摘要:

The development and evaluation of an expert advisor for system identification (EASI) is described. The principles behind a suitable knowledge representation paradigm for a system which includes both intelligent tutoring and software package front-end concepts are outlined. The system has been constructed using an expert system ‘text-animation’ shell with linkage into Prolog-2 to provide enhancements. These extensions have included an online dictionary and bibliographic material. The identification domain aspects covered include experimental design, model structure determination, estimation algorithms, with applications to SISO and MIMO linear systems, and SISO nonlinear dynamics. Different levels of user-model are provided, and the advisor acts as a front-end to a number of in-house identification packages.

DOI:10.1049/ip-d.1990.0001

出版商:IEE    

年代:1990

数据来源: IET

摘要:

The paper describes the extension of pole-placement self-tuning algorithms to the multivariable control of human blood pressure in post-operative patients. The work is based on two nonlinear nonpulsatile models for the cardiovascular system due to Moller and Wesselinget al. These models have a well-grounded physiological basis and include several reflex control systems which are inherent in the body. Two forms of control are presented, the first of which considers a fast dynamic response controller which manipulates heart rate and systemic resistance directly. The second control strategy includes the drug dynamics for sodium nitroprusside and dopamine being administered simultaneously. Both control schemes gave good performance using poleplacement self-tuning, although the first approach gave significant interaction between the loops.

DOI:10.1049/ip-d.1990.0002

出版商:IEE    

年代:1990

数据来源: IET

摘要:

A new adaptive chattering alleviation algorithm for variable structure systems (VSS) control is proposed. The adaptive control algorithm consists of two phases. In phase one, the authors try to minimise the time required to reach the switching surface. In phase two, they alleviate the chattering about the switching surfaces in the sliding mode. The automatic switching between these two phases is based on a recursive prediction procedure performed at each step. The automatic adjustment of the controllers is called an adaptive VSS control algorithm. The algorithm can be applied to uncertain linear and nonlinear systems. The resulting trajectories of a nonlinear robotic experiment indicate almost no chattering at all. Moreover, this clear-cut benefit is not obtained at the expense of any added time required to reach the steady state.

DOI:10.1049/ip-d.1990.0003

出版商:IEE    

年代:1990

数据来源: IET

摘要:

The paper investigates the input—output energy balances in linear dynamical systems subjected to unmodelled dynamics for which an aprioriknowledge is needed in terms of frequency and time-domain specifications. A discussion about the synthesis of linear controllers in the linear and time-invariant case is also given. The controllers have robustness properties, in the sense that the system subjected to unmodelled dynamics has a close behaviour, in an input-output energy sense, to the nominal (perfectly modelled) case.

DOI:10.1049/ip-d.1990.0004

出版商:IEE    

年代:1990

数据来源: IET

摘要:

A modified linear model-following speed controller for current-source-inverter (CSI) fed induction motor drives is proposed in the paper. The proposed controller is designed so that only the measured plant output is used in the feedback loop. Furthermore, a reduced reference model is set to simplify the design without degrading the performance very much. To ensure the stability of the resulting system when the reduced-order control law is applied to the original system, an analysis based on an equivalent feedback system is provided and the stability criteria are derived. Finally, some experimental results are given to demonstrate the effectiveness of the proposed controller.

DOI:10.1049/ip-d.1990.0005

出版商:IEE    

年代:1990

数据来源: IET