Radar Target Angle Estimation With Long Beam Vectors for Sidelobe Reduction

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Solution Overview

Problem

Existing radar systems face challenges in accurately determining the angle of target objects with respect to a host vehicle due to high computational and hardware costs, ambiguity in angle determination, and sidelobe issues, which are exacerbated by the need for multiple antennas and complex signal processing, making them unsuitable for cost-effective integration in vehicles.

Innovation Solution

A method and device using a radar system with a processing unit to generate a long beam vector and correlate it with a reference vector based on a signal model, suppressing sidelobes and reducing peak width, thereby improving angle estimation accuracy without increasing computational effort or hardware costs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If Fourier transform techniques or iterative adaptive approach are used for angle estimation, then angle determination capability is improved, but computational effort increases significantly

Engineering Contradiction:
Improveangle determination accuracyVSAvoidcomputational effort
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent extracts only the necessary components for angle estimation by using a simplified beamforming approach that processes radar signals without requiring full iterative adaptive computation. The method extracts angle information directly from radar measurements through a streamlined transformation process, eliminating unnecessary computational steps while maintaining essential angle determination capability

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent employs a computationally efficient angle estimation method that can be executed quickly and discarded for each new radar measurement cycle. This approach uses a simplified mathematical model that requires minimal processing power compared to iterative methods, making it suitable for real-time automotive radar applications where rapid repeated measurements are necessary

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Measurement precision

If a higher number of antennas are used to improve angular resolution, then angle estimation accuracy is improved, but package size increases

Engineering Contradiction:
Improveangular resolutionVSAvoidradar system package size
Core Design Contradiction:
Measurement precisionVSArea of stationary object

Solution Approach 1:

The patent improves angular resolution by changing signal processing parameters rather than physical antenna parameters. The method uses advanced signal transformation techniques that extract higher resolution angle information from the same antenna array, effectively achieving better resolution through mathematical processing instead of increasing the physical number of antennas

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent creates a virtual expansion of the antenna array through signal processing techniques that simulate additional antenna elements. By processing the signals from existing antennas through specialized transformations, the system achieves the resolution equivalent of having more physical antennas without actually installing them, thus maintaining a compact package size

Inventive Principle:
Principle #26Copying

3Measurement precision

If antenna configuration and signal processing are optimized for angle estimation, then angle accuracy is improved, but sidelobes and ambiguities increase

Engineering Contradiction:
Improveangle accuracyVSAvoidsidelobes and ambiguities
Core Design Contradiction:
Measurement precisionVSObject-generated harmful factors

Solution Approach 1:

The patent converts the potentially harmful sidelobe effects into beneficial information by using a signal processing approach that identifies and utilizes the structured nature of sidelobes. Instead of treating sidelobes as noise to be suppressed, the method incorporates them into the angle estimation process, transforming what would be interference into additional measurement information that can actually improve robustness

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

Solution Approach 2:

The patent introduces an intermediate signal transformation step that acts as a mediator between the raw radar measurements and the final angle estimation. This intermediate processing stage reorganizes the signal data in a way that separates true target information from sidelobe artifacts, allowing accurate angle determination while minimizing the harmful effects of ambiguities

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP4047384B1Method and device for determining an angle of a target object
Publication Date: 2025.08.27 APTIV TECHNOLOGIES AG
  • EP4047384B1 patent drawingFigure 1
  • EP4047384B1 patent drawingFigure 2
  • EP4047384B1 patent drawingFigure 3A~3B

AI summary

A method is provided for estimating an angle of an object with respect to a vehicle. A transformation of reflected radar signals is calculated, wherein the result of the transformation depends on a range with respect to the vehicle. A long beam vector is generated for respective range bins provided by the transformation by rearranging the result of the transformation such that the respective long beam vector comprises elements of the transformation from radar all receiver elements for each range bin. A reference vector is calculated for each range bin based on a signal model which depends on the motion of the target object relative to the vehicle and which is parameterized regarding the angle of the target object. The long beam vector and the reference vector are correlated, and the angle of the target object is determined based on the correlation result.