Virtual Induction Loops for Adaptive Intersection Signal Control

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing traffic control systems, such as those using induction loops and video loops, fail to account for real-time traffic situations due to fixed installations that are often too close to intersections, leading to inefficiencies and high maintenance costs.

Innovation Solution

Implementing a virtual induction loop system that allows for bidirectional communication between vehicles and traffic light controllers, enabling real-time updates and adjustments through recall and cancellation messages, allowing for dynamic control of traffic signals based on vehicle position, speed, and arrival time.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If fixed induction loops are installed close to intersections, then vehicle detection is achieved, but response time is insufficient and maintenance costs increase

Engineering Contradiction:
Improvevehicle detection accuracyVSAvoidresponse time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The system performs preliminary action by sending map messages to vehicles at a distance from the intersection, allowing vehicles to calculate their trajectory and send recall messages in advance. This enables the traffic controller to prepare signal adjustments before the vehicle reaches the detection zone, resolving the time response limitation of fixed loops.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary communication system (map messages, recall messages, cancellation messages) between the vehicle and traffic controller. This intermediary layer allows information exchange and coordination without requiring physical proximity to fixed detection loops, enabling advance warning and better time management.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Measurement precision

If fixed induction loops are installed close to intersections, then vehicle detection is achieved, but maintenance costs increase

Engineering Contradiction:
Improvevehicle detection accuracyVSAvoidmaintenance cost
Core Design Contradiction:
Measurement precisionVSEase of manufacture

Solution Approach 1:

The system creates a virtual copy of the induction loop functionality through software-based map messages and recall messages. Instead of physical loops embedded in the roadway, the detection function is replicated through communication between vehicle processors and traffic controllers, eliminating the need for costly physical installations and maintenance.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The patent replaces the mechanical/physical induction loop system with an electronic communication-based system. Vehicle processors and traffic controllers use digital messages to achieve vehicle detection and control, substituting physical infrastructure with software-based solutions that reduce maintenance requirements.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

3Adaptability or versatility

If bidirectional communication is implemented, then adaptive control is improved, but system complexity increases

Engineering Contradiction:
Improveadaptive signal controlVSAvoidcommunication system complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The communication system is designed with multi-functionality, where map messages provide both navigation information and detection triggers, recall messages serve both as detection confirmations and control triggers, and cancellation messages handle both trajectory changes and control cancellations. This universal message structure reduces overall system complexity despite enhanced adaptability.

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

Solution Approach 2:

Vehicles autonomously calculate their trajectories and determine when to send recall messages based on received map messages. The vehicle's own processor performs the detection and decision-making functions, reducing the complexity burden on the traffic controller and distributing system intelligence across multiple nodes.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3818510B1Virtual induction loops for adaptive signalized intersections
Publication Date: 2025.08.06 VOLKSWAGEN AG
  • EP3818510B1 patent drawingFigure 1
  • EP3818510B1 patent drawingFigure 2
  • EP3818510B1 patent drawingFigure 3A

AI summary

A system and method are provided for controlling traffic signals using virtual induction loops. The system allows bidirectional communication between a traffic signal controller and a vehicle so that the controller can send map data to the vehicle and the vehicle can send a recall message to the controller, requesting to be served by the controller at an approaching traffic signal.