The Design And Research Of Inertial Pulse Output Signal Measurement Based On The FPGA

Currently, measuring the output of pulse of inertial navigation with traditional methods, which is in not high degree of automation and in poor accuracy has been unable to meet the modern needs. In order to satisfied the majority of users who need more accurate and automated measuring system, it is very necessary to design a set of system measuring the output signal of pulse of inertial navigation.This paper designs a system of measuring the output signal of pulse of inertial navigation based on FPGA, adopting the technology of finite state machine, direct pulse counting and FIFO storage, and accurately counting the pulse waveform signal. In the module of processing pulse waveform signal, adopting the method of recording waveform moment, the edge moment of first signal is using as the baseline, then recording the edge moment of afterwards waveform signal, as well as the number of passageway and state of electrical level, and then realizing pulse counting by counting the number of pulse waveform. The module of processing pulse waveform includes preprocessing circuit of pulse signal and the module of data processing inside FPGA. In the preprocessing circuit of pulse signal, adopting the technology of signal shaping and opto-couplers isolation and so on, shaping to smaller deformation signals, opto-couplers isolation to bigger amplitude signal. In the upper computer, we adopt the method of Lab VIEW graphic language programming, handlers can use the function of setting serial port baud rate, filtering time and so on in the interface of upper computer, at the same time,we can observe data waveform directly and storage experimental data automatically, and developing the automation degree of measuring system.In order to test the correctness of the design, we used the random pulse generated by FPGA as the pulse signal source, to imitate pulse signal transmitting with interference. Analyzing to measuring data and error can further develop the accuracy of measuring. Going through the experimental verification, the measuring system can make true that pulse counting, improving the degree of automation of measuring system.