In the context of PID controllers, what does "reset" relate to?

In PID controllers, "reset" refers to the integral action of the controller. The term is associated with how the controller accumulates the error over time. When there is a persistent error – meaning the set point is not being met – the integral component effectively "resets" the control signal by integrating the error signal, which helps eliminate steady-state error.

This continuous integration allows the controller to respond to accumulated errors, driving the overall control action towards a point where the error is minimized. In practical terms, if a system is consistently off from its desired set point, the integral action responds by increasing the output until the error is corrected. Thus, the "reset" involves the integral of the error signal and plays a critical role in ensuring that any sustained deviation from the set point gets addressed, enhancing system stability and performance.