A Proportional-Integral-Derivative (PID) controller is an ubiquitous closed-loop feedback mechanism that continuously corrects system tracking errors in robotic drives. The controller measures deviation e(t) between a desired trajectory setpoint r(t) and process output y(t). Corrective command effort u(t) combines proportional gain for immediate tracking, integral gain to eliminate steady-state offset, and derivative damping to suppress dynamic overshoot.