Optimal Control of Piezoelectric Laminated Parabolic Cylindrical Panels

Author(s):  
S. D. Hu ◽  
H. Li ◽  
H. S. Tzou

Vibration control of parabolic cylindrical shell panels by piezoelectric patches using optimal control algorithm is presented in this study. Laminated piezoelectric patches serve as distributed sensors and actuators. Dynamic behaviors and mode shape functions in three directions are obtained by the Rayleith-Ritz method. The sensing sensitivity of the piezoelectric sensor and the actuation force of the piezoelectric actuator are obtained. Feedback control gain between sensing and control signals is solved using the LQ optimal control algorithm. LQ controllers for independent modes are designed, and relative optimal control gains and control voltages are presented. Control results with respect to independent mode and optimal design parameters are evaluated in case studies. Numerical results show that the LQ optimal controller with optimal feedback control gain is effective for the vibration control of parabolic cylindrical shell panels. The damping ratio can be greatly enhanced; the maximal damping ratio reach 7.79% for mode (1,3). Studies on parametric designs suggest that relatively larger Q22 and/or smaller R results in rapider reduction of mechanical motion with more control energy cost, and vice versa. These results would provide a design reference in practical engineering.

1999 ◽  
Author(s):  
Qingfeng Wang ◽  
Linyi Gu ◽  
Yongxiang Lu

Abstract The smoothness of acceleration and deceleration process is a serious problem in valve control system with high inertia load, especially in the hydraulic systems in construction machines. In this paper, a meter-in and meter-out independent regulating method, in which the two sides of actuator are controlled by a meter-in valve and a meter-out valve respectively, is put forward, in one hand, the meter-out valve could control the actuator’s outlet pressure to avoid the ultra-high outlet pressure when actuator decelerates or brakes suddenly. On the other hand, the dynamic damping ratio of valve control system could be raised through calculated flow feedback control algorithm. Secondly, a grading control algorithm in dynamic process of high inertia load is adopted. When the actuator’s velocity is far from its command value, the actuator’s inlet and outlet pressure are controlled. After the velocity error decrease to a threshold, a state feedback control algorithm based on parameters on line estimating is employed to realize both its velocity accuracy and the smoothness of dynamic process. Experiments show that the actuator’s velocity could increase or decrease to its command value accurately, smoothly and rapidly after the above method and algorithm are applied.


2019 ◽  
Vol 5 (1) ◽  
pp. 409-411
Author(s):  
Tobias Salesch ◽  
Jonas Gesenhues ◽  
Dirk Abel

AbstractThis paper deals with the design, simulation and control of a new lightweight hybrid Mock-Loop (MCL) concept. The proof of concept is evaluated by two simulation approaches. First, the design parameters are chosen by an optimal control problem. Second, a cascading controller structure is evaluated in a simulation. Both show that with a suitable range of the design parameter the new lightweight concept can be used as a MCL. To validate these findings, further investigations with the MCL under realistic test conditions are required.


2011 ◽  
Vol 22 (2) ◽  
pp. 137-147 ◽  
Author(s):  
Jian-Ping Jiang ◽  
Dong-Xu Li

This study deals with decentralized robust vibration control of a smart composite panel with parameter uncertainties. The composite panel with four collocated piezoelectric actuators and velocity sensors is modeled using finite element method, and then the size of the model is reduced in the state space using Modal Hankel Singular Value. The parameter uncertainties presented by natural frequencies and modal damping ratios are considered in controller design process. To suppress the vibration induced by external disturbance, a decentralized robust H∞ controller is developed using linear matrix inequality techniques. Numerical simulation for the smart panel is performed in order to investigate the effectiveness of decentralized vibration control (DVC). When the system is subjected to an initial displacement field or distributed white noise disturbance, numerical results show that the DVC system is very effective. Although there are 20% parameter uncertainties for modal frequencies, damping ratio, and control input, the decentralized controller can effectively suppress the vibration excited by the external disturbance. Furthermore, the decentralized controller composed of four three-order systems can be practically implemented well.


2001 ◽  
Vol 17 (4) ◽  
pp. 173-177
Author(s):  
Der-An Wang ◽  
Yii-Mai Huang

ABSTRACTActive vibration control of a flexible beam subjected to arbitrary, unmeasurable disturbance forces is investigated in this paper. The concept of independent modal space control is adopted. Both the feedforward and feedback control is implemented here to reduce the beam vibration. Because of the existence of the disturbance forces, the feedforward control is applied by employing the idea of force cancellation. A modal space disturbance force observer is then established in this paper to observe the disturbance modal forces for the feedforward control. For obtaining the feedforward and feedback control gains with the optimal sense, the nearly optimal control law is derived, where the modal disturbance forces are regarded as additional states. The vibration control performances and the asymptotic properties of the control law are discussed.


2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Xing Shen ◽  
Yuke Dai ◽  
Mingxuan Chen ◽  
Lei Zhang ◽  
Li Yu

In wind tunnel tests, cantilever stings are often used as model-mount in order to reduce flow interference on experimental data. In this case, however, large-amplitude vibration and low-frequency vibration are easily produced on the system, which indicates the potential hazards of gaining inaccurate data and even damaging the structure. This paper details three algorithms, respectively, Classical PD Algorithm, Artificial Neural Network PID (NNPID), and Linear Quadratic Regulator (LQR) Optimal Control Algorithm, which can realize active vibration control of sting used in wind tunnel. The hardware platform of the first-order vibration damping system based on piezoelectric structure is set up and the real-time control software is designed to verify the feasibility and practicability of the algorithms. While the PD algorithm is the most common method in engineering, the results show that all the algorithms can achieve the purpose of over 80% reduction, and the last two algorithms perform even better. Besides, self-tuning is realized in NNPID, and with the help of the Observer/Kalman Filter Identification (OKID), LQR optimal control algorithm can make the control effort as small as possible. The paper proves the superiority of NNPID and LQR algorithms and can be an available reference for vibration control of wind tunnel system.


Author(s):  
V. P. Belavkin

A brief account of the quantum information dynamics and dynamical programming methods for optimal control of quantum unstable systems is given to both open loop and feedback control schemes corresponding respectively to deterministic and stochastic semi-Markov dynamics of stable or unstable systems. For the quantum feedback control scheme, we exploit the separation theorem of filtering and control aspects as in the usual case of quantum stable systems with non-demolition observation. This allows us to start with the Belavkin quantum filtering equation generalized to demolition observations and derive the generalized Hamilton–Jacobi–Bellman equation using standard arguments of classical control theory. This is equivalent to a Hamilton–Jacobi equation with an extra linear dissipative term if the control is restricted to Hamiltonian terms in the filtering equation. An unstable controlled qubit is considered as an example throughout the development of the formalism. Finally, we discuss optimum observation strategies to obtain a pure quantum qubit state from a mixed one.


Author(s):  
Yang Lin ◽  
Yang Shi ◽  
Richard Burton

Hydraulic position control systems play an important role in industrial automation. This paper explores the application of discrete-time H2-optimal control for a hydraulic position control system (HPCS). By minimizing the H2-norm of the system, the discrete-time robust H2-optimal control both stabilizes the plant and minimizes the root-mean-square of the servo position error simultaneously. The intuitive nature of this advanced approach helps to manage the selection of design parameters, whereas, classical methods provide less insight into strategies for parameter selection and control design. Additionally, the powerful ability to address disturbances and uncertainty in the robust H2-optimal design offers a more direct alternative to the ad hoc and iterative nature of classical methods for the hydraulic servo position system. Computer simulations illustrate the design procedure and the effectiveness of the proposed method. Experimental studies which employ the H2-optimal control on a hydraulic positioning system are also conducted and the results show that the method is suitable for practical applications.


2013 ◽  
Vol 456 ◽  
pp. 603-606
Author(s):  
Zhi Hong Yang

In this paper a method is proposed to anti-control the discrete chaos. When the control gain meets the certain conditions, the common discrete system occurs chaotic behaviors in the sense of Li and Yorke under the oblique wave states feedback control. Using Matlab to simulate one and N-dimensional discrete linear systems, the numerical results demonstrate the validity of the control algorithm.


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