2015届毕业设计说明书
模拟飞机速度控制系统的分析与仿真
院 、 系：学生姓名：指导教师：专 业：班 级：完成时间：
电气与信息工程学院 职称 自动化 2015年6月
摘 要
此次设计研究的内容主要是围绕模拟飞机控制系统，利用自动控制原理中的多种方法分析该控制系统的性能，比如系统的稳定性，动态性能，静态性能以及它们之间的相互关系，并且运用MATLAB软件对该控制系统进行仿真，直观的分析系统参数对系统动态特性和稳态特性的影响，来知道参数调节，让系统具备良好的控制效果。
首先从时域角度出发，根据系统中各个环节的物理或者化学规律，得到系统的微分方程，由微分方程经过拉普拉斯变化解得系统的开环传递函数或者闭环传递函数，然后求解闭环特征方程的特征方程和特征根，零极点的分布以及劳斯判据来分析判断该系统的稳定性。对于一个稳定的系统，又有上升时间、超调量、峰值时间、调节时间和稳态误差这些指标来对比系统的性能。
其次根据系统的传递函数，设计相应的控制器，提高系统的性能。由于被控对象组成的闭环系统存在着静态误差，并且系统的调节时间比较长，超调量也不满足要求，所以根据系统的情况设计了PID控制器。在Matlab软件中仿真之后，系统的性能指标得到提升，验证了PID控制器的有效性。另外根据系统参数对系统性能指标的影响，将系统的阻尼比调节到最佳阻尼比0.707，进一步提升了系统的性能。
最后，根据系统中存在着参数不确定的情况，传统控制方法很难设计控制器对于所有的参数都适用，所以设计了模糊控制器。由于模糊控制器不需要控制对象的精确模型，所以设计的模糊控制器对于所有的参数都实现了很好的效果，大幅度的提升了系统的性能。
在分析的过程中，使用了计算机技术的MATLAB软件，该软件可以比较方便地得到系统的根轨迹图、阶跃响应图和频域分析的曲线，并且可以高效的对比系统各个参数对系统时域特性和频域特型的影响，通过这些对比，能够加深对控制系统的认识和理解，对于系统的学习有着很大的帮助。
关键词：模拟飞机控制；稳定性；模糊控制；MATLAB软件
I
ABSTRACT
The research content mainly around the simulation of aircraft control systems, using many methods of automatic control principle to analyze the performance of the control system, such as the stability of the system, dynamic performance, static performance and their relationships, using MATLAB software to simulate the control system and study the impacts of different parameters to the performance of the system, in order to adjust the parameters to obtain good control effect.
First from the angle of the time domain, according to all aspects of the physical or chemical law in the system, the differential equations of the system can be obtained. Then the transfer function can be obtained after Laplace transform of the differential equations. And according to the eigenvalues of the closed-loop characteristic equation, pole zero distribution and Routh criterion, we can analyze the stability of the system.
Secondly, according to the transfer function of the system, design the controller and improve the performance of the system. Due to the closed-loop system composed of the controlled object has the static error and system of regulating time is relatively long, overshoot also does not meet the requirements, so we design the PID controller to control the system. After the simulation of Matlab, the performance of the system is improved, and the validity of PID controller is verified. In addition, according to the influence of system parameters on the performance of the system, the damping ratio of the system is adjusted to the optimum damping ratio by 0.707, and the performance of the system is further improved.
At last, according to the uncertain parameters of the system, the traditional control method is very difficult to design the controller for all the parameters, so the fuzzy controller is designed. Since the fuzzy controller does not need the precise model of the object, the fuzzy controller is designed for all the parameters to achieve a good effect, greatly improving the system performance.
Matlab software of computer technology is used in the analysis of the process, the software can more easily get system root locus order and step response curve and frequency domain analysis, and high contrast of the system parameters on system characteristics in time domain and frequency domain contoured influence, through the comparison, the understanding of the control system can be deepen, and has a great help for learning.
II