摘要:

AbstractThis paper considers the deterministic adaptive feedforward control problem for disturbance rejection. A new indirect adaptive control algorithm is presented as an alternative to the well‐known ‘filtered‐X LMS’ algorithm when the disturbance is periodic with unknown frequency and the plant, possibly non‐minumum phase, is unknown. This new algorithm requires the solution of a Diophantine equation and a simple scheme to recursively solve this type of equation is suggested. the new algorithm is shown to converge without the use of a dither signal for plant modelling. Simulations demonstrate that the proposed algorithm has a substantially better transient response and convergence speed than the filtered‐X LMS algorithm. the applicability of the algorithm to the adaptive active‐noise‐cancelling problem is demonstrated using an identified

ISSN:0890-6327    

DOI:10.1002/acs.4480090302

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractMotion control systems with dry friction and high‐order uncertain plants suffer from one or more limit cycles which can be predicted with describing function theory. In this paper quantitative design theory is presented to satisfy given frequency domain tolerances in these systems. The case of linear time‐invariant (LTI) compensation is studied first. Then it is shown how, in those systems with a limit cycle, self‐oscillating design with an adaptive loop (SOAL) can be used to reduce the LTI compensator bandwidth for a large class of pro

ISSN:0890-6327    

DOI:10.1002/acs.4480090303

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractA simple relay feedback auto‐tuning method is proposed for the Smith predictor, an advanced controller for processes with long dead time. the relay feedback control gives information on one point of the Nyquist curve in terms of ultimate gain and frequency. With an additional measurement of the static gain, a reduced order process model in terms of a first‐ or second‐order dynamics plus dead time could be computed and used to auto‐tune the Smith predictor. When the process dynamics changes more frequently, a self‐tuning controller is required. In this case the Fast Fourier Transform technique can be further employed to track the points on the Nyquist curve by estimating the process frequency response and then used to update the Smith predictor. Excellent performance of the auto‐tuned and self‐tuned Smith predictor has been substantiated b

ISSN:0890-6327    

DOI:10.1002/acs.4480090304

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractFor the velocity control of an asymmetric hydraulic actuator the servovalve is not operated in the vicinity of zero. Thus the linearized model is not easily defined and the classical controller cannot be readily found. Also, because of its asymmetry, a fixed reference model of adaptive control cannot result in optimal performances for both directions.In this paper, to minimize the performance index associated with the estimated model and control penalty, the self‐optimization α‐adaptive control shows an ability to adapt to variations in directions and operating conditions. Thus it will provide similarly optimal performances for both extending and retracting processes. Then, comparing with the variable gain control, the experimental results clearly show its superior performance and disturbance rejec

ISSN:0890-6327    

DOI:10.1002/acs.4480090305

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

摘要:

AbstractThis paper considers the problem of adaptive LQG control design when the system control input is subject to an amplitude constraint. A first‐order stochastic system is considered mainly because its output can be satisfactorily described by a Gaussian probability density function (PDF) or can be calculated numerically. In this light, two algorithms are proposed. In the first algorithm an approach given by Toivonen has been adopted where the PDF of the output is approximated by the Gaussian density in order to develop a suboptimal adaptive feedback controller. the approach in the second algorithm is based on the numerically calculated PDF of the system output yielding a near‐optimal feedback gain. the proposed algorithms are compared with existing ones via simulati

ISSN:0890-6327    

DOI:10.1002/acs.4480090306

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY

ISSN:0890-6327    

DOI:10.1002/acs.4480090301

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1995

数据来源: WILEY