Research On An Automatic Calibration Device For For Revolution Speed Transducers

In this dissertation,an automatic calibration device for revolution speed transducers was researched aimed at the current calibration devices' narrow speed span,low speed resolution,low degree of automation and other imperfect problems.In chapter 1,the backgrounds of the research,significance and main research contents of this dissertation were presented.First,the application and classification of revolution speed transducers were introduced,and the characteristics,working principles and calibration methods of two typical kinds of transducers—the eddy current and magneto-electrical revolution speed transducer were introduced respectively.Then the development status of calibration devices for revolution speed transducers at home and abroad was analyzed.At last,the research purposes and contents of the dissertation were presented.In chapter 2,the design scheme of the automatic calibration device for revolution speed transducers was researched.First,the technical specifications of the device were proposed according to the requirement and national metrological verification regulation.Secondly,the design scheme was analyzed.Finally,the composition and working principle of the revolution speed generation system,the control systems in the slave and host computers were introduced respectively.In chapter 3,the design scheme for the revolution speed generation system in the automatic calibration device for revolution speed transducers was studied.First,according to the analysis and comparison of two drive line systems,a direct drive scheme of a servo motor was presented.And then the type of the driving motor was selected and its parameters were analyzed.Finally,the dynamic balance analysis and calculation were carried out for the high speed rotating parts in the device.In chapter 4,the design principle of the control system in the slave computer based on FPGA was studied.First,the working principle of the FPGA and the design flow of the system were introduced.Then,the hardware circuit of the slave computer system based on FPGA was designed,including a FPGA controller circuit,a FPGA configuration circuit,a power circuit,an encoder signal processing circuit,a sensor signal processing circuit and an Ethernet controller circuit.Finally,the software for the slave computer system was designed,including the design of the pulse generator in the servo motor control module,the Ethernet controller in the communication module,the rotary encoder interface in the revolution speed measuring module and the equal precision frequency counter in the sensor signal reading module.In chapter 5,the design principle of the control system for the host computer based on ARM was researched.First,the characteristics of the Embedded System and the selections of its processor,operating system and development environment were introduced.Then,the embedded hardware platform and software development platform were introduced.Finally,the design method of each function module in the host computer system,which was developed on the platform of Lab VIEW,was studied.In chapter 6,the experimental research was carried out on the automatic calibration device for revolution speed transducers.First,two functional modules in the device were tested,including the frequency accuracy of the pulse generator module and the frequency measurement precision of the frequency meter module.Then,the span,stability and resolution of the revolution speed were tested and the revolution speed span,stability,resolution and speed relative expanded uncertainty of the device were evaluated according to the tested data,which determines the final performance of the device.In chapter 7,the achievements of this dissertation were summarized,and the further research work need to be done was prospected.