Chris Leshikar successfully defended his Ph.D. dissertation on May 28th, 2025. Chris has been with VSCL since his freshman year in Fall 2016 setting the record for longest duration working in VSCL of 8.83 years. The title of his dissertation is: Markov Parameter Based Methods for System Identification
Chris’s dissertation investigates modifying and extending subspace system identification methods for flight vehicle system identification. The development of accurate dynamical models of flight vehicles is a critical aspect of ensuring overall safety of flight. The development of accurate models using flight data requires the utilization of system identification techniques, which are often denoted as white-box or black-box models. This dissertation develops an approach which extends the Eigensystem Realization Algorithm, a black-box, Markov Parameter based subspace identification method, which permits the inclusion of prior model knowledge, the computation of parameter confidence bounds, and direct identification of continuous-time matrices. This is accomplished by the inclusion of the output model structure which results in a recursive Markov Parameter definition which may be reformulated into the ordinary least squares problem using the Markov Parameters. The effects of process and measurement noise, sampling rate, and data filtering on the developed approach are investigated using a simple second-order system. The theory is further extended for the identification of non-dimensional stability & control derivatives. The benefits of the approach in identifying open-loop models from closed-loop data are also presented. The developed technique is evaluated against standard flight vehicle system identification methods using experimental flight test data of multirotor and fixed-winged Unmanned Air Systems, a fixed-wing manned transport aircraft, and a supersonic commercial transport aircraft.
Chris will do a short postdoc with VSCL and then begin seminary formation for the Catholic Diocese of Victoria later this year. Chris’s research is supported by the National Science Foundation under the Center for Autonomous Air Mobility and Sensors (CAAMS). Chris’s is the 63rd graduate degree that Dr. John Valasek has advised, and 16th Ph.D. student.