Pose Graph Fusion of Position Data for Real-Time Localization

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Solution Overview

Problem

Existing positioning techniques, particularly those using sensor fusion based on Kalman filters, face limitations in flexibility and accuracy when handling a wide variety of positioning systems and are not suitable for real-time applications, especially in scenarios where positioning systems do not function reliably or transition between different data sources.

Innovation Solution

A pose graph with chain geometry is used to efficiently optimize the fusion of odometry and absolute position data from multiple sources, allowing for flexible sensor fusion and accurate position estimation by employing a block three-diagonal system matrix for computationally efficient inversion and reduced optimization time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a pose graph with chain geometry is used for sensor fusion, then computational efficiency and real-time performance are improved, but the ability to handle complex positioning scenarios with multiple data sources may be limited

Engineering Contradiction:
Improvecomputational efficiencyVSAvoidhandling capability
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The pose graph is segmented into a chain geometry structure where the graph is divided into sequential nodes and edges representing position data at different time points. This segmentation enables efficient computational processing while maintaining the ability to represent complex positioning scenarios through the sequential arrangement of nodes that can capture multiple data sources in a time-ordered sequence.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If traditional sensor fusion methods are used to handle a wide variety of positioning systems, then flexibility and accuracy are improved, but computational complexity and time consumption increase

Engineering Contradiction:
Improveposition estimation accuracyVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The invention changes the parameter representation by organizing position data into a pose graph structure with nodes representing positions at different time points and edges representing transitions. This parameter transformation enables the system to handle multiple positioning systems with different accuracies and time stamps efficiently, reducing computational complexity while maintaining position estimation accuracy through the structured graph representation.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If comprehensive sensor fusion of multiple positioning systems is performed, then position estimation accuracy is improved, but processing time and computational resources increase

Engineering Contradiction:
Improveposition estimation accuracyVSAvoidprocessing time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The pose graph structure performs preliminary organization of position data from multiple positioning systems before actual fusion computation. By pre-structuring the data into nodes and edges with proper time ordering and relationships, the system reduces the computational burden during the actual fusion process, enabling faster processing while maintaining comprehensive use of multiple data sources for accurate position estimation.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3359914B1Fusion of position data by means of pose graph
Publication Date: 2023.07.05 VOLKSWAGEN AG
  • EP3359914B1 patent drawingFigure 1
  • EP3359914B1 patent drawingFigure 2
  • EP3359914B1 patent drawingFigure 3

AI summary

Absolute position data (605) of a machine are determined for respective multiple times (t.1, t.3, t.5, t.8, t.11), and odometry position data of the machine are alsodetermined. A pose graph (661) is generated, wherein edges (672) of the pose graph (661) correspond to the odometry position data, and nodes (671) of the pose graph (661) correspond to the absolute position data (605). The pose graph (661) is optimised to obtain an estimated position. Optionally, the odometry can also be estimated. A driver assistance functionality of the machine, for example a motor vehicle, can be controlled optionally on the basis of the estimated position. For example, the driver assistance functionality can relate to autonomous driving.