAV is subject to disturbances such as wind-gusts or changes in thrust due to nearby obstacles. As confirmed by the interest shown in recent literature on the topic, improving the robustness of motion control is clearly an important practical and theoretical problem.
Robust pose tracking control for a fully-actuated hexarotor UAV based on Gaussian processes
Published in SICE Journal of Control, Measurement, and System Integration, 2022
Tatsuya Ibuki, Hiroto Yoshioka, Mitsuji Sampei
A multirotor unmanned aerial vehicle (UAV) has become one of the most common vehicles for these decades, thanks to its high mobility in three-dimensional (3D) space. Its industrial application is expected in various fields including agriculture monitoring [1], building inspection [2], load transportation [3], and work with a robotic arm [4]. In standard structures of multirotor UAVs, each rotor is placed at the vertex of a regular polygon and in the same direction as shown in Figure 1(a). This same direction property causes underactuation, that is, UAVs cannot move in the horizontal direction without tilting their bodies. This motion limitation is often undesired, e.g. in the aforementioned application. To guarantee the full actuation property, i.e. to control the 6D pose (3D position and 3D attitude) individually, special structures have been recently developed [5–9]. One of the common approaches is to introduce tilted rotors as shown in Figure 1(b). Here, at least six rotors are required to individually control the 6D pose, and multirotor UAVs with six rotors are called hexarotors.
TAMS: development of a multipurpose three-arm aerial manipulator system
Published in Advanced Robotics, 2021
Hannibal Paul, Ryo Miyazaki, Robert Ladig, Kazuhiro Shimonomura
Aerial multirotor type vehicles are best suited for aerial manipulation due to their ability to hover in a fixed position compared to a fixed-wing UAV. Moreover multirotor UAV's vertical take-off and landing (VTOL) ability allows them to be used in congested areas. However, because of their inability to land on certain types of terrain due to the danger of rolling over, they always require a flat surface to do so. Rollover accidents may occur on terrains with uneven surface, slopes or on dynamic surfaces such as unstable ship decks. There are two types of rollover accidents i.e. static and dynamic rollover [21]. Dynamic rollover occurs when the UAV is taking off or landing. Static rollover is a rolling action when the propellers of the multirotor are turned off (after landing) and is the byproduct of the UAV's center of gravity (CoG).