摘要:

Generalised predictive control (GPC) has many attributes which make it an effective practical tool for the control of scalar systems. The method is easy to understand/implement and has won popularity among many practicising engineers. Despite its success it does not have a general stability and robust stability theory. The paper proposes a new algorithm which deploys most of the ideas of GPC but yields control configurations with guaranteed stability and provides a systematic means of optimising robust stability margins. It achieves this through the use of a particular stabilising feedback controller which replaces the relevant transfer function operators by simple polynomial operators. This simplification also reduces the computational burden of a computer implementation of the method. The superiority of the results of the paper are illustrated by means of numerical examples.

DOI:10.1049/ip-d.1992.0047

出版商:IEE    

年代:1992

数据来源: IET

摘要:

This study presents a method to observe the rotor flux of a current-controlled induction motor. To ensure maximum robustness, a feedback loop is used to eliminate the error between actual system and model outputs. A reduced-order observation model is used to decrease the computation time. Various perturbation tests, particularly for large parameters variations, have been carried out by simulation, yielding an excellent state observer performance. Some experimental results allow a check on the state observation model.

DOI:10.1049/ip-d.1992.0048

出版商:IEE    

年代:1992

数据来源: IET

摘要:

Two modified versions of continuous-time generalised predictive control (CGPC): CGPC with end-point state constraints (CGPC_C) and CGPC with end-point state weighting (CGPC_W), are presented. It is shown that both CGPC_C and CGPC_W have guaranteed stability properties, whereas stability is not guaranteed in CGPC. The relationships between the three methods are also discussed, and it is shown that CGPC_W includes the other two, namely CGPC and CGPC_C, as submethods. Some features of the methods are also illustrated by simulations.

DOI:10.1049/ip-d.1992.0049

出版商:IEE    

年代:1992

数据来源: IET

摘要:

Various SISO feedback control techniques have been applied successfully to muscle relaxant anaesthesia in simulations and clinical trials. SISO generalised predictive control (GPC) altogether with self-organising control using fuzzy logic theory (SOFLC) are among these techniques. A multivariable model combining muscle relaxation (paralysis) and anaesthesia (unconsciousness) has been identified. The multivariable version of GPC in its basic form as well as its different extensions to include model following and observer filter polynomials is outlined in addition to the multivariable version of SOFLC. Both of these strategies are applied to the previous model whose parameters were chosen according to a Monte-Carlo method. The robustness of both control strategies is investigated and the results presented and discussed, enabling a comparison to be made between self-adaptive and self-organising techniques. It is concluded that, when a detailed mathematical model structure is available, GPC provides better control than SOFLC.

DOI:10.1049/ip-d.1992.0050

出版商:IEE    

年代:1992

数据来源: IET

摘要:

A polynomial array method is developed to extend array (table) techniques for polynomials with literal coefficients. Systematic procedures are presented for computing the coefficients of the polynomial in each array entry. The method is then applied for one- and two-dimensional discrete system stability tests. For one-dimensional systems, stability conditions for the system lead to a direct method for computing the critical gain. For two-dimensional filter stability tests, the proposed method removes the requirement for conjugate polynomials (or their coefficients) in constructing the array for a two-dimensional polynomialF(z1,z2) on |z1|=1 . It needs only simple computations on a set of second-order determinants with numerical entries and is very easy to program regardless of the orders ofF(z1,z2).

DOI:10.1049/ip-d.1992.0051

出版商:IEE    

年代:1992

数据来源: IET

摘要:

The development and evaluation of generalised predictive control (GPC) for on-line administration of muscle-relaxant drugs in the operating theatre is described. The necessary software and hardware environment was established using a SUN workstation and then a PC-based controller linked to an analogue patient simulator. The validated system was then transferred into the operating theatre for a series of clinical evaluation trials. Successful trials were performed at two sites, with decreasing involvement of the design engineers. Excellent regulation has been achieved, with a much reduced drug consumption compared with manual methods of drug administration. The GPC algorithm displayed good robustness properties against heavy electrical interference from disturbances such as surgical diathermy.

DOI:10.1049/ip-d.1992.0052

出版商:IEE    

年代:1992

数据来源: IET

摘要:

A generalised output tracking design for affine nonlinear system via variable structure system is proposed. It is shown that if the left invertibility condition for affine nonlinear system with unequal numbers of input and output channels is satisfied, then the system outputs can be controlled to track the desired smooth trajectory. Moreover, the redundant inputs are used to improve the tracking performance of the system. Examples illustrate the design processes.

DOI:10.1049/ip-d.1992.0053

出版商:IEE    

年代:1992

数据来源: IET