Browsing by Author "CHEN, ST"

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ACTIVE CONTROL OF AN ASYMMETRICAL RIGID ROTOR SUPPORTED BY MAGNETIC BEARINGS
(1992-11-01)
FAN, YH
;
CHEN, ST
;
LEE, AC
;
交大名義發表
;
機械工程學系
Vibration control of a horizontal rotor with an asymmetrical moment of inertia is investigated. A linear optimal control system is developed to stabilize and control the rotor system by using the mathematical model of a rotor system expressed in the rotating coordinates. An approximated dynamical equation of a long rotor system is derived and used to obtain the compensator in analytical form (which saves much computational effort in control design), and is particularly useful in hardware implementation. Simulation results show the efficiency of the proposed strategy. The influences of weighting matrices and the effects of the asymmetrical moment of inertia on system performance for different controllers are also assessed.
COLLOCATED SENSOR ACTUATOR POSITIONING AND FEEDBACK DESIGN IN THE CONTROL OF FLEXIBLE STRUCTURE-SYSTEM
(1994-04-01)
LEE, AC
;
CHEN, ST
;
交大名義發表
;
機械工程學系
;
National Chiao Tung University
This paper presents a new control design method for the control of flexible systems that not only guarantees closed-loop asymptotic stability but also effectively suppresses vibration. This method allows integrated determination of actuator/sensor locations and feedback gain via minimization of an energy criterion, which is chosen as the integrated total energy stored in the system. The energy criterion is determined via an efficient solution of the Lyapunov equation and minimized with a quasi-Newton or recursive quadratic programming algorithm. The prerequisite for this optimal design method is that the controlled system be asymptotically stable. This study shows that when the controller structure is a collocated direct velocity feedback design with positive definite feedback gain, the number and placement of actuators/sensors are the only factors needed to determine necessary and sufficient conditions for ensuring closed-loop asymptotic stability. The application of this method to a simple flexible structure confirms the direct relationship between our optimization criterion and effectiveness in vibration suppression.
EFFECTIVE ACTIVE DAMPING DESIGN FOR SUPPRESSION OF VIBRATION IN FLEXIBLE SYSTEMS VIA DISLOCATED SENSOR ACTUATOR POSITIONING
(1994-06-01)
CHEN, ST
;
FAN, YH
;
LEE, AC
;
交大名義發表
;
機械工程學系
In this paper we present a new controller design method that effectively suppresses vibration in flexible systems. The method allows integrated determination of sensor/actuator locations and feedback gain via minimization of an energy criterion which represents the integrated total energy stored in the system. This energy criterion is characterized by an effective representation of vibration, determined via an efficient solution of the Lyapunov equation and minimized with a quasi-Newton or recursive quadratic programming algorithm. The application of this method to a simple flexible structure confirms the direct relationship between our optimization criterion and effectiveness of vibration suppression.
OPTIMAL VIBRATION CONTROL FOR A FLEXIBLE ROTOR WITH GYROSCOPIC EFFECTS
(1992-09-01)
LEE, AC
;
CHEN, ST
;
交大名義發表
;
機械工程學系
;
National Chiao Tung University
Active vibration control of flexible rotor systems with gyroscopic effects is investigated in this paper. Using the finite element formulation for the mathematical model of flexible rotors, a new rotating velocity dependent output-feedback controller, in addition to the optimal independent modal-space control system, is proposed to suppress the vibration level and in consequence, achieve better operating conditions. This new active control loop is added in order to compensate the gyroscopic effects during rotation, especially in the higher-flexibility modes. Furthermore, stability analysis via the Kelvin Tait-Chetaev (KTC) stability theorem for a mechanical system is presented. It demonstrates that if the placement of actuators and sensors are collocated, the fulfillment of optimality and stability for each independently controlled mode is a prerequisite to guaranteeing full-order closed-loop (FOCL) stability. Simulation results are shown in order to confirm that the proposed controller effectively promotes control performance. In addition, the significant impact of the allocation of sensors and actuators on the effectiveness of such a controller is also discussed.
VIBRATION AND ROBUST-CONTROL OF SYMMETRICAL FLEXIBLE SYSTEMS
(1993-07-01)
CHEN, ST
;
LEE, AC
;
交大名義發表
;
機械工程學系
;
National Chiao Tung University
The use of symmetry in the vibration analysis and control of symmetric flexible systems is investigated. For a symmetric flexible system with actuators/sensors being symmetrically allocated, an internal and external decoupling control scheme is developed to simplify the controller design. The whole flexible system can be separated into two uncoupled subsystems under the decoupling scheme, and the control algorithm for each subsystem can be designed and implemented independently. Consider the case of a direct output feedback based controller design with actuators and sensors collocated. Two robustness properties of this controller, i.e., full-order closed-loop stability and reliable control, are exploited. For demonstrative purposes, the optimal modal space approach is adopted for controller design of each subsystem and to illustrate the advantages of the decoupling control scheme. Simulation results of the control of a uniform simply supported beam are given to show the effectiveness of this proposed scheme.