This paper presents an experimental study of different non-linear PI controllers using an academic platform based on an Air Levitation System. The comparison is based on common performance indexes, computed over the data extracted from the experiments. The results verify that, in addition to the PID controller in its classic form, several non-linear modifications can be considered to cope with different control needs, such as optimization on the number of control actions, or go beyond the restrictions that linearity impose on the performance that can be obtained by a PID controller. (C) 2018, IFAC (International Federation of Automatic Control) Hosting by Elsevier Ltd. All rights reserved.