Vision-Aided Inertial Navigation With Linear Feature Constraints

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Solution Overview

Problem

Existing navigation technologies, such as GPS-based systems, face challenges in urban and indoor environments due to poor signal reception and inability to detect obstacles, and suffer from sensor errors and limitations in close-quarter navigation and vehicular accident avoidance.

Innovation Solution

A system that processes visual information from cameras and inertial sensor data using an Extended Kalman filter to estimate pose and localization information, with computational complexity linearly related to the number of tracked features, allowing for high-precision pose estimation in large-scale environments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If the number of tracked visual features is increased, then localization precision is improved, but computational complexity increases

Engineering Contradiction:
Improvelocalization precisionVSAvoidcomputational complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent segments the computational task by processing visual features independently and forming constraints for each feature separately. Each visual feature generates its own pose constraint equation, which can be processed and accumulated independently. This segmentation allows the system to handle multiple features without exponentially increasing computational complexity, as each feature contributes additively to the overall constraint set rather than creating combinatorial interactions.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If visual features are used for navigation, then navigation accuracy is improved in GPS-denied environments, but the system becomes unable to detect moving obstacles

Engineering Contradiction:
Improvenavigation accuracyVSAvoidobstacle detection capability
Core Design Contradiction:
Measurement precisionVSDifficulty of detecting and measuring

Solution Approach 1:

The patent applies dynamics by treating the detection status of visual features as a time-varying property. The system continuously monitors whether detected features are static or moving, and dynamically adjusts which features are used for navigation constraints. Features identified as moving (potential obstacles) are excluded from constraint formation, while static features continue to provide localization information. This dynamic classification allows the system to maintain navigation accuracy using static features while simultaneously detecting moving obstacles that are excluded from the constraint set.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentUS11519729B2Vision-aided inertial navigation
Publication Date: 2022.12.06 REGENTS OF THE UNIVERSITY OF MINNESOTA
  • US11519729B2 patent drawing
  • US11519729B2 patent drawing
  • US11519729B2 patent drawing

AI summary

Localization and navigation systems and techniques are described. An electronic device comprises a processor configured to maintain a state vector storing estimates for a position of the electronic device at poses along a trajectory within an environment along with estimates for positions for one or more features within the environment. The processor computes, from the image data, one or more constraints based on features observed from multiple poses of the electronic device along the trajectory, and computes updated state estimates for the position of the electronic device in accordance with the motion data and the one or more computed constraints without computing updated state estimates for the features for which the one or more constraints were computed.