Speedometer Installation on Curved Roads Using Reference Axis

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current methods for installing traffic control speedometers are inadequate for measuring vehicle speeds on curved roads, as they fail to maintain the required measurement angle precision, leading to invalid speed measurements.

Innovation Solution

A method involving a sighting system with a fixed mounting angle, where a reference axis is determined based on the road's curvature to adjust the speedometer's orientation, ensuring the measurement angle deviation remains within acceptable limits, even on bends, by placing marks at specific distances and using a chord to establish a reference axis parallel to the vehicle's speed vector.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the speedometer is installed using conventional methods on curved roads, then the installation process remains simple, but the measurement angle precision deteriorates and becomes invalid

Engineering Contradiction:
Improveinstallation simplicityVSAvoidmeasurement angle precision
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The method determines a reference axis before installing the speedometer, based on the road's curvature characteristics. This preliminary determination of the correct orientation reference allows the speedometer to be installed with proper measurement angle precision even on curved roads, rather than using conventional simple installation methods that ignore road geometry

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The invention changes the installation parameters by introducing a reference axis that accounts for road curvature radius and bend angle. Instead of using fixed installation angles, the method adjusts the speedometer orientation based on calculated parameters derived from road geometry, ensuring measurement validity on curved sections

Inventive Principle:
Principle #35Parameter changes

2Reliability

If the speedometer is oriented to maintain measurement angle precision on bends, then measurement reliability improves, but the installation complexity increases

Engineering Contradiction:
Improvespeed measurement validityVSAvoidinstallation complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The method introduces a reference axis as an intermediary element that mediates between the road geometry and the speedometer orientation. This reference axis, determined from road curvature parameters, serves as a simple guide for installers to achieve correct positioning without complex adjustment procedures

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

By pre-calculating the reference axis based on road survey data before installation, the method eliminates the need for complex real-time adjustments during installation. The reference axis provides a clear orientation guide that simplifies the installation process while ensuring measurement reliability

Inventive Principle:
Principle #10Preliminary action

3Manufacturing precision

If marks are placed at greater distances from the speedometer, then the reference axis determination becomes more accurate, but the installation time increases

Engineering Contradiction:
Improvereference axis determination accuracyVSAvoidinstallation time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The method optimizes the mark placement distance as a parameter, determining the appropriate distance based on road curvature radius and required precision. This parameter-based approach allows installers to quickly determine correct mark positions without trial and error, balancing accuracy requirements with installation efficiency

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method allows for precise and reliable speed measurements on roads with bends, adhering to industry standards by minimizing the difference between the mounting and measurement angles, thus ensuring valid speed data across various road configurations.

Implementation Method 1

The speed of the vehicle is then deduced from the measurement carried out by a method which is known per se, for example by Doppler effect quantification

Methodology Applied
Scientific EffectDoppler effect: Doppler Effect

Data Source

PatentEP2875385B8Method for installing a speed-detection device on a windy road
Publication Date: 2018.06.27 IDEMIA IDENTITY & SECURITY FRANCE SAS

AI summary

The invention relates to a method for installing a speed-detection device on a road (100), said speed-detection device having a radioelectric line (11) for measuring a speed of at least one vehicle (30) travelling along the road (100), and a line of sight (12) forming a fixed mounting angle (?) with said radioelectric line (11), wherein the road (100) forms a bend such that a difference (a) between the measuring angle (?) and the mounting angle (?) would be higher than 0.5? if one of the methods of the prior art for a substantially straight road were to be implemented, said method thus comprising a step of determining a reference axis (106) for identifying a longitudinal direction of the road (100) according to the radius of curvature of the bend, in such a way that when the line of sight (12) is parallel to the reference axis (106), the difference (a) is reduced to less than 0.5?.