Optoelectronic Sensor Calibration via Parallel Line Detection

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Solution Overview

Problem

Current methods for calibrating optoelectronic sensors in motor vehicles are inefficient and require specialized calibration targets, making the process cumbersome and time-consuming.

Innovation Solution

A method that uses emitted light beams reflected off objects represented as parallel, line-shaped measurement structures in the sensor image to determine angular positions, allowing for calibration without predefined targets, and enables detection and correction of misalignments using evaluation units.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If calibration targets with defined shapes and patterns are used for sensor calibration, then measurement precision can be achieved, but device complexity and ease of operation deteriorate due to requiring special targets and predefined positioning

Engineering Contradiction:
Improvesensor calibration precisionVSAvoidcalibration target requirements
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The invention extracts the essential calibration function from specialized calibration targets and transfers it to everyday objects with linear structures. Instead of requiring complex calibrated targets, the system extracts geometric information (parallel lines, angles) from common objects like book spines, window frames, or architectural features, thereby eliminating the need for special calibration equipment while maintaining calibration precision.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The calibration method becomes universal by accepting any object containing parallel linear structures as a valid calibration reference. This multi-functional approach allows the same calibration algorithm to work with diverse objects (books, buildings, furniture, architectural features) without requiring object-specific calibration procedures, thereby simplifying the overall calibration process and eliminating the need for specialized calibration targets.

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

2Measurement precision

If specialized calibration targets are required for optoelectronic sensor calibration, then measurement precision is maintained, but productivity and ease of operation worsen due to time-consuming setup and positioning requirements

Engineering Contradiction:
Improveangular position determination accuracyVSAvoidcalibration speed
Core Design Contradiction:
Measurement precisionVSProductivity

Solution Approach 1:

The calibration system performs self-calibration by automatically detecting parallel linear structures in the environment and computing angular positions without requiring manual target positioning or specialized calibration equipment. The optoelectronic sensor itself captures images of everyday objects, and the evaluation unit automatically extracts geometric features and calculates calibration parameters, making the system self-sufficient and eliminating time-consuming manual setup procedures.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

Instead of having the sensor actively scan or track specific calibration targets as in traditional methods, the invention inverts the approach by having the sensor passively capture images of everyday objects and deriving calibration information from the geometric structures within those images. This inversion transforms calibration from an active, target-dependent process into a passive, environment-independent process, dramatically improving calibration speed and productivity.

Inventive Principle:
Principle #13The other way round (Inversion)

3Measurement precision

If calibration targets must be positioned at predefined locations, then measurement precision can be ensured, but ease of operation and adaptability deteriorate due to rigid positioning requirements

Engineering Contradiction:
Improveangular deviation measurement accuracyVSAvoidcalibration environment flexibility
Core Design Contradiction:
Measurement precisionVSAdaptability or versatility

Solution Approach 1:

The calibration method achieves universality by accepting any object containing parallel linear structures regardless of its location, orientation, or type in the environment. The evaluation unit detects parallel lines and computes angular positions based solely on the geometric relationship between these lines, making the calibration process adaptable to diverse environments (workshops, assembly plants, field conditions) without requiring predefined target positions or specialized calibration equipment.

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

Solution Approach 2:

The calibration system dynamically adapts to any environmental context by automatically detecting and utilizing parallel linear structures wherever they appear in the sensor's field of view. Rather than requiring static, pre-positioned calibration targets, the system dynamically identifies suitable calibration features in the captured image and adjusts its calibration calculations accordingly, providing both precision and environmental flexibility.

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

Enables quick and reliable calibration of optoelectronic sensors by determining angular deviations such as yaw, pitch, and roll angles, improving sensor operation without the need for specialized targets or precise environmental alignment.

Implementation Method 1

Light beams are emitted into the surroundings of the motor vehicle by means of the optoelectronic sensor (5), and the light beams reflected from an object are received by a receiving unit (7)

Methodology Applied
Scientific EffectLight reflection: Reflection

Implementation Method 2

At least two linear measurement structures are detected in the sensor image. The at least two linear measurement structures are arranged parallel and spaced apart from one another

Methodology Applied
Scientific EffectGeometric analysis: Geometry

Data Source

PatentEP3788405B1Method for determining the angular position of an optoelectronic sensor, and test stand
Publication Date: 2024.04.17 VALEO SCHALTER & SENSOREN GMBH
  • EP3788405B1 patent drawingFigure 1
  • EP3788405B1 patent drawingFigure 2
  • EP3788405B1 patent drawingFigure 3

AI summary

The invention relates to a method for determining at least one angular position of an optoelectronic sensor (5) of a motor vehicle (1). The optoelectronic sensor comprises at least one transmission device (6), at least one receiving unit (7) with at least two receiving elements, and at least one analysis unit (10). The method has the following steps: - emitting light beams (8) into the surroundings (4) of the motor vehicle (1) by means of the transmission device (6), and - receiving light beams (8) reflected on an object (3) by means of the receiving unit (7), wherein the light beams (8) are represented by the analysis unit (10) as scanning points (17, 18, 19, 20) in a sensor image (S) of the surroundings (4) of the motor vehicle (1), said sensor image being generated by the optoelectronic sensor (5), and each scanning point (17, 18, 19, 20) is assigned to a receiving element (7a, 7b). In order to determine the at least one angular position, at least two linear measurement structures (14, 15) are detected in the sensor image (S), said structures being arranged in a parallel manner at a distance to each other. In order to determine the at least one angular position of the optoelectronic sensor (5), at least one angular deviation of the optoelectronic sensor (5) from a target angular position is determined on the basis of the scanning points (17, 18, 19, 20), which represent the first and the second measurement structure (14, 15), and the optoelectronic sensor (5) is calibrated on the basis of the at least one angular deviation. The invention additionally relates to a test stand (12).