Constraint-Based Sensor Map Data Fusion for Dead Reckoning Error Correction

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Dead reckoning-based tracking systems suffer from cumulative error over long periods, and existing aiding sensors face challenges in indoor environments and non-Gaussian noise, limiting their accuracy and reliability for pedestrian tracking.

Innovation Solution

The implementation of a constraint-based convex optimization method for sensor and map data fusion, which uses convex SLAM algorithms to enforce distance and angle constraints on the tracking path, allowing for robust navigation solutions without assumptions on error distributions and maintaining the entire trajectory history for correction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of moving object

If dead reckoning process is used for tracking, then continuous position estimation is achieved, but cumulative error increases over long periods

Engineering Contradiction:
Improvetracking durationVSAvoidposition accuracy
Core Design Contradiction:
Duration of action of moving objectVSMeasurement precision

Solution Approach 1:

The patent implements feedback by using detected map features and range measurements to provide corrections to the dead reckoning trajectory through SLAM algorithms. The system continuously compares estimated position with observed features and adjusts the trajectory to reduce cumulative error, enabling accurate long-duration tracking.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent combines multiple data sources including dead reckoning sensors, map features, and range measurements into a unified SLAM framework. This merging of information sources allows the system to compensate for dead reckoning drift while maintaining continuous position estimation over extended periods.

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If SLAM algorithms with Bayes filter are used for map and tracking fusion, then corrections for dead reckoning drift are provided, but computational complexity increases

Engineering Contradiction:
Improvetracking reliabilityVSAvoidalgorithm complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent changes the mathematical parameters and assumptions in the SLAM formulation to enable more efficient computation. By modifying the error distribution assumptions and optimization parameters, the system achieves reliable tracking with reduced computational complexity compared to traditional Bayes filter approaches.

Inventive Principle:
Principle #35Parameter changes

3Measurement precision

If aiding sensors are used to compensate for dead reckoning errors, then position accuracy is improved, but system complexity and indoor environment limitations increase

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

Solution Approach 1:

The patent creates a universal SLAM framework that can process multiple types of sensor data and map features through a unified algorithmic approach. This multi-functional system handles various sensor inputs and environmental conditions without requiring separate specialized processing paths, reducing overall system complexity while maintaining accuracy.

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

Data Source

PatentUS10571270B2Fusion of sensor and map data using constraint based optimization
Publication Date: 2020.02.25 TRX SYST
  • US10571270B2 patent drawing
  • US10571270B2 patent drawing
  • US10571270B2 patent drawing

AI summary

Disclosed herein are methods and systems for fusion of sensor and map data using constraint based optimization. In an embodiment, a computer-implemented method may include obtaining tracking data for a tracked subject, the tracking data including data from a dead reckoning sensor; obtaining constraint data for the tracked subject; and using a convex optimization method based on the tracking data and the constraint data to obtain a navigation solution. The navigation solution may be a path and the method may further include propagating the constraint data by a motion model to produce error bounds that continue to constrain the path over time. The propagation of the constraint data may be limited by other sensor data and/or map structural data.