FMCW Radar Detection With Differentiated Resolution

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Solution Overview

Problem

Current automotive radar systems using FMCW waveforms face challenges in achieving high distance and speed resolution simultaneously, leading to inadequate anti-collision capabilities at high speeds due to limited processing resources and the need for optimized waveform efficiency.

Innovation Solution

A method for radar detection using an FMCW waveform with a recurrence pattern divided into sub-patterns, performing distance compression and Doppler processing to create low-resolution distance-Doppler maps, followed by coherent integration for enhanced resolution, allowing for improved discrimination of targets and reduced processing volume.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If high distance resolution is used to detect fixed objects at high speed, then the number of distance boxes increases significantly, but the processing volume becomes excessively large

Engineering Contradiction:
Improvedistance resolutionVSAvoidprocessing volume
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent applies local quality by differentiating processing resolution based on target type. High distance resolution is applied locally to fixed objects (where discrimination is critical), while lower resolution is used for moving objects. This is achieved through Doppler-based classification that directs computational resources to where they are most needed, resolving the contradiction between high resolution requirements and limited processing capacity.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent segments the processing task by dividing the radar detection space into different domains based on Doppler characteristics. By separating fixed objects from moving objects through Doppler filtering, the system can apply high resolution only to the fixed object domain, reducing the overall processing volume while maintaining necessary discrimination capabilities.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If differentiated waveforms are used for short range and long range modes, then range optimization is achieved, but waveform efficiency is reduced due to loss of integration time

Engineering Contradiction:
Improverange optimizationVSAvoidwaveform efficiency
Core Design Contradiction:
Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent applies dynamics by making the waveform configuration adaptable based on detected target characteristics. Instead of using fixed differentiated waveforms for different ranges, the system dynamically adjusts the waveform parameters (including the number of sub-patterns and frequency bands) based on the Doppler characteristics of detected objects, optimizing both range performance and waveform efficiency simultaneously.

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If multiple beams are processed simultaneously for beam forming by calculation, then angular discrimination is improved, but the processing requirement is multiplied by the number of beams

Engineering Contradiction:
Improveangular discriminationVSAvoidprocessing requirement
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The patent applies local quality by implementing beam-specific processing only where needed. By using Doppler information to identify fixed objects, the system can apply high-resolution processing locally to beams containing fixed objects, while using lower-resolution processing for beams with only moving objects, thereby reducing the overall processing requirement while maintaining angular discrimination capability.

Inventive Principle:
Principle #3Local quality

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 the radar system to achieve high distance and speed resolution, enhancing its ability to detect obstacles at high speeds without generating false alarms, thereby improving safety and reliability.

Implementation Method 1

The waveforms are essentially frequency modulated, called FMCW

Methodology Applied
Scientific EffectFrequency modulation: Phase Modulation

Implementation Method 2

the speed resolution is favored, which implies a significant Doppler resolution

Methodology Applied
Scientific EffectDoppler effect: Doppler Effect

Data Source

PatentEP3282283B1Fmcw radar detection method with multiple resolution and radar using such a method
Publication Date: 2020.08.19 THALES SA
  • EP3282283B1 patent drawingFigure 1~2
  • EP3282283B1 patent drawingFigure 3
  • EP3282283B1 patent drawingFigure 4

AI summary

The detection process implementing an FMCW type waveform, the waveform at emission is made according to a recurrence pattern (10) of given period Tr covering a band of emission frequencies of given width B, each pattern being cut into a given number P of sub-patterns (21, 22, 23, 24) of duration Tr/P covering a band of excursion frequency ΔF=B/P, said sub-patterns being spaced from each other by a frequency difference equal to ΔF.The radar performs: - a first distance compression processing carrying out a low-resolution distance compression at the scale of each recurrence pattern (10) from a fraction B/P of said emission band of width B, corresponding to the frequency band covered by each of said sub-patterns (21, 22, 23, 24); - a Doppler processing on a given number N of successive recurrences so as to constitute P ambiguous low-resolution distance-Doppler maps, said maps being segmented according to different speed domains; - a second distance compression processing with differentiated resolution according to the speed domain to which the relative speed of said target with respect to said radar belongs.