On-Board Sensor Extrinsic Calibration Using Map Feature Points

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Solution Overview

Problem

The reliability of automatic driving systems in autonomous vehicles is compromised due to the need for frequent depot recalibration of on-board sensors, which is costly and negatively impacts user experience, as external factors like vibration and collisions cause offsets in sensor spatial relationships.

Innovation Solution

A method and device for automatically calibrating extrinsic sensor parameters using first and second feature point information, determined through a position and orientation system, allowing calibration without reliance on fixed check places or laboratories, by establishing a mapping parameter from the sensor to the vehicle body based on geographic locations and coordinates within a world coordinate system.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If manual calibration with preset markers in fixed areas is used, then initial sensor spatial relationship accuracy is achieved, but frequent depot recalibration is required due to vibration and collision offsets

Engineering Contradiction:
Improvesensor spatial relationship accuracyVSAvoidrecalibration time cost
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs automatic self-calibration by utilizing the vehicle's own sensors (camera, GPS, inertial sensor) to detect and correct spatial relationship offsets between sensors without requiring external calibration equipment or depot intervention. The calibration is executed automatically during vehicle operation based on sensed environmental features.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The calibration system dynamically adapts to changing sensor spatial relationships caused by vibration and collision by continuously monitoring and adjusting calibration parameters in real-time, rather than relying on static initial calibration that degrades over time.

Inventive Principle:
Principle #15Dynamics

2Measurement precision

If manual calibration with preset markers in fixed areas is used, then initial sensor spatial relationship accuracy is achieved, but transportation and time costs increase due to frequent depot visits

Engineering Contradiction:
Improvesensor spatial relationship accuracyVSAvoidtransportation cost
Core Design Contradiction:
Measurement precisionVSLoss of energy

Solution Approach 1:

The system performs automatic self-calibration by utilizing the vehicle's own sensors (camera, GPS, inertial sensor) to detect and correct spatial relationship offsets between sensors without requiring external calibration equipment or depot intervention. The calibration is executed automatically during vehicle operation based on sensed environmental features.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The calibration system dynamically adapts to changing sensor spatial relationships caused by vibration and collision by continuously monitoring and adjusting calibration parameters in real-time, rather than relying on static initial calibration that degrades over time.

Inventive Principle:
Principle #15Dynamics

3Measurement precision

If manual calibration with preset markers is used, then calibration accuracy is achieved, but user experience deteriorates due to frequent depot recalibration requirements

Engineering Contradiction:
Improvecalibration accuracyVSAvoiduser experience
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The system performs automatic self-calibration by utilizing the vehicle's own sensors (camera, GPS, inertial sensor) to detect and correct spatial relationship offsets between sensors without requiring external calibration equipment or depot intervention. The calibration is executed automatically during vehicle operation based on sensed environmental features.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The calibration system dynamically adapts to changing sensor spatial relationships caused by vibration and collision by continuously monitoring and adjusting calibration parameters in real-time, rather than relying on static initial calibration that degrades over time.

Inventive Principle:
Principle #15Dynamics

4Ease of operation

If automatic calibration using environmental features is implemented, then depot recalibration is eliminated, but calibration reliability must be maintained without controlled check field conditions

Engineering Contradiction:
Improvecalibration convenienceVSAvoidcalibration reliability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The system uses environmental features (buildings, trees, poles, road markings) as intermediary reference objects to establish spatial relationships between sensors. These naturally occurring features serve as calibration targets, replacing the need for artificial check field markers while enabling calibration in real-world operating conditions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The calibration system dynamically adapts to changing sensor spatial relationships caused by vibration and collision by continuously monitoring and adjusting calibration parameters in real-time, rather than relying on static initial calibration that degrades over time.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentUS11670193B2Extrinsic parameter of on-board sensor
Publication Date: 2023.06.06 YINWANG INTELLIGENT TECHNOLOGIES CO LTD
  • US11670193B2 patent drawing
  • US11670193B2 patent drawing
  • US11670193B2 patent drawing

AI summary

A method for calibrating an extrinsic parameter of an on-board sensor includes obtaining first feature point information collected by a first on-board sensor; determining a geographic location of a vehicle body in which the first on-board sensor is located in a world coordinate system; determining second feature point information within a collection range of the first sensor in a map database based on the geographic location of the vehicle body in the world coordinate system; determining a plurality of first feature points and a plurality of second feature points based on the first feature point information and the second feature point information.