In a PID controller, what is the role of the integral term?

In a PID controller, what is the role of the integral term?

• A. It accelerates response through proportional action
• B. It eliminates steady-state error by accumulating past error
• C. It reduces overshoot by damping
• D. It differentiates the error for prediction

Answer: (B)

The integral term accumulates the error over time and converts that history into a corrective action. This means it targets any persistent offset between the desired and actual output, which is steady-state error. If the error remains nonzero, the integral action grows and pushes the output until the error is eliminated, even in the presence of disturbances or biases. That’s why it’s described as eliminating steady-state error by accumulating past error. The proportional term responds to the current error for a quick, immediate response but doesn’t remove a constant offset on its own. The derivative term reacts to how quickly the error is changing, helping to damp and predict future behavior to reduce overshoot. Proper tuning is important, though, because too much integral action can cause sluggish response or windup when actuators saturate.

The integral term accumulates the error over time and converts that history into a corrective action. This means it targets any persistent offset between the desired and actual output, which is steady-state error. If the error remains nonzero, the integral action grows and pushes the output until the error is eliminated, even in the presence of disturbances or biases. That’s why it’s described as eliminating steady-state error by accumulating past error. The proportional term responds to the current error for a quick, immediate response but doesn’t remove a constant offset on its own. The derivative term reacts to how quickly the error is changing, helping to damp and predict future behavior to reduce overshoot. Proper tuning is important, though, because too much integral action can cause sluggish response or windup when actuators saturate.