Automotive Radar Sensor Blockage Detection via Clutter Doppler Analysis

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Solution Overview

Problem

Automotive radar systems face challenges in distinguishing between sensor blockage and a low-object environment, such as a desert, where few or no objects are detected, leading to difficulties in determining whether the sensor is blocked or functioning properly.

Innovation Solution

The Blockage Environmental Clutter Confirmation Approach (BECCA) utilizes the properties of distributed clutter, like a road surface, and changes in the host vehicle's motion state to differentiate between a blocked sensor and a clear, unblocked state by analyzing the zero-Doppler component of radar signals, performing a Fast Fourier Transform (FFT) on digital data signals to associate data range bins with Doppler velocities, and using the BeccaMetric to confirm blockage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If sensor blockage is detected based on absence of radar signal processing detections, then detection simplicity is improved, but measurement precision deteriorates due to inability to distinguish blockage from low-object environments

Engineering Contradiction:
Improvedetection simplicityVSAvoidblockage detection accuracy
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent introduces environmental clutter (road surface, ground objects) as an intermediary reference target. By detecting clutter returns and analyzing their Doppler characteristics, the system creates a mediator that enables comparison between expected and actual radar responses, thereby resolving the ambiguity between blockage and low-object scenarios

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the detection parameter from simple presence/absence of detections to analysis of Doppler velocity characteristics of clutter returns. By examining the velocity distribution of environmental clutter in the zero-Doppler bin and comparing it across motion state transitions, the system achieves precise blockage detection while maintaining operational simplicity

Inventive Principle:
Principle #35Parameter changes

2Reliability

If radar system monitors all detections continuously, then blockage detection reliability is improved, but processing time and computational resources increase

Engineering Contradiction:
Improveblockage detection reliabilityVSAvoidprocessing time
Core Design Contradiction:
ReliabilityVSLoss of time

Solution Approach 1:

The patent performs preliminary action by pre-identifying and tracking environmental clutter returns before blockage occurs. By continuously monitoring clutter characteristics and storing their Doppler velocity patterns in advance, the system prepares reference data that enables rapid blockage detection without requiring intensive real-time processing of all detections

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent segments the radar detection process by separating clutter detection from target detection. By dedicating specific processing to identify and track environmental clutter (road surface, ground objects) independently from vehicle targets, the system reduces the computational burden on the overall detection system while maintaining reliable blockage monitoring

Inventive Principle:
Principle #1Segmentation

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 allows for accurate and timely detection of sensor blockage, reducing false positives and enabling prompt intervention to clear debris, ensuring reliable radar system performance by differentiating between blockage and low-clutter scenarios.

Implementation Method 1

a radar detector for detecting reflected radar signals and converting the reflected radar signals into digital data signals

Methodology Applied
Scientific EffectRadar: Radar

Implementation Method 2

A motion detector detects motion of the host system and generates a signal indicative of velocity of the host system

Methodology Applied
Scientific EffectMotion detection:

Implementation Method 3

Each data range bin generated by the FFT is associated with a Doppler velocity

Methodology Applied
Scientific EffectDoppler effect: Doppler Effect

Data Source

PatentEP3256878B1Apparatus and method for detecting and correcting for blockage of an automotive radar sensor
Publication Date: 2024.05.15 ARRIVER SOFTWARE LLC
  • EP3256878B1 patent drawingFigure 1
  • EP3256878B1 patent drawingFigure 2
  • EP3256878B1 patent drawingFigure 3

AI summary

A radar system and method in a host system include a radar detector detecting reflected radar signals and converting the reflected radar signals into digital data signals. A motion detector detects motion of the host system and indicates velocity of the host system. A processor receives the digital data signals and processes the digital data signals to categorize the digital data signals into target categories, one of the target categories being an environmental clutter category, the processor associating each of a plurality of processed groups of the digital data signals with a velocity, one of the groups of digital data being associated with a first preselected velocity. When the velocity of the host system changes, if the velocity associated with the one of the groups of digital data of the environmental clutter category has not changed, then the processor indicates that the radar detector is at least partially blocked.