Development of c-means Clustering Based Adaptive Fuzzy Controller for A Flapping Wing Micro Air Vehicle

Advanced and accurate modelling of a Flapping Wing Micro Air Vehicle (FW MAV) and its control is one of the recent research topics related to the field of autonomous Unmanned Aerial Vehicles (UAVs). In this work, a four wing Natureinspired (NI) FW MAV is modeled and controlled inspiring by its advanced features like quick flight, vertical take-off and landing, hovering, and fast turn, and enhanced manoeuvrability when contrasted with comparable-sized fixed and rotary wing UAVs. The Fuzzy C-Means (FCM) clustering algorithm is utilized to demonstrate the NIFW MAV model, which has points of interest over first principle based modelling since it does not depend on the system dynamics, rather based on data and can incorporate various uncertainties like sensor error. The same clustering strategy is used to develop an adaptive fuzzy controller. The controller is then utilized to control the altitude of the NIFW MAV, that can adapt with environmental disturbances by tuning the antecedent and consequent parameters of the fuzzy system.Comment: this paper is currently under review in Journal of Artificial Intelligence and Soft Computing Researc

Simulation of Flapping-wing Unmanned Aerial Vehicle using X-plane and Matlab/Simulink

This paper presents the simulation of flapping-wing unmanned aerial vehicle model using X-plane and Matlab/ Simulink. The flapping-wing ornithopter model (i.e. an aircraft that flies by flapping its wings) has been developed in plane maker software and executed in the X-plane environment. The key idea of flapping-wing mechanism in X-plane software is by varying its dihedral angle sinusoidally. This sinusoidally varying dihedral angle of wing creates upward and downward stroke moments inturn this creates a lift and a forward thrust for flying the flapping-wing model. Here pitch, roll, yaw and throttle (flapping rate) is fed as reference input through the user datagram protocol (UDP) port. The difference between the reference inputs, the simulated outputs are again fed back to simulator through UDP port and the gains are observed for the responses of flapping-wing unmanned aerial vehicle in Matlab/Simulink environment. Here various gains are used to monitor the optimized flying of flapping-wing model.Defence Science Journal, Vol. 64, No. 4, July 2014, pp.327-331, DOI:http://dx.doi.org/10.14429/dsj.64.493

Survey of the Status of Small Armed and Unarmed Uninhabited Aircraft

The project ‘Preventive Arms Control for Small and Very Small Armed Aircraft and Missiles’ investigates the properties of ever smaller aircraft and missiles. This project report no. 1 covers the status of aircraft worldwide, including relevant unarmed vehicles but excluding hobby aircraft. Small and very small aircraft are defined by size: below 2 m and below 0.2 m, respectively. After an elementary introduction into aerodynamics a technical overview is given, looking at airframe configurations, materials and manufacturing, power and propulsion, guidance, launch and recovery, and payloads. Future possibilities and trends are illustrated by presenting military research and development of the technological leader, the USA. Short chapters deal with swarms and with countermeasures. The worldwide survey has resulted in a database that contains 129 types from 27 countries. The publicly available properties are given in 26 categories. Statistical evaluations cover several key parameters

Impact of Marine Locomotion Constraints on a Bio-inspired Aerial-Aquatic Wing:Experimental Performance Verification

This paper describes the design, fabrication, experimental testing and performance optimization of the morphology of a flapping wing for use on a robot capable of aerial and aquatic modes of locomotion. The focus of the optimization studies is that of wing design for aquatic propulsion. Inspiration for the research stems from numerous avian species which use a flapping wing for the dual purpose of locomotion (propulsion) in both air and water. The main aim of this research is to determine optimal kinematic parameters for marine locomotion that maximize nondimensionalized performance measures (e.g., propulsive efficiency), derived from analysis of avian wing morphing mechanisms that balance competing demands of both aerial and aquatic movement. Optimization of the kinematic parameters enables the direct comparison between outstretched (aerial) and retracted (aquatic) wing morphologies and permits trade-off studies in the design space for future robotic vehicles. Static foils representing the wing in both an extended and retracted orientation have been manufactured and subsequently subjected to testing over a range of kinematics. Details of the purpose built 2 degree-of-freedom (dof) flapping mechanism are presented. The gathered results enable validation of previously developed numerical models as well as quantifying achievable performance measures. This research focuses on the mechanical propulsive efficiencies and thrust coefficients as key performance measures whilst simultaneously considering the required mechanical input torques and the associated thrust produced.</jats:p

DEVELOPMENT OF COAXIAL ROTOR MICRO UNMANNED AERIAL VEHICLE

Micro Unmanned Helicopter with ability of takeoff, landing and hovering offeres excellent support tool for missions in indoor environment. In this paper, a review of preliminary studies towards the development of autonomous coaxial helicopter MAV is presented. The paper starts with the statement of coaxial helicoper MAV development. Then, it is continued by the introduction of development of dynamic model for a typical coaxial rotor platform. In the third issues, initial steps in development of sensory system and control system will be dealt with. In brief, an analytical mathematical model has successful derived. This model together with the developed sensor system will act important role towards the full development of the dynamics model as the system identification is carried out

꼬리날개 없는 날갯짓 초소형 비행체의 자세조절

학위논문 (박사) -- 서울대학교 대학원 : 공과대학 기계항공공학부, 2020. 8. 김현진.최근 생체모방에 대한 관심이 커지면서 생명체의 구조, 외형, 움직임, 행동을 분석하여 그들의 장점을 로봇에 적용시켜 기존의 로봇이 해결할 수 없거나 특별한 임무를 좀 더 효과, 효율적으로 해결하려는 시도가 늘어나고 있다. 이러한 시도는 무인비행체 개발에도 적용되고 있으며 날갯짓 비행체가 이에 해당된다. 날개짓 비행체는 날개의 반복운동을 통해 발생하는 힘을 통해 비행하는 비행체로 일반적으로 꼬리날개의 유무에 따라 새를 모방한 비행체(미익형 비행체)와 곤충을 모방한 비행체(무미익형 비행체)로 구분할 수 있다. 무미익형 비행체의 경우 제자리 비행을 할 수 있고, 크기가 작고 무게가 가벼워 공기저항도 줄일 수 있으며, 날렵한 비행이 가능하다는 장점이 있지만, 수동 안정성을 확보하기 위한 제어면이 충분하지 않고 추력 생성과 동시에 3축으로의 제어 모멘트를 만들 수 있는 복잡한 매커니즘을 가지고 있다는 특징을 가지고 있다. 본 논문에서는 저자의 미익형 비행체의 연구개발 사례를 토대로 자율 비행을 할 수 있는 무미익형 비행체를 개발하기 위한 요소기술들과 초기 비행체 개발을 목표로 한다. 해당 목표를 달성하기 위해 저자는 시중에서 판매되고 있는 RC장난감을 활용해 30 gram 이하의 무게를 가지고 30cm3 이내의 크기를 가지는 무미익형 날갯짓 비행체를 개발을 진행하였다. 비행체 내부에는 구동기로 DC 모터와 서보모터가 존재하며, DC 모터는 날갯짓을 일으키는 기어 박스를 작동시켜 비행체의 무게를 지탱하기 위한 thrust를 생성하며 roll축 방향으로의 moment 생성에 관여하며, 서보모터는 날갯짓에서 발생하는 좌우 thrust의 방향을 조절하여 pitch 와 yaw 축으로의 모멘트를 생성하는데 사용된다. 비행체 내부에는 아두이노 보드 기반의 마이크로프로세서가 탑재되어 있어 비행체를 제어하기 위한 신호를 생성할 수 있으며 블루투스 통신 모듈을 가지고 있기 때문에 외부와 통신 역시 가능하다. 비행체의 자세를 제어하기 위해서는 구동기의 상호작용으로 인해 발생하는 힘의 물리량을 파악하는 것이 중요하다. 이를 위해 날갯짓 메커니즘에서 발생하는 힘을 측정하는 실험을 수행하였다. 측정실험을 통해 DC모터 입력 대비 thrust 크기, 서보모터 command 입력 대비 moment 크기 등의 관계를 파악하였다. 또한 날갯짓 비행체를 공중에 띄울 수 있는 충분한 크기의 thrust를 발생하는 것을 확인하였으며 자세 제어를 위한 모멘트 생성 역시 가능하다는 것을 확인하였다. 비행체의 자세를 제어하기 위해서는 3축 방향으로의 운동방정식을 유도하는 것이 필요하다. 이를 위해 roll, pitch, yaw 축 방향으로 비행체에서 발생하는 힘과 회전 운동과 관련한 운동방정식을 유도했으며 이를 통해 비행체의 자세를 안정화시킬 수 있도록 하는 PID 제어기 형태의 제어기를 설계하였다. 뿐만 아니라, 비행체의 궤적추종 제어를 위해 내부의 자세 제어기에 비행체의 위치를 토대로 계산되는 추가적인 외부 제어기를 설계하여 이중루프 제어기 형태를 적용시켜 시뮬레이션을 통해 비행체의 자세 제어와 궤적 추종 제어가 이루어짐을 확인하였다. 개발한 비행체와 앞서 설계한 제어기가 사용자의 의도에 맞는 성능을 내는지 확인하기 위해 자이로 실험장치를 제작하여 자세 제어 실험을 수행하였다. 해당 실험장치는 roll, pitch, yaw 축으로 회전이 가능하도록 제작하였으며 실험장치 자체의 무게를 줄이기 위해 MDF 소재를 사용하여 구조물를 만들었다. roll, pitch, yaw 3축이 각각 독립적으로 제어하는 것과 3축을 동시에 제어하는 2가지 상황을 고려하였으며 앞서 설계한 제어기가 해당 실험 장치 내부에서 사용자의 의도에 맞게 제어 성능을 보이는지 확인할 수 있었다. 궤적 추종제어를 위해서는 2가지 비행 상황을 설정하였다. 첫 번째 경우, 천장과 비행체 상단부에 실을 연결하여 2D 평면상에서 비행체가 주워진 궤적에 따라 움직이는지, 두 번째 경우, 비행체 상단부에 헬륨이 주입된 풍선을 연결시켜 3D 공간상에서 주워진 궤적을 따라 추종 비행하는지를 확인할 수 있는 상황이다. 두 가지 상황에서 모두 다양한 형태의 궤적을 비행체가 잘 추종하는지를 확인할 수 있었다. 끝으로, 외부 장치(실, 풍선)를 제거하여 공중에서 비행체가 제자리 비행을 할 수 있는지를 검증하는 실험을 진행하였으며, 15초가량 1m3 공간 내에서 제자리 비행이 이루어지는 것을 확인하였다.Flapping wing micro air vehicles (FWMAVs) that generate thrust and lift by flapping their wings are regarded as promising flight vehicles because of their advantages in terms of similar appearance and maneuverability to natural creatures. Reducing weight and air resistance, insect-inspired tailless FWMAVs are an attractive aerial vehicle rather than bird-inspired FWMAVs. However, they are challenging platforms to achieve autonomous flight because they have insufficient control surfaces to secure passive stability and a complicated wing mechanism for generating three-axis control moments simultaneously. In this thesis, as preliminary autonomous flight research, I present the study of an attitude regulation and trajectory tracking control of a tailless FWMAV developed. For these tasks, I develop my platform, which includes two DC motors for generating thrust to support its weight and servo motors for generating three-axis control moments to regulate its flight attitude. First, I conduct the force and moment measurement experiment to confirm the magnitude and direction of the lift and moment generated from the wing mechanism. From the measurement test, it is confirmed that the wing mechanism generates enough thrust to float the vehicle and control moments for attitude regulation. Through the dynamic equations in the three-axis direction of the vehicle, a controller for maintaining a stable attitude of the vehicle can be designed. To this end, a dynamic equation related to the rotational motion in the roll, pitch, and yaw axes is derived. Based on the derived dynamic equations, we design a proportional-integral-differential controller (PID) type controller to compensate for the attitude of the vehicle. Besides, we use a multi-loop control structure (inner-loop: attitude control, outer-loop: position control) to track various trajectories. Simulation results show that the designed controller is effective in regulating the platforms attitude and tracking a trajectory. To check whether the developed vehicle and the designed controller are operating effectively to regulate its attitude, I design a lightweight gyroscope apparatus using medium-density-fiberboard (MDF) material. The rig is capable of freely rotating in the roll, pitch, and yaw axes. I consider two situations in which each axis is controlled independently, and all axes are controlled simultaneously. In both cases, attitude regulation is properly performed. Two flight situations are considered for the trajectory tracking experiment. In the first case, a string connects between the ceiling and the top of the platform. In the second case, the helium-filled balloon is connected to the top of the vehicle. In both cases, the platform tracks various types of trajectories well in error by less than 10 cm. Finally, an experiment is conducted to check whether the tailless FWMAV could fly autonomously in place by removing external devices (string, balloon), and the tailless FWMAV flies within 1 m^3 space for about 15 seconds1.Introduction 1 1.1 Background & Motivation 1 1.2 Literature review 3 1.3 Thesis contribution 7 1.4 Thesis outline 8 2.Design of tailless FWMAV 13 2.1 Platform appearance 13 2.2 Flight control system 17 2.3 Principle of actuator mechanism 18 3.Force measurement experiment 28 3.1 Measurement setup 28 3.2 Measurement results 30 4.Dynamics & Controller design 37 4.1 Preliminary 37 4.2 Dynamics & Attitude control 39 4.2.1 Roll direction 41 4.2.2 Pitch direction 43 4.2.3 Yaw direction 45 4.2.4 PID control 47 4.3 Trajectory tracking control 48 5.Attitude regulation experiments 50 5.1 Design of gyroscope testbed 50 5.2 Experimental environment 52 5.3 Roll axis free 53 5.3.1 Simulation 54 5.3.2 Experiment 55 5.4 Pitch axis free 56 5.4.1 Simulation 57 5.4.2 Experiment 58 5.5 Yaw axis free 59 5.5.1 Simulation 59 5.5.2 Experiment 60 5.6 All axes free 60 5.6.1 Simulation 60 5.6.2 Experiment 61 5.7 Design of universal joint testbed & Experiment 64 6.Trajectory tracking 68 6.1 Simulation 68 6.2 Preliminary 69 6.3 Experiment: Tied-to-the-ceiling 70 6.4 Experiment: Hung-to-a-balloon 71 6.5 Summary 72 6.6 Hovering flight 73 7.Conclusion 83 A Appendix: Wing gearbox 85 A.1 4-bar linkage structure 85 B Appendix: Disturbance observer (DOB) 87 B.1 DOB controller 87 B.2 Simulation 89 B.2.1 Step input 89 B.2.2 Sinusoid input 91 B.3 Experiment 92 References 95Docto