摘要:

An improved formulation for stochastic steady state optimizing control problems is presented. Owing to its different structure, it is applicable to a larger group of practical problems than an earlier version (Lin et al. 1989 a). Theoretical analysis is carried out to investigate the viability of the new formulation. A modified approach to stochastic steady state optimizing control problems under such a formulation is also presented. Here, a modified steady state identification technique is employed to estimate the mean derivative that is required in calculating the modifier. The dynamic information acquired from the real process between any two successive controller set point changes is used. The advantage of this approach is that it significantly reduces the required number of controller set point changes and is much less sensitive to noise than the modified two-step methods. Optimality and global-convergence conditions are provided. Consistency and asymptotic behaviour of the modified steady state identification method are also investigated. Comprehensive computer simulations are provided not only to show the effectiveness and reliability of the presented optimizing control algorithm, but also to demonstrate the accuracy of the steady state estimation. Comparisons are made between this approach and the modified two-step methods, showing that the presented approach is very efficient and reliable.

ISSN:0020-7179    

DOI:10.1080/00207179008953551

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

Two novel hierarchical structures are presented which extend the applicability of previous model-based double iterative loop techniques using input-output information feedback to non-convex problems. The techniques incorporate integrated system optimization and parameter estimation, which utilize process measurements to achieve real process optimality in spite of model reality differences. The double iterative loop structures of the proposed algorithms use the real process measurements within the output loops while the inner loops involve model-based computations only. By this means the algorithms use available information from the real process efficiently and a significant reduction in set-point alterations to real sub-processes is achieved. In order to cater for process complexity, the inner loops are organized in the form of two-level hierarchical structures. An applicability of the techniques to non-convex problems is achieved by a suitable convexification of an original process performance index. It is a very important property of the convexification that it preserves two-level decomposibility of the problem. Sufficient conditions for convergence of the augmented techniques are derived. Simulation examples are provided to illustrate the methods.

ISSN:0020-7179    

DOI:10.1080/00207179008953552

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

A design methodology for a class of non-linear singularly perturbed systems with fast actuators is proposed using the composite control technique. The origin of the nominally unforced unperturbed system is assumed to be asymptotically stable and a Lyapunov function for the nominal system is available. Then by appropriate choice of the design manifold, a composite feedback control can be constructed to guarantee the asymptotic stability of the origin of the closed-loop system.

ISSN:0020-7179    

DOI:10.1080/00207179008953553

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

In this paper we examine the stability of a proportional derivative (PD) controller for the trajectory-following problem of a robot manipulator. We use Lyapunov's second method to derive a uniform boundness result for the PD controller. We show that if the PD controller gains are chosen greater than a specific bound and if the initial tracking error is zero, the velocity and position tracking errors are uniformly bounded. We then develop two additional controllers that use auxiliary control inputs along with the PD controller. Both of these controllers are shown to yield a uniform ultimate boundness property for the tracking error.

ISSN:0020-7179    

DOI:10.1080/00207179008953554

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

This paper studies controllers employing multirate sampling of the plant output (Hagiwara and Araki 1988 a). Specifically, it is shown that arbitrary pole assignment is possible by a multirate output sampling mechanism with smaller output multiplicities if a multiframe control law is introduced. We refer to the new control law as the generalized multirate-output controller. It is also shown that type-1 robust servo controllers with two degrees of freedom can be designed and strong stabilization with loop transfer reovery is possible. The relation of the generalized multirate-output controllers to the two-delay output controllers (Mita et al. 1987, Mita and Chida 1988) is also discussed.

ISSN:0020-7179    

DOI:10.1080/00207179008953555

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

A method of designing a type-one optimal servo system is described. The design uses an exact model matching method with pole-zero cancellations. The initial values of the integrators are set according to the plant initial conditions at the beginning of control. This servo system is optimal in the sense that the performance index, comprising the quadratic forms of both the error vector and the deviation control vector from its steady-state, is minimized. The sensitivity to plant parameter variations can be reduced without loss of optimality for the nominal plant. Moreover, this servo system has the same robustness characteristic as typical optimal servo systems designed using different performance indices. Two numerical examples illustrate the efficiency of this servo system.

ISSN:0020-7179    

DOI:10.1080/00207179008953556

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

A method is presented for designing a full state feedback linear control law that will ensure the robust stability and performance of a given linear uncertain system. The systems under consideration are described by state equations that depend on uncertain parameters. These uncertain parameters may be time varying. Their values are constrained to lie within known compact bounding sets. The method is based on the guaranteed cost control concept of Chang and Peng (1972). The controller gains result from the solution of a Riccati equation in which the weighting matrices depend on the uncertainty bounds. Sufficient conditions for the existence of a solution arise from the standard LQG control theory.

ISSN:0020-7179    

DOI:10.1080/00207179008953557

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

This paper considers the problem of parametrizing (through the minimum number of parameters) the minimum-time output deadbeat controller (MTODC) for a given linear multivariable output-controllable system S(A, B, C, E) having n states, m inputs, p outputs and a transfer function matrixH(z)of full rankr. The main result is a new compact linear parametric form for a class of MTODC that zeros the outputs of the system S in the minimum number of control iterations μ(1), where μ(1), i = 1, 2,..., r (assumed to be decreasingly ordered) are equal lo the negatives of the right factorization indices at infinity ofH(z). The developed parametric class is a linear function in

ISSN:0020-7179    

DOI:10.1080/00207179008953558

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

RELION is an abbreviation for the relay-linear control law. It as a double structure—relay and linear—and it is a modification of the constructive time-sub-optimal control law,u= sgn(pMx + sgn(pM-1+ … + sgn(p2x + sgnpix)…)). For determining the RELION it is necessary to calculate then-vectors p1,… pmand to evaluate the factorKof the linear control lawu= Kp1x. Two algorithms for calculating these parameters are presented.

ISSN:0020-7179    

DOI:10.1080/00207179008953559

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor

摘要:

An approximation approach to the identification of stable continuous-time, possibly infinite dimensional systems is studied. For this purpose, concrete exponential Leg-endre series methods are proposed and analysed here for the L1and L2approximations of continuous-time systems. Rate of approximation results are given for the proposed methods for an important class of delay systems. The proposed exponential Legendre series method for the L2approximation has a certain optimal rate of approximation property for this class of delay systems. These results show that exponential Legendre series techniques have promising properties in connection with the L1and L2identifications of stable continuous-time systems. The proposed L1identification method has a direct application to the robust design of control systems.

ISSN:0020-7179    

DOI:10.1080/00207179008953560

出版商:Taylor & Francis Group    

年代:1990

数据来源: Taylor