In a PID controller, which term is primarily responsible for eliminating steady-state offset?

In a PID controller, which term is primarily responsible for eliminating steady-state offset?

• A. Proportional
• B. Integral
• C. Derivative
• D. Feedforward

Answer: (B)

The integral term is what removes steady-state offset. It continuously sums the accumulated error over time and feeds that back into the control signal. If there’s a persistent bias or a constant disturbance, the error won’t vanish with just the present-error response; the integral action keeps adding correction until the error is driven to zero in steady state. The proportional term reacts to the current error and reduces it quickly, but it can’t guarantee zero steady-state error on its own. The derivative term responds to how fast the error is changing, helping with damping and stability rather than eliminating a constant offset. Feedforward can help reduce offset for known disturbances, but in a standard PID loop it isn’t the term that fundamentally eliminates steady-state error.

The integral term is what removes steady-state offset. It continuously sums the accumulated error over time and feeds that back into the control signal. If there’s a persistent bias or a constant disturbance, the error won’t vanish with just the present-error response; the integral action keeps adding correction until the error is driven to zero in steady state. The proportional term reacts to the current error and reduces it quickly, but it can’t guarantee zero steady-state error on its own. The derivative term responds to how fast the error is changing, helping with damping and stability rather than eliminating a constant offset. Feedforward can help reduce offset for known disturbances, but in a standard PID loop it isn’t the term that fundamentally eliminates steady-state error.