ABSTRACT
The problem of disturbance decoupling in multivariable control systems is considered. It has been shown that different two-degree-of-freedom control structures used for unmeasurable disturbance estimation and compensation may be treated as a particular case of a general Inverse Model Control approach. The decomposition of the problem into the separate disturbance state and model estimation is suggested. Moreover the connection between inverse model design problems and unknown input observer theory has been established in order to give a practical way to inverse model parameterization and design. The properties of closed-loop system with model-based controllers have been also investigated with the aim of attainable accuracy estimation.
ABSTRACT
The study is based on the characterization of Output Stabilizable (C,A,B)- invariant subspaces through two coupled quadratic stabilization conditions. The paper shows the equivalence between the existence of a solution to this set of conditions and the possibility to stabilize the system by output feedback. An algorithm and a numerical example are provided to illustrate the approach.
Key Words. Output feedback, geometric approach, quadratic stabilizability, LMIs.
ABSTRACT
The classical result of Gilbert on the testing of con- trollability based on the Jordan canonical description is extended here by providing a new characteriza- tion of input decoupling zeros based on the properties of appropriate Piecewise Arithmetic Progression Se- quences defined on spectral matrices determined from the Jordan canonical description. For any eigenvalue for which there is loss of modal controllability the de- grees of the corresponding decoupling zeros are de- fined. The results given here for input decoupling zeros have their equivalent statement for the case of output decoupling zeros.
ABSTRACT
The fundamental and the transition matrices of the continuous-time generalized state-space system are defined. Then the solution of the generalized state-space model is given in terms of the fundamental matrix directly for the given system, without applying any decomposition in fast and slow subsystems. The proposed solution is actually a generalization of the solution of the regular state-space equation and provides insight for the particular properties of the generalized systems. The set of admissible initial conditions is directly determined from the solution and the decomposition of the solution into two orthogonal subspaces easily results by applying orthogonal operators. The fundamental and the transition matrices may be calculated in terms of the system's matrices via algebraic recursive algorithms.
Key Words. Singular systems, generalized systems, fundamental matrix, transition matrix.