Username: ControlTheory
Posted: 4 days ago
Building a temperature controller for a heated enclosure and struggling with PID tuning. System overshoots by 5 degrees then oscillates before settling. Tried adjusting P, I, and D values but cant seem to get it stable. Any tips for tuning PIDs? Using an arduino with a relay to control a heating element.

Reply by: PIDMaster
Relay control makes PID harder because its on/off not continuous. Consider using pwm if possible. For tuning, start with only P gain until you get oscillations, then reduce it by half. Then slowly add I to eliminate steady state error. D is usually not needed for temp control and can make things worse. Also make sure your sampling rate is fast enough - you should be reading temp and updating output at least once per second, preferably faster.

Reply by: ControlTheory
Ah didnt think about the relay being an issue. Ill try implementing pwm with a ssr. Thanks!