Tunnel Midsection Lighting Standards Based on Safe Visual Recognition
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Solution Overview
Problem
Current illumination standards for tunnel middle sections are unreliable and complex, failing to account for the driver's psychological and physiological factors, and do not consider different light source characteristics that affect visual recognition.
Innovation Solution
A method and system for calculating illumination standards for tunnel middle sections based on safe visual recognition, which combines data on driver response and visual recognition of small targets under different light environments, using a data fitting mathematical model to determine the minimum brightness value required for safe driving.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If subjective experience evaluation or psychological/physiological indicators are used to assess tunnel illumination, then driver safety and comfort can be evaluated, but the measurement method becomes complex and difficult to operate
Solution Approach 1:
The patent replaces complex psychological and physiological measurement systems with a simple visual recognition test system. Instead of measuring driver psychology or physiology directly, the system uses objective visual recognition performance (detecting small targets) as a proxy indicator, substituting a simple optical measurement system for complex human factor assessment systems.
Solution Approach 2:
The patent enables the illumination standard assessment to be self-evaluating through the visual recognition test. The system automatically determines whether illumination standards are met by measuring whether drivers can successfully recognize small targets at specified distances, without requiring external expert evaluation or complex instrumentation.
2Measurement precision
If static measuring methods are used to study lighting source characteristics and visual recognition, then theoretic study can be conducted, but the selection of characteristic indicators is limited and does not reflect actual driving conditions
Solution Approach 1:
The patent transitions from static measurement methods to dynamic measurement methods that simulate actual driving conditions. The visual recognition test is conducted while drivers are in motion at specified speeds, and the system dynamically adjusts to different light source types (sodium lamps, LED, etc.), making the measurement both precise and adaptable to various lighting scenarios.
Solution Approach 2:
The patent changes key parameters including driving speed, target object characteristics, and light source types to create a versatile assessment system. By varying these parameters and observing their effect on visual recognition performance, the system achieves both measurement precision and adaptability across different tunnel illumination scenarios.
3Illumination intensity
If existing illumination standards based on sodium lamp characteristics are applied, then illumination can be provided, but the standards do not meet visual recognition requirements under different light source characteristics
Solution Approach 1:
The patent changes the fundamental parameter for illumination standard determination from fixed sodium lamp characteristics to variable parameters based on actual light source types and visual recognition performance. The system establishes different brightness requirements for different light sources (sodium lamps, LED, etc.) based on their spectral characteristics and how they affect driver ability to recognize small targets.
Data Source
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AI summary
This invention relates to an illumination standard calculation method for a tunnel middle section based on safe visual recognition: (a) Setting the light environment of the tunnel middle section; (b) Placing a target object in the tunnel middle section; (c) Making a driver drive a motor vehicle at different speeds toward the target object, and measuring the visual recognition distances D required by the driver to visually discover the target object at different speeds; (d) Resetting the average brightness L of the tunnel middle section and repeating the steps (b) and (c) to obtain a plurality of different sets of visual recognition distances D and corresponding brightness values L; (e) Using the S model to fit the data of the plurality of sets of visual recognition distances D and brightness values L to obtain the formula of the relational model of D and L to be L=0.683/(5.575-In(D)); (f) Substituting a safe stopping sight distance D0 corresponding to a maximum speed limit of the tunnel into the model formula to obtain the dynamic minimum brightness value L0 required for the tunnel middle section under this tunnel light environment. The method improves the accuracy of safety evaluation of the tunnel middle section brightness, and the method is simple and convenient, and provides a reference basis for the road traffic safety research. The invention also provides a system for implementing this method.