Active Vibration Control of Beams by Combining Precompressed Layer Damping and ACLD Treatment: Performance Comparison of Various Robust Control Techniques

2012 ◽  
Vol 134 (2) ◽  
Author(s):  
Rajiv Kumar
Keyword(s):  
Robust Control ◽  
Closed Loop ◽  
Active Vibration Control ◽  
Flexible Structures ◽  
Performance Comparison ◽  
Loop System ◽  
Flexible Beam ◽  
Closed Loop System ◽  
Linear Quadratic ◽  
System Parameters

It is a well known fact that system parameters of the flexible structures keep on changing due to several reasons. Ordinary controllers lose their effectiveness in changed situations and do not guarantee the stability of the closed loop system. However, controllers designed based on robust control theory not only maintain the closed loop stability of the perturbed system with a large variation in system parameters but also maintain the best performance. H∞ loop shaping controller is designed and implemented experimentally on a smart flexible beam treated with precompressed layer damping and ACLD treatment. It outperforms linear quadratic Gaussian and standard H∞ controller both in terms of robust stability and robust performance. Relative merits and demerits of the μ-synthesis based controller are also discussed. Afterwards, these controllers were digitized at certain sampling frequencies and applied to the experimental flexible structure. Certain time domain parameters of the closed loop system discuss the relative superiority of these controllers which otherwise cannot be captured using frequency domain results alone.

Adaptive Contact Force Control of a Flexible Beam Using Output Feedback

2000 ◽  
Author(s):  
Woosoon Yim
Keyword(s):  
Contact Force ◽  
Contact Surface ◽  
Force Control ◽  
Closed Loop ◽  
Force Measurement ◽  
Transient Behavior ◽  
Loop System ◽  
Flexible Beam ◽  
Reference Trajectory ◽  
Closed Loop System

Abstract This paper presents an adaptive force trajectory control of a flexible beam using a piezoceramic actuator. Based on the adaptive backstepping method, a force control system using only force measurement is designed. For the derivation of the control law, it is assumed that parameters of the beam and contact surface stiffness are unknown. It is shown that in the closed-loop system, the contact force tracks a given reference trajectory and the beam vibration is suppressed as well. Digital simulations results show that the closed-loop system has good transient behavior and robust performance in the presence of uncertainties in the parameters of the flexible beam and the contact surface.

On the control of a single flexible arm robot via Youla-Kucera parameterization

Robotica ◽  
2014 ◽  
Vol 34 (1) ◽  
pp. 150-172 ◽  
Author(s):  
Habib Esfandiar ◽  
Saeed Daneshmand ◽  
Roozbeh Dargahi Kermani
Keyword(s):  
Closed Loop ◽  
Optimization Techniques ◽  
Loop System ◽  
Flexible Manipulator ◽  
Order System ◽  
Flexible Beam ◽  
Closed Loop System ◽  
Stabilizing Controller ◽  
Main Challenge ◽  
Tip Mass

SUMMARYIn this paper, based on the Youla-Kucera (Y-K) parameterization, the control of a flexible beam acting as a flexible robotic manipulator is investigated. The method of Youla parameterization is the simple solution and proper method for describing the collection of all controllers that stabilize the closed-loop system. This collection comprises function of the Youla parameter which can be any proper transfer function that is stable. The main challenge in this approach is to obtain a Youla parameter with infinite dimension. This parameter is approximated by a subspace with finite dimensions, which makes the problem tractable. It is required to be generated from a finite number of bases within that space and the considered system can be approximated by an expansion of the orthonormal bases such as FIR, Laguerre, Kautz and generalized bases. To calculate the coefficients for each basis, it is necessary to define the problem in the form of an optimization problem that is solved by optimization techniques. The Linear Quadratic Regulator (LQR) optimization tool is employed in order to optimize the controller gains. The main aim in controller design is to merge the closed-loop system and the second order system with the desirable time response characteristic. The results of the Youla stabilizing controller for a planar flexible manipulator with lumped tip mass indicate that the proposed method is very efficient and robust for the time-continuous instances.

scholarly journals Nonlinear modelling and optimal control via Takagi-Sugeno fuzzy techniques: A quadrotor stabilization

2020 ◽  
Vol 71 (1) ◽  
pp. 1-10
Author(s):  
Miroslav Pokorný ◽  
Tomáš Dočekal ◽  
Danica Rosinová
Keyword(s):  
Closed Loop ◽  
Fuzzy Controller ◽  
Fitness Function ◽  
Fuzzy Model ◽  
Loop System ◽  
Linear Matrix ◽  
Closed Loop System ◽  
Linear Quadratic ◽  
Fuzzy Aggregation ◽  
Takagi Sugeno

AbstractUsing the principles of Takagi-Sugeno fuzzy modelling allows the integration of flexible fuzzy approaches and rigorous mathematical tools of linear system theory into one common framework. The rule-based T-S fuzzy model splits a nonlinear system into several linear subsystems. Parallel Distributed Compensation (PDC) controller synthesis uses these T-S fuzzy model rules. The resulting fuzzy controller is nonlinear, based on fuzzy aggregation of state controllers of individual linear subsystems. The system is optimized by the linear quadratic control (LQC) method, its stability is analysed using the Lyapunov method. Stability conditions are guaranteed by a system of linear matrix inequalities (LMIs) formulated and solved for the closed loop system with the proposed PDC controller. The additional GA optimization procedure is introduced, and a new type of its fitness function is proposed to improve the closed-loop system performance.

Analysis and Feedback Control of Planar SOFC Systems for Fast Load Following in APU Applications

2006 ◽  
Author(s):  
Handa Xi ◽  
Jing Sun
Keyword(s):  
Feedback Control ◽  
Closed Loop ◽  
High Efficiency ◽  
Open Loop ◽  
Loop System ◽  
System Response ◽  
Closed Loop System ◽  
Linear Quadratic ◽  
Load Following ◽  
Model Linearization

Solid Oxide Fuel Cell (SOFC) based Auxiliary Power Unit (APU) systems have many practical advantages given their high efficiency, low emissions and flexible fueling strategies. This paper focuses on model-based analysis and feedback control design for planar SOFC systems to achieve fast load following capability. A dynamic model is first developed for the integrated co-flow planar SOFC and CPOX (Catalytic Partial Oxidation) system aiming at APU applications. Simulation results illustrate that an open-loop system with optimal steady-state operating setpoints exhibits a slow transient power response when load increases. Feedback control is then explored to speed up the system response by controlling the flow rates of fuel and air supplies to the system. Model linearization, balanced truncation and Linear Quadratic Gaussian (LQG) approaches are used to derive the low-order observer-based controller. With the feedback controller developed, we show, through simulations, that the closed-loop system can have faster load following capability. Different feedback strategies are also considered and their impacts on closed-loop system performance are analyzed.

scholarly journals Active Vibration Control of PID Based on Receptance Method

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Lijuan Peng ◽  
Jian Wang ◽  
Guicheng Yu ◽  
Zuoxue Wang ◽  
Aijun Yin ◽  
...  
Keyword(s):  
Vibration Control ◽  
Closed Loop ◽  
Damping Ratio ◽  
Active Vibration Control ◽  
Loop System ◽  
Closed Loop System ◽  
Integral Control ◽  
Active Vibration ◽  
Receptance Method ◽  
Poles And Zeros

Active vibration control approaches have been widely applied on improving reliability of robotic systems. For linear vibratory systems, the vibration features can be altered by modifying poles and zeros. To realize the arbitrary assignment of the closed-loop system poles and zeros of a linear vibratory system, in this paper, an active PID input feedback vibration control method is proposed based on the receptance method. The establishment and verification of the proposed method are demonstrated. The assignable poles during feedback control are calculated and attached with importance to expand the application of the integral control. Numerical simulations are conducted to verify the validity of the proposed method in terms of the assignment of closed-loop poles, zeros, and both. The results indicate that the proposed method can be used to realize the active vibration control of closed-loop system and obtain the desired damping ratio, modal frequency, and dynamic response.

Robust Control of Double-Machine Wind Turbines with DFIG Using Hamiltonian Energy Method

2012 ◽  
Vol 443-444 ◽  
pp. 941-947
Author(s):  
Bing Wang ◽  
Xiao Ling Yuan ◽  
Jin Zhu
Keyword(s):  
Robust Control ◽  
Control Problem ◽  
Wind Turbines ◽  
Energy Method ◽  
Closed Loop ◽  
Loop System ◽  
Closed Loop System ◽  
Machine System ◽  
Nonlinear Design ◽  
Finite Gain

- In this paper, the robust control problem of the doubly fed induction generator (DFIG) wind turbines is investigated based on Hamiltonian energy method. A nonlinear design method is proposed for the double-machine system, such that the closed-loop system is stable simultaneously under the action of the controller. Moreover, we study the robust control problem of double-machine system in the presence of disturbances. On the basis of the proposed theorem, the Hamiltonian controller is designed to render the closed-loop system finite-gain stable. In order to illustrate the effectiveness of the proposed method, the simulations are performed which show that the gotten nonlinear controller can enhance the transient stability and improve the robustness property of the closed-loop system.

Adaptive Servoregulation of a Projectile Fin Using Piezoelectric Actuator

Aerospace ◽  
2005 ◽  
Author(s):  
Smitha Mani ◽  
Sahjendra N. Singh ◽  
Surya Kiran Parimi ◽  
Woosoon Yim
Keyword(s):  
Piezoelectric Actuator ◽  
Closed Loop ◽  
Angular Rate ◽  
Adaptive Controller ◽  
Loop System ◽  
Laboratory Model ◽  
Flexible Beam ◽  
Closed Loop System ◽  
Real Time Control ◽  
Aerodynamic Moment

This paper treats the question of adaptive control of a projectile fin using a piezoelectric actuator. The hollow projectile fin is rigid, within which a flexible cantilever beam with a piezoelectric active layer is mounted. The model of the fin-beam system includes the aerodynamic moment which is a function of angle of attack of the projectile. The rotation angle of the fin is controlled by deforming the flexible beam which is hinged at the tip of the rigid fin. It is assumed that the system parameters are completely unknown and that only the fin angle and its derivative are measured for synthesis. A linear combination of the fin angle and fin’s angular rate is chosen as the controlled output variable and an adaptive servoregulator is designed for the control of the fin angle and the rejection of the disturbance input (aerodynamic moment). In the closed-loop system, the fin angle asymptotically converges to the desired value and the elastic modes converges to their equilibrium values. Computer simulation is performed which shows that in the closed-loop system, the fin angle is precisely controlled in spite of uncertainties in the fin-beam parameters and the aerodynamic moment coefficients. Furthermore, a laboratory model of the projectile fin is developed and the adaptive controller is implemented for real-time control. Experimental results are presented which show that adaptive servoregulator accomplishes fin angle control.

scholarly journals Harnessing the Kelvin–Helmholtz instability: feedback stabilization of an inviscid vortex sheet

2018 ◽  
Vol 852 ◽  
pp. 146-177 ◽  
Author(s):  
Bartosz Protas ◽  
Takashi Sakajo
Keyword(s):  
Degrees Of Freedom ◽  
Closed Loop ◽  
Linear Quadratic Regulator ◽  
Vortex Sheet ◽  
Shear Layers ◽  
Feedback Stabilization ◽  
Loop System ◽  
Closed Loop System ◽  
Linear Quadratic ◽  
Mass Fluxes

In this investigation, we use a simple model of the dynamics of an inviscid vortex sheet given by the Birkhoff–Rott equation to obtain fundamental insights about the potential for stabilization of shear layers using feedback control. As actuation, we consider two arrays of point sinks/sources located a certain distance above and below the vortex sheet and subject to the constraint that their mass fluxes separately add up to zero. First, we demonstrate using analytical computations that the Birkhoff–Rott equation linearized around the flat-sheet configuration is in fact controllable when the number of actuator pairs is sufficiently large relative to the number of discrete degrees of freedom present in the system, a result valid for generic actuator locations. Next, we design a state-based linear-quadratic regulator stabilization strategy, where the key difficulty is the numerical solution of the Riccati equation in the presence of severe ill-conditioning resulting from the properties of the Birkhoff–Rott equation and the chosen form of actuation, an issue that is overcome by performing computations with a suitably increased arithmetic precision. Analysis of the linear closed-loop system reveals exponential decay of the perturbation energy and the corresponding actuation energy in all cases. Computations performed for the nonlinear closed-loop system demonstrate that initial perturbations of non-negligible amplitude can be effectively stabilized when a sufficient number of actuators is used. We also thoroughly analyse the sensitivity of the closed-loop stabilization strategies to the variation of a number of key parameters. Subject to the known limitations of inviscid vortex models, our findings indicate that, in principle, it may be possible to stabilize shear layers for relatively large initial perturbations, provided that the actuation has sufficiently many degrees of freedom.

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