The problem of controlling a rigid bilateral teleoperator with time-delays has been effectively addressed since the late 80's. However, the control of flexible joint manipulators in a bilateral teleoperation scenario is still an open problem. In the present paper we report two versions of a proportional plus damping injection controller that are capable of globally stabilizing a nonlinear bilateral teleoperator with joint flexibility and variable time-delays. The first version controls a teleoperator composed by a rigid local manipulator and a flexible joint remote manipulator and the second version deals with local and remote manipulators with joint flexibility. For both schemes, it is proved that the joint and motor velocities and the local and remote position error are bounded. Moreover, if the human operator and remote environment forces are zero then velocities asymptotically converge to zero and position tracking is established. Simulations are presented to show the performance of the proposed controllers.

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.

In this paper, an adaptive control structure based on the well-known four-channel (4C) control architecture is proposed to achieve transparency in non-ideal (high friction) teleoperation devices. The choice of the parameters to be adapted is motivated using a modified version of the 4C model. Next, two experiments are proposed to define the boundaries of the parameters values to be tuned during the adaptive process. Finally, the adaptive control scheme is successfully applied experimentally to a one degree of freedom (dof) teleoperation device.