Design Of Temperature Control System On Thermostatic Water Tank Of Intelligent Ubbelohde Viscometer Based On STM32

Fluid viscosity measurement plays an important role in the petroleum, chemical, transportation, and other areas of national economy. Ubbelohde viscometer is commonly used instrument for measuring liquid viscosity based on gravity capillary measurement method. Thermostatic water tank is one of the key components of Ubbelohde viscometer, and its temperature control is the key technology of viscometer.Both the automation degree of Ubbelohde viscosity tube measuring instrument and the temperature control accuracy of thermostatic water tank are not enough high. Also imported viscosity measuring instrument is so expensive that an intelligent Ubbelohde viscometer based on dual MCU architecture is designed by this issue. Temperature control unit and management unit can work in parallel so that measurement efficiency is improved. The control system on temperature of thermostatic water tank of intelligent Ubbelohde viscometer is designed by this article.This paper is divided into six parts. The first chapter mainly introduces the concept of viscosity, measurement methods and influencing factors. It discusses the status quo of the existing water tank temperature control system and points out the key points of this paper. The second chapter introduces the system structure, working principle and working process of the intelligent Ubbelohde viscometer. Referring to viscosity measurement national standard "viscosity measurement method GB/T 10247-2008", according to nonlinear, large lag and not easy to modeling of thermostatic water tank, combining the improved Bang-Bang control, self-tuning fuzzy control and PID control and taking advantage of the PWM control of STM32F407, an improved fuzzy control method is constructed. The third chapter achieves a rapid and accurate control of thermostatic water tank and discussing parameter tuning method of controller. The fourth chapter introduces the hardware platform architecture based on ADC with ARM. Temperature acquisition and control hardware circuit, human-computer interaction and communication hardware circuit and power supply circuit are constructed with these major electronic devices which are DS18B20, PT100, AD7793, SSR, MD050SD and LM1117. The fifth chapter introduces the software design of temperature control system, which includes software driver for digital devices, digital filtering software processing of water temperature data, software implementation of temperature control algorithm and software design of human computer interaction and communication. The sixth chapter analyzes the source of error based on intelligent Ubbelohde viscometer. The reliability design technology of intelligent viscosity instrument is discussed through introducing two aspects of anti interference design and low power design.The temperature control system of water tank designed in this paper has the function of heating and cooling. Temperature control ranges from 15? to 50?. Temperature sampling resolution of water tank is 0.005? and temperature control accuracy of water tank is 0.05?. These research work has some reference value for engineering application of thermostatic Water tank of intelligent Ubbelohde viscometer.