Offset Reflection Unit for Laser Scanner Calibration

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Solution Overview

Problem

Existing methods for calibrating vehicle laser scanners, particularly for autonomous vehicles, are inefficient, require significant space, and lack precision, leading to inaccurate obstacle detection.

Innovation Solution

A device comprising reflection units with specific reflective surfaces and configurations, allowing for precise calibration of laser scanners by reflecting laser beams at defined angles and distances, enabling accurate alignment of laser beams to be horizontal.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If conventional calibration devices with multiple calibration objects are used, then calibration coverage is improved, but device complexity and space requirements increase

Engineering Contradiction:
Improvecalibration coverageVSAvoiddevice complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent combines multiple calibration functions into a single integrated reflection unit. The first and second shields with their respective reflective surfaces are merged into one device, along with the screen, to perform comprehensive laser scanner calibration including horizontal alignment and angular deviation detection, eliminating the need for multiple separate calibration objects

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The reflection unit serves multiple calibration purposes simultaneously: it calibrates the horizontal alignment of laser beams through the screen reflection, detects angular deviations using the shields' reflective surfaces, and provides reference points for distance measurements. This multi-functional design improves calibration coverage without proportionally increasing device complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Reliability

If conventional calibration devices are used, then calibration functionality is provided, but space requirements and costs increase

Engineering Contradiction:
Improvecalibration functionalityVSAvoidspace requirements
Core Design Contradiction:
ReliabilityVSArea of stationary object

Solution Approach 1:

The reflection unit employs a nested arrangement where the first shield is positioned between the second shield and the screen. This compact nested structure allows multiple calibration surfaces to be arranged in a space-efficient configuration, reducing the overall footprint of the calibration device while maintaining all necessary calibration functions

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent utilizes the vertical dimension by arranging the shields and screen at different vertical positions and angles. The first and second shields are vertically offset from each other, and their reflective surfaces are oriented at different angles, allowing comprehensive calibration coverage in a compact horizontal footprint by exploiting the third dimension

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

3Device complexity

If simple reflection surfaces are used, then device simplicity is improved, but measurement precision deteriorates

Engineering Contradiction:
Improvedevice simplicityVSAvoidalignment precision
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent applies different reflective surface configurations to different parts of the reflection unit based on their specific calibration functions. The screen has a reflective surface optimized for horizontal alignment calibration, while the first and second shields have reflective surfaces positioned and angled specifically for detecting angular deviations. This localized optimization of surface properties achieves high measurement precision without requiring complex surfaces throughout the entire device

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

The device allows for high-precision calibration of vehicle laser scanners, reducing space requirements and costs while enhancing obstacle detection accuracy.

Implementation Method 1

at least one reflection unit for reflecting a laser beam from the laser scanner

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP4111227B1Device and method for calibrating a laser scanner
Publication Date: 2026.04.08 SEW EURODRIVE GMBH & CO KG
  • EP4111227B1 patent drawingFigure 1
  • EP4111227B1 patent drawingFigure 2
  • EP4111227B1 patent drawingFigure 3

AI summary

The invention relates to a device for calibrating a laser scanner (3), in particular of a vehicle (2), comprising at least one reflection unit (21, 22) for reflecting a laser beam (L) of the laser scanner (3), the at least one reflection unit (21, 22) comprising a first plate (7), a second plate (8) and a screen (5), the first plate (7) being arranged between the second plate (8) and the screen (5) in a beam direction (S), the first plate (7) having a first reflection face (31), which extends at least approximately at right angles to the beam direction (S), and the second plate (8) having a second reflection face (32), which extends at least approximately at right angles to the beam direction (S), and the screen (5) having a third reflection face (33), which extends at least approximately at right angles to the beam direction (S), the first plate (7) being arranged offset in relation to the second plate (8) in a vertical direction (Z) in such a way that a gap (9) is formed between the first plate (7) and the second plate (8), which gap extends in the vertical direction (Z) and in a transverse direction (Y), and the screen (5) being formed and arranged in such a way that a projection of the gap (9) in the beam direction (S) is fully incident on the third reflection face (33) of the screen (5). The invention also relates to a method for calibrating a laser scanner (3), in particular of a vehicle (2), by means of a device according to the invention, a laser beam (L) of the laser scanner (3) being directed at least approximately in the beam direction (S) towards the at least one reflection unit (21, 22), and the laser beam (L) being moved along the at least one reflection unit (21, 22) in the transverse direction (Y), and the distance (D) of the laser scanner (3) from the particular reflection face (31, 32, 33) from which the laser beam (L) is reflected being measured for a plurality of positions (P) of the laser beam (L) in the transverse direction (Y), and an orientation of the laser scanner (3) being determined on the basis of the measured distances (D) of the laser scanner (3) from the reflection faces (31, 32, 33).