High-precision real-time microwave speed measurement and distance measurement device based on symmetrical triangular lfmcw radar

Abstract

The invention provides a high-precision real-time microwave velocity and distance measuring device based on a symmetrical triangle LFMCW radar. In the signal emission stage, the device generates up and down frequency sweeping LFMCW signals whose scanning periods are short; in the signal reception stage, the device collects a path of I analog echo signals and a path of Q analog echo signals orthogonal with each other in real time in a de-sloping manner, accumulates echo data coherently, divides the data into an up frequency sweeping group and a down frequency sweeping group, calculates the peak frequency values of the power spectra of the two groups, offsets deviations of the peak frequency values caused by Doppler frequency generated by a target velocity, and combines CZT (Chirp Z Transform) to obtain a high-precision target distance; and at the same time, beating echo data obtained in multiple scanning periods is sampled to form a new data sequence, spectrum analysis is implemented, peak frequency point values are estimated, and the target movement velocity is calculated. According to the device, the symmetrical triangle LFMCW radar can be used to simultaneously measure the velocity and distance of a moving object in a highly precise manner.

Description

technical field [0001] The invention relates to the field of linear frequency modulation continuous wave (Linear Frequency Modulation Continuous Wave-LFMCW) radar, in particular to a high-precision real-time microwave speed measuring and ranging device based on symmetrical triangular LFMCW radar. Background technique [0002] The LFMCW system radar can be used to measure the speed and distance of the target. Its main advantages are small radiation power, relatively simple equipment, easy to realize solid-state design, good electronic countermeasures and low intercept probability performance, etc. Traditional LFMCW radars for speed measurement and ranging use symmetrical triangular LFMCW signals as transmission signals, such as figure 1 shown. The solid line in the upper part of the figure represents the transmitted signal, and the dotted line represents the echo signal. The echo signal has a delay proportional to the target distance relative to the transmitted signal. Th...

AI Technical Summary

Problems solved by technology

But the problem with this method: distance measurement and speed measurement accuracy is poor

[0022]In the traditional symmetrical triangular LFMCW radar, the fundamental reason why the speed measurement accuracy is difficult to improve is that the coherent accumulation time required for high-precision speed measurement is not enough

Prolonging the coherent accumulation time will cause the following problems: 1) The bandwidth of the transmitted signal increases; 2) The sampling rate of the analog-to-digital converter ADC (Analog to Digital Converter-ADC) increases; 3) The hardware resource overhead caused by the sharp increase in the calculation amount increases , the cost of equipment increases; 4) The time to obtain distance and speed increases, which reduces the real-time performance of distance measurement and speed measurement

In short, the traditional symmetrical triangular LFMCW radar has the problem that it is difficult to balance high-precision real-time ranging and speed measurement at the same time.

Images