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Integrated Flight Path Planning System and Flight Control System for Unmanned Helicopters  [PDF]
Shau-Shiun Jan,Yu-Hsiang Lin
Sensors , 2011, DOI: 10.3390/s110807502
Abstract: This paper focuses on the design of an integrated navigation and guidance system for unmanned helicopters. The integrated navigation system comprises two systems: the Flight Path Planning System (FPPS) and the Flight Control System (FCS). The FPPS finds the shortest flight path by the A-Star (A*) algorithm in an adaptive manner for different flight conditions, and the FPPS can add a forbidden zone to stop the unmanned helicopter from crossing over into dangerous areas. In this paper, the FPPS computation time is reduced by the multi-resolution scheme, and the flight path quality is improved by the path smoothing methods. Meanwhile, the FCS includes the fuzzy inference systems (FISs) based on the fuzzy logic. By using expert knowledge and experience to train the FIS, the controller can operate the unmanned helicopter without dynamic models. The integrated system of the FPPS and the FCS is aimed at providing navigation and guidance to the mission destination and it is implemented by coupling the flight simulation software, X-Plane, and the computing software, MATLAB. Simulations are performed and shown in real time three-dimensional animations. Finally, the integrated system is demonstrated to work successfully in controlling the unmanned helicopter to operate in various terrains of a digital elevation model (DEM).
Hybrid 3-D Formation Control for Unmanned Helicopters  [PDF]
A. Karimoddini,H. Lin,B. M. Chen,T. H. Lee
Mathematics , 2011,
Abstract: Teams of Unmanned Aerial Vehicles (UAVs) form typical networked cyber-physical systems that involve the interaction of discrete logic and continuous dynamics. This paper presents a hybrid supervisory control framework for the three-dimensional leader follower formation control of unmanned helicopters. The proposed hybrid control framework captures internal interactions between the decision making unit and the path planner continuous dynamics of the system, and hence improves the system's overall reliability. To design such a hybrid controller, a spherical abstraction of the state space is proposed as a new method of abstraction. Utilizing the properties of multi-affine functions over the partitioned space leads to a finite state Discrete Event System (DES) model, which is shown to be bisimilar to the original continuous-variable dynamical system. Then, in the discrete domain, a logic supervisor is modularly designed for the abstracted model. Due to the bisimilarity between the abstracted DES model and the original UAV dynamics, the designed logic supervisor can be implemented as a hybrid controller through an interface layer. This supervisor drives the UAV dynamics to satisfy the design requirements. In other words, the hybrid controller is able to bring the UAVs to the desired formation starting from any initial state inside the control horizon and then, maintain the formation. Moreover, a collision avoidance mechanism is embedded in the designed supervisor. Finally, the algorithm has been verified by a hardware-in-the-loop simulation platform, which is developed for unmanned helicopters. The presented results show the effectiveness of the algorithm.
Trajectory tracking controller for miniature unmanned helicopters with position and velocity constrains

控制理论与应用 , 2015, DOI: 10.7641/CTA.2015.50453
Abstract: 针对微型无人直升机在狭窄空间中的轨迹跟踪问题, 设计了一种可以限制直升机位置和速度的跟踪控制 器. 首先将直升机的模型简化为一个未建模的动态模型. 基于简化模型利用受限反步法设计控制器, 其中在位置控 制回路用障碍李雅普诺夫函数代替传统的纯二次型李雅普诺夫函数, 以此来限制直升机的位置和速度; 用指令滤 波器对反步过程中虚拟控制的导数进行估计, 避免了复杂的解析计算. 此外, 将未建模动态和指令滤波器误差合并 成有界扰动项, 并设计了自适应算法对扰动的上界进行估计和补偿. 稳定性分析证明了直升机的闭环跟踪误差最终 一致有界, 且位置和速度始终位于预设的限制集合中. 仿真结果验证了该控制器的有效性.
A trajectory tracking controller with position and velocity constraints is developed for miniature unmanned helicopters flying in narrow space. The helicopter model is firstly simplified to one with unmolded dynamics. Based on this model, the constrained backstepping technique is applied to design the controller, in which the barrier Lyapunov functions, instead of traditional pure quadratic Lyapunov functions, are introduced to the position control loop for maintaining the position and velocity constraints. Command filters are utilized to estimate derivatives of the virtual controls during the backstepping progress such that complex analytical calculations can be avoided. Furthermore, upper bounds of the disturbances due to the unmodeled dynamics and command filter errors are estimated and compensated with adaptive algorithms. The stability analysis shows that tracking errors of the closed-loop helicopter system are ultimately uniformly bounded and its position and velocity are restricted in the prescribed sets during the tracking progress. Simulation results validate the effectiveness of the proposed controller.
About Helicopters  [PDF]
Relly Victoria Petrescu, Raffaella Aversa, Bilal Akash, Juan Corchado, Filippo Berto, Antonio Apicella and Florian Ion Tiberiu Petrescu
Journal of Aircraft and Spacecraft Technology , 2017, DOI: 10.3844/jastsp.2017.204.223
Abstract: A helicopter is a type of rotorcraft in which lift and thrust are supplied by one or more engine-driven rotors. In contrast with fixed-wing aircraft, this allows the helicopter to take off and land vertically, to hover and to fly forwards, backward and laterally. These attributes allow helicopters to be used in congested or isolated areas where fixed-wing aircraft would not be able to take off or land. The capability to efficiently hover for extended periods of time allows a helicopter to accomplish tasks that fixed-wing aircraft and other forms of vertical takeoff and landing aircraft cannot perform. The word 'helicopter' is adapted from the French hélicoptère, coined by Gustave de Ponton d'Amecourt in 1861, which originates from the Greek helix/helik = "twisted, curved" and pteron = "wing". Helicopters were developed and built during the first half-century of flight, with the Focke-Wulf Fw 61 being the first operational helicopter in 1936. Some helicopters reached limited production, but it was not until 1942 that a helicopter designed by Igor Sikorsky reached full-scale production, with 131 aircraft built. Though most earlier designs used more than one main rotor, it was the single main rotor with antitorque tail rotor configuration of this design that would come to be recognized worldwide as the helicopter. The earliest references for vertical flight have come from China. Since around 400 BC, Chinese children have played with bamboo flying toys and the 4th-century AD Daoist book Baopuzi ("Master who Embraces Simplicity") reportedly describes some of the ideas inherent to rotary wing aircraft: Someone asked the master about the principles of mounting to dangerous heights and traveling into the vast inane. The Master said, "Some have made flying cars with wood from the inner part of the jujube tree, using ox-leather fastened to returning blades so as to set the machine in motion." It was not until the early 1480s when Leonardo da Vinci created a design for a machine that could be described as an "aerial screw" that any recorded advancement was made towards vertical flight. His notes suggested that he built small flying models, but there were no indications for any provision to stop the rotor from making the whole craft rotate. As scientific knowledge increased and became more accepted, men continued to pursue the idea of vertical flight.
Relative dynamic modeling and formation control of multiple unmanned helicopters

WANG Zheng,HE Yu-qing,HAN Jian-da,

控制理论与应用 , 2011,
Abstract: Based on the concept of relative dynamics and leader-follower formation strategy, a new formation control algorithm is developed to partially solve the formation problem. Firstly, the relative dynamics is derived by combining the 6-DOF rigid body relative dynamics with the individual unmanned helicopter dynamics. Secondly, with the cascade control structure which includes inner and outer loops, a tracking controller is designed by using the techniques of approximate feedback linearization and the extended high gain observer. Finally, simulations of the proposed method with two unmanned helicopter systems are conducted to test the desired tracking performance and feasible disturbance rejection.
An Automatic Take-off Method for Small-scale Unmanned Helicopters

DU Yu-Hu,FANG Jian-Cheng,SHENG Wei,LEI Xu-Sheng,

自动化学报 , 2012,
Abstract: Focusing on the problem that the take-off of a small- scale unmanned helicopter (SUH) mainly relys on the manoeu- vre of the pilot on the ground, an automatic take-off method for SUHs is proposed based on the knowledge of pilot and sys- tem identification theory. First, through studying the relation- ships between altitudes, throttle, and collective pitch during SUH take-off manoeuvred by a professional pilot, the feasibil- ity of realizing the take-off of SUH via studying the manoeuvre behavior of the pilot is analyzed, and the control flowchart of automatic take-off is designed. Safe altitude and variable gain control are introduced to improve flight safety of automatic take- off, incomplete differential algorithm is utilized to restrain the high frequency disturbance aroused by differential. Then, in or- der to acquire the flight control parameters of automatic take-off, adaptive genetic algorithm is adopted to identify the dynamics model, and flight control parameters are obtained based on the identified model. Finally, the results of flight experiment con- ducted upon a type of SUH show that the control algorithm proposed in this paper could realize the automatic take-off of SUH effectively.
Decentralized Hybrid Formation Control of Unmanned Aerial Vehicles  [PDF]
Ali Karimoddini1,Mohammad Karimadini,Hai Lin
Computer Science , 2014,
Abstract: This paper presents a decentralized hybrid supervisory control approach for a team of unmanned helicopters that are involved in a leader-follower formation mission. Using a polar partitioning technique, the motion dynamics of the follower helicopters are abstracted to finite state machines. Then, a discrete supervisor is designed in a modular way for different components of the formation mission including reaching the formation, keeping the formation, and collision avoidance. Furthermore, a formal technique is developed to design the local supervisors decentralizedly, so that the team of helicopters as whole, can cooperatively accomplish a collision-free formation task.
Project AURORA: Development of an Autonomous Unmanned Remote Monitoring Robotic Airship
Elfes, Alberto;Bueno, Samuel S.;Bergerman, Marcel;Ramos, Josué Jr. G.;Gomes, Sérgio Bittencourt Varella;
Journal of the Brazilian Computer Society , 1998, DOI: 10.1590/S0104-65001998000100009
Abstract: there exists an immense potential for the utilization of robotic airships as low speed, low altitude aerial vehicles in exploration, monitoring, and transportation tasks. this article discusses project aurora - autonomous unmanned remote monitoring robotic airship which focuses on the development of the control, navigation, sensing, and inference technologies required for substantially autonomous robotic airships. our target application areas include the use of robotic airships for environmental, biodiversity, and climate research and monitoring. based on typical mission requirements, we present arguments that favor airships over airplanes and helicopters as the ideal platforms for such missions. we outline the overall system architecture of the aurora robotic airship, discuss its main subsystems, and mention the research and development issues involved.
An analysis of the efficiency of Coanda - NOTAR anti-torque systems for small helicopters  [PDF]
Ionic? C?RCIU,Mircea BO?COIANU
INCAS Bulletin , 2010, DOI: 10.13111/2066-8201.2010.2.4.12
Abstract: The use of jet thrust for anti-torque for monorotor small helicopters is based on thecirculation control concept, which result in a distributed side force along the entire tail boomassembly. High velocity jets of air from a pressurized tail boom is blown tangential to the surface outof narrow slots that run lengthwise on the side of the tail boom. In combination with the downstreamvelocity produced by the main rotor, Coanda jets cause the flow to remain attached to the tail boomsurface. The anti-torque NOTAR system is in fact the result of Coanda effect and the interest is toanalyze the efficiency of replacing the tail rotor on a small monorotor helicopter.
Convergence of the Unmanned Aerial Industry  [PDF]
Johnny Elie Chamata
Theoretical Economics Letters (TEL) , 2017, DOI: 10.4236/tel.2017.72015
Abstract: Industry convergencethe merger of previously unrelated industriesis a model that has had a strong influence on various industries and received substantial attention among practitioners over the past years. Despite this, industry convergence has received little attention in the field of unmanned aircraft. As the unmanned aircraft industry is still in the infancy stage, exploring the industrial status may contribute to the technology’s body of knowledge and may be useful for entrepreneurial decision making. Thus, this research paper investigates the degree to which the unmanned aerial vehicle sector represents an example of industry convergence and predicts the consequences built upon it. The investigation is based on the convergence theory and evidence from the unmanned aerial systems industry is provided to support theoretical foundations. Conclusions show that unmanned aerial technology is converged to an undefined extent and the author calls for further related empirical research.
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