Intelligent Rotary Viscometer Design

The viscosity is one of the important parameters that characterize the fluid properties,it is an important indicator of the physical characteristic of the fluid.The viscosity measurement is widely used,it is also an important means to control the production process,to ensure the safety of production,to assess the quality of the product and to make scientific researches.The rotational viscometer is a necessary instrument for measuring high viscosity fluid.It can determine the dynamic viscosity,kinematic viscosity,intrinsic viscosity and rheological properties of the fluid.It is widely used in petroleum,medicine,chemical fiber and other industries.At present,the domestic rotary viscometer intelligent degree is low,complex circuit,for this purpose,this paper designs an intelligent rotary viscometer which is based on low power consumption MCU STM32F407.In this paper,The intelligent rotary viscometer designed include:power module,information processing unit,stepper motor drive module,measuring rotor,hairspring,angle detection module,keyboard and display module.When the instrument operated,the stepper motor is operated of smoothly and according to the scheduled speed,the rotor is rotated by the hairspring.The measuring rotor placed in the measured liquid will be subjected to the measured liquid resistance so that the rotation of the rotor will lag behind motor,when the tension of the hairspring and resistance of the liquid is balance,the rotor lags behind the motor,hairspring produced by the angle is fixed.Processor STM32F407 through the photoelectric device to detect the angle,which is according to set the rotor and speed to select the corresponding calculation formula,calculate the measured liquid viscosity.At the same time,in order to improve the measurement accuracy of the instrument,a nonlinear error compensation model based on segmented newton interpolation is established.The experiment proves the effectiveness of the model.The paper is divided into five part:In chapter 1,it focuses on the research background and significance of viscosity measurement,expounds the current viscosity measurement at home and abroad and the method of measuring viscosity,which is describes the work of key this paper.In chapter 2,on the basis of elaborating the working principle of the intelligent rotary viscometer,the instrument structure and working flow of the intelligent rotary viscometer are introduced in detail.In chapter 3,the nonlinear error compensation method of intelligent rotary viscometer based on Lagrangian linear interpolation and segmented newton interpolation is proposed,and the comparison experiment is carried out.In chapter 4 introduce the hardware structure and software design of intelligent rotary viscometer.The hardware circuit structure includes processor,motor drive module,angle detection module and power module.The software design includes main program module,angle detection module,newton interpolation measured liquid viscosity automatic calculation module.In chapter 5 analyzes the error sources of the intelligent rotary viscometer and the error of the measurement results of the intelligent rotary viscometer.Experimental results show that the indicators of intelligent rotary viscometer are better than the national standard of industrial viscometer requirements,instrument timing error less than 0.5%,measurement shows the results of the repeatability control in 0.35%,the instrument high degree of intelligence,accurate measurement results,easy to operate,to achieve the system design requirements.