基于MEMS技术的SU-8仿昆虫微扑翼飞行器设计及制作

为研制一种轻质仿昆虫微扑翼飞行器,提出了采用微机电系统(MEMS)领域的SU-8光刻胶作为结构材料的制作方案.基于仿生学原理和微机电系统加工技术,设计微扑翼飞行器结构及MEMS 工艺方法.研究结果表明,该种结构设计及制作方案满足设计要求,为仿昆虫微扑翼飞行器的研制提供了一种很好的途径.     

扑翼飞行的气动建模与仿真分析

用计算流体力学的数值仿真方法对微扑翼飞行的非定常空气动力学问题进行了建模与仿真研究。在对昆虫扑翼飞行运动的仿生模拟基础上，建立了简化的扑翼运动二维翼型的运动学与空气动力学模型。利用任意拉格朗日欧拉（ALE）有限元方法求解出N-S方程的数值解，将流场仿真结果与实验进行了对比，并分析了扑翼运动产生的前缘漩涡对升力的作用。文中的建模、分析方法和结论对微扑翼飞行器的分析设计和应用提供了一定的理论依据。     

仿昆扑翼微飞行器电磁驱动电路设计与制造

针对电磁驱动方式的仿昆扑翼微飞行器,设计了电磁线圈驱动电路,电路能够驱动微飞行器扑动双翼。驱动电路利用电池组和升压(BOOST)电路实现电路供电。研制了产生两路电压控制信号的最小系统板,能够在上位机在线实时控制输出信号的频率和幅值。电压控制信号通过电路后,电路输出稳定驱动电流,实现对仿昆扑翼微飞行器翅膀的控制。     

仿鸟扑翼飞行器姿态镇定研究

针对仿鸟扑翼飞行器的欠驱动特性,提出了一种简化其飞行控制问题并实现其局部渐近稳定的控制方法．建立并分析了仿鸟扑翼飞行器的动力学和运动学模型,证明其控制问题等价于升力、推力独立可控情况下的姿态控制问题．进一步分析的结果表明,仿鸟扑翼飞行器的升力、推力都是独立可控的,其姿态控制为耦合输入下刚体的姿态控制问题．通过设计光滑时变反馈控制律实现姿态控制的局部渐近稳定,从而解决扑翼飞行器的飞行控制问题．     

基于电磁驱动的微扑翼飞行器驱动器振动特性

电磁驱动的微扑翼飞行器翼端拍打振幅受到驱动电压、磁感应强度、电流角频率等因素的影响。为了探究上述三个因素对微扑翼飞行器翼端拍打振幅的影响规律,提出一种新型电磁驱动器方案,并建立电磁场中微梁振动模型,为验证电磁驱动器方案的可行性及进一步探究相关因素对微梁振动的影响规律,设计开展电磁驱动的微梁振动试验。结合理论振动模型与试验结果,得到驱动电压、磁感应强度、电流角频率对于梁端拍打振幅的影响规律,研究结果对于后续微扑翼飞行器电磁驱动器的研究发展具有一定的指导意义。     

仿鸟类扑翼飞行器研究进展

仿生扑翼飞行器有着优异的气动性能和灵活的飞行能力,在军民领域均有广泛的应用前景,学者们在原理样机研制、扑翼气动机理、驱动机构、飞行控制等多领域取得了一系列重要进展.本文从总体设计方法、驱动机构设计与优化、气动机理等方面综述了仿鸟类扑翼飞行器技术的发展历程与研究进展.首先,从扑翼总体设计方法入手,总结了仿鸟类扑翼飞行器仿生构型,归纳了总体设计参数估算方法;其次,综述了多种构型曲柄连杆机构在扑翼驱动中的应用与优缺点;接着总结了扑翼气动机理研究的实验方法与数值计算方法,分析了不同扑翼气动算法针对不同应用场景在计算成本和准确度方面的优劣情况;最后,对仿鸟类扑翼飞行器系统设计研究现状进行总结,针对原理样机研制过程提出展望.     

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．     

仿昆扑翼飞行器全解耦控制

针对仿昆扑翼飞行器飞行控制所面临的欠驱动问题,基于平均理论,提出采用周期时变反馈策略控制仿昆扑翼飞行器的策略,并给出了设计周期时变反馈控制器的输入参数化设计方法．该方法对飞行昆虫的扑翼运动进行仿生模拟,通过调整根翅运动参数,实现了对6个方向气动力和力矩的独立控制．本质上就是用参数表示欠驱动系统的输入,并以此构造周期时变反馈函数;从而在原系统中引入更多数目的独立控制量,将原系统转化为完全能控系统．然后,将此可控系统线性化,并利用线性反馈控制器设计工具设计其反馈控制律．仿真结果表明,基于该策略设计的控制器具有响应速度快、稳定误差小、鲁棒性强等特点．     

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.     

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。     

The design and micromachining of an electromagnetic MEMS flapping-wing micro air vehicle

An electromagnetic MEMS flapping-wing micro air vehicle at insect scale is presented. The detailed scheme, design, micro fabrication and experiment are given in this paper. Firstly, by commercial software ANSYS and MATLAB, electromagnetic analysis, modal analysis and kinetics analysis are proposed. Moreover, based on the result of theoretical analysis, appropriate structure, material and inherent frequency are selected. Then, a new LIGA-like process based on SU-8 photoresist technology is adopted to fabricate thorax, tergum and vein. Finally, a 3.5 cm wingspan, 144 mg weight prototype is integrated, and then we finish the flapping test for this prototype, which has a flapping resonance frequency range of 120–150 Hz. The test result demonstrates the feasibility solution in the development of FMAV based on MEMS, this work is a stepping-stone on the path toward flying robotic insects.     

基于ARM的超磁致伸缩微驱动器的偏置与驱动电路设计

超磁致伸缩微驱动器的工作主要需要提供一个可控的偏置磁场和驱动磁场,前者使超磁致伸缩材料的磁致伸缩特性得到优化,消除倍频效应,后者实现对微驱动器的输出位移控制;设计一个可控电流源,采用悬浮负载功率放大恒流电路,并通过ARM处理器的数模控制,使指定电流通过电磁线圈以产生所需磁场强度;该设计的可控电源,可输出最大±5A的电流,提供给偏置和驱动线圈,实现微驱动器的直观、灵活的控制。     

A Bio-Inspired Flapping-Wing Robot With Cambered Wings and Its Application in Autonomous Airdrop

Flapping-wing flight, as the distinctive flight method retained by natural flying creatures, contains profound aerodynamic principles and brings great inspirations and encouragements to drone developers. Though some ingenious flapping-wing robots have been designed during the past two decades, development and application of autonomous flapping-wing robots are less successful and still require further research. Here, we report the development of a servo-driven bird-like flapping-wing robot named USTBird-I and its application in autonomous airdrop. Inspired by birds, a camber structure and a dihedral angle adjustment mechanism are introduced into the airfoil design and motion control of the wings, respectively. Computational fluid dynamics simulations and actual flight tests show that this bionic design can significantly improve the gliding performance of the robot, which is beneficial to the execution of the airdrop mission. Finally, a vision-based airdrop experiment has been successfully implemented on USTBird-I, which is the first demonstration of a bird-like flapping-wing robot conducting an outdoor airdrop mission.      

A novel bending microactuator with integrated flexible electro-rheological microvalves using an alternating pressure source for multi-actuator systems

This paper presents a novel bending microactuator with integrated flexible electro-rheological microvalves (FERVs) using an alternating pressure source for multi-actuator systems. The proposed bending microactuator is a fluidic elastomer actuator that has two fluidic chambers inside and can bend with the chamber pressures controlled by the integrated FERVs, each of which has a flexible structure and changes a flow of electro-rheological fluid (ERF) through its viscosity change due to an applied electric field. The utilization of the FERVs in the actuator reduces the overall size, while the benefits of the alternating pressure source are reduction of the number of pipes in a multi-actuator system and removal of the fluid reservoir tank. The mathematical models were demonstrated and utilized for optimizing and designing the dimensions of the actuator to obtain the maximum bending angle, the fast response, and the highest output force. The designed actuator was successfully fabricated using MEMS technologies and experiments were conducted to investigate the bending angle and the response time of the successfully fabricated actuator. The results showed good agreement between the experimental results and the simulation results, which proved the validity of the proposed models. Comparing with the previously proposed microactuator with an FERV, the proposed actuator had 4.5 times larger bending angle. From the results, the optimized actuator showed the feasibility for use in e.g. micro gripper application.

     

Adaptive pole placement pitch angle control of a flapping-wing flying robot

An adaptive pole placement control scheme for the adaptive pitch angle control of a bird-like flapping-wing flying robot is designed and implemented. The salient aims of this work are notably twofold: first, since the dynamics of bird-like flapping-wing robots are still not well understood and hence obfuscate the process of deriving a high-fidelity aerodynamical model, we instead elect to designate the system identification component of the control scheme to provide real-time estimates of the low level robot parameters. Input and output data are collated during flight and the recursive least squares method is applied to obtain real-time parameter estimates. Estimated parameters are subsequently used in designing the control law using adaptive pole placement via the polynomial method where we prescribe the desired closed-loop characteristic equation. Secondly, even if the dynamics of the robot varies over time, it is accounted by the adaptive controller without any need to perform tuning since proportional gain values are spontaneously generated. Numerical simulations are first used to assist the design and validate the correct operation of the control scheme. It is then implemented on a real bird-like flapping-wing flying robot; experimental results obtained exhibit close congruence with simulation results.     

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.     

Analysis and test of a new MEMS micro-actuator

A large-deformation and low-voltage micro actuator is proposed in this paper to overcome the problems of high voltage and undersized deformation of electrostatic micro actuator. The principle of the proposed actuator is based on vertical-horizontal bending. Dynamic equations of the micro actuator under axial and horizontal loading are built based on Lagrange–Maxwell electromechanical dynamics equations. In addition, the influences of thermal stress, axial electrostatic force and squeezing force are analyzed. Furthermore, the horizontal distributed load and axial load are equivalent to horizontal centralized load based on the Runge–Kutta algorithm and finite difference method. The relationships of deformation with driving voltage, regulation voltage, and axial compression quantity and temperature difference are achieved by simulation. Simulation results show that the deformation of the proposed actuator is as high as 10.861 μm when the driving voltage is 16 V. The deformation of proposed micro actuator is larger than that of the existing one. Finally, the simulation results are verified by experiment and agree well with experiment results.     

Micro actuators on the basis of thin SMA foils

Three innovative micro actuator concepts on the basis of the differential SMA principle are presented in this paper: a high adaptive multi-actuator system, which is driven by numerous identical single actuators connected in parallel and in series, a micro gripper for handling and assembling of complex hybrid micro systems and a micro actuator system in medical tools for the percutaneous resection of aortic valves. The SMA material is used in the form of 50 μm thin NiTi foils because of their well-defined properties and high strength. In order to integrate them into micro systems, different manufacturing methods have been applied and improved at the Institute for Microtechnology. Laser cutting and wet chemical etching are used for example to microstructure the actuator elements. Different methods for electrical and mechanical connections of the actuators are employed like soldering by the use of an additional gold layer. A batch fabrication process of SMA actuators is realized by embedding NiTi foil elements into SU-8 structures. To optimize the design of SMA actuator elements according to its application different simulation procedures are used.