Automotive Radar Object Classification via Micro-Doppler Analysis

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Solution Overview

Problem

Current radar systems on motor vehicles face complexity in processing signals for accurate object classification, particularly in distinguishing pedestrians from stationary objects and handling multiple objects at different speeds and distances, requiring powerful processing devices and complex modulation techniques.

Innovation Solution

A system combining a first FMCW radar device for distance and angle information and a continuous wave radar device for relative velocity and angle, with a processing unit for micro-Doppler analysis, allowing for improved classification by analyzing the spectrum of relative velocities and movement patterns, and integrating both radar devices for alternating operation to reduce computational complexity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If complex modulation techniques such as chirp sequences are used for object classification in a moving radar system, then measurement precision is improved, but device complexity increases due to resource-intensive processing requiring powerful processing units

Engineering Contradiction:
Improveobject classification precisionVSAvoidprocessing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the object classification task into two parts: first using FMCW radar to identify objects and their basic parameters, then using continuous-wave radar specifically for velocity-based micro-Doppler analysis. This segmentation allows each radar type to perform its optimized function without requiring complex processing of all data types, reducing overall device complexity while maintaining classification precision.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent extracts the velocity analysis function from the main FMCW processing chain and handles it separately using continuous-wave radar. By taking out the micro-Doppler analysis as a distinct processing stream that operates on velocity data rather than full radar signals, the system avoids the computational burden of applying complex modulation processing to all objects, thereby reducing device complexity while preserving measurement precision.

Inventive Principle:
Principle #2Taking out (Extraction)

2Measurement precision

If multiple radar devices operate simultaneously for comprehensive object scanning, then measurement precision is improved, but loss of time increases due to alternating operation between different radar devices

Engineering Contradiction:
Improveobject information accuracyVSAvoidscanning time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent implements dynamic coordination between FMCW and continuous-wave radar operations, where the continuous-wave radar operates continuously for velocity measurement while FMCW performs periodic distance and angle scanning. This dynamic arrangement allows the system to maintain comprehensive object information accuracy by combining both radar types' data, while minimizing scanning time through optimized operational scheduling rather than simple alternating operation.

Inventive Principle:
Principle #15Dynamics

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 enables precise object classification, including pedestrian detection, with reduced processing complexity and cost, allowing for enhanced driving assistance and accident prevention systems by accurately determining object movement and location, even in complex scenarios.

Implementation Method 1

A first radar device scans first information about the object, which includes a distance, a first object angle, and a first relative velocity

Methodology Applied
Scientific EffectRadar: Radar

Implementation Method 2

A Doppler shift of the reflected radar signal compared to the transmitted signal can indicate the relative velocity of the object with respect to the radar system

Methodology Applied
Scientific EffectDoppler effect: Doppler Effect

Implementation Method 3

a continuous-wave radar device for scanning second information about the object, which includes a second relative velocity and a second object angle

Methodology Applied
Scientific EffectContinuous-wave radar: Radar

Implementation Method 4

A Doppler shift of the reflected radar signal compared to the transmitted signal can indicate the relative velocity of the object with respect to the radar system

Methodology Applied
Scientific EffectDoppler effect: Doppler Effect

Data Source

PatentEP3485290B1Method and system for scanning an object
Publication Date: 2024.01.17 ROBERT BOSCH GMBH
  • EP3485290B1 patent drawingFigure 1
  • EP3485290B1 patent drawingFigure 2
  • EP3485290B1 patent drawingFigure 3

AI summary

The invention relates to a system for scanning an object from a motor vehicle, comprising a first radar device for scanning first pieces of information of the object, said pieces of information comprising a distance, a first object angle, and a first relative speed; a periodic continuous-wave radar device for scanning second pieces of information of the object, said pieces of information comprising a second relative speed and a second object angle; and a processing device for assigning the first and second pieces of information pertaining to the same object and for classifying the object on the basis of a characteristic of the second relative speed.