Automotive Radar Blockage Detection via Range-Doppler Averaging

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Solution Overview

Problem

Automotive radar systems face challenges in distinguishing between sensor blockage and the absence of objects in the field of view, leading to inaccurate detection of sensor functionality, especially in scenarios like deserts where few objects are present, resulting in potential false alerts and inefficient resource usage.

Innovation Solution

The system employs a method involving the generation of range-Doppler maps, averaging of multiple maps to enhance signal-to-noise ratio, and blob detection to differentiate between blocked and unblocked states by identifying radar returns from stationary objects like roads, using threshold comparisons and blob identification techniques to determine sensor blockage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If blockage detection is performed by checking absence of radar signal processing detections, then processing time and resources are minimized, but accuracy deteriorates due to inability to distinguish blocked case from case with few objects

Engineering Contradiction:
Improveprocessing efficiencyVSAvoidblockage detection accuracy
Core Design Contradiction:
ProductivityVSMeasurement precision

Solution Approach 1:

The patent segments the detection process into two distinct modes: normal operation mode and blockage detection mode. The system divides the field of view into multiple regions and segments the analysis by creating range-Doppler maps for different spatial zones. This segmentation allows the system to perform comprehensive blockage detection only in specific conditions while maintaining efficient normal operation, thus resolving the contradiction between processing efficiency and detection accuracy.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements preliminary action by pre-defining regions of interest and pre-processing radar returns to create range-Doppler maps before actual blockage detection is needed. The system prepares multiple range-Doppler maps in advance for different regions, and only performs the computationally intensive averaging and blob detection when blockage is suspected. This preliminary preparation reduces the processing burden during critical detection moments.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If blockage detection is performed continuously with comprehensive analysis, then detection accuracy is improved, but processing time and resource usage increase

Engineering Contradiction:
Improveblockage detection accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent implements periodic action by performing comprehensive blockage detection only at specific intervals when object detections are absent or reduced. The system alternates between normal efficient operation and periodic comprehensive blockage detection based on detection conditions. This periodic comprehensive analysis maintains high accuracy while avoiding continuous resource-intensive processing, thus resolving the time-cost contradiction.

Inventive Principle:
Principle #19Periodic action

Solution Approach 2:

The patent applies partial action by performing blockage detection only in specific regions where it is most needed, rather than continuously analyzing the entire field of view. The system focuses computational resources on detecting blobs in predetermined regions of interest within range-Doppler maps, performing partial rather than complete analysis. This selective approach maintains detection accuracy while significantly reducing overall processing time and resource consumption.

Inventive Principle:
Principle #16Partial or excessive action

3Measurement precision

If radar signals with higher frequency are used, then detection capability is improved, but susceptibility to blockage increases

Engineering Contradiction:
Improvedetection capabilityVSAvoidsusceptibility to blockage
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent addresses this contradiction by changing the analysis parameters rather than the physical radar parameters. The system processes high-frequency radar signals through range-Doppler map generation and blob detection algorithms that can distinguish between signal attenuation from blockage and signal characteristics from distant objects. By changing the processing parameters and analysis methods rather than lowering the radar frequency, the system maintains both detection capability and blockage susceptibility characteristics of high-frequency signals.

Inventive Principle:
Principle #35Parameter changes

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 reduces processing time and resource usage by performing blockage detection only when object detections are absent and improves accuracy in detecting road presence even with weak radar reflections, effectively distinguishing between desert scenarios and actual blockages.

Implementation Method 1

a radar transmitter for transmitting a plurality of radar signals into a region and a radar detector for detecting reflected radar signals

Methodology Applied
Scientific EffectRadar: Radar

Data Source

PatentEP3332265B1Apparatus and method for detecting blockage of an automotive radar sensor
Publication Date: 2023.04.12 VEONEER US LLC
  • EP3332265B1 patent drawingFigure 1
  • EP3332265B1 patent drawingFigure 2~3
  • EP3332265B1 patent drawingFigure 4A~4B

AI summary

An automotive radar system and method transmit a plurality of radar signals into a region, detect reflected radar signals, and convert the reflected radar signals into digital data signals. A plurality of range-Doppler maps for the region are generated from the digital data signals, and the plurality of range-Doppler maps are averaged to generate an averaged range-Doppler map for the region. Data points in the averaged range-Doppler map are analyzed to detect blobs in the averaged range Doppler map. If a blob is detected in the averaged range-Doppler map, the radar detector is indicated to be unblocked.