Design And Realization Of Grating Data Acquisition Card Oriented To Rotational Inertia Measurement

As one of the key physical parameters of missiles,satellites and other aircraft,the moment of inertia is an important basis for system modeling and characteristic analysis of velocity and acceleration,so the accurate measurement of moment of inertia is of great significance.When torsional pendulum method is employed to measure moment of inertia of the system,the grating ruler displacement sensor can be introduced to implement dynamic measurement which is helpful to improve the measuring accuracy of oscillating cycle and ensure the accuracy of measuring moment of inertia.Based on the application of grating displacement sensor in the measurement of moment of inertia,this paper designs and implements a data acquisition card with isochronic and isometric measurement by using FPGA chip and Verilog HDL language.The data acquisition card is equipped with standard PCI bus interface,can realize accurate and real-time data acquisition of displacement sensor,and has multiple flexible data acquisition modes,which can better solve the measurement problem of rotational inertia.This paper mainly completed the following works.1.Firstly,the basic principle of the moment of inertia is analyzed.According to the measurement requirements of the moment of inertia,the technical requirements of the grating data acquisition card are determined,and the overall scheme of the grating data acquisition card is proposed.2.The components selection and hardware circuits design are carried out.The key chips,such as FPGA and PCI interface chip,are selected.And the schematic diagrams of FPGA peripheral circuit,interface circuit,PCI bus circuit and so on are designed.3.The basic principle and implementation method of each functional module are analyzed.And with Quartus IDE,Verilog HDL language is used to implement the design and comprehensive simulation analysis of each component to be realized in FPGA.4.After the circuit card is made and debugged,isochronous and isometric measurement experiments for moment of inertia are carried out.The experimental results showed that the function and performance of the data acquisition card satisfies the design index and meets the measurement requirements of moment of inertia well.