Vehicle Radar Azimuth Estimation via Doppler Conversion
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Solution Overview
Problem
Conventional radar apparatuses installed in mobile units face challenges in accurately estimating the azimuth angle of objects due to the presence of side lobes and grating lobes, leading to incorrect object detection and reduced accuracy.
Innovation Solution
The radar apparatus employs a system with a radar transmission unit that transmits high-frequency signals, a reception unit with antenna system processing units generating correlation signals, a Doppler frequency-azimuth conversion unit, and a stationary object azimuth estimation unit to improve the accuracy of object detection by converting Doppler frequencies into azimuth components, thereby reducing the impact of side lobes and grating lobes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional radar apparatuses use array antennas to estimate azimuth angles over a wide angle range, then the measurement coverage is improved, but side lobes and grating lobes are generated causing incorrect azimuth angle estimation
Solution Approach 1:
The patent extracts and removes side lobes and grating lobes from the azimuth angle estimation process. By identifying these spurious signals as harmful factors and excluding them from the measurement, the system maintains wide angle coverage while preventing incorrect azimuth angle estimations caused by these artifacts
Solution Approach 2:
The patent introduces an intermediary processing mechanism that separates and filters side lobes and grating lobes from actual target reflections. This intermediary layer allows the system to distinguish between genuine target signals and spurious artifacts, enabling accurate azimuth estimation across wide angles without contamination from false signals
2Productivity
If the radar apparatus uses correlation signal computation to generate Doppler frequencies, then the detection capability is improved, but side lobes and grating lobes are amplified leading to reduced detection accuracy
Solution Approach 1:
The patent converts the harmful effect of side lobes and grating lobes into a beneficial filtering mechanism. By analyzing the characteristics of these spurious signals during correlation processing, the system develops methods to identify and reject them, transforming what was previously a source of error into a cue for improving detection reliability
Solution Approach 2:
The patent implements feedback mechanisms that continuously monitor and adjust the correlation signal processing. By comparing expected signal patterns with actual correlations and detecting deviations caused by side lobes and grating lobes, the system dynamically corrects detection results to maintain high accuracy despite the presence of spurious signals
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach enhances the accuracy of object detection by effectively distinguishing between actual reflected signals and side lobes or grating lobes, improving the estimation of the azimuth angle of objects in the radar apparatus.
Implementation Method 1
generate a correlation signal including arrival delay information for the reflected wave signal by computing a correlation between the reflected wave signal and the radar transmission signal
Implementation Method 2
a Doppler frequency-azimuth conversion unit that converts a second plurality of Doppler frequencies estimated frequencies caused by the stationary objects into a first azimuth component
Data Source
AI summary
A radar apparatus is installed in a vehicle that moves along its direction of travel. A radar transmission unit transmits a high frequency radar transmission signal from a transmit antenna in each transmit period. In a radar reception unit, antenna system processing units each generate a correlation vector by computing the correlation between reflected wave signal from a stationary object or a moving object and the radar transmission signal. A Doppler frequency-azimuth conversion unit converts Doppler frequencies into the components of an azimuth in which the stationary object is present using an estimated vehicle speed vector for the vehicle. A stationary object azimuth estimation unit generates the power profile of the reflected wave signal using the correlation vector and a direction vector corresponding to the components of the azimuth in which the stationary object is present.