摘要:

Changes in the input function, variations in the plant parameters and the presence of dead time are among the difficulties considered in the design of a robust controller for the braking system of a heavy-duty dump truck used in the mining industry. Zakian's design criteria are used to guarantee required performance despite the difficulties.

DOI:10.1049/ip-d.1987.0001

出版商:IEE    

年代:1987

数据来源: IET

摘要:

The paper considers the problem of deriving perturbed plant models from noisy input/output data. It is motivated by the use of the former in robust multivariable control analysis/design procedures. The approach taken centres around constructing confidence regions for the plant frequency response at a finite number of frequencies via spectral estimates and on an elementwise basis. The basic building block is the derivation of the distributions required for obtaining the gain and phase confidence intervals at a single frequency for a SISO frequency response.

DOI:10.1049/ip-d.1987.0002

出版商:IEE    

年代:1987

数据来源: IET

摘要:

Linear quadratic optimal filtering theory is used to extend a deterministic system for bank-to-turn control under CLOS guidance, for use in stochastic conditions. Both stationary and moving targets are treated, and the modifications to the deterministic designs are established. Simulation results demonstrate the potential of the new filter controllers for BTT control in terms of improved terminal accuracy and reduced susceptibility to noise-induced roll motion.

DOI:10.1049/ip-d.1987.0003

出版商:IEE    

年代:1987

数据来源: IET

摘要:

A new procedure for designing controllers and explicit self-tuning regulators is presented. This method allows the placement of closed-loop poles of a given system arbitrarily like other existing methods. The additional attractive feature of the new procedure is the elimination of tracking error for a given set of input (reference) signals. This is done by placing the zeros of the ‘error transfer function’ at the modes of reference signals. This is very useful in some practical applications like radar tracking and robotics. Some results of simulations are included which illustrate these aspects of the proposed method.

DOI:10.1049/ip-d.1987.0004

出版商:IEE    

年代:1987

数据来源: IET

摘要:

A method for multivariable self-tuning control is proposed. A recursive-prediction-error type algorithm is used for joint parameter and state estimation in the controller canonical form. Linear-state feedback is then used to arbitrarily place closed-loop poles. The main contribution of the proposed method is that, due to the canonical realisation adopted, online computation of transformation matrices is avoided.

DOI:10.1049/ip-d.1987.0005

出版商:IEE    

年代:1987

数据来源: IET

摘要:

For a second-order linear retarded delay-differential equation with two independent delays, two methods are used to demonstrate an interference effect that can reduce the likelihood of instability. Both methods rely on the basic result that stability changes only take place at pure imaginary values of the complex eigenvalue. One method uses the eliminant, which is zero if and only if both real and imaginary parts of the characteristic equation are satisfied. The other is an extension of a method used in problems with one delay, in which a certain curve is plotted to find whether it intersects the unit circle. When this interference effect is present, equal delays are particularly unlikely to destabilise.

DOI:10.1049/ip-d.1987.0006

出版商:IEE    

年代:1987

数据来源: IET

摘要:

In the paper, we study the stability and performance robustness of composite feedback systems under decentralised control. It is shown that, if the perturbed system transfer matrix is a compositeH-matrix for everyson the Nyquist contour, then stabilisation of the diagonal blocks of the composite system implies stabilisation of the overall system, provided the number of unstable poles of the composite system coincide with those of the diagonal blocks. This is then used to define decentralised controllers for robust stability. When restricted to regular multivariable systems, the new criterion leads to an interesting and simple condition on the peak magnification factorMpof the closed-loop system.

DOI:10.1049/ip-d.1987.0007

出版商:IEE    

年代:1987

数据来源: IET

摘要:

The use of the linear quadratic optimal problem (LQ) and the linear quadratic Gaussian (LQG) methodologies for the design of multivariable control systems is reviewed. The past decade has seen further developments in the solution procedures for these problems; in particular, the frequency domain techniques have experienced considerable refinement. The practical problems arising from the LQ/LQG methodology have also been the subject of considerable theoretical analysis. In the sequel, the recent frequency domain ideas are presented including the use of generalised spectral factor and polynomial systems theory. The practical aspects which are reviewed include the selection of performance criterion weighting matrices, robustness and integrity. Looking to the future, the newer research areas of optimal robustness and the application of LQG controllers in self-tuning control systems are also discussed.

DOI:10.1049/ip-d.1987.0012

出版商:IEE    

年代:1987

数据来源: IET