Research On High Precision Counting Method For Multi-channel Pulse Signal

To solve the problem of low accuracy and small range of traditional pulse frequency measurement, the parper designs a high precision counting system that adopts the combination of divided frequency bands and multi-cycle synchronous measurement.The system builds logic control and pulse counting module in FPGA, and uses AVR microcontroller as the data processing controller. It can measure 6 channel pulse signals of Inertial Navigation Components in the range of 0.1Hz-5MHz, and display the data on the computer interface written by Visual C++6.0 and LCD in real time.First, the paper introduces Inertial Navigation Technology, and describes the purpose and significance of research. It compares the advantages and disadvantages of several conventional pulse frequency measurement methods. Meanwhile, it relates the work principle and development process of FPGA and AVR ATmega128. Then it proposes the theoretical and implemental plan of frequency measurement system, and analyses the feasibility of this plan.The design of frequency measurement system is divided into circuit design and software design. In the circuit design, Altera Corporation's EPF10K30RC240-4U is the core of logic control and counting module. Atmel Corporation's AVR ATmegal28 is the system controller. This paper sets up the hardware platform, and completes each functional module and data transfer interface. The software design includes ATmega128 program and computer process program. The former uses C language to send address and initial counting value to FPGA, and read counting value from FPGA by ICCAVR 6.31. It can process and send the data to LCD and USART. It achieves simultaneously measurement for 6 channel pluse signals of Inertial Navigation Component. The latter sends control commands to microcontroller, and receives measurement data from microcontroller every second by Visual C++6.0. The computer process program can process, dynamically display and save the data in order to achieve testing for 6 channel pulse signals and controlling for system in real time.Finally, the frequency measurement system is debugged. The data and error are analysed. The measurement accuracy is further improved by correction. The results show that this system can achieve testing for 6 channel pulse signals of Inertial Navigation Component dynamically. Every function can meet the design requirements, and the operation is stable.