A Real-Time Laser-Based Prototype Detection System for Measuring Delineations of Moving Vehicles

Problem

The goal of this project is to build a system that can gather reliable travel time data non-intrusively for use in traffic planning and ITS. Laser detection systems offer several advantages over other methods like loop detectors: ease of installation and maintenance (no digging or rerouting of traffic required), simple computational needs, and no dependence on existing lighting conditions.

Method

A laser is projected onto the ground, and an optical sensor collects the reflected light, focusing it onto a photo sensor that converts the signal to a readable sample. It can detect a vehicle as it passes under the laser by the absence of reflected light. With two such systems set a known distance apart, the speed of the passing vehicle can be measured, as well as its length (useful for identifying and re-identifying vehicles).

We built and tested an indoor prototype to prove the concept and develop algorithms, and are developing a full-scale system for outdoor testing. This report describes the design and implementation of the components of the lab prototype, the configuration of the field testing system, and software design and implementation.

Findings

The lab prototype can detect the profile and measure the length of a small test vehicle passing at varying speeds with high repeatability.

Problems we encountered include electrical noise and sunlight interfering with sensors; these can be fixed with continued work.