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随着控制规模的扩大和以太网技术在工业中日益广泛的应用，基于以太网的网络化控制系统成为控制界研究的热点。本文基于以太网的现场网络化控制系统的研究和开发，对基于以太网的网络化控制系统的数据安全性进行研究，着眼于在考虑资源有限和成本约束条件下，如何提高网络化控制系统的实时性和实用性，并将其应用到所开发的NetCon系统中。 论文的主要研究内容和创新之处如下： 随着网络化控制系统的广泛应用，网络化控制系统的数据安全问题日益重要，它对网络化控制系统的应用起着关键性的作用。在这个背景下，本文结合NetCon网络化控制系统，提出一种低成本、高性能的数据硬件加密方法，该方法基于FPGA技术和DES加密算法，利用Verilog硬件语言实现DES加密算法，并将DES数据安全模块成功应用于NetCon网络化控制系统。论文中给出数据安全模块在网络化电机控制系统的应用实验，并给出实时响应曲线。 为使控制系统具有很好的操作性和开发性，进行了嵌入式Linux操作系统的移植；带有操作系统的软件结构是层次化的，从底层到应用层。因此为了与NetCon系统的结合，先后开发了数据安全模块、数字信号采集模块、PWM模块所需的相关底层驱动程序和应用层S-Function程序，并且给出每个模块的应用实验。 结合网络化控制系统本身的特点，提出网络化控制系统面临的数据安全方面的隐患。对攻击者的攻击目的、攻击手段、攻击目标进行了全面分析，给出部分攻击示例，并做出相对应的防御策略。结合NetCon网络化控制系统，在数据加密、入侵检测研究中给出详细的设计说明，并配有解决方案的实验研究结果。 对NetCon网络化控制器进行系统级的升级与设计，采取模块化设计方案，工业级的设计标准。详细讲解GPIO扩展模块、PWM模块、数字信号采集模块、信号连接模块的硬件设计方法，并进行性能分析与优化，给出实物电路。升级后的NetCon网络化控制器可以实现对控制领域绝大部分对象诸如倒立摆控制系统、水箱控制系统、球杆控制系统、电机控制系统、磁悬浮控制系统等进行网路化控制，丰富了NetCon网络化控制系统的各类工业接口，使其完全符合工业级应用标准，在系统设计中充分考虑对过流、过压、短接等的安全措施。

With the expansion of the control scale and the increasingly wide range of applications of the Ethernet technology in industry, the research on networked control systems based on Ethernet becomes hot in the control system area. This thesis studies the data security of networked control systems, which discusses how to improve the real-time characteristics and practicality with the limit of resources and cost and how to apply the data security module to the NetCon system (a NETworked CONtrol system). The main contributions are as follows: With the extensive application of networked control systems, the data security of the networked control systems becomes more and more important. A hardware data encryption method is proposed with low-cost and high-performance for NetCon system. This method is based on FPGA technology and DES encryption algorithm, and realizes the DES encryption algorithm in Verilog language. The DES data security module is applied in the NetCon system successfully. An experiment of a networked DC motor speed control based on the DES data security module is carried out and the real-time control performance is given. In order to make control systems operate and develop easily, the embedded Linux operation system is transplanted into the NetCon controller. Since the software architecture with the operation system is hierarchical, such as the bottom layer and application layer, the underlying drivers and s-function program are developed for the data security module, digital signal acquisition module and PWM module. The application experiment of each module is also described. In accordance with the characteristics of networked control systems, the hidden troubles about the data security are discussed. The purpose means and targets of the attackers are analysed and some examples of attacks and the corresponding defence strategies are described. The detailed design description on data encryption and intrusion detection and the experiment results are given. The modular design and industrial-class design standards are employed to upgrade the NetCon system. The hardware design method of GPIO expansion module, PWM module, digital signal acquisition module and signal connection module is explained in details and the performance analysis is be done. The upgraded networked controller—NetController can control many systems, such as inverted pendulum systems, water tank systems, ball and beam systems, motor systems and magnetic levitation systems, etc...