Level Control of a Conical Tank System Using Switched Fractional Order PI Controllers: An Experimental Application

This paper presents the design, tuning, validation and implementation at experimental level of switched fractional order proportional integral (PI) controllers for the level control of a conical tank system. The controller switches among a fractional order PI controller and an integer order PI controller, according to the control error level. Parameters of the switching strategy are tuned using particle swarm optimization. Results at simulation and experimental level show that switched controllers allow obtaining a best combination of controlled system behavior and control energy used, compared to the non switched strategies. Also, switched controllers present lower variance of the controlled variable at experimental level.