Variable Speed Sign Estimation via Vehicle Probe Data Clustering

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Solution Overview

Problem

Current systems for determining variable speed sign values are unreliable, particularly in low visibility conditions and lack widespread vehicle compatibility, leading to inconsistent speed limit detection and adherence.

Innovation Solution

A system that collects probe data from vehicles, calculates center distance values, and uses clustering algorithms to identify speed clusters, allowing for accurate lane assignment and speed limit determination, which can be communicated to vehicles without camera or radar technology.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If camera or radar technology is used to detect speed limits, then detection accuracy is improved, but device cost and complexity increase

Engineering Contradiction:

Improvespeed limit detection accuracyVSAvoidsensor infrastructure cost

Core Design Contradiction:

Measurement precisionVSDevice complexity

Solution Approach 1:

The patent replaces optical detection systems (cameras) and electromagnetic detection systems (radar) with a data processing system that analyzes probe data from vehicles. Instead of using sensors to directly detect speed limits, the system processes speed and location data from multiple vehicles to infer and determine variable speed sign values, thereby eliminating the need for costly camera and radar infrastructure.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If probe data from multiple vehicles is collected and analyzed, then speed limit detection reliability is improved, but data processing complexity increases

Engineering Contradiction:

Improvespeed limit detection reliabilityVSAvoiddata processing complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges data from multiple probe sources (vehicles) to collectively determine speed limit information. By combining speed data, location data, and probe data from numerous vehicles passing through the same geographic area, the system achieves reliable speed limit detection through data aggregation and clustering algorithms, making the detection process more robust and reliable.

Inventive Principle:

Principle #5Merging (Combining)

3Measurement precision

If clustering algorithms are used to identify speed clusters, then lane assignment accuracy is improved, but computational requirements increase

Engineering Contradiction:

Improvelane assignment accuracyVSAvoidcomputational processing power

Core Design Contradiction:

Measurement precisionVSPower

Solution Approach 1:

The patent applies clustering algorithms to identify distinct speed clusters corresponding to different lanes, but only processes data from geographic areas where variable speed signs are present and only when sufficient probe data is available. This partial application of the clustering methodology reduces unnecessary computational overhead while maintaining accuracy where needed.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS11636760B2Detection and estimation of variable speed signs

Publication Date: 2023.04.25 HERE GLOBAL BV

AI summary

Systems, methods, and apparatuses are disclosed for predicting or estimating the value of a variable speed sign (VSS). Probe data is received from multiple vehicles associated with a road segment. Location values are derived from the probe data. Center distance values are calculated based on the location values and the road segment. Clusters are derived from the probe data. Center distance values are grouped according to the respective clusters and a lane is assigned to at least one cluster based on the center distance values. The speed of the cluster predicts or estimates the corresponding lane of the VSS.