A Laboratory for Dynamic Systems and Human-Robot Interface

Thursday February 3, 2011 4:00-5:00 p.m.
ME-EM building, Room 112

Assistant Professor Mohammad Rastgaar
Michigan Technological University

In this talk, I will introduce two areas of my research at Michigan Tech. In the first part, “Orthogonal Eigenstructure Control for Active Vibration Cancellation”, I will present Orthogonal Eigenstructure Control (OEC) and its application to structural vibration cancellation. OEC is a feedback control method applicable to general multi-input multi-output linear systems. While the available control design methodologies for large flexible structures offer a large and complex design space of options, this control methodology offers a significant simplification of the design task while still allowing some experience-based design freedom. Specifically, OEC eliminates the need for shaping and defining the desirable eigenstructure as required in eigenstructure assignment methods. The mathematical aspects of orthogonal eigenstructure control as well as the results of implementing this method to cancellation of vibrations in a steel test plate under tonal and wideband disturbances will be presented. In the second part of the talk, “Stochastic Estimation of Multi-variable Human Ankle Mechanical Impedance”, I will present a lower extremity rehabilitation robot and the results of estimation of multi-variable dynamic ankle impedance in humans with different types of muscle activities utilizing this robot. The results suggest that different dynamics may govern standing and walking which needs to be considered in the design of lower-extremity assistive or prosthetic robots.