Name the three terms in a PID controller and the role of each.

Name the three terms in a PID controller and the role of each.

• A. Proportional responds to current error; Integral eliminates steady-state error; Derivative predicts future error and improves stability.
• B. Proportional eliminates steady-state error; Integral responds to current error; Derivative measures system gain.
• C. Proportional predicts future error; Integral prevents oscillations; Derivative scales the input signal.
• D. All three terms are combined to produce a single corrective action without individual roles.

Answer: (B)

A PID controller combines three actions: proportional, integral, and derivative. The proportional term responds to the current error, providing an immediate correction proportional to how far you are from the target. The integral term accumulates past errors over time, which helps remove steady-state offset so the process settles at the setpoint. The derivative term looks at how quickly the error is changing, predicting future error and damping the response to improve stability and reduce overshoot. The option that assigns proportional to eliminating steady-state error, integral to current error, and derivative to measuring system gain mixes up these roles. Proportional does not remove steady-state error—that’s the integral’s job; integral does not respond to only the current error; and derivative does not measure system gain but the rate of change of the error.

A PID controller combines three actions: proportional, integral, and derivative. The proportional term responds to the current error, providing an immediate correction proportional to how far you are from the target. The integral term accumulates past errors over time, which helps remove steady-state offset so the process settles at the setpoint. The derivative term looks at how quickly the error is changing, predicting future error and damping the response to improve stability and reduce overshoot. The option that assigns proportional to eliminating steady-state error, integral to current error, and derivative to measuring system gain mixes up these roles. Proportional does not remove steady-state error—that’s the integral’s job; integral does not respond to only the current error; and derivative does not measure system gain but the rate of change of the error.