Quadrotor: a detailed analysis on construction and operation

It is a type of an unmanned air vehicle (UAV) which by its name suggests that consists of 4 engines to drive it. Usually we use BLDC motors and propellers as the engines of a quad. Its motion and dynamics can be compared with that of a helicopter in regards to its transverse and longitudinal motion. It has various uses in various fields of military, business, rescue mission, modern warfare etc. They have a vertical take-off and landing system. Unlike a helicopter the propellers or blades of a “Quadrotor” have fixed pitch. Control of vehicle motion is achieved by altering the pitch and/or rotation rate of one or more rotor discs, thereby changing its torque load and thrust/lift characteristics. This will be explained in details in course of the following discussion. If we look into history of the “Quadrotor”, we get to know that it was the first step towards vertical take-off and landing vehicle. At first it was a manned vehicle but now mainly the research is focused upon a unmanned “Quadrotor” which is controlled with the help of electronic signals and various other mechanisms

Automatic Flight Control Systems

The history of flight control is inseparably linked to the history of aviation itself. Since the early days, the concept of automatic flight control systems has evolved from mechanical control systems to highly advanced automatic fly-by-wire flight control systems which can be found nowadays in military jets and civil airliners. Even today, many research efforts are made for the further development of these flight control systems in various aspects. Recent new developments in this field focus on a wealth of different aspects. This book focuses on a selection of key research areas, such as inertial navigation, control of unmanned aircraft and helicopters, trajectory control of an unmanned space re-entry vehicle, aeroservoelastic control, adaptive flight control, and fault tolerant flight control. This book consists of two major sections. The first section focuses on a literature review and some recent theoretical developments in flight control systems. The second section discusses some concepts of adaptive and fault-tolerant flight control systems. Each technique discussed in this book is illustrated by a relevant example

Penentuan Spesifikasi Motor BLDC pada UAV Militus

Teknologi Pesawat udara tanpa awak (drone) saat ini berkembang dengan pesat, pesawat tanpa awak (drone) banyak digunakan pada dunia militer maupun keperluan komersil. Karena mempunyai banyak kelebihan yaitu memperkecil resiko human error, pengoperasian mudah, dan lebih efektif dibandingkan dengan pesawat berpilot. Pesawat tanpa awak sengaja dibuat dengan bodi yang ringan serta aerodinamis. Untuk mengetahui gaya aerodinamik serta penentuan spesifikasi motor BLDC pesawat UAV Militus, maka digunakan software SolidWorks 2016 dan aplikasi Static Thrust Calculate. Tujuan dari tugas akhir ini adalah menganalisa pesawat UAV Militus, meliputi kontur tekanan, koefisien drag (CD), koefisien lift (CL) menggunakan software SolidWorks 2016, lalu diintegrasikan dengan penentuan motor BLDC menggunakan aplikasi Static Thrust Calculate, dan sistem mekatronika dari pesawat tersebut. Dari hasil analisa aliran yang melintas pada bodi pesawat UAV Militus, koefisien drag (CD) yang diperoleh selama simulasi pesawat UAV Militus senilai 0,0611 dan koefisien lift (CL) pada pesawat UAV Militus senilai 0.0753. Lalu hasil analisa teoritis kebutuhan gaya thrust (TR) harus sama atau kurang dari thrust propeller (T) yang dihasilkan dan didukung hasil dari aplikasi didapatkan static thrust pada putaran konstan diperoleh senilai 5,68 kg. ================================================================================================================== Technology unmanned aircraft (drone) is currently growing rapidly, unmanned aircraft (drone) is widely used in the military as well as commercial purposes. Because it has many advantages that minimize the risk of human error, easy operation, and more effective than piloted aircraft. Drone deliberately made with a lightweight body and aerodynamics. To determine the aerodynamic forces and specification of BLDC motor UAV Militus, then used software SolidWorks 2016 and aplication Static Thrust Calculate. The purpose of this thesis is to compare including the coefficient of drag (CD), the coefficient of lift (CL), then determination of BLDC motor using aplication static thrust calculate, and system mechatronics of that plane. From the analysis of the flow passing through the fuselage UAV Militus, the coefficient of drag (Cd) obtained during the flight simulation UAV Militus worth 0,0611, and coefficient of lift (Cl) at Flyingwing ,UAV aircraft worth 0.0753. Then theoritical analysis of requirement thrust must to equal or lower than thrust propeller and supported of aplication static thrust at constant rotation obtained 5,68 kg

Fault Diagnosis and Fault-Tolerant Control of Unmanned Aerial Vehicles

With the increasing demand for unmanned aerial vehicles (UAVs) in both military and civilian applications, critical safety issues need to be specially considered in order to make better and wider use of them. UAVs are usually employed to work in hazardous and complex environments, which may seriously threaten the safety and reliability of UAVs. Therefore, the safety and reliability of UAVs are becoming imperative for development of advanced intelligent control systems. The key challenge now is the lack of fully autonomous and reliable control techniques in face of different operation conditions and sophisticated environments. Further development of unmanned aerial vehicle (UAV) control systems is required to be reliable in the presence of system component faults and to be insensitive to model uncertainties and external environmental disturbances. This thesis research aims to design and develop novel control schemes for UAVs with consideration of all the factors that may threaten their safety and reliability. A novel adaptive sliding mode control (SMC) strategy is proposed to accommodate model uncertainties and actuator faults for an unmanned quadrotor helicopter. Compared with the existing adaptive SMC strategies in the literature, the proposed adaptive scheme can tolerate larger actuator faults without stimulating control chattering due to the use of adaptation parameters in both continuous and discontinuous control parts. Furthermore, a fuzzy logic-based boundary layer and a nonlinear disturbance observer are synthesized to further improve the capability of the designed control scheme for tolerating model uncertainties, actuator faults, and unknown external disturbances while preventing overestimation of the adaptive control parameters and suppressing the control chattering effect. Then, a cost-effective fault estimation scheme with a parallel bank of recurrent neural networks (RNNs) is proposed to accurately estimate actuator fault magnitude and an active fault-tolerant control (FTC) framework is established for a closed-loop quadrotor helicopter system. Finally, a reconfigurable control allocation approach is combined with adaptive SMC to achieve the capability of tolerating complete actuator failures with application to a modified octorotor helicopter. The significance of this proposed control scheme is that the stability of the closed-loop system is theoretically guaranteed in the presence of both single and simultaneous actuator faults

Development of a Low-Cost Sub-Scale Aircraft for Flight Research: The FASER Project

An inexpensive unmanned sub-scale aircraft was developed to conduct frequent flight test experiments for research and demonstration of advanced dynamic modeling and control design concepts. This paper describes the aircraft, flight systems, flight operations, and data compatibility including details of some practical problems encountered and the solutions found. The aircraft, named Free-flying Aircraft for Sub-scale Experimental Research, or FASER, was outfitted with high-quality instrumentation to measure aircraft inputs and states, as well as vehicle health parameters. Flight data are stored onboard, but can also be telemetered to a ground station in real time for analysis. Commercial-off-the-shelf hardware and software were used as often as possible. The flight computer is based on the PC104 platform, and runs xPC-Target software. Extensive wind tunnel testing was conducted with the same aircraft used for flight testing, and a six degree-of-freedom simulation with nonlinear aerodynamics was developed to support flight tests. Flight tests to date have been conducted to mature the flight operations, validate the instrumentation, and check the flight data for kinematic consistency. Data compatibility analysis showed that the flight data are accurate and consistent after corrections are made for estimated systematic instrumentation errors

CONTROL STRATEGY OF MULTIROTOR PLATFORM UNDER NOMINAL AND FAULT CONDITIONS USING A DUAL-LOOP CONTROL SCHEME USED FOR EARTH-BASED SPACECRAFT CONTROL TESTING

Over the last decade, autonomous Unmanned Aerial Vehicles (UAVs) have seen increased usage in industrial, defense, research, and academic applications. Specific attention is given to multirotor platforms due to their high maneuverability, utility, and accessibility. As such, multirotors are often utilized in a variety of operating conditions such as populated areas, hazardous environments, inclement weather, etc. In this study, the effectiveness of multirotor platforms, specifically quadrotors, to behave as Earth-based satellite test platforms is discussed. Additionally, due to concerns over system operations under such circumstances, it becomes critical that multirotors are capable of operation despite experiencing undesired conditions and collisions which make the platform susceptible to on-board hardware faults. Without countermeasures to account for such faults, specifically actuator faults, a multirotors will experience catastrophic failure. In this thesis, a control strategy for a quadrotor under nominal and fault conditions is proposed. The process of defining the quadrotor dynamic model is discussed in detail. A dual-loop SMC/PID control scheme is proposed to control the attitude and position states of the nominal system. Actuator faults on-board the quadrotor are interpreted as motor performance losses, specifically loss in rotor speeds. To control a faulty system, an additive control scheme is implemented in conjunction with the nominal scheme. The quadrotor platform is developed via analysis of the various subcomponents. In addition, various physical parameters of the quadrotor are determined experimentally. Simulated and experimental testing showed promising results, and provide encouragement for further refinement in the future