Abstract

The control of bilateral haptic telemanipulation systems in the presence of multiple uncertain sources including uncertain communication time-delay is indeed a non-trivial problem. Such control is typically evaluated by three criteria: stability, performance and transparency. This thesis discusses these criteria in the context of how linear fractional transformation (LFT) technique and o-theory can be applied into the design of robust bilateral haptic telemanipulation systems. As a result, a framework of controller design for such a system based on PHANToM haptic devices is presented under the assumptions that all of the components in the system, including the communication channel with time-delay, possess uncertainty. The proposed design framework possesses following new characteristics compared to the previous work in the literature: (1) all components in the system are potentially uncertain and the environment possesses parametric uncertainty; (2) the master controller is structured as of two-degree-of-freedom (2-DOF) to avoid poor transient performance; (3) force reflection from slave to master is realized as a function of environment reaction forces and differences between master and slave displacements to meet the system transparency requirement, and (4) the communication channel is treated as a second-order system with parametric and multiplicative uncertainties, which represents a more accurate and less conservative realization. The analysis of the resulting controllers made in both frequency and time domain shows that the resulting system realizes well the robust stability and performance requirements that are envisaged in this problem