摘要:

The unknown parameters of physical laws which govern the dynamics of processes can be gained from measured input and output signals in a two step procedure. First the parameters of differential equations are estimated and then the physical parameters are calculated based on algebraic relations. After considering the model structures a suitable parameter estimation method for continuous time signals is described and the influence of aprioriknown parameters on the convergence is shown. Then the determination of physical parameters is considered based on nonlinear algebraic relations known from theoretically modelling. Applying the implicit function theorem identifiability conditions for the unique determination of physical parameters are given. Then applications are shown for the estimation of the ratios of inertia, d.c. motor damping coefficients and Coulomb friction coefficients of an 6-axis-industrial robot.

ISSN:0020-7179    

DOI:10.1080/00207179208934285

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Layered networks are used in a nonlinear adaptive control problem. The plant is an unknown feedback-linearizable discrete-time system, represented by an input-output model. A state space model of the plant is obtained to define the zero dynamics, which are assumed to be stable. A linearizing feedback control is derived in terms of some unknown nonlinear functions. To identify these functions, it is assumed that they can be modelled by layered neural networks. The weights of the networks are updated and used to generate the control. A local convergence result is given. Computer simulations verify the theoretical result.

ISSN:0020-7179    

DOI:10.1080/00207179208934286

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A fundamental objection to many control system design techniques is that the possible inputs to a system are considered in a vague manner, if at all. Zakian has introduced a new principle of design, called matching, which uses a simple set theoretic approach and results in quantitative design criteria in terms of the inputs. The principle of matching gives rise to a design framework applicable to multi-criterion design problems, to which a solution can be sought by interactive numerical methods. This gives independent control over conflicting design criteria and the ability to specify the controller structure. A significant development within the design framework is the ability to model accurately complex inputs with both persistent and transient characteristics. This paper illustrates the modelling of complex inputs, and uses the principle to design a cheap, reliable and easily implementable add-on automatic speed control (sometimes referred to as ‘cruise control’) system for motor vehicles. The final design guarantees, for the plant model adopted, that for all possible inputs the system satisfies the conflicting design criteria, which are that the speed stays within its prescribed margins and that the vehicle travels within acceptable margins of ride comfort.

ISSN:0020-7179    

DOI:10.1080/00207179208934287

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A new method of designing a robust control law is proposed for a general class of non-linear or linear systems with bounded uncertainties. The method uses the property that the Lyapunov function is not unique for a stable or stabilizable system. It is shown that the proposed control law normally guarantees the stability of the system if there are two Lyapunov functions whose null sets have a trivial intersection. The null set of a Lyapunov function is defined to be the set in state space in which the product of the transpose of the system input matrix and the gradient of the Lyapunov function is equal to zero. The robust control results impose no restriction on the structure and size of the input-unrelated uncertainties. Moreover, it is shown that asymptotic stabilization of the nominal system is not necessarily required in this method.

ISSN:0020-7179    

DOI:10.1080/00207179208934288

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

In this paper, we deal with the problem of designing non-overshooting feedback control systems when the input is a step. We also consider the more general problem of designing controllers to track a step optimally with some predetermined amount of allowable overshoot. These problems are cast as infinite linear programming problems. We show that both these problems always have a solution (under some standard assumptions). It is then shown that the counterpart of this problem, that is, the problem of designing non-undershooting feedback control systems, need not have a solution in general. But it is proved that one can always design a feedback controller to achieve as little percentage undershoot as desired. Finally, it is shown that the problem of designing controllers to simultaneously satisfy bounds on the overshoot and undershoot always has a solution if some undershoot is allowed for. The duals to the infinite linear programming problems are formulated and the absense of a duality gap is established for each of the problems using the concept of quasi-relative interiors. Most of the paper deals with discrete-time single-input single-output systems through extensions of the techniques to a class of multi-input multi-output systems are also discussed.

ISSN:0020-7179    

DOI:10.1080/00207179208934289

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Electrical and The decentralized stabilization problem of multivariable finite-dimensional systems is considered in a fractional set-up. A new synthesis procedure for decentralized stabilizing compensators is proposed. The class of all admissible local compensators that can be applied to a specified channel as an element of a decentralized compensator is identified. The conditions under which the class of admissible local compensators is generic are investigated. The problem of making a multi-channel system stabilizable and detectable from a single channel applying decentralized feedback around the other channels has been shown to be generically solvable for a given set of dynamic compensators if and only if the plant is strongly connected.

ISSN:0020-7179    

DOI:10.1080/00207179208934290

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

ℋ∞norm bounds are useful in control design for disturbance rejection. For discrete systems, ℋ∞norm optimizing controls can be characterized via the solution of the Discrete Algebraic Riccati Equation, (DARE). In addition, the DARE can be used to characterize controls that guarantee a uniform ℋ∞norm bound. In this paper we identify an entire class of state feedback controls that guarantee an ℋ∞norm bound, and provide new lower bounds for the ℋ∞norm of stable systems, as well as for the best achievable ℋ∞norm using state feedback controls.

ISSN:0020-7179    

DOI:10.1080/00207179208934291

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

Control systems described in terms of a class of linear differential-algebraic equations are introduced. Under appropriate relative degree assumptions, a computational procedure for obtaining an equivalent state realization is developed using a singular value decomposition. Properties such as stability, controllability, observability, etc, for the differential-algebraic system may be studied directly from the state realization. For linear constrained hamiltonian systems, it is shown that the procedure provides a state realization in which the hamiltonian structure is preserved. Similar results are obtained for constrained gradient systems. Control of systems described by this class of differential-algebraic equations, using a transformation to obtain a state realization, completely avoids the need for any new control theoretic machinery.

ISSN:0020-7179    

DOI:10.1080/00207179208934292

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

A game theory approach to the state-estimation of linear discrete-time systems is presented. The resulting state estimation suggests an alternative to the Kalman filter, in cases where the exact statistics of the input and the measurement noise processes is not known. It turns out that the game-theoretic filter provides anH∞-optimal estimation. Moreover, it is shown that the covariance matrix of the estimation error is bounded, from above, by the solution of a modified Riccati equation.

ISSN:0020-7179    

DOI:10.1080/00207179208934293

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor

摘要:

This paper deals with two problems for the improvement of the control performance of simple adaptive control (SAC) techniques. First, it is discussed that the introduction of a robust adaptive control term much robustifies the SAC system concerning plant uncertainties such as state dependent disturbance. Second, a practical procedure is described for designing the parallel feedforward compensator, which is necessary for the actual realization of the SAC system, given prior information concerning the plant such that: (1) the plant is minimum phase; (2) an upper bound on the relative degree exists; and (3) approximate values of high and low frequency gains are known. The effectiveness of the proposed methods is confirmed through the simulation of typical examples of adaptive control systems.

ISSN:0020-7179    

DOI:10.1080/00207179208934294

出版商:Taylor & Francis Group    

年代:1992

数据来源: Taylor