What is the role of a PID controller in a control system?

The role of a PID controller in a control system is to regulate a process by applying proportional, integral, and derivative actions to an error signal. This error signal represents the difference between a desired setpoint and a measured process variable.

The proportional component addresses the current error by producing an output that is proportional to this error. The integral component focuses on the accumulation of past errors, helping to eliminate the residual steady-state error that can occur if only proportional control is used. The derivative component predicts future errors based on the rate of change of the error, helping to dampen the response and improve stability.

In essence, by combining these three actions, a PID controller enhances the control loop's ability to achieve desired performance, maintaining the process variable close to the setpoint despite disturbances or changes in the system dynamics. This ability makes it a fundamental tool in various industrial applications, where precise control is crucial.

The other options do not encompass the full scope of a PID controller's function. While improving processor speed, tuning signal isolation, and measuring temperature can be related to different aspects of control systems and measurement techniques, they do not accurately describe the primary role of a PID controller.