During initial testing of the temperature control system, a noticeable overshoot was observed when the heater approached the set temperature.

The system uses PID-based control with thermocouple feedback. While the steady-state regulation was reasonably stable, the heating phase exhibited a tendency to exceed the target temperature before settling back.

This behavior was more pronounced at higher temperature settings and during rapid heating cycles.

Initial investigation suggested that the issue was not with sensor accuracy, but with the control response near the setpoint. The heater, being a relatively high-power element, continued to deliver residual heat even after the control output was reduced.

To address this, a simple software-based tapering approach was introduced.

Instead of allowing full control output until the setpoint is reached, the system gradually reduces heater drive as the temperature approaches the target. This effectively softens the control action near the setpoint and reduces thermal inertia effects.

After implementing this change:

• Temperature overshoot was significantly reduced

• Settling time improved

• Control behavior became more predictable

This approach proved to be effective without requiring major changes to the PID parameters.

It highlights the importance of considering system dynamics and thermal inertia in addition to pure control loop tuning.

Would be interested to know how others handle overshoot in similar thermal control systems.