View source for A Design Study for Thermal Control of a CVD Reactor for YBCO

{{HTDB paper
| authors = Martha Gallivan, David Goodwin, and Richard M. Murray
| title = A Design Study for Thermal Control of a CVD Reactor for YBCO
| source = 1998 Conference on Control Applications
| year = 1998
| type = Conference paper
| funding = NSF, AFOSR, DARPA
| url = http://www.cds.caltech.edu/~murray/preprints/ggm98-cca.pdf
| abstract =  A reactor for the deposition of superconducting \ybcolong\;thin films is modeled and
studied from a control perspective to determine the heat transfer dynamics of the reactor
under active thermal control. A nonlinear wavelength-dependent heat transfer model is
developed to predict reactor heat transfer throughout the film growth process, and
preliminary component testing is conducted to validate the model. The model is linearized
about a typical operating point and analyzed with linear feedback control methods to
determine the performance of the reactor under observer-based feedback control with film
growth disturbances. The controller and observer are selected through linear quadratic
regulator and linear quadratic estimator methods. Rates of convergence of the controller
and observer are determined through examination of the eigenvalues of the linearized
system, and disturbance rejection is assessed with ${\mathcal H}_2$ and ${\mathcal
H}_\infty$ norms. The eigenvalue and norm analysis is applied to varying reactor design
parameters to quantify performance tradeoffs. The maximum errors associated with control
and with estimation of a nominal design case are both 21 K, and the longest time scales
are 45 seconds and 10 seconds for the controller and observer, respectively. 
| flags = 
| filetype = PDF, 6 pages
| filesize = 214K
| tag = ggm98-cca
| id = 1998a
}}