摘要:

AbstractIn this work we analyse singularH2andH∞problems for which the usual Riccati equations become ill‐posed owing to the existence of plant zeros at infinity.We adopt a two‐step approach to the analysis. First we replace the usual Riccati equations with two generalized eigenproblems; these problems are always well‐posed. Next we extract those structural elements which pertain to the troublesome plant zeros. We do this by introducing pre‐compensators which cancel the offending zeros. In so doing, we temporarily relax the controller properness constraint that is traditionally imposed inH2andH∞problems by allowing pole‐zero cancellations between the plant and controller at infinity. Since no significant added complexity of analysis results, we also treat the case of singularity due to finite jω‐axis plant zeros by relaxing the internal stability requirement and allowing finite jω‐axis pole‐zero cancellations.The resultant theory allows us to specify necessary and sufficient conditions for the existence of solutions to singularH2andH∞problems. The existence conditions and the resultant control laws are expressed directly in terms of the eigenvalues and eigenvectors of two Hamiltonian matrices associated with the problem. The theory also gives some insight into the character of the subset of all proper, internally stabilizing solutions, including whether this set is nonempty.

ISSN:1049-8923    

DOI:10.1002/rnc.4590050202

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractPresented in this paper is a loop‐shaping solution to theH∞robust performance problem for a class of SISO systems. The key feature of this work is the explicit incorporation of phase information into the controller synthesis to facilitate loop‐shaping over all frequencies. Consequently, a significant reduction in the required controller gain/bandwidth is achieved. It is also shown that the optimal solution, in the sense of controller gain/bandwidth minimization, to the robust performance problem is that which makes μ = 1 over all frequencies. This is different from the usual definition of optimality in theH∞/μ literature. An example is included for com

ISSN:1049-8923    

DOI:10.1002/rnc.4590050203

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractThis paper considers a minimax control problem for an uncertain system containing structured uncertainties. The uncertainties in this system are assumed to satisfy a certain integral quadratic constraint. For a given initial condition, the minimax optimal controller is constructed by solving a parameter‐dependent Riccati equation of the game type. This controller leads to a closed‐loop uncertain system which is absolutely sta

ISSN:1049-8923    

DOI:10.1002/rnc.4590050204

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractSeveral algorithms for adaptive control, as well as for static state feedback decoupling, feedback linearization, or inversion of nonlinear multivariable systems require that the systems have full vector relative degree, in order to be applied. In this paper, we provide a parameter‐independent method of achieving full vector relative degree for nonlinear multivariable systems which do not have it. We determine conditions under which a diagonal dynamic precompensation is sufficient to achieve vector relative degree for multivariable nonlinear systems, and describe a simple algorithm which determines such compensatio

ISSN:1049-8923    

DOI:10.1002/rnc.4590050205

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

ISSN:1049-8923    

DOI:10.1002/rnc.4590050206

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

ISSN:1049-8923    

DOI:10.1002/rnc.4590050201

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY