摘要:

We propose a practical discontinuous feedback control scheme for the regulation of joint positions of robotic manipulators. A robust on-off switching control strategy based on a pulse-width-modulation (PWM) feedback scheme is proposed for the joint torques. The discontinuous PWM controller design is carried out on the basis of a suitable controller designed for an average model which is of continuous nature. Simulations of the closed-loop performance of the proposed control scheme are presented for a two-link robotic manipulator.

ISSN:0020-7721    

DOI:10.1080/00207729308949572

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A standard recursive identification algorithm for lumped parameter systems is applied in this paper for a class of distributed parameter systems using explicit two time level finite difference models. Each time level has two neighbouring discrete points. The identification is performed in a scalar manner at each time level beginning from the left border of a 2-dimensional spatial-time area. The time level is increased when the computation for the last point at the present level is completed. The nature of the procedure is 1 -dimensional and is recursive for both spatial and time variables. The two neighbouring points at thekth time level influence the values in the discrete model at the (k+ l)th time level. Having obtained the estimates of the parameters at thekth time level we consider in the discrete scalar model the appropriate signals at this level asinputsfor the (k+ l)th level. The proposed procedure of parameter identification is studied via several numerical examples of heat transfer problems with constant parameters.

ISSN:0020-7721    

DOI:10.1080/00207729308949573

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Four rendezvous problems fornnon-identical simple-integral plants (K1/s,K2/s, ⃛,Kn/s), with a common inputx(t)=Amimu(t),m= 0,1,2, ⃛, and initial output conditions of (ξ1,ξ2, ⃛, ξn), are studied in this paper. These rendezvous problems, generally speaking, are concerned with transferring thenplants outputs to meet one another in afinitetime (at a.fixedtarget or on anon-stationaryone).

ISSN:0020-7721    

DOI:10.1080/00207729308949574

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Numerical algorithms incorporating condition and accuracy estimates for solving state-space design problems of linear control systems are considered. The reliability and efficiency of various algorithms and estimates as well as their program implementation are discussed. Some new results concerning numerical controllability analysis and the pole assignment condition are presented. Several numerical tests illustrate the performance of the algorithms and accuracy estimators.

ISSN:0020-7721    

DOI:10.1080/00207729308949575

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

This paper discusses the achievable nominal performance of a well-parametrized neural feedback control system, and proposes an efficient training method for parametrizing such a controller. A self-organizing neural control (SONC) system is presented in which a layered feedforward neural network is adopted as the controller structure in order to apply directly existing back-propagated learning techniques. A self-organizing methodology is introduced to provide the training set for adjusting parameters of the neural controller. One important feature of the proposed adaptive mechanism is that, though it should lack extensive knowledge of the process dynamics at the outset of controller design, it will still be able to achieve its desired results by employing the subjective experience of control specialists as its training aids. Tuning variables of the SONC system are reviewed through exploring their effects on five typical transfer functions. The applicability of the SONC system is also demonstrated on a continuous stirred tank reactor. Simulation results show that a well-parametrized neural controller can improve nominal performance for a wide variety of different processes, and the proposed self-organizing mechanism can direct a controller to achieve the desired final parametrization.

ISSN:0020-7721    

DOI:10.1080/00207729308949576

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The environment of the manufacturing systems designer who at the early design stage is preoccupied with modelling and identification processes, is increasing in complexity. To deal with this complexity, systems analysts need to he supported in a number of areas and stages of their activities. This paper looks at the early stage of such activities that concerns decomposition of tasks and functions identifying a manufacturing system. Decomposition occurs at the highest level of abstraction and it must provide enough information for the lower level design stages where manufacturing functions are transformed into manufacturing agents that are further integrated through the flow of information into the informational model of the overall system. The proposed approach includes incorporation of logic into functional space and some elements of optimization in this space. The methodology presented is illustrated with examples.

ISSN:0020-7721    

DOI:10.1080/00207729308949577

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

This paper deals with the minimization of a scalar measure of the matrix which solves the Lyapunov equationP = [A − HC]P[A − HC]′ + BWB′ + HVH′with respect to the pair (H, C). This problem arises in the prediction of the state of a discrete-time, stochastic linear system, when one is concerned with minimizing the prediction error covariance both with respect to the predictor gain and with respect to the output matrix, which accounts for the physical device by which the state of the system is observed. By duality, the problem can be interpreted as the optimization of a suitable performance index for a linear regulator with respect both to the input matrix and to the feedback regulator gain. First, the index to be minimized is carefully chosen, in order to obtain a meaningful optimization problem, and the optimization with respect to the predictor gain or with respect to the output matrix, when the other matrix is fixed, is considered. The related results suggest an algorithm which generates a sequence of pairs (output matrix, predictor gain) which ensure stability of the matrix [A − HC], and to which a decreasing sequence of values of the index there corresponds. Results about boundedness and convergence of the sequence thus obtained are proved. The problem and the related solution algorithm is also extended to deal with the singular case of no measurement noise. Numerical experiments, in which comparison is made with the behaviour of a standard gradient-based method, confirm the robustness of the proposed algorithm, anticipated on the basis of its theoretical properties.

ISSN:0020-7721    

DOI:10.1080/00207729308949578

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A practical method of designing windows by usingC-spline functions is proposed. Given sidelobe fall-off controls the frequency characteristics at higher frequencies, while desired characteristics and specified error tolerance control those at lower frequencies. The optimal dimension is determined as the minimum to satisfy the tolerance of error in approximating the desired characteristics in the logarithmic scale. The effectiveness of this method is demonstrated by several design examples superior to Kaiser-Bessel, gaussian, Hanning, Blackman, Parzen or cosxxwindows, respectively.

ISSN:0020-7721    

DOI:10.1080/00207729308949579

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A discrete-time time-invariant linear system (DILS) is considered which has resulted from the discretization of a continuous-time time-invariant linear system (CILS) by the zero order hold. In this system, the system and input matrices are given by exp(AT) and $ whereAandBare the system and input matrices of the CILS, andTis a sampling interval. Since they involve the matrix exponential, their computations are not easy.

ISSN:0020-7721    

DOI:10.1080/00207729308949580

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Starting from the relations between entries of block pulse operational matrices, block pulse regression equations corresponding to the original differential equation models with time-varying parameters are obtained. Based on simple forms of the regression equations, algorithms developed in discrete-time model identification can be applied directly to estimate the time-varying parameters of the continuous models without much modification. Compared with other identification methods for the same problem, this new method is simple, and can be applied to both batch and recursive estimations of continuous time-varying linear systems from their sampled input and output data by means of digital computers.

ISSN:0020-7721    

DOI:10.1080/00207729308949581

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor