Multi-Sensor Pose Graph Mapping for Accurate Robot Navigation

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Solution Overview

Problem

Robots face challenges in generating accurate maps of spaces using multiple sensors, leading to errors in position identification and navigation due to sensor limitations and movement processes.

Innovation Solution

A robot system utilizing a combination of LiDAR and camera sensors, along with artificial intelligence, generates a map by creating a pose graph with LiDAR and visual branches, and sets correlations between nodes using wheel odometry information, LiDAR, and visual odometry to enhance the accuracy of Simultaneous Localization and Mapping (SLAM) and navigation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a robot uses multiple sensors to generate a map, then the map quality and position identification accuracy are improved, but errors are produced due to sensor features and movement processes

Engineering Contradiction:
Improveposition identification accuracyVSAvoidmap accuracy
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent combines data from multiple sensors (LiDAR, camera, wheel encoder) to generate a fused map. The controller integrates LiDAR frames, visual frames, and wheel odometry information to create a comprehensive pose graph that leverages the strengths of each sensor while compensating for individual weaknesses, thereby improving position identification accuracy while managing error propagation

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The system implements feedback mechanisms by continuously comparing sensor measurements with the generated map and adjusting the pose graph accordingly. The controller uses the correlations between nodes to detect and correct errors in real-time, ensuring that position identification accuracy is maintained despite sensor limitations and movement-induced errors

Inventive Principle:
Principle #23Feedback

2Measurement precision

If a robot uses various sensors to generate and correct maps, then map accuracy is improved, but device complexity increases

Engineering Contradiction:
Improvemap accuracyVSAvoidsensor system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The controller serves multiple functions by simultaneously processing data from LiDAR, camera, and wheel encoders, generating the pose graph, calculating node correlations, and performing error correction. This multi-functional approach consolidates the complexity into a single processing unit rather than requiring separate dedicated systems for each function

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

Solution Approach 2:

The system creates a composite data structure (pose graph) that integrates information from heterogeneous sensors. By fusing LiDAR frames, visual frames, and wheel odometry into a unified representation with defined node correlations, the system manages the complexity of multiple sensors through a structured composite framework

Inventive Principle:
Principle #40Composite materials

3Measurement precision

If a robot stores detailed map information and node correlations, then navigation accuracy is improved, but information storage requirements increase

Engineering Contradiction:
Improvenavigation accuracyVSAvoiddata storage volume
Core Design Contradiction:
Measurement precisionVSQuantity of substance

Solution Approach 1:

The map is segmented into discrete nodes and edges forming a pose graph structure. Instead of storing continuous detailed information, the system divides the environment into key positional nodes with correlated relationships, reducing storage requirements while maintaining navigation accuracy through the graph's topological structure

Inventive Principle:
Principle #1Segmentation

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 system allows for precise map generation and accurate robot positioning, improving navigation and reducing errors by fusing data from multiple sensors, thereby enhancing the accuracy of SLAM and map quality.

Implementation Method 1

a LiDAR sensor sensing a distance between an object outside the robot and the robot and generating a LiDAR frame

Methodology Applied
Scientific EffectLiDAR: LIDAR

Implementation Method 2

a camera sensor photographing an object outside the robot and generating a visual frame

Methodology Applied
Scientific EffectPhotography: Photography

Data Source

PatentUS11614747B2Robot generating map and configuring correlation of nodes based on multi sensors and artificial intelligence, and moving based on map, and method of generating map
Publication Date: 2023.03.28 LG ELECTRONICS INC
  • US11614747B2 patent drawing
  • US11614747B2 patent drawing
  • US11614747B2 patent drawing

AI summary

Disclosed herein are a robot that generates a map and configures a correlation of nodes, based on multi sensors and artificial intelligence, and that moves based on the map, and a method of generating a map, and the robot according to an embodiment generates a pose graph comprised of LiDAR branch, visual branch, and backbone, and the LiDAR branch includes one or more of the LiDAR frames, the visual branch includes one or more of the visual frames, and the backbone includes two or more frame nodes registered with any one or more of the LiDAR frames or the visual frames, and to generate a correlation between nodes in the pose graph.