Schappert, W. Gonnella, D. Holzbauer, J.P. Liepe, M. Pischalnikov, Y.M. JACoW Geneva, Switzerland 978-3-95450-178-6 10.18429/JACoW-SRF2015-TUPB095 English 828-831 TUPB095 cavity resonance feedback SRF operation Contribution to a conference proceedings 2015 2015-12 http://dx.doi.org/10.18429/JACoW-SRF2015-TUPB095 http://srf2015.vrws.de/papers/tupb095.pdf Optimal control techniques have been employed in a variety of applications since they were first developed more than 60 years ago but until now they have been used in few if any accelerator-related applications. The next generation of superconducting accelerators will require both precise control of the gradient and active stabilization of the resonance frequency. Optimal control techniques provide a self-consistent framework within which to construct a combined electro-mechanical controller. Results from recent cold cavity tests at Fermilab are presented.