UFC921A101 控制系统

控制系统已被广泛应用于人类社会的各个领域。在工业方面，对于冶金、化工、机械制造等生产过程中遇到的各种物理量，包括温度、流量、压力、厚度、张力、速度、位置、频率、相位等，都有相应的控制系统。在此基础上通过采用数字计算机还建立起了控制性能更好和自动化程度更高的数字控制系统，以及具有控制与管理双重功能的过程控制系统。在农业方面的应用包括水位自动控制系统、农业机械的自动操作系统等。
控制系统其实从20世纪40年代就开始使用了，早期的现场基地式仪表和后期的继电器构成了控制系统的前身。以PLC和DCS为代表，从70年****始应用以来，在冶金、电力、石油、化工、轻工等工业过程控制中获得迅猛的发展。从90年****始，陆续出现了现场总线控制系统、基于PC的控制系统等，将简要介绍各种常见的控制系统，并分析控制系统的演进过程和发展方向。
70年代中期，由于设备大型化、工艺流程连续性要求高、要控制的工艺参数增多，而且条件苛刻，要求显示操作集中等，使已经普及的电动单元组合仪表不能完全满足要求。在此情况下，业内厂商经过市场调查，确定开发的DCS产品应以模拟量反馈控制为主，辅以开关量的顺序控制和模拟量开关量混合型的批量控制，它们可以覆盖炼油、石化、化工、冶金、电力、轻工及市政工程等大部分行业。

UFC921A101

Control systems have been widely used in various fields of human society. In industry, there are corresponding control systems for various physical quantities encountered in the production process of metallurgy, chemical industry, machinery manufacturing, including temperature, flow rate, pressure, thickness, tension, speed, position, frequency, phase, etc. On this basis, a digital control system with better control performance and higher degree of automation, and a process control system with dual functions of control and management have been established by using digital computer. Applications in agriculture include automatic water level control system, automatic operating system of agricultural machinery, etc.
In fact, the control system has been in use since the 1940s, and the early field ground-based meters and the later relays formed the predecessor of the control system. Represented by PLC and DCS, since the application of **** in 70 years, it has achieved rapid development in industrial process control such as metallurgy, electric power, petroleum, chemical industry and light industry. Since **** in 1990, fieldbus control systems and PC-based control systems have appeared one after another. This paper will briefly introduce various common control systems, and analyze the evolution process and development direction of control systems.
In the mid-1970s, due to the large size of equipment, high requirements for process continuity, increased process parameters to be controlled, harsh conditions, and centralized display operations, the already popular electric unit combination instrument can not fully meet the requirements. In this case, the industry manufacturers through market research, determined that the development of DCS products should be based on analog quantity feedback control, supplemented by switching quantity sequence control and analog quantity switching quantity mixed batch control, they can cover oil refining, petrochemical, chemical, metallurgy, electric power, light industry and municipal engineering and other most industries.

UFC921A101