Line follower PID tuning, lessons from a season
Posted: Sat Jun 27, 2026 8:00 am
Comp ended. Bot finished 3rd. Sharing what worked on PID after months of bench testing.
Starting point: Kp=20, Kd=0, Ki=0. Bot oscillates, can't track curves.
Final values that worked: Kp=14, Kd=380, Ki=0.05. Wheel diameter 40mm, track speed 1.2m/s.
Key insights:
Anyone tried PIDF (F=feed-forward)? Heard it helps on speed transitions but never implemented.
Starting point: Kp=20, Kd=0, Ki=0. Bot oscillates, can't track curves.
Final values that worked: Kp=14, Kd=380, Ki=0.05. Wheel diameter 40mm, track speed 1.2m/s.
Key insights:
- Kd is your friend on tight curves. Without it, bot overshoots and never settles.
- Ki small but non-zero saves you on long straights with sensor bias.
- Always anti-windup the integral. Mine clamped at +/-50.
- Sample at ~200Hz minimum. Slower and PID fights itself.
Anyone tried PIDF (F=feed-forward)? Heard it helps on speed transitions but never implemented.