In this paper, a new design method for adaptive output feedback control systems with a switching function for sets of compensators is proposed. The proposed switching function can automatically select an appropriate p...
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In this paper, a new design method for adaptive output feedback control systems with a switching function for sets of compensators is proposed. The proposed switching function can automatically select an appropriate parallel feedforward compensator and pre-compensator so that the resulting augmented plant is almost strictly positive real (or stabilizable). This paper also shows that all of the signals in the switching adaptive control system are bounded and that the switching action ceases after a finite number of switches.
The goal of this paper is to show an approach of multi-model control for a nonlinear system. The idea of the multi-model control is to design a set of identifiers combined with controllers. Each of them will identify ...
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The goal of this paper is to show an approach of multi-model control for a nonlinear system. The idea of the multi-model control is to design a set of identifiers combined with controllers. Each of them will identify in fact the system in a special environment. The problem is to determine the best identifier with the smallest identification error and to apply to the plant the control law provided by the controller combined with the latter. The paper shows a new switching algorithm: the latter is based on a symbolic fuzzy system.
In this article, an electric power amplifier, a stack actuator and a hydrostatic displacement amplifier are introduced, which control a hydraulic valve. A switching controller concept is used by the electrical amplifi...
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In this article, an electric power amplifier, a stack actuator and a hydrostatic displacement amplifier are introduced, which control a hydraulic valve. A switching controller concept is used by the electrical amplifier. A switching period must not exceed one microsecond. The actuator works with a voltage up to 200 V. The displacement amplifier works as a hydrostatic gear. This gear consists of two corrugated tubes of different diameters. The design of the hydraulic control unit is a seat-valve. It uses a cylindrical guided part combined with an axial force compensated seat. The size of flow amounts about 120 dm 3 /min and the pressure to about 30 Mpa.
The goal of this paper is to compare two approaches of the multi-model control for a nonlinear system with a real-time implementation for a wrist of a robot. The paper shows two switching algorithms: the former is bas...
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The goal of this paper is to compare two approaches of the multi-model control for a nonlinear system with a real-time implementation for a wrist of a robot. The paper shows two switching algorithms: the former is based on the selection of only one controller thanks to a special criterion; the latter is a new switching algorithm because it is based on a symbolic fuzzy system. The objective of this apporach is to blend the control laws provided by several controllers.
In this paper, a modified Independent Modal Space Control (IMSC) that relaxes the fundamental hardware requirement of IMSC is proposed for handling the vibration and attitude control problem of large, flexible structu...
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In this paper, a modified Independent Modal Space Control (IMSC) that relaxes the fundamental hardware requirement of IMSC is proposed for handling the vibration and attitude control problem of large, flexible structures. The method incorporates a new switching algorithm for dynamically selecting controlled modes and a novel design technique for determining the modal control force. The main advantage of the proposed method is that it minimizes the discontinuity of the modal control forces and assures the asymptotic stability of the closed-loop system. The simplicity and efficiency of the method is demonstrated through an example involving vibration control of a cantilevered beam. The system performance and stability of the proposed method is compared with previously published methods that also seek to reduce the number of actuators in IMSC.
In the last years piezoelectric actuators have proven to be more and more attractive for many applications with demands for very high speed, very high forces and minimal actuator size. Significant improvements in manu...
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In the last years piezoelectric actuators have proven to be more and more attractive for many applications with demands for very high speed, very high forces and minimal actuator size. Significant improvements in manufacturing technology of piezoelectric actuators and the electronic components necessary for their operation, are only some of the reasons for this trend. In this paper a nonlinear model based control of a piezoelectric actuated hydraulic valve is presented. The controller structure is developed on the basis of a very realistic nonlinear mathematical model of the actuator's and valve's physical behavior.
In this paper we present an adaptive stabilization control for systems with unknown constant parameters and stochastic disturbances, which may be neither open-loop stable nor minimum phase. The ideas come from previou...
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In this paper we present an adaptive stabilization control for systems with unknown constant parameters and stochastic disturbances, which may be neither open-loop stable nor minimum phase. The ideas come from previous works [J. F. Zhang and H. F. Chen, Adaptive stabilization under the weakest condition, Proc. 31st Control and Design Conference, December 14-18, 1992, pp. 3620-3621, and H. F. Chen, Continuous-Time Stochastic Adaptive Control Stabilizing the System and Minimizing the Quadratic Loss Function, Tech. Report, Institute of Systems Science, Academia Sinica, Beijing, 1992], but here we not only simplify the construction procedure of an adaptive control but also reduce the computational load significantly, so that the adaptive control in this paper is more practical. Furthermore, parameter estimation is carried out in only a finite time period and, unlike previous work, the parameter estimates are generated by ordinary differential equations rather than stochastic differential equations.
A standard assumption in adaptive control is that the parameters being estimated are either constant or vary 'slowly' as a function of time. This paper investigates the adaptive control of a class of systems i...
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A standard assumption in adaptive control is that the parameters being estimated are either constant or vary 'slowly' as a function of time. This paper investigates the adaptive control of a class of systems in which the parameters vary as a specified function of state. The dynamic structure of the systems may be either linear or nonlinear. For this class of systems, the state space is separated into distinct subsets. The parameters are then required to remain constant, or be slowly time varying, within the subsets. Given a controller for the system, an analysis of the output error dynamics and the parameter error dynamics leads to a parameter adaptation algorithm with a variable structure. The stability and convergence of both the parameter error and the output tracking error are investigated. An analysis of SISO linear systems with full state information is used to motivate and illustrate the treatment of SISO feedback linearizable systems. (C) 1998 Elsevier Science B.V. All rights reserved.
The manufacturing and operation of window size (30cm x 90cm) electrochromic devices is described. Both the electrochromic electrode (WO3) and the counter electrode (V2O5) were deposited by sol-gel method. Electrochrom...
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ISBN:
(纸本)0819425583
The manufacturing and operation of window size (30cm x 90cm) electrochromic devices is described. Both the electrochromic electrode (WO3) and the counter electrode (V2O5) were deposited by sol-gel method. Electrochromic measurements were performed on both electrodes and the complete device to correlate device performance to fabrication conditions. The paper describes the effects of temperature on the switching characteristics of electrochromic window. The devices were tested in the temperature range between 10 degrees C and 50 degrees C. The switching algorithm described in this paper ensures identical optical performance of electrochromic device in the wide range of temperatures. The algorithm is based on the charge control and does not require monitoring of device transmittance.
For reduction of computational complexity in the 1A algorithm, the thinned-out 1A algorithm in which only one step size is updated every iteration is proposed and is complementarily switched with the HA algorithm acco...
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For reduction of computational complexity in the 1A algorithm, the thinned-out 1A algorithm in which only one step size is updated every iteration is proposed and is complementarily switched with the HA algorithm according to the convergence. The switching is determined by using the gradient of the error signal power. These are investigated through the computer simulations.
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