Illumination standard calculation method and system for a tunnel entrance section in daytime based on safe visual recognition
US10452929B2 · kind B2 · utility
Assignees
Inventors
Key dates
| Filing date | Oct 15, 2015 |
| Grant date | Oct 22, 2019 |
| Priority date | — |
| Expiry date | Apr 16, 2036 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02B20/40
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
The invention relates to an illumination standard calculation method for a tunnel entrance section in daytime based on safe visual recognition. The method includes: (a) setting light environment parameters of the tunnel entrance section; (b) determining a feature position in the tunnel, and measuring the average road surface brightness L of the feature position; (c) placing a target object in the feature position and then making a driver drive at different speeds from outside the tunnel towards the target object to measure visual recognition distances D required by the driver to visually discover the target object under different driving speeds, and measuring the road surface brightness L20 at the position where the driver visually discovers the target object and calculating the brightness reduction factor K to be the ratio between L and L20; (d) resetting the average road surface brightness L of the tunnel entrance section and repeating steps (b) and (c) to obtain a plurality of different sets of visual recognition distances D and corresponding brightness reduction factors K; (e) using Sigmoid function model to calculate and fit the data of the plurality of sets of D and K to obta…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.