Bilateral Controller Design for Telemanipulation in Soft Environments

Previous research on teleoperation has focused on manipulation of hard objects. However, the design constraints are different in applications that involve manipulation of deformable objects, such as robotic telesurgery. In this paper a new measure for fidelity in teleoperation is introduced which quantifies the teleoperation system’s ability to transmit changes in the compliance of the environment. This sensitivity function is highly appropriate for the application of telesurgery, where the ability to distinguish small changes in tissue compliance is essential for tasks such as tumor detection. The bilateral teleoperation controller design problem is then formulated as the optimization of this new metric with constraints on free space tracking requirements and robust stability of the system under environment and human operator uncertainties. The robust stability analysis can be applied to any teleoperator plant and guarantee stability given an uncertainty model. The analysis is also extended to evaluate effectiveness of using a force sensor in the teleoperation system.