Investigation of the Effects of Increased Order Compensators in Mixed H2/H(Infinity) Optimization
Abstract
The problem of minimizing the 2-norm of one transfer function subject to an infinity-norm bound on another transfer function is examined for increased order controllers. In particular, the theoretical results of the full order case are extended to the higher order case, and SISO and MIMO numerical examples are given for increasingly higher order compensators. Some of the key proofs for higher order compensators include: the global minimum 2-norm is unachievable under output feedback for certain levels of gamma regardless of compensator order; the solution to the mixed H2/H infinity problem lies on the boundary of the infinity-norm constraint for this same range of gamma's; and the suboptimal mixed problem converges to the optimal in the limit for higher order controllers. Also, it is shown that the optimal compensator order for the mixed H2/H infinity problem is greater than the order of the plant under certain conditions, and a conjecture about the optimal order for the mixed problem is made.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 01, 1991
- Accession Number
- ADA243874
Entities
People
- Scott R. Wells
Organizations
- Air Force Institute of Technology