IEEE Transactions on Automatic Control, Vol.45, No.2, 286-290, 2000
A note on H-2 optimal control problems with passivity constraints
This note considers the problem of determining the closest function that has a positive real part on the unit disk to a given function in H-2. An explicit characterization of the projection is given. Remarks on potential applications using this projection result to control synthesis and system identification problems are made.
Keywords:passive system;positive real part