FMCW radar distance resolution and distance measurement range dynamic adjusting method

Abstract

The invention relates to an FMCW radar distance resolution and distance measurement range dynamic adjusting method. The method includes: confirming an actual distance of a target by adjusting an IF filter bandwidth of a radar system; adjusting an IF filter bandwidth according to the actual distance of the target, and then obtaining the optimal RF frequency modulation bandwidth and the optimal distance resolution of the radar system at the current distance; continuously identifying the actual distance of the target, and determining whether the target distance change rate is greater than a second threshold, and returning to the previous step if so, otherwise continuing to maintain the current IF filter bandwidth and the current RF frequency modulation bandwidth, and calculating the distancemeasurement range of the radar system. The method dynamically adjusts the bandwidth of the IF filter to achieve dynamic adjustment of target parameters at different distances, so that a better distance resolution can be obtained when a close range target is measured, and a far distance measurement distance can be obtained when a distant target is measured, and the dynamic adjustment of the invention can make the radar system performance better according to the actual distance of the target.

Description

technical field [0001] The invention relates to the technical field of radar signal processing, in particular to a method for dynamically adjusting FMCW radar distance resolution and range measurement range. Background technique [0002] With the rapid development of the automobile industry, the penetration rate of automobiles has increased significantly, and automobile safety driving has become the main focus of attention at this stage. The millimeter wave radar plays an important role in the sensor of the assisted driving system. For future advanced assisted driving and even automatic driving, millimeter wave radar will become standard. [0003] The millimeter wave radar system can realize the distance measurement, speed measurement and angle measurement of the target object. For FMCW (Frequency Modulation Continuous Waves) radar, the larger the frequency modulation bandwidth, the higher the range resolution, and the more accurate the identification of objects at differe...

AI Technical Summary

Problems solved by technology

[0005] a. After the difference frequency increases, the upper limit cut-off frequency of the IF filter needs to be adjusted, thereby increasing the broadband noise, which will increase the BIF (bandwidth of the IF filter), thereby deteriorating the sensitivity

[0006] b. The increase of the difference frequency will cause the signal strength to be attenuated by the intermediate frequency filter, thereby reducing the strength of the received useful signal. Under the condition of constant noise, the SNR (signal-to-noise ratio) will decrease, thereby deteriorating the sensitivity

[0007] However, radar range and sensitivity are inversely related

Therefore, the sensitivity deterioration caused by the above two situations will lead to a decrease in the power range of the radar.

[0008] Therefore, there is a contradiction between the range resolution and the range of radar ranging power, and the two cannot have both

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