21 research outputs found
HAVOK Model Predictive Control for Time-Delay Systems with Applications to District Heating
A computationally efficient Model-Predictive Control (MPC) approach is
proposed for systems with unknown delay using only input/output data. We use
the Koopman operator framework and the related Hankel Alternative View of
Koopman (HAVOK) algorithm to identify a model in a basis of projected
time-delay coordinates and demonstrate a novel MPC structure that reduces and
bounds the computational complexity. The proposed HAVOK-MPC approach is
validated experimentally on a laboratory-scale District Heating System (DHS),
demonstrating excellent prediction and tracking performance while only
requiring knowledge of a conservative upper bound on the system delay.Comment: This work has been accepted for publication at IFAC World Congress
202
Observer-based fault diagnosis and field oriented fault tolerant control of induction motor with stator inter-turn fault
In Situ TEM Creation and Electrical Characterization of Nanowire Devices
We demonstrate the observation and measurement of simple nanoscale devices over their complete lifecycle from creation to failure within a transmission electron microscope. Devices were formed by growing Si nanowires, using the vapor-liquid-solid method, to form bridges between Si cantilevers. We characterize the formation of the the nature of the connection depends on the flow of heat and V contact between the nanowire and the cantilever, showing that electrical current during and after the moment of contact. We measure the electrical properties and high current failure characteristics of the resulting bridge devices in situ and relate these to the structure. We also describe processes to modify the contact and the nanowire surface after device formation. The technique we describe allows the direct analysis of the processes taking place during device formation and use, correlating specific nanoscale structural and electrical parameters on an individual device basis