H2 optimal controller design for micro-teleoperation with delay

This study aims to develop a force-reflecting macromicro teleoperator with different scaled worlds. A bilateral control system for scaled teleoperation provides the human operator with a feel of the task at the micro-scale. However, reliable and efficient tele-micromanipulation systems with haptic feedback over the Internet face to strong problems due to the nonlinear nature of microenvironment and time-varying delays in communication lines. A robust bilateral controller design framework using H₂-optimal control approach is proposed. A comparative study for assessing the robustness against time-varying delays is performed through two different designs, i.e., a μ-synthesis framework and a Pade approximation. The proposed approaches allow a convenient means to tradeoff the robustness for a pre-specified time-delay margin. The validity of the proposed method is demonstrated by simulations.