Browsing by Author "YEN, NZ"

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A MULTIRATE CONTROLLER-DESIGN OF LINEAR PERIODIC TIME-DELAY SYSTEMS
(1992-11-01)
YEN, NZ
;
WU, YC
;
電控工程研究所
;
Institute of Electrical and Control Engineering
This paper presents a multirate controller design for a linear periodic system with multiple delays at input and output. The approach first converts the periodic time-delay system into a periodic delay-free system, and then stabilizes and optimizes it by a multirate controller with pulse compensation. A significant advantage of this approach is that by using multirate sampling, the controller can provide more substantial design freedoms, so that although the system does not provide complete state information, it remains possible to convert the controller design into the dual of a regular complete state feedback problem. This enables one to derive a simple algorithm for choosing the optimal parameters of the controller and, by use of the optimal pulse compensation, to improve the transient response.
A RIPPLE FREE SAMPLED-DATA ROBUST SERVOMECHANISM CONTROLLER USING EXPONENTIAL HOLD
(1994-06-01)
WU, YC
;
YEN, NZ
;
電控工程研究所
;
Institute of Electrical and Control Engineering
In a general command tracking and disturbance rejection problem, it is known that a sampled-data controller using zero-order hold may only guarantee the asymptotic tracking at the sampling instances, but cannot smooth out the ripples between the sampling instances. In this paper, a sampled-data robust servomechanism controller using exponential hold is developed for guaranteeing the asymptotic tracking not only at, but also between, the sampling instances In this development, a so called ''internally-reducible'' condition to characterize a class of robust servomechanism controllers is derived first, then the proposed controller is shown to be contained in this class. Generally speaking, a sampled-data structure using exponential hold can provide more design freedoms so that it tends to simplify the construction of a robust servomechanism controller and facilitate the implementation on digital computers. An example for a dc motor control is presented to illustrate the advantages of this approach.
AN OPTIMAL ALGORITHM FOR SAMPLED-DATA ROBUST SERVOMECHANISM CONTROLLER USING EXPONENTIAL HOLD
(1994-01-01)
WU, YC
;
YEN, NZ
;
電控工程研究所
;
Institute of Electrical and Control Engineering
A new structure of sampled-data robust Servomechanism controller using exponential hold is developed. An optimal algorithm is also proposed for choosing the controller parameters of two important special classes. The algorithm is derived by minimizing a square-error performance index, and the solution can be solved from a discrete-time algebraic Riccati equation.
MULTIRATE ROBUST SERVOMECHANISM CONTROLLERS OF LINEAR DELAY SYSTEMS USING A HYBRID STRUCTURE
(1994-12-01)
YEN, NZ
;
WU, YC
;
電控工程研究所
;
Institute of Electrical and Control Engineering
A multirate robust servomechanism controller design for a linear time delay system is presented. The proposed controller is constructed by using a preparatory continuous internal model followed by a multirate error feedback compensator. An optimal algorithm for choosing the controller parameters is also derived. The algorithm is derived by minimizing a squared deviation error performance index, and the practical optimal solution can simply be solved from a discrete-time algebraic Riccati equation. A distinctive feature of the algorithm is that an optimal pulse compensation is also employed to improve the transient characteristics. Such a pulse compensation tends to eliminate the undesired influence arising from the initial deviation from the ultimate steady-state. In particular, if the initial deviation from the ultimate steady-state is known, then the optimal pulse compensation can drive the system into the steady-state in a time no larger than the input delay time plus the sampling period.
ON A GENERAL OPTIMAL ALGORITHM FOR MULTIRATE OUTPUT-FEEDBACK CONTROLLERS OF LINEAR STOCHASTIC PERIODIC-SYSTEMS
(1993-06-01)
YEN, NZ
;
WU, YC
;
電控工程研究所
;
Institute of Electrical and Control Engineering
A modified optimal algorithm for multirate output feedback controllers of linear stochastic periodic systems is developed. By combining the discrete-time linear quadratic regulation (LQR) control problem and the discrete-time stochastic linear quadratic regulation (SLQR) control problem as the extended linear quadratic regulation (ELQR) control problem, one derives a general optimal algorithm to balance the advantages between the optimal transient response of LQR control problem and the optimal steady-state noise regulation of SLQR control problem. In general the solution of this algorithm is solved from a set of coupled matrix equations. Special cases for which the coupled matrix equations can be reduced to a discrete-time algebraic Riccati equation are also discussed. A reducible case is the well-known optimal algorithm derived by AL-Rahmani and Franklin [1], where the system has complete state information, and the discrete-time quadratic performance index is transformed from a continuous-time quadratic performance index.
OPTIMAL PERIODIC CONTROL IMPLEMENTED AS A GENERALIZED SAMPLED-DATA HOLD OUTPUT-FEEDBACK CONTROL
(1993-10-01)
YEN, NZ
;
WU, YC
;
電控工程研究所
;
Institute of Electrical and Control Engineering
In this note, a conversion method to convert the analog linear quadratic regulation control to a generalized sampled-data hold output feedback control for a linear periodic system or a linear time-invariant system is presented. It is shown that by using such a conversion, one can implement the optimal periodic control scheme in the presence of incomplete and delayed state measurements.