Inductive sensor for vehicle detection

// Overview

Inductive sensors detect metallic objects by measuring perturbations in an oscillating magnetic field. Embedding them in road surfaces to detect vehicles is a well-established technique — but understanding the physics and building a working prototype from scratch is a different challenge.

The project covered the full chain: designing the resonant circuit, building a bench prototype with inductive coils, and using MATLAB to analyze the magnetic field response. The system successfully identified vehicle arrival and departure events from the measured B-field versus time curve.

// What I did

• Designed a resonant RLC detection circuit and selected components.
• Built and assembled the inductive coil prototype on a lab bench.
• Measured the magnetic field response during vehicle presence and modeled the transfer function.
• Analyzed frequency response using a Bode diagram in MATLAB — before and after perturbation.