Identification of a hybrid model for simulation of the instrument/trocar interaction force

Trocars used in Minimally Invasive Surgery (MIS) are equipped with a sealing mechanism. During the motion of an instrument through a trocar, the sealing mechanism deforms itself. The Extended Maxwell Slip model has been developed in order to capture the deformation of the sealing mechanism. Two operating phases are distinguished, corresponding to the deformation of the sealing mechanism on the one hand, and to the sliding phase through the trocar on the other hand. This article addresses the identification procedure for this model. The deformation phase uses a PieceWise Affine (PWA) model. This model is identified using a PWARX (PieceWise ARX) identification technique namely the clustering based technique. Identification and validation are achieved using experimental data recorded on a dedicated test setup.