Design of Fractional Order Controllers for Conical Tank Process

This paper discusses two fractional order controllers, Fractional Order Proportional Integral (FOPI) controller and Fractional Order Internal Model Controller (FOIMC) applied to a nonlinear system. Internal Model Control (IMC) was suitable for plants like conical tank, because it considers model uncertainty, disturbance rejection and desired performance. PID controller was common in the industry because of its simplicity in tuning and robustness. All the controller parameters of FOPI and FOIMC were tuned using Particle Swarm Optimization (PSO) algorithm. A tool called FOMCON was used for simulation of the controlled process. Set point tracking and regulatory responses were compared using various performance indices and time-domain parameters.