3D Keypoint Learning for Monocular Ego-Motion Estimation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current autonomous systems rely on hand-engineered keypoint features for ego-motion estimation, which are limited in performance due to lack of invariance to lighting and viewpoint changes, and require expensive ground-truth labels for supervised learning, making them ineffective for real-world, non-planar 3D scenes.

Innovation Solution

A self-supervised learning method that trains a keypoint network and depth network to learn depth-aware keypoints and descriptors from monocular video, using a differentiable pose estimation module and multi-view adaptation to optimize keypoints and depths in a structure-from-motion setting, enabling ego-motion estimation without ground-truth labels.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If hand-engineered keypoint features are used for ego-motion estimation, then the system can operate without ground-truth labels, but the performance is limited due to lack of invariance to lighting and viewpoint changes

Engineering Contradiction:
Improvekeypoint detection robustnessVSAvoidinvariance to lighting and viewpoint changes
Core Design Contradiction:
ReliabilityVSAdaptability or versatility

Solution Approach 1:

The system uses self-supervised learning where the model learns to detect keypoints and estimate depth from monocular video sequences without requiring ground-truth labels. The ego-motion itself provides the supervision signal, allowing the system to improve its keypoint detection robustness while adapting to various lighting and viewpoint conditions through autonomous learning from available data.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The patent introduces depth as an additional dimension by jointly learning depth-aware keypoints alongside 2D keypoint detection. This transforms the problem from purely 2D image space to 3D space, enabling the system to achieve invariance to lighting and viewpoint changes by incorporating depth information that remains stable across different viewing conditions.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Measurement precision

If supervised learning with ground-truth labels is used to improve keypoint detection accuracy, then performance improves, but it requires expensive ground-truth labels that are unavailable in real-world scenarios

Engineering Contradiction:
Improvekeypoint detection accuracyVSAvoidavailability of training data
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The system employs self-supervised learning where the model generates its own supervision signals from the input data. By using the geometric constraints and ego-motion information from monocular video sequences, the system can train deep neural networks to achieve high keypoint detection accuracy without requiring expensive ground-truth annotations, making it feasible for real-world deployment.

Inventive Principle:
Principle #25Self-service

3Device complexity

If conventional 2D keypoint features are used, then the system is simpler to implement, but it fails to achieve accurate ego-motion estimation in non-planar 3D scenes

Engineering Contradiction:
Improvesystem implementation complexityVSAvoidego-motion estimation accuracy
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent extends conventional 2D keypoint detection by introducing depth-aware 3D keypoints. The system jointly learns depth maps and keypoint locations, allowing it to accurately represent points in 3D space. This dimensional extension enables reliable ego-motion estimation in non-planar 3D scenes while maintaining a unified network architecture that does not significantly increase implementation complexity.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Data Source

PatentUS11900626B2Self-supervised 3D keypoint learning for ego-motion estimation
Publication Date: 2024.02.13 TOYOTA JIDOSHA KK
  • US11900626B2 patent drawing
  • US11900626B2 patent drawing
  • US11900626B2 patent drawing

AI summary

A method for learning depth-aware keypoints and associated descriptors from monocular video for ego-motion estimation is described. The method includes training a keypoint network and a depth network to learn depth-aware keypoints and the associated descriptors. The training is based on a target image and a context image from successive images of the monocular video. The method also includes lifting 2D keypoints from the target image to learn 3D keypoints based on a learned depth map from the depth network. The method further includes estimating ego-motion from the target image to the context image based on the learned 3D keypoints.