Factor-Graph Road Map Updates for Real-Time Lane Correction

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Solution Overview

Problem

Autonomous vehicles rely on pre-built maps that cannot be corrected in real-time, leading to errors in lane recognition and navigation, potentially causing vehicles to leave lanes unintentionally or fail to account for unanticipated road conditions.

Innovation Solution

A dynamically modifiable map using a factor graph with variable nodes and factor nodes that allow the vehicle to self-adjust lane line positions based on sensor data, enabling real-time corrections while moving.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a pre-built static map is used for navigation, then the map structure is simple and easy to store, but the map cannot be corrected in real-time leading to navigation errors

Engineering Contradiction:
Improvenavigation accuracyVSAvoidmap structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent transforms the static map into a dynamic structure by introducing variable nodes that can be modified in real-time. The factor graph allows the map to adapt its structure during vehicle operation, enabling corrections to lane line positions and other map features without requiring a complete map replacement. This resolves the contradiction by making the map dynamically updatable while maintaining a manageable structural framework through the factor graph architecture.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system enables self-correction of map errors through the vehicle's own sensor data. When the vehicle detects discrepancies between the pre-built map and actual road conditions captured by sensors, it automatically adjusts the variable nodes in the factor graph to correct these errors. This self-service mechanism eliminates the need for external manual map updates while improving navigation reliability.

Inventive Principle:
Principle #25Self-service

2Measurement precision

If the map is updated in real-time using sensor data, then navigation accuracy is improved, but the computational complexity and processing requirements increase

Engineering Contradiction:
Improvelane line position accuracyVSAvoidcomputational processing complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the map into discrete variable nodes representing different road features such as lane lines, intersections, and other navigational elements. Each variable node can be independently adjusted based on sensor observations, allowing localized updates rather than processing the entire map. This segmentation reduces computational complexity by focusing processing only on relevant map segments that require correction.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system implements a feedback mechanism where sensor data continuously compares actual road conditions with the pre-built map, and corrections are fed back to update the variable nodes. This closed-loop feedback process enables precise lane line position tracking while managing computational load by only processing corrections when discrepancies are detected, rather than continuously recalculating the entire map.

Inventive Principle:
Principle #23Feedback

3Ease of operation

If a static pre-built map is used, then the system is simple to implement, but errors in the map cannot be corrected until the vehicle is powered off

Engineering Contradiction:
Improvesystem implementation easeVSAvoidmap error correction capability
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The factor graph structure serves multiple functions: it maintains the pre-built map structure for normal operation, enables real-time correction of map errors, and provides a framework for integrating sensor data. This multi-functionality allows the system to maintain simplicity of implementation while gaining dynamic error correction capability, as the same factor graph infrastructure supports both static map storage and dynamic updates.

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

Data Source

PatentUS12172638B2Dynamically modifiable map
Publication Date: 2024.12.24 EMBARK TRUCKS INC
  • US12172638B2 patent drawing
  • US12172638B2 patent drawing
  • US12172638B2 patent drawing

AI summary

Provided are systems and methods for controlling a vehicle based on a map that designed using a factor graph. Because the map is designed using a factor graph, positions of the road can be modified in real-time while operating the vehicle. In one example, the method may include storing a map which is associated with a factor graph of variable nodes representing a plurality of constraints that define positions of lane lines in a road and factor nodes between the variable nodes on the factor graph which define positioning constraints amongst the variable nodes, receiving an indication from the road using a sensor of a vehicle, updating positions of the variable nodes based on the indication and an estimated location of the vehicle within the map, and issue commands capable of controlling a steering operation of the vehicle based on the updated positions of the factor nodes.