摘要:

The usual proof of the Nyquist theorem depends heavily on the argument principle. The argument principle, however, supplies unneeded information in that it counts the number of encirclements of ‘ − 1 ’. System stability requires only a binary decision on the number of encirclements. Using homotopy theory, a branch of algebraic topology, we construct new proofs of the classical Nyquist criteria along with the more recent linear multivariable results. In both cases the proof is essentially the same. Moreover, we believe our point of view to be more intuitive and capable of generalization to systems characterized by functions of several complex variables.

ISSN:0020-7179    

DOI:10.1080/00207177708922309

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Two classes of large-scale systems are identified, which can always be stabilized by decentralized feedback control. For the class of systems composed of interconnected linear subsystems, we can choose local controllers for the subsystems to achieve stability of the overall system. The same linear feedback scheme can be used to stabilize a class of linear systems with bilinear interconnections. In this case, however, the scheme is used to establish a finite region of stability for the overall system. The stabilization algorithm is applied to the design of a control system for the Large-Space Telescope.

ISSN:0020-7179    

DOI:10.1080/00207177708922310

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

Frequency domain characteristics of Otto Smith regulators are investigated. It is shown that the regulator can be regarded as an ordinary regulator in cascade with a lead network with considerable lead.

ISSN:0020-7179    

DOI:10.1080/00207177708922311

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor

摘要:

This note discusses several recent definitions of the zeros of a multivariable system and establishes some upper bounds on their number.

ISSN:0020-7179    

DOI:10.1080/00207177708922312

出版商:Taylor & Francis Group    

年代:1977

数据来源: Taylor