Michele Palladino of Pennsylvania State University and Richard Vinter of University College London received the SIAM Activity Group on Control and Systems Theory Best SICON Paper Prize at the 2017 SIAM Conference on Control and Its Applications (CT17) held July 10–12 in Pittsburgh, PA.
Michele Palladino (center) and Richard B. Vinter (right) received their award plaques from SIAM President Nicholas J. Higham at the AN17 Prizes and Awards Luncheon.
The SIAM Activity Group on Control and Systems Theory (SIAG/CST) awards the SIAG/CST Best SICON Paper Prize every two years to the authors of the two most outstanding papers published in the SIAM Journal on Control and Optimization (SICON) in the two calendar years preceding the award year. Palladino and Vinter were recognized for the contributions of their paper, “Regularity of the Hamiltonian Along Optimal Trajectories,” published in SICON Volume 53 Issue 4 in 2015. Vinter presented the paper as part of CT17.
Michele Palladino holds a postdoctoral position in the Mathematics Department of the Eberly College of Science at Pennsylvania State University. He received his PhD from Imperial College London in 2015 under the supervision of Richard Vinter. His research interests are in the areas of variational analysis, dynamic systems, and game theory.
Richard B. Vinter is a professor in the Department of Electrical and Electronic Engineering at Imperial College London and a member of the department’s Control and Power (CAP) Research Group. He received a BSc from Oxford University and a PhD in Engineering in 1972 from Cambridge University, which awarded him the Doctor of Science (ScD) in Mathematics in 1988. He has served as associate editor for numerous journals, including the SIAM Journal on Control and Optimization (SICON). He was made a Fellow of the Institute of Electrical Engineers (IEE) in 2001 and is also a Fellow of IEEE and the Royal Academy of Engineering. His research interests include control systems, filtering and estimation, calculus of variations, and non-linear analysis.
Q: Why are you excited about winning this prize?
A: Our research is an outgrowth of new analytic tools for the local approximation of ‘non-smooth’ functions and their application in control theory. The pioneering work of Francis Clarke has been an inspiration to us. We are thrilled to receive this prize. We hope this honor will draw attention to the power of these methods and will broaden the research community that benefits from their use.
Q: What does your research mean to the public?
A: There are many ingredients in a successful space exploration mission, the most visible being space vehicle, sensors and communication systems design. But optimal control is the important behind-the-scenes ingredient, providing the algorithms for choosing optimal flight paths to minimize fuel consumption, restricting damage from atmospheric friction on re-entry, and achieving further goals. Likewise, optimal control has an important role, providing the rules for optimal operation in chemical manufacture (process control), control of driverless vehicles and in other fields. Our theoretical work reveals fundamental properties that simplify the calculation of optimal controls, broadening the scope of optimal control applications in an increasingly complex world.
Q: Could you tell us a bit about the research that won you the prize?
A: Optimal control problems, involving time varying dynamic constraints, are often encountered in control engineering. They arise in tracking a time-varying nominal flight path in aeronautical control or, more dramatically, in the control of rockets whose structure changes abruptly when a stage is ejected. While powerful analytic tools are available for investigating the optimal control of time-varying systems, including the Pontryagin Maximum Principle, other useful optimality conditions are valid only for constant systems, or at least mildly time varying systems. Prominent among these ‘supplementary’ conditions are conditions on the Hamiltonian function, notably `the Hamiltonian is constant along an optimal trajectory’ for constant control systems. Conditions involving the Hamiltonian can be very useful. In Hamiltonian mechanics, for example, they permit us to predict physical laws, such as conservation of energy, from the Principle of Least Action, without performing any detailed calculations. The prize paper was part of a larger research program, aimed at deriving modified versions of the supplementary optimality conditions, valid for time-varying, even discontinuously varying, systems, and exploring their implications, regarding quantitative properties of optimal controls and computation. The final picture is that many of the classical “supplementary” optimality conditions extend to allow for time-varying systems, with significant consequences.
Q: What does SIAM mean to you?
A: SIAM offers a superb range of journals. At a time when journals are deluged by increased number of submissions, suffering back-office cutbacks and reviewer overload, the SIAM journals maintains a gold standard, fairly assessing and accepting only quality papers, and offering a very high quality of technical editing. SIAM events reach out across disciplines. They are not just forums for established academics but give opportunities to young researchers to promote their work. They provide the opportunity for networking and they strengthen the sense of mathematical community among their participants.