LiDAR-Assisted Wheel Encoder to Camera Calibration

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Solution Overview

Problem

Current methods for calibrating a wheel encoder to a camera are cumbersome or lack robust estimation, particularly in hand-eye calibration processes.

Innovation Solution

The method involves using LiDAR signals to separate the calibration process into camera to LiDAR calibration and wheel encoder to LiDAR calibration, allowing for the determination of scaling factors and estimating rotations and translations without Z-axis movement, thereby calibrating the camera and wheel encoder signals effectively.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If traditional wheel encoder to camera calibration methods are used, then the calibration can be performed, but the process is cumbersome and lacks robust estimation

Engineering Contradiction:
Improverobust estimationVSAvoidcalibration process complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent introduces LiDAR as an intermediary sensor to bridge the calibration between wheel encoder and camera. The LiDAR provides accurate 3D point cloud data that serves as a reliable reference for establishing the transformation relationship, thereby improving robust estimation while maintaining a manageable calibration process through intermediate reference data

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If LiDAR assisted calibration is used, then robust hand-eye calibration estimation is achieved, but additional LiDAR signal processing is required

Engineering Contradiction:
Improvehand-eye calibration precisionVSAvoidsignal processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the calibration process into distinct stages: LiDAR-to-world calibration, camera-to-world calibration, and wheel encoder-to-world calibration. Each sensor type is calibrated independently against a common world coordinate system, which improves measurement precision while organizing the signal processing into manageable, modular segments

Inventive Principle:
Principle #1Segmentation

3Manufacturing precision

If multi-sensor calibration is performed, then accurate sensor integration is enabled, but the calibration time and computational resources increase

Engineering Contradiction:
Improvesensor integration accuracyVSAvoidcalibration time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent performs preliminary calibration of each sensor (LiDAR, camera, wheel encoder) to a common world coordinate system before final integration. This preliminary action establishes stable reference frames in advance, enabling accurate sensor integration while reducing the computational burden and time required for the final multi-sensor calibration

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentUS11508089B2LiDAR assisted wheel encoder to camera calibration
Publication Date: 2022.11.22 BLACK SESAME TECH INC
  • US11508089B2 patent drawing
  • US11508089B2 patent drawing
  • US11508089B2 patent drawing

AI summary

A method of wheel encoder to camera calibration, including receiving a LiDAR (Light Detection and Ranging) signal, receiving a camera signal, receiving a wheel encoder signal, calibrating the camera signal to the LiDAR signal, calibrating the wheel encoder signal to the LiDAR signal and calibrating the camera signal to the wheel encoder signal based on the calibration of the camera signal to the LiDAR signal and the wheel encoder signal to the LiDAR signal.