摘要:

Based on a recently developed approach to the design of unknown input observers, this paper presents a fault detection method for unknown systems with unknown input. By exploiting the properties of an assumed model structure, a residual signal is formed which is independent of the unknown input but dependent on the measurements and the unknown system parameters. With this signal, an identification algorithm with a residual-based resetting technique for the covariance matrix is obtained and used to track parameter changes caused by system faults. The method is demonstrated through its application to a simulated hydraulic turbine generating unit.

ISSN:0020-7179    

DOI:10.1080/00207179308934386

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

An adaptive sliding mode scheme is developed for accurate tracking control of robotic manipulators. By coupling on-line estimation of unknown manipulator and payload parameters to sliding mode control, tracking performance is effectively improved. The introduction of a boundary layer solves the problem of chattering and provides a consistent rule on when to stop adaptation. The algorithm is computationally simple, because of an effective exploitation of the structure of manipulator dynamics. The approach is demonstrated by simulations.

ISSN:0020-7179    

DOI:10.1080/00207179308934387

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Iterative learning control serves to enhance the performance of robots carrying out repetitive cycles of operation. A new discrete learning method is developed which (a) is computationally not too demanding since the full model of the robot is not involved and (b) can reduce design tuning to simply choosing the sampling interval in order to provide satisfactory performance. The convergence issue and robustness problem are particularly addressed. The effectiveness of the learning control method is demonstrated by experimental results obtained using a commercial robot.

ISSN:0020-7179    

DOI:10.1080/00207179308934388

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

This paper considers problems of simultaneous stabilization using a linear time-invariant compensator incorporated with a sampler and zeroth-order hold function. It is shown that this controller strongly stabilizes a number of plants which may not be stabilizable by a conventional linear time-invariant controller. A controller design procedure is given which is illustrated by an example.

ISSN:0020-7179    

DOI:10.1080/00207179308934389

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A general orthogonal parameter estimation algorithm is derived to estimate both the structure and the parameters for a wide range of stochastic nonlinear systems which can be described by a nonlinear rational model. Simulation studies are included to demonstrate the performance of the algorithm.

ISSN:0020-7179    

DOI:10.1080/00207179308934390

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The problem of optimal fixed order observers for continuous-time linear systems with deterministic input and coloured process and measurement noises is considered. Optimal estimation of the state involves augmentation of the system, and as a result the observer has the augmented dimension. In this paper, the order of the observer is prefixed to a value which ranges between the dimension of the original system and that of the augmented system. The presence of a deterministic input imposes the structure of an observer on the estimator. The optimal observer-estimator, under these dimensional and structural constraints, is then derived. Solution is given for the general case where the intensity of the white noise component of the measurement noise may be singular. Necessary conditions fully characterizing the optimal observer-estimate are given. The solution consists of a modified Riccati and three modified Lyapunov equations coupled by three projection matrices. The three projections correspond to the order reduction, the singularity of the measurement, and the structural constraint. The problem is shown to be the most general reduced order optimal estimation problem and previously solved cases are all specializations of our results.

ISSN:0020-7179    

DOI:10.1080/00207179308934391

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

In this paper a finite horizon H∞optimal control problem is posed and solved. It is shown by way of examples that the finite horizon performance is useful for the fast computation of the infimal H∞norm in the infinite interval case. Also, a differential equation is derived for the measure of performance. A general suboptimal control problem is then posed and an expression for a suboptimal controller is derived solving the saddle point conditions. An expression for a feedback controller can be derived by solving a dynamic Riccati equation. In the time-invariant case, the finite horizon controller converges to a static controller as the final time becomes large. Examples are given to illustrate the usefulness of the theory.

ISSN:0020-7179    

DOI:10.1080/00207179308934392

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A general suboptimal control problem is posed and an expression for a suboptimal controller is derived solving the saddle point conditions. An expression for a state feedback suboptimal controller can be derived by solving a dynamic Riccati equation. Then, an expression for a suboptimal output feedback controller is developed in a general case via the solution of two dynamic Riccati equations.

ISSN:0020-7179    

DOI:10.1080/00207179308934393

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

This paper describes the rational approximation of a certain class of delay systems in the frequency domain using Pad£ approximants of exp(−sT). Three classes of approximants characterized by their relative degrees are considered. Easily computable a priori L∞and L L2error bounds are provided.

ISSN:0020-7179    

DOI:10.1080/00207179308934394

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A duality is demonstrated between optimal feedforward control and optimal deconvolution, or input estimation. These two problems are normally discussed separately in the literature, but have close similarities. Duality between them can be demonstrated if and only if one uses general problem formulations, with frequency-shaped weighting in the criteria. From one of the problems, the dual problem can then be obtained immediately from the block diagram, by reversing the directions of arrows, interchanging summation points and node points and transposing all transfer function matrices. This result applies for continuous and discrete time problems, as well as for minimization of J = ||G||, for any transfer function norms for which ||GT|| = ||G||. A derivation of a polynomial solution to the frequency-weighted discrete-time MIMO LQG feedforward control problem illustrates the use of the duality.

ISSN:0020-7179    

DOI:10.1080/00207179308934395

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor