Table 1: The PID terms and their effect on a control system.

 Term Math Function Effect on Control System P Proportional Typically the main drive in a control loop, KP reduces a large part of the overall error. I Integral ${K}_{I}\int {V}_{error}dt$ Reduces the final error in a system. Summing even a small error over time produces a drive signal large enough to move the system toward a smaller error. D Derivative ${k}_{D}\frac{d{V}_{error}}{dt}$ Counteracts the KP and KI terms when the output changes quickly. This helps reduce overshoot and ringing. It has no effect on the final error.