Performance analysis of non-integer order PID controller for liquid level control of conical tank system

The design of a controller for the conical tank system is a challenging problem, because of its non-linearity behavior. The Proportional-Integral-Derivative controllers have played a vital role in many process oriented industrial applications, for past few decades. This paper deals with design of Non-Integer order Proportional Integral Derivative or Fractional Order Proportional Integral Derivative (FOPID) controller for a level control process of single conical tank system. FOPID provides more flexibility in designing a controller than using standard Proportional Integral Derivative (PID) controllers, due to selection of five parameters instead of three. Though the tuning of FOPID is complex, it can guarantee the desired control performance and the robustness to the loop gain deviations. The comparison of various tuning methods using PID controller is simulated. FOPID controller has been designed for the same conical tank system and the performances of both the PID and FOPID controllers have been simulated and compared.