Non-Intrusive Methods of Characterizing Vehciles on the Highway

摘要

Over the past year we have worked on the development of a real-time laser-based non-intrusive field-deployable detection system for delineation of moving vehicles. The primary goal of the project is to develop a roadway detection system that can be used to gather reliable travel time data non-intrusively. Microprocessor is used to control digital-controlled potentiometer (DCP), which adjusts the gain of sensors signals. It adjusts the system quickly on highway with only pushing a button. The adjustment, which used to take half or an hour, needs only several seconds. Meantime, the microprocessor is also able to filter noise after having finished the task of adjustment. The software of the system is rebuilt for 8 channels, which used to be for 4 channels, to be able to obtain more information of vehicles even like the outline of vehicle. In order to improve the precision of the system, we improved the mechanical design, optical design and electric circuit design. The frequency of laser pulse is 10 kHz and the sample rate of computer DIO96 board is also 10 kHz. This document describes the design and implementation of each functional component of the field-deployment system, the configuration of the field detection system, and software design and implementation. This report also discusses optical techniques that may potentially be used for the detection of trace amounts of gases such as CO, CO2, NO and NO2 through the use of an overhead detector that employs signal reflection from a roadway like the Laser-Based Detection System. These gas species are relevant to detection of highly polluting vehicles.