Radar Swaying Object Detection Using Range-Doppler Frequency Peaks

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Solution Overview

Problem

Existing radar systems struggle to differentiate between moving objects like cars or people and swaying objects such as grass, trees, and poles, which are not of interest, leading to unnecessary processing and potential distractions.

Innovation Solution

A method and device that analyze range-Doppler maps to identify swaying objects by calculating differences in energy values for positive and negative velocities, detecting periodic patterns, and filtering out irrelevant detections based on frequency thresholds.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If radar systems process all detected objects including swaying objects, then detection completeness is improved, but computational load and processing time increase

Engineering Contradiction:
Improvedetection completenessVSAvoidprocessing efficiency
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The patent extracts and separates swaying objects from the set of all detected objects by analyzing velocity variations over time. Objects exhibiting periodic velocity changes characteristic of swaying motion are identified and removed from further processing, allowing the system to maintain detection completeness for relevant objects while reducing computational load by excluding irrelevant swaying objects.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent performs preliminary analysis of velocity patterns before full object processing. By calculating velocity variations and identifying swaying characteristics in advance, the system prepares a filtered set of objects for subsequent detailed processing, thereby improving overall processing efficiency without compromising detection reliability.

Inventive Principle:
Principle #10Preliminary action

2Measurement precision

If radar systems track all moving objects, then tracking accuracy is improved, but system complexity and processing resources increase

Engineering Contradiction:
Improvetracking accuracyVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts swaying objects from the tracking pipeline by identifying their characteristic velocity patterns. These extracted objects are excluded from tracking algorithms and classification processes, reducing system complexity and resource consumption while maintaining tracking accuracy for non-swaying objects of interest.

Inventive Principle:
Principle #2Taking out (Extraction)

3Measurement precision

If radar systems classify all detected objects, then classification accuracy is improved, but processing time and computational resources increase

Engineering Contradiction:
Improveclassification accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent performs preliminary identification of swaying objects based on velocity variation analysis before the classification stage. By filtering out swaying objects in advance, the system reduces the number of objects requiring classification, thereby decreasing processing time and computational resource usage while maintaining classification accuracy for remaining objects.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent extracts and removes swaying objects from the classification pipeline by identifying their distinctive velocity patterns. This extraction prevents unnecessary classification processing of irrelevant objects, reducing overall processing time while preserving classification accuracy for objects that require classification.

Inventive Principle:
Principle #2Taking out (Extraction)

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

Effectively identifies and filters out swaying objects, reducing computational load and avoiding unnecessary processing, thus enhancing surveillance system efficiency.

Implementation Method 1

range-Doppler maps provided by a radar system... Each range-Doppler map... comprises a respective energy value for a plurality of velocity intervals

Methodology Applied
Scientific EffectDoppler effect: Doppler Effect

Data Source

PatentEP4664156B1Method and device for identifying swaying objects in radar data
Publication Date: 2026.05.20 AXIS
  • EP4664156B1 patent drawingFigure 1a
  • EP4664156B1 patent drawingFigure 1b~2
  • EP4664156B1 patent drawingFigure 3a~3b

AI summary

A device, a non-transitory computer-readable storage medium, and a method for determining that there are one or more swaying objects for a range interval of a plurality of range intervals based on a plurality of range-Doppler maps provided by a radar system are disclosed. Each range-Doppler map of the plurality of range-Doppler maps corresponds to a time interval of a sequence of time intervals and comprises a respective energy value for a plurality of velocity intervals for each range interval of the plurality of range intervals. A sequence of differences is calculated for the sequence of time intervals. Specifically, for each time interval of the sequence of time intervals, a difference between a statistical measure of energy values for a set of velocity intervals with positive velocities of the plurality of velocity intervals for the range interval and the statistical measure of energy values for a set of velocity intervals with negative velocities of the plurality of velocity intervals for the range interval is calculated from the range-Doppler map corresponding to the time interval. A frequency spectrum is then determined from the calculated sequence of differences. On condition that there is a peak in the frequency spectrum for a frequency above a frequency threshold, it is determined that there are one or more swaying objects at the range interval.