Line-Following Robot with Obstacle Avoidance

Context

A differential-drive robot that follows a taped line using an array of infrared reflectance sensors, and when an obstacle appears on the track, drives around it and reacquires the line on the far side.

My role

Sole builder: chassis design, electronics, and firmware.

Constraints & tradeoffs

Budget capped the sensor count at five, which limits how sharp a curve the controller can track at speed. A simple PD loop was chosen over PID because the integral term added windup problems on long straights without improving cornering.

Approach

3D-printed chassis, an Arduino Nano running a PD line-tracking loop in C++, and an ultrasonic sensor triggering a fixed detour maneuver state machine.

Result

Completes a 12 m test track with two obstacles reliably. Placeholder metrics — to be replaced with real ones.