Metric Representation Learning for Robot Self-Localization

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Solution Overview

Problem

Existing self-localization algorithms for autonomous mobile devices, such as robots, face challenges in providing accurate metric position information without relying on external sensors, which are costly and prone to synchronization issues, and are not well-suited for small commercial robots due to limited computing resources.

Innovation Solution

A method that uses unsupervised learning, specifically Slow Feature Analysis (SFA), to generate a metric representation from onboard sensor data, including odometer displacement data, allowing for the determination of metric position information without external sensors, and integrates this with odometry data for improved accuracy using Kalman filtering.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If external sensors are used to generate ground truth metric position measurements, then position accuracy is improved, but device complexity and cost increase

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

Solution Approach 1:

The mobile device uses its own onboard sensors and odometer to generate ground truth metric position measurements through unsupervised learning, eliminating the need for external sensors. The device serves itself by processing its own sensor data to create environmental representations and learn mapping parameters without external assistance.

Inventive Principle:
Principle #25Self-service

Solution Approach 2:

The system creates an environmental representation R that serves as a learned copy of the physical environment, which can then be used to determine metric position information. This learned representation replaces the need for direct measurements from external sensors.

Inventive Principle:
Principle #26Copying

2Measurement precision

If external sensors are used for ground truth measurements, then position accuracy is improved, but synchronization issues arise

Engineering Contradiction:
Improveposition accuracyVSAvoidsynchronization reliability
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The system uses only onboard sensors and odometer data that are inherently synchronized through the device's internal timing system. By eliminating external sensors, the synchronization problem is resolved as all data sources are controlled by a single clock.

Inventive Principle:
Principle #25Self-service

3Measurement precision

If SLAM algorithms are used for self-localization, then metric position information can be obtained, but computing resources are excessive for small commercial robots

Engineering Contradiction:
Improvemetric position informationVSAvoidcomputing resource consumption
Core Design Contradiction:
Measurement precisionVSUse of energy by moving object

Solution Approach 1:

The system extracts only the essential components needed for localization from full SLAM algorithms. Instead of performing complete simultaneous localization and mapping, it focuses on generating environmental representations and learning mapping parameters from odometer data, removing unnecessary computational complexity.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The approach changes the problem parameters by using unsupervised learning to directly map sensor data to metric positions through environmental representations, rather than using the complex iterative optimization processes typical of SLAM algorithms. This reduces computational burden while maintaining accuracy.

Inventive Principle:
Principle #35Parameter changes

4Productivity

If environment representations are generated without metric data, then computational effort is reduced, but direct inclusion of odometer data becomes impossible

Engineering Contradiction:
Improvecomputational efficiencyVSAvoidodometer data integration
Core Design Contradiction:
ProductivityVSAdaptability or versatility

Solution Approach 1:

The system changes the nature of environmental representations by making them metric through unsupervised learning. The mapping parameters W learned from odometer data transform the environmental representation R into a metric space, enabling direct inclusion of odometer information while maintaining computational efficiency.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The approach merges environmental representations from onboard sensors with metric information from the odometer through the learned mapping parameters. This combination allows the system to benefit from both the computational efficiency of sensor-based representations and the accuracy of metric odometer data.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentUS11580364B2Unsupervised learning of metric representations from slow features
Publication Date: 2023.02.14 HONDA MOTOR CO LTD
  • US11580364B2 patent drawing
  • US11580364B2 patent drawing
  • US11580364B2 patent drawing

AI summary

A method of unsupervised learning of a metric representation and a corresponding system for a mobile device determines a metric position information for a mobile device from an environmental representation. The mobile device comprises at least one sensor for acquiring sensor data and an odometer system configured to acquire displacement data of the mobile device. An environmental representation is generated based on the acquired sensor data by applying an unsupervised learning algorithm. The mobile device moves along a trajectory and the displacement data and the sensor data are acquired while the mobile device is moving along the trajectory. A set of mapping parameters is calculated based on the environmental representation and the displacement data. A metric position estimation is determined based on a further environmental representation and the calculated set of mapping parameters.