Multi-Sensor Robot Mapping With Fusion SLAM and Pose Graphs

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Solution Overview

Problem

Current robots face challenges in generating accurate maps of their environment using multiple sensors, as these sensors have distinct features and errors, which affect their ability to navigate and avoid obstacles effectively.

Innovation Solution

A robot system that utilizes a combination of LiDAR and camera sensors, along with artificial intelligence, to generate heterogeneous maps and perform fusion SLAM, allowing the separation of maps for single-type sensor usage, enabling accurate position estimation and obstacle avoidance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If multiple sensors (LiDAR and camera) are used to generate maps, then measurement precision and navigation accuracy are improved, but device complexity and computational requirements increase

Engineering Contradiction:
Improveposition estimation accuracyVSAvoidsensor system complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent combines LiDAR and camera sensors into a unified mapping system where both sensors contribute to generating a single integrated map. The LiDAR sensor provides depth and spatial information while the camera sensor provides visual features, and both are fused through a common coordinate system and mapping algorithm to create a comprehensive environmental representation that improves position estimation accuracy.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent introduces a controller as an intermediary that processes and fuses data from multiple sensors. The controller integrates LiDAR distance measurements with camera visual features, performs coordinate transformations, and generates a unified map representation. This intermediary component manages the complexity of multi-sensor integration while delivering improved measurement precision.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Speed

If sensors are used to generate maps while the robot is moving, then real-time navigation capability is improved, but measurement errors and map accuracy deteriorate

Engineering Contradiction:
Improvereal-time mapping speedVSAvoidmap accuracy
Core Design Contradiction:
SpeedVSMeasurement precision

Solution Approach 1:

The patent implements feedback mechanisms where the robot's current position and orientation are continuously estimated using odometry information from wheel encoders and IMU sensors. This feedback is used to correct and update the map as the robot moves, compensating for motion-induced errors. The system continuously refines position estimates by comparing expected vs. actual sensor measurements, maintaining map accuracy during dynamic operation.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent performs preliminary odometry calculations and pose estimations before final map updates. By pre-processing sensor data and calculating expected positions based on motion models, the system prepares correction factors that are applied during map generation. This preliminary action reduces the computational burden during real-time operation and minimizes errors introduced by rapid motion.

Inventive Principle:
Principle #10Preliminary action

3Adaptability or versatility

If heterogeneous maps from different sensors are generated, then adaptability to different sensor types is improved, but ease of operation and system simplicity worsen

Engineering Contradiction:
Improvemulti-sensor compatibilityVSAvoidsystem operation simplicity
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent creates a universal map representation that can accommodate multiple sensor types through a common data structure and coordinate system. The mapping algorithm is designed to process both LiDAR range data and camera image data using unified mathematical transformations, allowing the same system to handle heterogeneous sensors without requiring separate processing pipelines or complex configuration.

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

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 the generation of high-quality maps and accurate position estimation for robots using multiple sensors, enhancing navigation and obstacle avoidance capabilities.

Implementation Method 1

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

Methodology Applied
Scientific EffectLight reflection and time of flight: Reflection

Implementation Method 2

a camera sensor capturing an image of an object placed outside of the robot and generating a visual frame

Methodology Applied
Scientific EffectLight detection: Photoelectric Effect

Data Source

PatentUS11960297B2Robot generating map based on multi sensors and artificial intelligence and moving based on map
Publication Date: 2024.04.16 LG ELECTRONICS INC
  • US11960297B2 patent drawing
  • US11960297B2 patent drawing
  • US11960297B2 patent drawing

AI summary

Disclosed herein is a robot generating a map based on multi sensors and artificial intelligence and moving based on the map, the robot according to an embodiment including a controller generating a pose graph that includes a LiDAR branch including one or more LiDAR frames, a visual branch including one or more visual frames, and a backbone including two or more frame nodes registered with any one or more of the LiDAR frames or the visual frames, and generating orodometry information that is generated while the robot is moving between the frame nodes.