Adaptive Servoregulation of a Projectile Fin Using Piezoelectric Actuator

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.

Download Full-text

Adaptive Servoregulation of a Projectile Fin Using Piezoelectric Actuator

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.2397159 ◽

2006 ◽

Vol 129 (1) ◽

pp. 100-104 ◽

Cited By ~ 4

Author(s):

Smitha Mani ◽

Sahjendra N. Singh ◽

Surya Kiran Parimi ◽

Woosoon Yim

Keyword(s):

Piezoelectric Actuator ◽

Closed Loop ◽

Rotation Angle ◽

Control Law ◽

Flexible Beam ◽

Test Results ◽

Closed Loop System ◽

Laboratory Test Results ◽

Aerodynamic Moment ◽

Elastic Modes

This brief 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. An adaptive servoregulator is designed for the control of the fin angle using the fin angle and its derivative for feedback. Interestingly, the knowledge of the dimension and parameters of the system is not essenstial for the synthesis of the control law. In the closed-loop system, the fin angle asymptotically converges to the desired set point and the elastic modes converge to their equilibrium values. Computer simulation and laboratory test results are presented to show the performance of the controller.

Download Full-text

Adaptive Contact Force Control of a Flexible Beam Using Output Feedback

10.1115/imece2000-2312 ◽

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.

Download Full-text

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

Robotica ◽

10.1017/s0263574714001337 ◽

2014 ◽

Vol 34 (1) ◽

pp. 150-172 ◽

Cited By ~ 1

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.

Download Full-text

A Parametric Study of the Modified Model Reference Adaptive Control Scheme

Journal of Vibration and Acoustics ◽

10.1115/1.2893902 ◽

1998 ◽

Vol 120 (3) ◽

pp. 814-821

Author(s):

H. M. Sardar ◽

M. Ahmadian

Keyword(s):

Closed Loop ◽

Simulation Analysis ◽

Adaptive Controller ◽

Loop System ◽

Closed Loop System ◽

Model Reference ◽

Modified Model ◽

Control Scheme ◽

Inertial Nonlinearities ◽

Model Reference Adaptive

The validity of the claim by many studies that the damping and stiffness forces can be ignored when designing a model reference adaptive controller, is examined. For a simple plant, the sensitivity of the closed loop system to the inertial, damping, and stiffness nonlinearities are investigated, through a simulation analysis. It is shown that the closed loop system is sensitive to the changes in the inertial nonlinearities, and relatively insensitive to variations in the damping and stiffness forces. This supports the assumption made in many previous studies.

Download Full-text

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

Journal of Vibration and Acoustics ◽

10.1115/1.4004997 ◽

2012 ◽

Vol 134 (2) ◽

Cited By ~ 6

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.

Download Full-text

A Robustly Stable Multiestimation-Based Adaptive Control Scheme for Robotic Manipulators

Journal of Dynamic Systems Measurement and Control ◽

10.1115/1.2196418 ◽

2005 ◽

Vol 128 (2) ◽

pp. 414-421 ◽

Cited By ~ 11

Author(s):

A. Ibeas ◽

M. de la Sen

Keyword(s):

Adaptive Systems ◽

Closed Loop ◽

Sudden Change ◽

Robotic Manipulators ◽

Adaptive Controller ◽

Time Instant ◽

Loop System ◽

System Stability ◽

Closed Loop System ◽

Control Scheme

A multiestimation-based robust adaptive controller is designed for robotic manipulators. The control scheme is composed of a set of estimation algorithms running in parallel along with a supervisory index proposed with the aim of evaluating the identification performance of each one. Then, a higher-order level supervision algorithm decides in real time the estimator that will parametrize the adaptive controller at each time instant according to the values of the above supervisory indexes. There exists a minimum residence time between switches in such a way that the closed-loop system stability is guaranteed. It is verified through simulations that multiestimation-based schemes can improve the transient response of adaptive systems as well as the closed-loop behavior when a sudden change in the parameters or in the reference input occurs by appropriate switching between the various estimation schemes running in parallel. The closed-loop system is proved to be robustly stable under the influence of uncertainties due to a poor modeling of the robotic manipulator. Finally, the usefulness of the proposed scheme is highlighted by some simulation examples.

Download Full-text

Adaptive Control of a Smart Projectile Fin With Unknown High-Frequency Gain by Piezoelectric Actuation

Volume 9: Mechanical Systems and Control, Parts A, B, and C ◽

10.1115/imece2007-41216 ◽

2007 ◽

Author(s):

Venkat Mudupu ◽

Sahjendra Singh ◽

Woosoon Yim

Keyword(s):

Adaptive Control ◽

Control System ◽

High Frequency ◽

Closed Loop ◽

Aerodynamic Force ◽

Angular Rate ◽

Loop System ◽

Reference Trajectory ◽

Piezoelectric Bimorph ◽

Closed Loop System

This paper delves into adaptive control of a smart projectile fin with unknown high frequency gain using a piezoelectric bimorph. The hollow projectile smart fin is actuated using a cantilevered piezoelectric bimorph that is completely enclosed within the fin. The model of the smart fin system includes the aerodynamic moment which is a function of the angle of attack of the projectile. The rotation angle of the fin is controlled by deforming the piezoelectric bimorph which is hinged at the tip of the rigid fin. It is assumed that fin parameters as well as the high frequency gain of the model are unknown. Moreover, the model includes an unknown bounded time varying aerodynamic disturbance. An adaptive control system using the Nussbaum gain is designed. The structure of the control system is independent of the dimension of the flexible fin model. This is important because the fin model has large number of flexible modes. For the design of the control law, a linear combination of the fin angle and fin angular rate is chosen as the controlled output variable. In the closed loop system, all the signals are bounded and the fin angle tracks the reference trajectory. Simulation results are presented along with the experimental validation done using the subsonic wind tunnel at the University of Nevada, Las Vegas (UNLV). Both simulation and experimental results show that in the closed-loop system, the fin angle is precisely controlled in spite of the uncertainties in the fin parameters and the aerodynamic force.

Download Full-text