A novel fractional-order model and controller for vibration suppression in flexible smart beam

Review on the use of piezoelectric materials for active vibration, noise, and flow control

Abstract: Considering the number of applications, and the quantity of research conducted over the past few decades, it wouldn't be an overstatement to label the piezoelectric materials as the cream of the crop of the smart materials. Among the various smart materials, the piezoelectric materials have emerged as the most researched material for practical applications. They owe it to a few key factors like low cost, large frequency bandwidth of operation, availability in many forms, and the simplicity offered in handling and implementation. For piezoelectric materials, from an application standpoint, the area of active control of vibration, noise, and flow, stands, alongside energy harvesting, as the most researched field. Over the past three decades, several authors have used piezoelectric materials as sensors and actuators, to (i) actively control structural vibrations, noise and aeroelastic flutter, (ii) actively reduce buffeting, and (iii) regulate the separation of flows. These studies are spread over several engineering disciplines-starting from large space structures, to civil structures, to helicopters and airplanes, to computer hard disk drives. This review is an attempt to concise the progress made in all these fields by exclusively highlighting the application of the piezoelectric material. The research carried out in the past five years, in the areas of modeling, and optimal positioning of piezoelectric actuators/sensors, for active vibration control, are covered. Along with this, investigations into different control algorithms, for the piezoelectric based active vibration control, are also reviewed. Studies reporting the use of piezoelectric modal filtering and self sensing actuators, for active vibration control, are also surveyed. Additionally, research on semi-active vibration control techniques like the synchronized switched damping (on elements like resistor, inductor, voltage source, negative capacitor) has also been covered

Active vibration control of smart composite plates using optimized self-tuning fuzzy logic controller with optimization of placement, sizing and orientation of PFRC actuators

Abstract: This paper deals with optimization of the sizing, location and orientation of the piezo-fiber reinforced composite (PFRC) actuators and active vibration control of the smart composite plates using particle-swarm optimized self-tuning fuzzy logic controller. The optimization criteria for optimal sizing, location and orientation of the PFRC actuators is based on the Gramian controllability matrix and the optimization process is performed by involving the limitation of the plates masses increase. Optimal configurations of five PFRC actuators for active vibration control of the first six modes of cantilever symmetric ((90°/0°/90°/0°)S), antisymmetric cross-ply ((90°/0°/90°/0°/90°/0°/90°/0°)) and antisymmetric angle-ply ((45°/-45°/45°/-45°/45°/-45°/45°/-45°)) composite plates are found using the particle swarm optimization. The detailed analysis of influences of the PFRC layer orientation and position (top or bottom side of composite plates), as well as bending-extension coupling of antisymmetric laminates on controllabilities is also performed. The experimental study is performed in order to validate this behavior on controllabilities of antisymmetric laminates. The particle swarm-optimized self-tuning fuzzy logic controller (FLC) adapted for the multiple-input multiple-output (MIMO) control is implemented for active vibration suppression of the plates. The membership functions as well as output matrices are optimized using the particle swarm optimization. The Mamdani and the zero-order Takagi–Sugeno–Kang fuzzy inference methods are employed and their performances are examined and compared. In order to represent the efficiency of the proposed controller, results obtained using the proposed particle swarm optimized self-tuning FLC are compared with the corresponding results in the case of the linear quadratic regulator (LQR) optimal control strategy.

Generalization of the FOPDT Model for Identification and Control Purposes

Abstract: This paper proposes a theoretical framework for generalization of the well established first order plus dead time (FOPDT) model for linear systems. The FOPDT model has been broadly used in practice to capture essential dynamic response of real life processes for the purpose of control design systems. Recently, the model has been revisited towards a generalization of its orders, i.e., non-integer Laplace order and fractional order delay. This paper investigates the stability margins as they vary with each generalization step. The relevance of this generalization has great implications in both the identification of dynamic processes as well as in the controller parameter design of dynamic feedback closed loops. The discussion section addresses in detail each of this aspect and points the reader towards the potential unlocked by this contribution.

Event-Based Implementation of Fractional Order IMC Controllers for Simple FOPDT Processes

Abstract: Fractional order calculus has been used to generalize various types of controllers, including internal model controllers (IMC). The focus of this manuscript is towards fractional order IMCs for first order plus dead-time (FOPDT) processes, including delay and lag dominant ones. The design is novel at it is based on a new approximation approach, the non-rational transfer function method. This allows for a more accurate approximation of the process dead-time and ensures an improved closed loop response. The main problem with fractional order controllers is concerned with their implementation as higher order transfer functions. In cases where central processing unit CPU, bandwidth allocation, and energy usage are limited, resources need to be efficiently managed. This can be achieved using an event-based implementation. The novelty of this paper resides in such an event-based algorithm for fractional order IMC (FO-IMC) controllers. Numerical results are provided for lag and delay dominant FOPDT processes. For comparison purposes, an integer order PI controller, tuned according to the same performance specifications as the FO-IMC, is also implemented as an event-based control strategy. The numerical results show that the proposed event-based implementation for the FO-IMC controller is suitable and provides for a smaller computational effort, thus being more suitable in various industrial applications.

Fractional Order Impedance Control

Abstract: This paper proposes a novel fractional order impedance control. In traditional impedance control model, the orders of inertia, damping, and stiffness are integers and the contact force can be reduced effectively to some extent in robots and manipulators. However, there exists a tracking error of end-effector at the stable state due to the existence of stiffness, which is not conducive to tackle tasks based on high performance position control for robots and manipulators. Thus, an integral item is added into the traditional impedance model to eliminate the tracking error. Besides, the idea of fractional order is introduced to make the orders of inertia, damping, and stiffness change from integers to fractions to achieve more significant compliant performance. Simulation results validate the advantages of proposed fractional order impedance control and it can be also employed to absorb/increase, hold/keep, and dissipate/decrease system energy to achieve jumping, bouncing and friendly contact, respectively. Also, three criterions of choosing and tuning all these 14 parameters in the proposed fractional order impedance control are given out. This provides an insight for robot dynamic interaction, bouncing and jumping control.

Fractional-order systems and PI/sup /spl lambda//D/sup /spl mu//-controllers

Abstract: Dynamic systems of an arbitrary real order (fractional-order systems) are considered. The concept of a fractional-order PI/sup /spl lambda//D/sup /spl mu//-controller, involving fractional-order integrator and fractional-order differentiator, is proposed. The Laplace transform formula for a new function of the Mittag-Leffler-type made it possible to obtain explicit analytical expressions for the unit-step and unit-impulse response of a linear fractional-order system with fractional-order controller for both open- and closed-loops. An example demonstrating the use of the obtained formulas and the advantages of the proposed PI/sup /spl lambda//D/sup /spl mu//-controllers is given.

Fractional-order systems and control : fundamentals and applications

Abstract: Fundamentals of Fractional-order Systems and Controls.- Fundamentals of Fractional-order Systems.- State-space Representation and Analysis.- Fundamentals of Fractional-order Control.- Fractional-order PID-Type Controllers.- Fractional-order Proportional Integral Controller Tuning for First-order Plus Delay Time Plants.- Fractional-order Proportional Derivative Controller Tuning for Motion Systems.- Fractional-order Proportional Integral Derivative Controllers.- Fractional-order Lead-lag Compensators.- Tuning of Fractional-order Lead-lag Compensators.- Auto-tuning of Fractional-order Lead-lag Compensators.- Other Fractional-order Control Strategies.- Other Robust Control Techniques.- Some Nonlinear Fractional-order Control Strategies.- Implementations of Fractional-order Controllers: Methods and Tools.- Continuous-time and Discrete-time Implementations of Fractional-order Controllers.- Numerical Issues and MATLAB Implementations for Fractional-order Control Systems.- Real Applications.- Systems Identification.- Position Control of a Single-link Flexible Robot.- Automatic Control of a Hydraulic Canal.- Mechatronics.- Fractional-order Control Strategies for Power Electronic Buck Converters.