锅炉是典型的复杂热工系统。对蒸汽锅炉而言，维持汽包水位在一定的范围内是保证锅炉安全运行的首要条件。锅炉汽包水位的控制一直是控制领域的一个典型问题。随着控制理论及技术的发展，已有很多基于经典控制理论和现代控制理论的控制系统应用于汽包水位控制。然而，它们都是根据被控对象的数学模型建立起来的，而由于汽包水位对象的复杂性，其精确的数学模型往往无法获得，也就不能得到较好的控制效果；同时模糊理论应用于控制系统设计，不需要知道被控对象精确的数学模型，对于许多无法建立精确数学模型的复杂系统往往能获得较好的控制效果，同时又能简化系统硬件电路的设计。因此，本文采用了模糊理论进行汽包水位控制器的设计。 文中较为详尽地分析了汽包水位对象的动态特性和传统的控制技术以及模糊控制理论。在此基础上，提出了用模糊理论实现对汽包水位进行控制的方案，设计了以SOC单片机C8051F040作为核心的模糊控制系统，并配以键盘和显示电路构成控制系统，实现信号采集、数据显示、键盘控制、数据计算等功能。 作者主要从以下三个方面对汽包水位控制系统进行论述：第一、系统模糊控制器控制规律及控制算法的设计和实现；第二、硬件电路设计和使用MATLAB的模糊工具箱结合SIMULINK对系统进行仿真，比较模糊控制和PID控制的仿真结果；第三、软件程序设计和针对嵌入式系统的硬件、软件方面的一些工程上实用的抗干扰措施，并利用C8051F040单片机的开发系统对系统的各个模块进行了实验调试。 本文工作注重理论与工程实际的结合，并在此研制过程中取得了比较全面的资料和数据，为类似的控制系统研究打下了良好的基础。

The boiler is a typical complex thermodynamic system. For steam boiler, maintaining water level of the steam drum in a certain range is the chief requirement to guarantee the boiler running safely. The water level control for the steam drum is all along a typical issue in the control domain. With the development of control theory and technology, there have been many control systems based on classical control or modern control theory applied to water level control of the steam drum. However, they are all established on the basis of the mathematical models of the objects being controlled. The mathematical model of the complexity of the water level of the steam drum often can not be obtained, so we often can not get the better effects. On the other hand if fuzzy theory is applied to design control system, we need not know the exact mathematical models of the objects being controlled. Thus, as to many complex systems whose exact mathematical models can not be established, we could get the better control effects. According to this, fuzzy theory is applied to design the controller of the steam drum water level in this paper. The dynamic characteristics of steam drum water level along with its traditional control technology and the fuzzy control theory have been detailedly analyzed in this paper. On the basis of these analyses, a scheme using fuzzy theory to control steam drum water level has been proposed, and designed the embed system with the core of C8051F040. What's more, a small system with keyboard input and Light Emitting Diode is designed for the system which has the function of signal collecting, data displaying, keyboard controlling, data computing. Three points are focused on this paper. Firstly, the control algorithm and control laws of the system are designed and realized. Secondly, the design of the hardware is described in this dissertation and simulation of control system is also performed to study the performance of fuzzy control by MATLAB. At last, the design of software is described in detail and some practical hardware and software reliability measures of embedded system are introduced. At the same time, using C8051F040 debugging system, it carries out an experiment on control system in the laboratory. The research work is closely connected to the practical application, during the research, I have got the general data and information which can be used by the study of other similar system.