TORE Collection: Publications without fulltext files
Publications without fulltext files
http://hdl.handle.net/11420/2093
2023-02-03T06:28:45Z
2023-02-03T06:28:45Z
Spatial control of a large PHWR by piecewise constant periodic output feedback
Tiwari, A. P.
Bandyopadhyay, B.
Werner, Herbert
http://hdl.handle.net/11420/14730
2023-02-02T23:03:23Z
2000-01-01T00:00:00Z
Title: Spatial control of a large PHWR by piecewise constant periodic output feedback
Authors: Tiwari, A. P.; Bandyopadhyay, B.; Werner, Herbert
Abstract: The paper presents the design of piecewise constant periodic output feedback control for a discrete-time singularly perturbed system resulting from the discretization of a continuous-time standard singularly perturbed system. By a suitable linear transformation of state variables, the given continuous-time singularly perturbed model is converted into a block triangular form in which the fast subsystem is decoupled. The discrete-time model corresponding to the transformed model also exhibits a two time scale property if sampling period is larger than the parameter e. Now, an output injection matrix is found that stabilizes the slow subsystem. The periodic output feedback gain is then calculated only for the slow subsystem and the same for the fast subsystem is set equal to zero. Finally the periodic output feedback gain for the composite system is obtained using the periodic output feedback gains computed separately for the slow and fast subsystems. An approach has been suggested whereby the determination of periodic output feedback gain for the slow subsystem can be converted into an optimization problem. By minimization of the suggested performance index the closed loop system behavior is improved. The method has been applied to a large pressurized heavy water reactor (PHWR) for control of xenon-induced spatial oscillations. A particular grouping of state variables has been suggested for obtaining the model in standard singularly perturbed form. The periodic output feedback gain is then calculated. The efficacy of control has been demonstrated by simulation of transient behavior of the nonlinear model of the PHWR. Index Terms-Large heavy water reactor, periodic output feedback, singular perturbation, spatial control.
2000-01-01T00:00:00Z
Generalized sampled-data hold functions for robust multivariable tracking and disturbance rejection
Werner, Herbert
http://hdl.handle.net/11420/14729
2023-02-02T23:03:23Z
2001-03-01T00:00:00Z
Title: Generalized sampled-data hold functions for robust multivariable tracking and disturbance rejection
Authors: Werner, Herbert
Abstract: A new design procedure for a multivariable sampled-data output feedback controller with generalized hold function is proposed. The controller can be designed for different operating points simultaneously. The design of the hold function is carried out in two steps: first the closed-loop discrete-time behaviour is determined by choosing a suitable output injection gain; integral action is incorporated to guarantee zero steady-state error. In a second step this discrete-time behaviour is approximately realized by output feedback with generalized hold. Minimization of a quadratic performance index simultaneously for all operating points yields hold functions with good intersample behaviour. A practical design example and experimental results illustrate the proposed method. Copyright © 2001 John Wiley & Sons, Ltd.
2001-03-01T00:00:00Z
Simple algorithm for sampled-data output feedback control with suboptimal generalized hold functions
Werner, Herbert
http://hdl.handle.net/11420/14728
2023-02-02T23:03:23Z
1998-01-01T00:00:00Z
Title: Simple algorithm for sampled-data output feedback control with suboptimal generalized hold functions
Authors: Werner, Herbert
Abstract: In this paper, control of linear time-invariant plants by sampled-data output feedback control with generalized, piecewise constant hold functions is considered. An iterative algorithm is proposed which yields a sub-optimal solution to the linear quadratic regulator problem. The hold function is obtained by alternatingly improving closed-loop behavior at sampling instants and intersample behavior. Because the solution is guaranteed stable, this algorithm provides a computationally simple method for stabilization by output feedback. A numerical example is presented for a harmonic oscillator.
1998-01-01T00:00:00Z
Robust control of a laboratory flight simulator by nondynamic multirate output feedback
Werner, Herbert
http://hdl.handle.net/11420/14727
2023-02-02T23:03:23Z
1996-01-01T00:00:00Z
Title: Robust control of a laboratory flight simulator by nondynamic multirate output feedback
Authors: Werner, Herbert
Abstract: This paper describes the application of a new nondynamic multirate output feedback control law to a robust tracking problem for an unstable plant. The nonlinear plant is linearized around its nominal operating point and around two possible failure modes. The controller design is carried out in two steps: convex programming methods can be used to find a state feedback gain which meets given specifications in the nominal operating point and under failure conditions. Then this state feedback gain is realized by a multirate output feedback control law. Experimental results show that this output feedback controller maintains the performance achieved by state feedback.
1996-01-01T00:00:00Z