Radar Sensor Elevation Misalignment Determination

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Solution Overview

Problem

Existing methods for determining elevation misalignment of radar sensors in vehicles are not sufficiently accurate and reliable, affecting the classification of objects and horizontal angle detection due to deviations in antenna diagrams and multipath propagation.

Innovation Solution

A method that determines elevation misalignment by analyzing the frequency distribution of radar object locations using at least two antenna directional characteristics, with a ground reflection correction value to account for multipath propagation, ensuring precise estimation of elevation angles and reducing systematic errors.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If existing methods for determining elevation misalignment are used, then the process is simple, but the accuracy and reliability of misalignment detection is insufficient

Engineering Contradiction:
Improveelevation misalignment detection accuracyVSAvoiddetection method complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent transitions from analyzing single-antenna radar signals to utilizing signals from multiple antennas with different elevation directional characteristics. By adding the dimensional aspect of multiple antenna perspectives, the system can determine elevation misalignment angles through comparing frequency distributions from different antenna viewpoints, thereby improving measurement precision without excessive complexity increase

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent implements a feedback mechanism where the determined elevation misalignment angle is used to correct the antenna diagram in subsequent radar object detections. This closed-loop approach continuously refines the accuracy of elevation angle measurements by compensating for systematic errors, thereby progressively improving measurement precision while maintaining operational simplicity

Inventive Principle:
Principle #23Feedback

2Reliability

If ground reflection effects are not corrected, then the processing is simpler, but systematic errors increase particularly when sensor is misaligned obliquely downwards

Engineering Contradiction:
Improveobject classification reliabilityVSAvoidsignal processing complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies preliminary correction by determining a ground reflection correction value based on the elevation misalignment angle before using this value to correct subsequent radar object detections. This proactive approach prevents systematic errors from affecting object classification and horizontal angle detection, thereby improving reliability while managing processing complexity through structured correction steps

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces a ground reflection correction value as an intermediary element that mediates between the raw radar signals affected by multipath propagation and the final object classification results. This correction value acts as a compensating factor that eliminates the harmful effects of ground reflections, particularly when the sensor is misaligned obliquely downwards, thereby improving reliability without directly increasing processing complexity

Inventive Principle:
Principle #24Intermediary (Mediator)

3Measurement precision

If antenna diagram differences are not accounted for, then the evaluation is simpler, but horizontal angle detection accuracy deteriorates

Engineering Contradiction:
Improvehorizontal angle detection accuracyVSAvoidantenna pattern matching complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent changes the parameter of antenna directional characteristics by selecting at least two antennas with different elevation directional characteristics. This parameter variation allows the system to detect elevation misalignment through frequency distribution comparison and subsequently correct horizontal angle detections, thereby improving measurement precision while managing complexity through systematic parameter selection and correction

Inventive Principle:
Principle #35Parameter changes

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 accurate and reliable detection of elevation misalignment, improving the reliability of object classification and reducing errors in radar sensor alignment, particularly when the sensor is misaligned obliquely downwards.

Implementation Method 1

a radar sensor (10) of a vehicle, in particular a motor vehicle, having a coordinate system and having at least two antenna directional characteristics (20, 21) differing in the elevation direction

Methodology Applied
Scientific EffectRadar: Radar

Implementation Method 2

an expected multipath propagation of the radar signals by reflection from the ground

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP2999975B1Determination of an elevation misalignment angle of a radar sensor of a motor vehicle
Publication Date: 2020.01.01 ROBERT BOSCH GMBH
  • EP2999975B1 patent drawingFigure 1~2
  • EP2999975B1 patent drawingFigure 3~4
  • EP2999975B1 patent drawingFigure 5~6

AI summary

The invention relates to a method for determining an elevation misalignment angle (φ) of a radar sensor (10) of a vehicle, comprising the steps: determination of elevation angles (α) of radar object locations in relation to a coordinate system of the radar sensor (10), wherein an elevation angle (α) of each radar objection location is determined based on radar echoes that are received having at least two antenna alignment characteristics (20, 21) that differ in the elevation direction; and determination of an elevation misalignment angle (φ) based on a frequency distribution of the elevation angle (α) of at least some of the radar object locations; and radar sensor for vehicles having an evaluation device (15) configured for carrying out the method.