无尾扑翼无人机动力学建模及仿真

近年来,仿生无人机在战场侦察和飞行巡逻等方面应用广泛,使其成为无人机领域的研究热门,传统仿生无尾扑翼无人机的飞行建模问题通常较为复杂,计算难度较大,因此亟待对此类无人机进行飞行控制的研究。文章针对仿昆虫无尾扑翼无人机的动力学建模问题进行了研究,基于叶素法、准稳态假设模型以及刚体动力学建模方法,对机翼运动进行受力分析,得到机翼的动力学模型;机体采用刚体动力学方法,建立无人机飞行模型。仿昆虫无尾扑翼无人机系统采用PID控制模型对机体纵向动力学模型控制,以俯仰角、阶跃输入方式,通过实验表明,系统的超调量分别为和,调节时间分别为0.5和1,稳态误差符合实验要求。     

基于聚类分析和运动描述语言的扑翼飞行机器人行为规划

为了解决扑翼飞行机器人实时控制过程中操作者工作量大、操作较为复杂的难题,实现扑翼飞行机器人的分布式智能控制,提出了基于聚类分析和运动描述语言的扑翼飞行机器人行为规划方法.利用扑翼飞行机器人飞行数据聚类分析的结果,将机器人运动行为进行合理分类.在保证了运动描述语言的基元关系的同时,合理提取了扑翼飞行机器人的行为特征,并针对扑翼飞行机器人绕杆任务定义了4类运动基元.以扑翼飞行机器人和机载陀螺仪搭建了扑翼飞行机器人实验系统.通过直接控制方法和基于运动描述语言的机器人行为规划方法进行了实物实验和仿真实验,实验结果验证了所提方法的可行性和有效性.     

微型仿昆扑翼飞行器解耦操控机制

提出一种解耦操控机制，用于解决微型仿昆扑翼飞行器飞行控制中的欠驱动问题．首先通过理论分析和仿真试验分析了翅膀的振翅运动参数对气动力旋量的控制作用；然后在对昆虫飞行所采用的生物学振翅运动进行模拟的基础上，通过调整翅膀的振翅运动参数，设计了一个能对气动力和气动力矩实现独立控制的解耦操控机制．此操控机制采用周期函数将控制输入量参数化，从而在仿昆扑翼布局的动力学模型中引入更多数目的独立控制量．通过将原动力学系统转化为完全能控系统，解决了仿昆扑翼布局的欠驱动控制问题．同时，此操控机制仅仅要求转动角可控，有效地降低了仿昆扑翼飞行器的设计难度．     

仿生变形飞行器的飞行特性研究

随着无人飞行器的小型化甚至微型化发展,扑翼飞行的优势逐渐显现出来。受鸟类及昆虫飞行运动的启发,分析鸟类及昆虫的扑翼运动特性,设计了一种鸟类扑翼飞行方式,使用涡格法进行了扑翼的气动计算,并采用质点弹道学模型分析了仿生飞行的轨迹特性。仿真结果表明,设计的扑翼运动效果良好。     

微扑翼飞行机器人姿态反演自适应模糊控制

研究微扑翼飞行机器人姿态控制优化问题,因扑翼飞行的复杂性、系统的非线性、时变参数以及各种干扰而极具挑战性.为了提高系统姿态稳定性,提出了一种反演自适应模糊控制策略,针对传统反演控制律设计的不足之处,对微扑翼飞行机器人控制律设计中需要知道被控对象精确模型信息的部分,采用模糊控制法去逼近,从而实现了无需微扑翼飞行器精确模型的全新控制律,避免了因建模误差对控制带来的不良影响,并在此基础上证明了系统的稳定性.仿真结果证实了控制方法的有效性.     

微型仿鸟扑翼飞机设计与仿真系统开发

基于仿生学的微扑翼飞行器是一种模仿鸟类飞行的新概念飞行器.鉴于扑翼飞行理论及实践本身的困难,为了减少设计制造中的风险,开发了微型仿鸟扑翼飞机设计与仿真系统.采用Visual C 和MATLAB进行仿生学设计模块、驱动机构和气动力计算模块的开发,由此进行扑翼飞机结构及动力学设计,生成初步样机.结合OpenGL技术,建立微型扑翼飞机的三维可视化结构模型,进行扑翼飞机的运动和虚拟飞行仿真.进行扑翼飞机的开发实例分析,结果与实际制作的扑翼飞机各项特征吻合.该系统有很高的实用价值,可以有效地辅助进行微型仿鸟扑翼飞机的研制工作.     

仿鸟扑翼飞行器仿真研究

针对仿鸟扑翼飞行器的柔性翼动力学仿真需要,在非定常空气动力学原理下,用修正的准定常气动力计算模型估算出了扑翼的动力学模型,并建立了其相应的状态空间方程,进而分析研究了在Matlab语言和Simulink环境下,对其仿真系统设计得需求和要求。     

面向扑翼飞行控制的建模与奇异摄动分析

针对扑翼飞行中的周期性和时标不一现象,以及扑翼飞行实际控制中的问题,本文基于奇异摄动理论,提出了一种针对扑翼周期系统的稳定性分析方法.具体而言,首先建立了扑翼飞行器的多刚体模型,为后文对翅翼动力学的奇异摄动分析铺平道路;其次,对多刚体模型进行简化,抽象出扑翼飞行动力学的核心问题,并针对实际控制中的问题,提出了利用奇异摄...     

微型飞行器飞行仿真软件开发

该文简要介绍了微型飞行器飞行仿真软件的总体结构和模块划分。首先建立了飞行器的三维结构模型，根据飞行器的扑翼运动规律进行了运动仿真。采用随机分形技术生成的具有真实感的地形为仿真飞行提供了一个虚拟环境。在此基础之上讨论了飞行器虚拟飞行过程中的静态与动态模拟方法。仿真软件中的三维图形实时显示采用Visual C 和Open GL来共同完成。     

微扑翼飞行器控制系统相关技术研究进展

微型扑翼飞行器(FMAV)由于微型化和采用扑翼飞行方式的特征,许多传统理论和设计方法不再完全适用,相关理论和技术仍在不断地发展中,所以对国内外相关理论和技术的发展现状进行及时跟踪和研究,具有非常重要的参考意义;通过调查研究,介绍了与微型扑翼飞行器控制系统有关的低雷诺数非定常空气动力学、控制系统数学模型、控制方案和控制方法等的研究进展,总结出了微型扑翼对飞行器控制系统的设计要求,控制系统的特点和需要解决的关键问题,并展望了未来发展趋势。     

Modeling Synchronous Muscle Function in Insect Flight: a Bio-Inspired Approach to Force Control in Flapping-Wing MAVs

Micro-aerial vehicles (MAV) and their promising applications—such as undetected surveillance or exploration of environments with little space for land-based maneuvers—are a well-known topic in the field of aerial robotics. Inspired by high maneuverability and agile flight of insects, over the past two decades a significant amount of effort has been dedicated to research on flapping-wing MAVs, most of which aim to address unique challenges in morphological construction, force production, and control strategy. Although remarkable solutions have been found for sufficient lift generation, effective methods for motion control still remain an open problem. The focus of this paper is to investigate general flight control mechanisms that are potentially used by real insects, thereby providing inspirations for flapping-wing MAV control. Through modeling the insect flight muscles, we show that stiffness and set point of the wing’s joint can be respectively tuned to regulate the wing’s lift and thrust forces. Therefore, employing a suitable controller with variable impedance actuators at each wing joint is a prospective approach to agile flight control of insect-inspired MAVs. The results of simulated flight experiments with one such controller are provided and support our claim.     

Efficient Flight Control via Mechanical Impedance Manipulation: Energy Analyses for Hummingbird-Inspired MAVs

Within the growing family of unmanned aerial vehicles (UAV), flapping-wing micro aerial vehicles (MAV) are a relatively new field of research. Inspired by small size and agile flight of insects and birds, these systems offer a great potential for applications such as reconnaissance, surveillance, search and rescue, mapping, etc. Nevertheless, practicality of these vehicles depends on how we address various challenges ranging from control methodology to morphological construction and power supply design. A reasonable approach to resolving such problems is to acquire further inspiration from solutions in nature. Through modeling synchronous muscles in insects, we have shown that manipulation of mechanical impedance properties at wing joints can be a very efficient method for controlling lift and thrust production in flapping-wing MAVs. In the present work, we describe how this approach can be used to decouple lift/thrust regulation, thus reducing the complexity of flight controller. Although of simple design, this controller is still capable of demonstrating a high degree of precision and maneuverability throughout various simulated flight experiments with different types of trajectories. Furthermore, we use these flight simulations to investigate the power requirements of our control approach. The results indicate that these characteristics are considerably lower compared to when conventional control strategies—methods that often rely on manipulating stroke properties such as frequency or magnitude of the flapping motion—are employed. With less power demands, we believe our proposed control strategy is able to significantly improve flight time in future flapping-wing MAVs.     

Longitudinal modelling and control of a flapping-wing micro aerial vehicle

A simulation model, flight-dynamics oriented, of a flapping-wing micro aerial vehicle (MAV) is presented here. The model, based on animal flapping flight, integrates the aerodynamic forces computed along each wing to determine the global motion of the MAV with respect to an inertial reference frame. After some analytic simplifications, and taking into account the periodic nature of the system inputs, an averaged model is derived, and a simple, nonlinear closed-loop control law is designed for the dynamics along the vertical and pitch axis, allowing an efficient stabilization of the naturally unstable model.     

Study on the structural optimization of a flapping wing micro air vehicle

The development of flapping wing micro air vehicles (MAVs) has yielded remarkable progress over the last decades. Achieving high component stiffness is often in conflict with low weight requirement, which is highly desirable for longer flight time and higher payload. Moreover, vibration originated predominantly from the wings, gears and frames excitations, may compromise the flapping wing MAV’s stability and fatigue life. In order to improve the vehicle’s efficiency and performance, optimization of these various parameters is necessary. In this work, we present the structural optimization of a flapping wing micro air vehicle. We focus particularly on the gearbox optimization using Simulia Tosca Structure in Abaqus, which is a robust tool for designing lightweight, rigid and durable components. Various numerical experiments have been conducted towards optimizing the components’ topology, aimed at increasing the stiffness and reducing weight. The finding and results provide a better understanding of the optimal design topology for a spur gear among other structural components used in MAVs.     

Flapping flight for biomimetic robotic insects: part I-system modeling

This paper presents the mathematical modeling of flapping flight inch-size micro aerial vehicles (MAVs), namely micromechanical flying insects (MFIs). The target robotic insects are electromechanical devices propelled by a pair of independent flapping wings to achieve sustained autonomous flight, thereby mimicking real insects. In this paper, we describe the system dynamic models which include several elements that are substantially different from those present in fixed or rotary wing MAVs. These models include the wing-thorax dynamics, the flapping flight aerodynamics at a low Reynolds number regime, the body dynamics, and the biomimetic sensory system consisting of ocelli, halteres, magnetic compass, and optical flow sensors. The mathematical models are developed based on biological principles, analytical models, and experimental data. They are presented in the Virtual Insect Flight Simulator (VIFS) and are integrated together to give a realistic simulation for MFI and insect flight. VIFS is a software tool intended for modeling flapping flight mechanisms and for testing and evaluating the performance of different flight control algorithms.     

Development of a Rotorcraft Micro air Vehicle for Indoor Flight Research

Autonomous flight of micro air vehicles (MAVs) in hostile indoor environments poses significant challenges in terms of control and navigation. In order to support navigation and control research for indoor micro air vehicles, a four-wing tail-sitter type rotorcraft MAV weighing less than 350g has been designed in this paper. In an effort to achieve autonomous indoor flight, an embedded integrated avionic system has been developed. The modeling process has been conducted to obtain accurate six degrees of freedom dynamical model for the designed rotorcraft MAV. In addition, aerodynamic coefficients are evaluated from the results of Computational Fluid Dynamics A PI-ADRC double loop controller with inner-loop outer-loop control scheme has been proposed which takes into account the system’s nonlinearities and uncertainties. The proposed flight controller was implemented on the designed rotorcraft MAV that has undergone various simulation and indoor flight tests. Experimental results that demonstrate robustness of the proposed controller with respect to external disturbances and the capabilities of the designed rotorcraft MAV are presented.     

仿生扑翼“0”形轨迹机构的设计及气动力特性

针对仿生扑翼飞行器的驱动结构进行设计,提出了一种空间摇杆式的驱动机构与机翼扭转机构,实现机翼扑动过程中的"0"形空间运动轨迹.针对机翼的空间"0"字形运动,建立仿生飞行器气动分析模型,采用动网格与非定常数值计算方法,对机翼拍动过程中不同相位下的升阻特性进行分析,并通过空气动力效率与流场对比分析,得到不同参数条件下的气动效率,为仿生扑翼飞行器的设计及扑动模式的选择提供参考.通过气动力测量实验、台架姿态标定和外场飞行测试,验证了结构设计的合理性.     

Inertially Aided Visual Odometry for Miniature Air Vehicles in GPS-denied Environments

Unmanned miniature air vehicles (MAVs) have recently become a focus of much research, due to their potential utility in a number of information gathering applications. MAVs currently carry inertial sensor packages that allow them to perform basic flight maneuvers reliably in a completely autonomous manner. However, MAV navigation requires knowledge of location that is currently available only through GPS sensors, which depend on an external infrastructure and are thus prone to reliability issues. Vision-based methods such as Visual Odometry (VO) have been developed that are capable of estimating MAV pose purely from vision, and thus have the potential to provide an autonomous alternative to GPS for MAV navigation. Because VO estimates pose by combining relative pose estimates, constraining relative pose error is the key element of any Visual Odometry system. In this paper, we present a system that fuses measurements from an MAV inertial navigation system (INS) with a novel VO framework based on direct image registration. We use the inertial sensors in the measurement step of the Extended Kalman Filter to determine the direction of gravity, and hence provide error-bounded measurements of certain portions of the aircraft pose. Because of the relative nature of VO measurements, we use VO in the EKF prediction step. To allow VO to be used as a prediction, we develop a novel linear approximation to the direct image registration procedure that allows us to propagate the covariance matrix at each time step. We present offline results obtained from our pose estimation system using actual MAV flight data. We show that fusion of VO and INS measurements greatly improves the accuracy of pose estimation and reduces the drift compared to unaided VO during medium-length (tens of seconds) periods of GPS dropout.     

独立驱动的仿鸟扑翼飞行机器人的系统设计与实验EI北大核心CSCD

扑翼飞行机器人模仿自然界中的飞行生物,通过扑动翅膀拍打空气驱动飞行.它们机动性好、飞行效率高、噪音小,在某些应用场景比传统的固定翼飞机和旋翼飞机更有优势.目前扑翼飞行机器人的研究大多集中在机理研究和理论的建模与控制,鲜有实现室外的自主飞行,难以应对复杂的实际应用需求.在本文中,设计了一种独立驱动的仿鸟扑翼飞行机器人USTBird,通过两个舵机独立驱动左右翅膀可实现无可控尾翼的机动飞行.通过搭载自主设计的微型飞控板、GPS以及惯性导航模块,采用PD控制实现了扑翼飞行机器人的室外自主巡航飞行.设计了针对扑翼机器人的轻型两自由云台,很大程度上消除了机翼扑动飞行引起的图像抖动问题.针对机身振动和GPS测量误差带来的位置误差,采用无迹卡尔曼滤波算法对GPS采集的位置信息进行估计,提升了位置估计精度.设计了面向扑翼飞行机器人的地面站系统.考虑到扑翼飞行机器人存在的转向滞后问题,对偏航角设计双闭环分段PD控制器,最终实现了在外圆半径40 m和内圆半径10 m的圆环内的自主巡航任务.