Jillian Bennett successfully defended her M.S. thesis on June 11th, 2025. Jill has been with VSCL since her senior year in Spring 2023 and is highly engaged in control theory, and flight testing. The title of her thesis is: Nonlinear Adaptive Multiple Time Scale Stability Analysis For An Arbitrary Number Of Time Scales
Multiple time scale systems are a set of subsystems that are dependent on each other yet have a large separation in the time which the dynamics progress. Systems of this sort are often simplified by dismissing the dependencies between vehicle states, however, the true dynamics get lost and are important to the stability of the system. Additionally, true systems have uncertain plant dynamics and disturbances that can cause instability. Therefore, a method of control must be used to account for uncertainties. Adaptive control has been shown to counteract these additional sources of motion. A combination of adaptive control and multiple time scale control for nonlinear systems is applicable to and necessary for the systems mentioned above and has been demonstrated in a method called [K]Control of Adaptive Multiple Time Scale Systems (KAMS), yet only accounts for two time scale systems. This work extends the theory and stability proof of KAMS to account for a system with any number of time scales. It also further analyzes the limitations to the time scale separation parameter size of a two and three time scale system.
Jill developed and conducted outstanding theory for nonlinear time scale systems, and the work will continue. Jill is doing a summer grad internship with Naval Research Laboratory to flight test the nonlinear multiple time scale control laws, and then she is staying with VSCL and continuing on to the Ph.D. Very glad to have you for another degree Jill!
Jill’s research is supported by the Office of Naval Research on the project Novel Multiple Time Scale Adaptive Control for Uncertain Nonlinear Dynamical Systems. Jill’s is the 64th graduate degree completed that Dr. John Valasek has advised.
