Digital signal processing system of phase rangefinder

Abstract

The embodiment of the invention discloses a digital signal processing system of a phase rangefinder, relates to the field of digital signal processing, provides a solution for the defects existing in traditional FFT calculation and can balance the precision and the calculation speed of an algorithm. The system comprises a main vibration unit used for generating a main vibration signal and modulating the intensity of a laser signal emitted by a laser emission unit with stable frequency, a local vibration unit used for generating a local vibration signal, a phase-locked loop unit used for adjusting the frequency of the main vibration signal and providing a sampling pulse for a digital signal processing unit, a laser emission unit used for emitting a laser signal, a laser receiving unit used for converting a reflected laser signal into an electric signal, a frequency mixing unit used for carrying out frequency mixing on the electric signal and the main vibration signal to obtain a low-frequency signal including phase information, a power amplification unit used for amplifying and shaping the low-frequency signal, and a digital signal processing unit used for sampling the amplified and shaped low-frequency signal, calculating the phase information with a Goertzel algorithm and converting the phase information into distance information. The digital signal processing system is used for range finding of the phase rangefinder.

Description

technical field [0001] The invention relates to the field of digital signal processing, in particular to a digital signal processing system of a phase range finder. Background technique [0002] Phase Distance Meter (Phase Distance Meter) is an electromagnetic wave distance meter that obtains the distance indirectly by measuring the phase change of the continuous wave between the instrument and the target, and obtains the distance. It has high precision, low power and portability. It is suitable for civil use and has a large market and application prospect. [0003] The phase rangefinder obtains the distance value by calculating the direct modulation frequency of the laser, the speed of light and the detected phase difference. The laser light emitted by the light source, after entering the modulator, is received by the high-frequency ranging signal f from the master oscillator (referred to as the master oscillator). 1 The modulated wave becomes an amplitude modulated wave....

AI Technical Summary

Problems solved by technology

[0027] If only complex multiplication and addition are implemented with programs, even though FFT saves a lot of calculation compared to DFT, when the number of points involved in the calculation reaches a certain scale, the calculation volume is very considerable, and the requirements for the digital processing part are very high, which seriously affects Real-time performance of the system

[0028] Therefore, the signal processing method provided by the prior art has high precision but complicated calculation

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