Summary of Implementation of an Artificial Lighting System for Automated Visual Distress Rating System

15. Supplementary Notes Project performed in cooperation with the Texas Department of Transportation and the Federal Highway Administration. 16. Abstract The artificial lighting system called a light bar is a specially designed lighting device for the automated pavement distress measurement system (VCrack) developed in a previous TxDOT project. The basic function of this device is to provide intense, uniform, and linear illumination for the VCrack’s line-scan camera and helps it provide high quality pavement images under any exterior lighting conditions. It consists of three major units: one 6-foot long central unit and two one-foot long wing units (see Figure 1). Each unit utilizes three rows of red LED’s, a cylindrical lens and two mirrors, forming a one-inch wide beam at a distance 16-inch (see Figure 2). The energy consumption of the light bar is <250 watts, eliminating the need for a special generator. Along with a matching band pass filter, the light bar enables the camera to avoid the variations of the ambient light. The lighting intensity is sufficient enough for nighttime surveys. The light bar has been merged with the existing rut bar that is installed on the front bumper, and its wing assemblies break-away should they collide with a foreign object. The light bar is eyesafe, durable, and easy to maintain. Figure 3 shows the light bar that is mounted on a survey vehicle and provides beam illumination.