Eccentric Cylinder Based On Embedded System Design Of Measuring And Controlling System For Rheometer

The eccentric cylinder rheometer is a new type of rheometer.Compared with the traditional rotary rheometer,the inner cylinder and the outer cylinder of measuring jig in the eccentric cylinder rheometer have adjustable eccentricity,which can generate elongational flow,shear flow and a complicated flow field.So the rheological properties of polymers in the complex flow field can be studied.As the core of eccentric cylinder rheometer,measurement and control system directly affects the performance,accuracy and efficiency of rheometer.In this paper,the measurement and control system were researched and developed on the basis of the mechanical structure of the eccentric cylinder rheometer.In comparison with the traditional development program of PLC and NI controller,the lower cost and high-performance embedded technology was applied to complete the system hardware and software development,which perfect the function of eccentric cylinder rheometer,and is significant for realizing specialization,intelligence and subsequent commercialization of rheometer.In order to complete the development of measurement and control system of the eccentric cylinder rheometer,by analyzing the measuring principle and working characteristics of the eccentric cylinder rheometer,the overall design scheme of the system was determined.And the modular idea is adopted to carry out the research and development of the system.According to the function,the system is divided into five parts,the power module,the main control module,the data acquisition module,the pulse output module and the digital input and output module,and each module is combined into a whole by the way of bottom plate connection.According to the requirements of the measurement and control system,each module is studied and analyzed,the appropriate devices are selected to complete the design of the hardware schematic diagram of each module.The design and production of the hardware circuit board are realized with the help of the relevant cooperative units.To confirm the reliability of the system,the reliability of the system hardware is simulated.Finally,the hardware development of the measurement and control system is completed.Based on the hardware platform of the measurement and control system,software development was carried out.For each module,CAN communication of system,program development of Ethernet communication,sensor data acquisition,and motor control were implemented on the platform of UCOS-iii operating system.The upper computer software of the measurement and control system and the software development of measurement and control system of the eccentric cylinder rheometer were completed.After completing the development of the system hardware and software,the basic performance of system was tested using single function test method first and then the overall test method.The testing result showed that it achieved the viscosity measurement function of rheometer and completed the development of measurement and control system of the eccentric cylinder rheometer based on the embedded system.