IEEE Transactions on Automatic Control, Vol.51, No.1, 135-139, 2006
A sufficiently smooth projection operator
In this note, we introduce a new parameter projection operator for adaptation laws. The projection operator replaces the common Lipschitz continuity property with the stronger property of arbitrarily many times continuous differentiability. The proposed projection is useful for backstepping-based, robust adaptive controllers which require multiple differentiations of the adaptation law.