Boundary Layer Tuning Procedure for First Order Sliding Mode Controllers

Chattering alleviation in Sliding Mode control has attracted many researchers in the last decades providing many valuable contributions to this field. One possible way to address this problem is by means of replacing a discontinuous function in the command law definition with an interpolating one, introducing the concept of the boundary layer and quasi-sliding mode control. On the one hand the introduction of this boundary layer helps alleviate the chattering phenomenon but on the other hands deteriorate the performance of the controller itself. In particular, the boundary layer width is the parameter that must be chosen as result of a trade-off and its choice is extremely important for the controller correct operation. Since no straightforward procedures on how to tune this key parameter are available in the technical literature this paper aims at proposing a simple and effective procedure able to satisfactorily address this problem.