摘  要

双容水箱系统是一种比较常见的工业现场液位系统，由两个串连的单容水箱构成的双容水箱比较典型。在实际生产中，双容水箱控制系统在石油、化工、环保、水处理、冶金等行业尤为常见。充分利用自动化仪表技术，计算机技术，通讯技术和自动控制技术，超声波传感器、光电传感器广泛应用于物位测量之中。

本课题拟集成应用多传感器、GPRS、虚拟仪器和嵌入式控制器技术，设计一种双容水箱液位无线监控系统，并制作实验模型予以功能验证。以实现对水箱液位的串级控制，对被控对象的模型进行液位的检测与控制从而调节容器内的输入输出物料的平衡，以便保证生产过程中各环节的物料搭配得当。通过控制计算机可以不断监控生产的运行过程，即时显示容器的液位，保证产品的质量和数量。根据物料平衡原理，建立双容水箱的数学模型及系统方案设计。以LabVIEW为开发软件，以S7-300作为硬件系统，建立液位控制系统的实验平台，研究传统PID控制、数字式PID控制以及模糊自适应PID控制的控制效果，对参数的整定及各个参数的控制性能的比较，对所得到的仿真曲线进行分析，总结了参数变化对系统性能的影响。

关键词：双容水箱；PID控制；labVIEW；PLC

ABSTRACT

Double tank system is a common industrial field liquid level system，which is composed of two series single tank. In actual production，double tank control system is especially common in petroleum，chemical industry，environmental protection，water treatment，metallurgy and other industries. Full use of automatic instrument technology，computer technology，communication technology and automatic control technology，ultrasonic sensors，photoelectric sensors are widely used in the measurement of object position.

Based on the application of multi-sensor，GPRS、virtual instrument and embedded controller technology，a wireless monitoring system for liquid level of dual tank is designed，and an experimental model is made to verify the function. In order to realize the cascade control of the water tank level，the model of the controlled object is detected and controlled so as to adjust the balance of the input and output materials in the container，so as to ensure that the materials in each link in the production process are matched properly. By controlling the computer，we can continuously monitor the operation process of production，display the liquid level of the container immediately，and ensure the quality and quantity of the product. According to the principle of material balance，the mathematical model and system square of double tank are established Case design. Using LabVIEW as the software and S7-300 as the hardware system，the experimental platform of liquid level control system is established，the control effects of traditional PID control，digital PID control and fuzzy adaptive control are studied，the parameters are set and the control performance of each parameter is compared，the simulation curve is analyzed，and the influence of parameter change on system performance is summarized.

Keywords: Double tank；PID control；labVIEW；PLC