Proportional-Derivative Controller

A Proportional-Derivative (PD) Controller is a control system that helps machines or processes stay at or reach a desired state. It does this by quickly reacting to errors—how far the current state is from the target—and adjusting the output accordingly. The "Proportional" part makes adjustments based on the current error size, providing a response proportional to how far off the system is. The "Derivative" part predicts future errors by considering how fast the error is changing, helping to prevent overshoot or oscillations. Together, they ensure smooth, accurate, and stable control.