Estimation of Average Speed of Road Vehicles by Sound Intensity Analysis

Area of Science:

• Acoustic sensing
• Smart city technology
• Traffic engineering

Background:

• Effective road traffic monitoring is crucial for smart city infrastructure.
• Existing methods may have limitations in certain urban environments.
• A novel approach using passive acoustic sensing is proposed.

Purpose of the Study:

• To develop and validate a novel method for estimating average road vehicle speed.
• To utilize sound intensity analysis with a passive acoustic vector sensor.
• To assess the accuracy of the proposed method against established sensors.

Main Methods:

• Measuring sound intensity in two orthogonal axes using a road-side sensor.
• Estimating sound source position via analysis in three frequency bands (1 kHz, 2 kHz, 4 kHz).
• Calculating average speed using linear regression on averaged position signals.

Main Results:

• The method demonstrated high accuracy in controlled and real-traffic experiments.
• Average estimation error was 1.4%, with a maximum error of 3.2%.
• Results were validated against lidar and radar sensors.

Conclusions:

• The proposed acoustic sensing method provides accurate road traffic speed estimation.
• The technique is suitable for traffic statistics gathering in smart city applications.
• This novel approach offers a viable alternative for traffic monitoring.