High-precision method for acquiring FMCW radar distance measurement value

Abstract

The invention discloses a high-precision method for acquiring an FMCW radar distance measurement value and aims to discloses a distance measurement value method with high ranging precision and capableof reducing frequency spectrum errors. The method is implemented by adopting the following technical scheme; sending target beat signals subjected to analog-digital conversion into four parallel timedomain extraction module; sending digital beat signals and sampling rate data acquired respectively into a data zero fill module for time domain zero filling; acquiring discrete frequency domain signals having a length of Ns through discrete Fourier transform (DFT) on time domain signals having a length of Ns acquired by the four time domain extraction module through corresponding DFT modules; sending the discrete frequency domain signals are sent into a data interception and splicing module by the four DFT modules in common-end manner for frequency domain data splicing operation, and an FMCWradar distance measurement value is acquired through a distance measurement value acquiring module based on a mathematic interpolation operation result.

Description

technical field [0001] The invention relates to a method for obtaining distance measurement values ​​with gradually improved precision in the process of moving a target from far to near, which is applicable to an FMCW radar system. Background technique [0002] Radar systems can be divided into continuous wave radar and pulse radar according to the waveform. FMCW radar is widely used in various ranging systems because of its high and excellent distance resolution and ranging accuracy, low power and no measurement distance blind zone. middle. The ranging accuracy problem in the FMCW radar ranging system is common to all ranging systems using the FMCW system. In FMCW radar ranging, the simplest method is to directly measure the difference frequency between the transmitted wave and the echo signal to obtain the distance, but the ranging accuracy is not high. At present, FMCW radar ranging generally uses the FFT method to obtain the power spectrum curve (distance spectrum) of ...

AI Technical Summary

Problems solved by technology

The disadvantage of ZFFT is that the refinement factor cannot be too large

Since ZFFT needs to perform FIR filtering in the second step, and the passband design of the FIR filter is too narrow, the order will be too large, and the design difficulty will increase. A large refinement factor is achieved, but multiple filtering and decimation lead to an increase in the amount of calculation, so the refinement factor of ZFFT cannot be too high

When the refinement multiple is large, the Chirp-Z transform method has an advantage, but because the calculation amount of the Chirp-Z transform method is large when the refinement multiple is large, the FFT-DTFT combination method is obviously small, and the calculation amount of the Chirp-Z is different from that of the fine-grained method. multiplier is related

Images