Distributed Traffic Prediction Models for Privacy-Safe Route Planning

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Solution Overview

Problem

Existing route planning methods for vehicular traffic systems are inadequate due to the dynamic nature of traffic conditions, reliance on potentially misleading crowdsourced information, and limitations in centralized and on-board learning, which fail to provide accurate short-term, medium-term, and long-term traffic predictions, leading to suboptimal route planning and increased congestion.

Innovation Solution

A distributed machine learning approach using federated learning and multi-task learning techniques, where infrastructure devices act as learning servers and data collectors as agents, train localized traffic models based on clustered data to create robust global traffic models, considering location, time, and weather factors, and predict traffic with multi-horizon time domains, while maintaining data privacy and reducing communication overhead.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Quantity of substance

If centralized learning at cloud is used to collect sufficient data for training machine learning algorithms, then data completeness for training is improved, but communication bandwidth requirements increase and data privacy/security issues worsen

Engineering Contradiction:
Improvedata completenessVSAvoidcommunication overhead
Core Design Contradiction:
Quantity of substanceVSDevice complexity

Solution Approach 1:

The patent segments the centralized learning system into distributed edge learning nodes (vehicles and infrastructure devices) that independently train local models. Each node processes data locally rather than centralizing all data at the cloud, thereby reducing communication bandwidth requirements while maintaining model training effectiveness through federated learning aggregation.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent introduces federated learning as an intermediary mechanism that enables collaborative model training without direct data sharing. The global model serves as an intermediary that aggregates knowledge from multiple local models through parameter sharing, eliminating the need for raw data transmission while achieving comprehensive learning.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If machine learning algorithms are trained using large amount of different data types for accurate traffic prediction, then prediction accuracy is improved, but data privacy and security risks worsen

Engineering Contradiction:
Improveprediction accuracyVSAvoiddata privacy risk
Core Design Contradiction:
Measurement precisionVSObject-affected harmful factors

Solution Approach 1:

The patent extracts only the essential model parameters and gradients needed for training from the raw traffic data, leaving the sensitive raw data localized at each edge device. This extraction approach enables accurate model training while eliminating the privacy risks associated with centralized raw data storage and transmission.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses model parameter copies instead of original data copies for sharing between nodes. Each vehicle and infrastructure device maintains local copies of the global model parameters and contributes updated parameters through federated learning, achieving collaborative training without exposing sensitive raw traffic data.

Inventive Principle:
Principle #26Copying

3Area of stationary object

If existing route planning methods rely on crowdsourcing information from multiple vehicles, then route planning coverage is improved, but traffic density estimation accuracy worsens due to misleading decisions

Engineering Contradiction:
Improveroute planning coverageVSAvoidtraffic density accuracy
Core Design Contradiction:
Area of stationary objectVSMeasurement precision

Solution Approach 1:

The patent implements a feedback mechanism where vehicles receive predicted traffic information from the distributed learning model and use this information to make route decisions. The system continuously updates predictions based on actual traffic conditions observed by edge devices, creating a closed-loop feedback system that improves both coverage and accuracy over time.

Inventive Principle:
Principle #23Feedback

Data Source

PatentEP4252217B1Distributed multi-task machine learning for traffic prediction
Publication Date: 2026.01.14 MITSUBISHI ELECTRIC CORP
  • EP4252217B1 patent drawingFigure 1
  • EP4252217B1 patent drawingFigure 2
  • EP4252217B1 patent drawingFigure 3A

AI summary

A distributed machine learning based traffic prediction method is provided for predicting traffic of roads. In this case, the distributed machine learning based traffic prediction method includes distributing global multi-task traffic models by a learning server to learning agents to locally train the traffic models, uploading locally trained traffic models by learning agents to the learning server, updating global multi-task traffic models by the learning server using locally trained traffic model parameters acquired from learning agents, generating a time-dependent global traffic map by the learning server using the well trained global multi-task traffic models, distributing the time dependent global traffic map to vehicles traveling on the roads, and computing an optimal travel route with the least travel time by a vehicle using the time-dependent global traffic map based on a driving plan.