1、2015年11月一、课题提出的背景 1.四旋翼飞行器是一种能够垂直起降的多旋翼飞行器,它非常适合近地侦察、监视、航拍、农业播撒 任务。国外某些科技公司，如亚马逊，正在开发研究利用多旋翼飞行器进行快递投送等自动化的物流业 务，可见其具有广泛的军事和民事应用前景。但是四旋翼飞行器控制难度较大,难点在于飞行器具有欠驱动、多变量、非线性等比较复杂的特性。因此四旋翼飞行器的建模与控制也成了控制领域的热点和难 点。四旋翼飞行器有各种的运行状态,比如:爬升、下降、悬停、滚转运动、俯仰运动、偏航运动等。本 文采用牛顿-欧拉模型来描述四旋翼飞行器的飞行姿态。本文限于作者能力未对四旋翼飞行器的机架结 构和动力学特
2、性做详尽的分析和研究,而是一定程度上简化了四旋翼飞行器的数学模型，在一定姿态角 度内近似将其看作线性系统，以方便使用 PID 控制算法对飞行器在空中的三个欧拉角进行控制。 2.本文提出了四旋翼飞行器的系统设计方案,设计了四旋翼飞行器的机械结构,对其进行了模块化设计。系统选用STM32开发板作为主控芯片，对MPU-6050芯片采集到的三轴角度和三轴角速度数据进行PID算法处理，通过输出相应的PWM占空比对电机进行控制，从而达到控制飞行器不同的飞行姿态。同时利用超声波传感器来实时检测飞行器与地面的距离，并不断地进行调整以此保证飞行器能达到所需的要求。二、 课题研究的内容及目标2.1设计目标及面向对
3、象2.2设计方案本系统主要由控制模块、高度测量模块、电机调速模块、角速度和角加速度模块组成，下面分别论证这几个模块的选择。2.3控制系统的选择 STM32开发板作为主控模块来控制飞行器的飞行姿态与方向。2.4 飞行姿态控制的论证与选择 方案一：单片机将从MPU-6050中读取出来的飞行原始数据进行PID算法运算，得到当前的飞行器欧拉角，单片机得到这个欧拉角后根据欧拉角的角度及方向输出相应的指令给电调，从而达到控制飞行器平稳飞行的目的方案三:采用全桥驱动 PWM 电路。这种驱动的优点是使管子工作在占空比可调的开关状态，提高使用效率实现电机转速的微调。并且保证了可以简单的方式实现方向控制。基于上述
4、理论分析，选择方案三。2.5电机的选择方案一：采用有刷电机。有刷电机采用机械转向，寿命短，噪声大，产生电火花，效率低。它长期使用碳刷磨损严重，较易损坏，同时磨损产生了大量的碳粉尘，这些粉尘落轴承中，使轴承油加速干涸，电机噪声进一步增大。有刷电机连续使用一定时间就需更换电机内碳刷。方案二：采用无刷电机。无刷电机以电子转向取代机械转向。无机械摩擦，无摩擦，无电火花，免维护且能做到更加密封等特点所以技术上要优于有刷电机。考虑到各方面，我们采用无刷电机，选用新西达A2212无刷电机。2.6高度测量模块的论证与选择采用bmp085气压传感器测量大气压并转换为海拔高度，把当前的海拔测量值减去起飞时的海拔值
5、即得飞机的离地高度。但芯片价格较贵，误差较大，而且以前也没用过这个芯片。采用HC-SR04超声波传感器测量飞行器当前的飞行高度。考虑到对元件的熟悉程度、元件的价格和程序的编写，选择方案二。2.7电机调速模块的选择 由于本四旋翼飞行器选用的是无刷直流电机，所以电调只能选用无刷电机的电调，自己做电调需要的时间长，而且可能不稳定，所以直接用的是成品电调，我们选用与新西达A2212电机配套的电调。2.8角速度与加速度测量模块选择选用MMA7361 角度传感器测量飞行器的的与地面的角度，返回信号给单片机处理，从而保持飞行器的平衡。 方案二：用MPU-6050芯片采集飞行器的飞行数据，过采用MPU-605
6、0整合的3轴陀螺仪、3轴加速器，功能MPU-6000（6050）整合了3轴陀螺仪、3轴加速器，并含可藉由第二个I2C端口连接其他厂牌之加速器、磁力传感器、或其他传感器的数位运动处理（DMP: Digital Motion Processor）硬件加速引擎，由主要串口端口以单一数据流的形式，向应用端输出完整的9轴融合演算技术InvenSense的运动处理资料库，可处理运动感测的复杂数据，降低了运动处理运算对操作系统的负荷，并为应用开发提供架构化的API。免除了组合陀螺仪与加速器时之轴间差的问题，减少了大量的包装空间。综上，选择方案二。三.设计与论证3.1控制方法设计 3.1.1降落及飞行轨迹控制
7、3.1.2飞行高度控制 飞行高度的采集采用超声波模块来实现，通过超声波发出时开始计时，收到返回信号时停止计时，单片机利用声音在空气中的传播速度与时间的数学关系来计算出飞行器距离地面的时间，从而控制飞行器的飞行高度达到我们所需的高度。 3.1.3飞行姿态控制 通过MPU6050模块来测量当前飞行器的三轴角度和三轴角速度（只需要用到角度和角速度），利用从MPU6050中读取出数据，解读飞行器的飞行姿态，并经过PID算法来对数据进行处理，并将处理后的信号传给电调，控制电机的转速，从而达到控制飞行器的飞行姿态的目的。程序流程图如图三。3.2参数计算 四旋翼自主飞行器控制算法设计 四旋翼飞行器动力学模型
8、 设计的小型四旋翼飞行器适用于室内低速飞行，因此忽略空气阻力的影响。因此，简化后的飞行器动力学模型为 x = u 4 （sin q cos f cos j + sin f sin j） / my = u 4 （sin q cos f sin j - sin f cos j） / mz = （u 4 cos f sin j - mg ） / m式 1-1 l / I Xf = u1l / IYq = u2j = u3/ I z式中 x xyzT 为运动加速度，m为飞行器质量，j, q , f 分别为机体的偏航角、俯仰角和横滚角，l 为旋翼面中心到四旋翼飞行器质心的距离，I X , I Y , I
9、Z 为轴向惯性主矩。该动力学模型对四旋翼飞行器的真实飞行状态进行了合理的简化，忽略了空气阻力等对系统运行影响较小的参数，使得飞行控制算法更加简 洁。2.2 PID 控制算法结构分析 在动力学模型的基础上，将小型四旋翼飞行器实时控制算法分为两个控制回路，即位置Opinions and suggestions on the partys mass line educational practiceAccording to the central and provincial, municipal unified deployment, according to municipal Party co
10、mmittee about carrying out the partys mass line educational practice activity in the citys implementation opinions, the spirit of the partys mass line educational practice activities from 20* in January to 99 months, carried out at all levels of departments and directly affiliated institutions and g
11、rass-roots party organizations. According to my actual County, the county to carry out the education practice put forward the following implementation opinions.First, the overall requirementsCounty county education practice to the eighteen Party of eight, the spirit of the the third Plenary Session
12、of the 18th CPC Central Committee as the guidance, conscientiously implement the spirit of general secretary Xi Jinping book series of important speech, earnestly implement the Central Committee really, opinions and advice , party implementing the guiding ideology of opinions to determine the object
13、ives and requirements, step method, in accordance with the look in the mirror, dress up, wash bath, cure treatment, the general requirements of for the people pragmatic honest people as the theme, in carrying forward the spirit of Zhuanglang Zhuang, improve their work style, service to the masses of
14、 the people, the foundation of consolidating grassroots, promote transformation across efforts, to further implement the central eight regulations and The opposition party and government austerity waste regulations , double section provincial regulations, municipal provisions of the twelve plan and
15、the implementation measures for on improving the work style of close ties with the masses law, highlight style building, carry out the whole wind spirit, resolutely oppose formalism, bureaucracy, hedonism and wasteful extravagance to solve the problems, Party members and cadres of the style and the
16、masses of people strong, the Ministry of Party members and cadres to further improve their thinking and understanding, to further change the style of the wind, the masses to close, honest and pragmatic people honest image to further establish the foundation to further reinforce the basic level. Styl
17、e of the building of the new results to promote the construction of a powerful force of the county and the ecological culture of the county and county construction.In educational practice activities of the unit is mainly: the county and below county departments under the organs, enterprises and inst
18、itutions directly under the township, street, and community, village, non-public economic organizations, social organizations and other grass-roots organizations. Agencies and branches, each single unit, follow the rules on internal institutions. Educational practice with step by step.To adhere to t
19、he county leadership, leadership and leading cadres to focus on outstanding catch to directly contact the service of the masses of law supervision departments and window units, service industry, educational practice, pay attention to grasp the heavy towns, streets and villages, community education a
20、ctivities and the masses of grassroots groups in close contact to strengthen, and the majority of Party members, cadres and the mass line line Marx doctrine view of the masses and the partys education.Always speak seriously as a basic attitude, adhere to positive education, to carry out criticism an
21、d self criticism group, adhere to the pragmatic, more emphasis on leadership, pay more attention to the layers of the demonstration, more focus on the four winds, solve the problem, pay more attention to open the door, the participation of the masses, pay more attention to the classification guidanc
22、e. Orderly, pay more attention to the cooperation and cohesion driven, more strict requirements on injection, really supervision practice, ensure education practice is not empty is not empty is not partial, not as a mere formality.Two, the key point of the taskThe main task of the countys education
23、practice is to seize against four wind this focus on centralized solve outstanding problems asked County, township leadership and leading cadres of the four winds, the disadvantages of the style, scale behavior to a large scale investigation, overhaul, cleaning greatly. At the same time, respond to
24、the concerns of the masses, safeguard the interests of the masses, pay attention to solve practical problems, solve the people around the unwholesome tendencies especially on eat, take the card, Yong lazy luxury, extravagance and waste fees, privileges and other issues, timely and effective, without
25、 any discount to solve, to improve the style of real implementation of the requirements of real to the grassroots, real let group Benefit the public.（a） focus on solving the four winds outstanding issuesThe central and provincial requirements, the county leadership and leading cadres of key performa
26、nce concept is not correct, do not dare to play, to engage in image project, political project, a leadership guide, a set of ideas, orders and prohibitions, and a policy, there are countermeasures county. The units directly under the heavy focus on solving Yung lazy drag, buck passing skin, work is
27、not implemented, the service is not active. The dynamic problem of law enforcement and supervision departments and window units, service industry mainly solve the door hard, ugly face, something difficult, and arbitrary charges, fines, levies, and breach of privilege, chinakayao, not the problem of
28、law. The township, street The collar of leading bodies and leading cadres to solve key does nottheir own conditions to develop the correct road, the maximum to avoid investment risk, gain profit.（three） vigorously promote the brand. To establish brand awareness, awareness of the use of brand, brand
29、value, brand acquisition performance, enhance the competitive strength. Concentrated manpower, careful planning, packaging and publicity of a number of unique, market influence and coverage of the brand, the implementation of key breakthroughs, to enhance the competitive strength, walking business r
30、oad the competition of alienation and characteristics, the pursuit of stability and development of the market.（four） to promote the integration of resources. To further broaden their horizons, effective integration of resources within the group, the city resources, other industries and regional reso
31、urces, mutual trust, mutual benefit, seeking win-win principle, in the framework of national policies and regulations, strict inspection and argumentation, legal consultation, examination and approval procedures, strict regulation of economic activities, attract injection the social investment to the industry group, to achieve leveraging the development, ensure that the value of st
