Question: Using the appropriate transfer functions and applying the final value theorem, determine the final values of the error for a step set point change for the heater in Example under P-only, PI, and PID control.
Example: To facilitate the solution, a simple process-the stirred-tank heater is selected, with the controlled variable being the tank temperature and the manipulated variable being the coolant flow valve, as shown in Figure. Since proportional control was considered a proportional-integral controller is selected, because this will ensure zero steady-state offset. The response to a step set point change will be determined.
