Experimental Validation of Simultaneous Gust Alleviation and Energy Harvesting for Multifunctional Composite Wing Spars

2012 ◽  
Author(s):  
Ya Wang ◽  
Daniel J. Inman
Keyword(s):  
Vibration Suppression ◽  
Fiber Composite ◽  
Autonomous Systems ◽  
Flexible Structures ◽  
Wind Gust ◽  
Light Weight ◽  
Energy Control ◽  
Control Laws ◽  
Gust Alleviation ◽  
Composite Wing

Vibration suppression in flexible structures is becoming an important design problem to develop energy-autonomous systems powered using the harvested ambient energy. Reduced energy control laws are developed to address the trend towards autonomous ultra-light weight aerospace structures with limited energy supply. Experiments build upon recent advances in harvester, sensor and actuator technology that have resulted in thin, light-weight multi-layered composite wing spars. These beam like multifunctional spars are designed to be capable of alleviating wind gust of small Unmanned Aerial Vehicles (UAVs) using the harvested energy. Experimental results are presented for cantilever wing spars with micro-fiber composite transducers controlled by reduced energy controllers with a focus on two vibration modes. A reduction of 16dB and 11dB is obtained for the first and the second mode using the harvested ambient energy. This work demonstrates the use of reduced energy control laws for solving gust alleviation problems in small UAVs, provides the experimental verification details, and focuses on applications to autonomous light-weight aerospace systems.

scholarly journals The Effect of Attack Angle On The Vibration Suppression Of Composite Wing Airfoil NACA 0012

2021 ◽  
Vol 27 (4) ◽  
pp. 17-21
Author(s):  
Hassan Ali Kadhem ◽  
Ahmed Abdul Hussein
Keyword(s):  
Vibration Control ◽  
Glass Fiber ◽  
Vibration Suppression ◽  
Fiber Composite ◽  
Active Vibration Control ◽  
Attack Angle ◽  
Sensors And Actuators ◽  
Glass Fiber Composite ◽  
Active Vibration ◽  
Composite Wing

Active vibration control is presented as an effective technique used for vibration suppression and for attenuating bad effects of disturbances on structure. In this work Proportional-Integral-Derivative control were employed to study suppression of active vibration wing affected by wind airflow. Two different composite wings with different manufacturing materials had been made with specific size to be suitable for using in wind tunnel. Piezoelectric (PZT (transducers are used as sensors and actuators in vibration control systems. The velocity was 25 m/s and three different attack angles (0, 10, 20 degrees) had been taken to show their effect on the wings vibrations suppression. The results shows that the suppression of the wing amplitude is reduced when the attack angle increases for both woven and random composite wing matt and this happened due to the vortex which became more violent at the increase of attack angle and also due to the area that face the wind which will increase when the attack angle increase and this will reduces the suppression. The maximum control amplitude of woven Glass-fiber matt was 1.75cm and the damping was about 38 % at zero attack angle while it was 2cm and the damping was about 26 % at 20 degree attack angle for random Glass-fiber composite matt

Simultaneous Energy Harvesting and Gust Alleviation for a Multifunctional Wing Spar Using Reduced Energy Control Laws via Piezoceramics

2011 ◽  
Author(s):  
Ya Wang ◽  
Daniel J. Inman
Keyword(s):  
Energy Harvesting ◽  
Gaussian White Noise ◽  
Linear Filter ◽  
Wind Gust ◽  
Beam Model ◽  
Cell Array ◽  
Energy Control ◽  
Op Amps ◽  
Gust Alleviation ◽  
Wing Spar

The increasing need for lightweight structures in Unmanned Aerial Vehicle (UAV) applications raise issues involving gust alleviation. Here we examine the gust alleviation problem using a self-sensing, self-charging, and self-actuating structure. The basic idea is that the wing itself is able to harvest and store energy from the normal vibrations during flight along with any available sunlight. If the wing experiences any strong, unexpected wind gust, it will sense the increased vibration levels and provide vibration control to maintain its stability. In this paper, a multifunctional wing spar is designed, which integrates a flexible solar cell array, piezoceramic wafers, a thin film battery and an electronics module into a composite structure. This multifunctional wing spar therefore carries on the functions of energy harvesting and storage, as well as the functions of gust alleviation via piezoelectric materials. The piezoceramic wafers act as sensors, actuators, and harvesters. The global modulus and stiffness of this multifunctional wing spar are estimated using both the rule of mixtures and the cross section transformation method. These values are then used in an Euler-Bernoulli cantilever beam model of the multifunctional spar. The first two dominant modes are predicted analytically for the distributed parameter model. The finite element method is employed to confirm the analytical eigenvalues estimation. Special attention is given to the self-contained gust alleviation with the goal of using harvested energy. The gust signals are generated using a Gaussian white noise source n (t) ∼ N (0,1) fed into a linear filter, with the required intensity, scale lengths, and power spectral density (PSD) function for the given flight velocity and height. The Dryden PSD function is implemented for atmospheric turbulence modeling. The recently developed reduced energy control law is combined with a positive strain feedback controller to minimize the actuation energy and the dissipated heat energy. Positive feedback operation amplifiers (op-amps) and voltage buffer op-amps are implemented for two dominant mode gust disturbance controls. This work builds off of our previous research in self-charging structures and holds promise for improving UAV performance in wind gust alleviation.

Industrial compliant robot bases in interaction tasks: a force tracking algorithm with coupled dynamics compensation

Robotica ◽  
2016 ◽  
Vol 35 (8) ◽  
pp. 1732-1746 ◽  
Author(s):  
Loris Roveda ◽  
Nicola Pedrocchi ◽  
Federico Vicentini ◽  
Lorenzo Molinari Tosatti
Keyword(s):  
Closed Loop ◽  
Control Law ◽  
Light Weight ◽  
Mobile Platforms ◽  
Control Laws ◽  
Assembly Task ◽  
Base Position ◽  
Force Tracking ◽  
Compliant Robot ◽  
Target Force

SUMMARYLight-weight manipulators are used in industrial tasks mounted on mobile platforms to improve flexibility. However, such mountings introduce compliance affecting the tasks. This work deals with such scenarios by designing a controller that also takes into account compliant environments. The controller allows the tracking of a target force using the estimation of the environment stiffness (EKF) and the estimation of the base position (KF), compensating the robot base deformation. The closed-loop stability has been analyzed. Observers and the control law have been validated in experiments. An assembly task is considered with a standard industrial non-actuated mobile platform. Control laws with and without base compensation are compared.

Control of Elastic Systems via Passivity-Based Methods

2004 ◽  
Vol 10 (11) ◽  
pp. 1699-1735 ◽  
Author(s):  
A. G. Kelkar ◽  
S. M. Joshi
Keyword(s):  
Flexible Structures ◽  
Robotic Manipulators ◽  
Mathematical Concept ◽  
Controller Synthesis ◽  
Control Laws ◽  
Linear Elastic ◽  
Elastic Systems ◽  
Different Types ◽  
Linear Controllers ◽  
Synthesis Approach

In this paper we present a controller synthesis approach for elastic systems based on the mathematical concept of passivity. For nonlinear and linear elastic systems that are inherently passive, robust control laws are presented that guarantee stability. Examples of such systems include flexible structures with col-located and compatible actuators and sensors, and multibody space-based robotic manipulators. For linear elastic systems that are not inherently passive, methods are presented for rendering them passive by compensation. The “passified” systems can then be robustly controlled by a class of passive linear controllers that guarantee stability despite uncertainties and inaccuracies in the mathematical models. The controller synthesis approach is demonstrated by application to five different types of elastic systems.

Vibration Reduction of Flexible Structures Using Extended Input Shaper and Smart Materials

2001 ◽  
Author(s):  
G. Song ◽  
B. Kotejoshyer ◽  
J. Fei
Keyword(s):  
Smart Materials ◽  
Vibration Suppression ◽  
Flexible Structures ◽  
Flexible Beam ◽  
Smart Sensor ◽  
New Approach ◽  
Active Vibration Suppression ◽  
Command Input ◽  
Active Vibration ◽  
Smart Actuator

Abstract This paper presents a new approach of integrating the method of command input shaping and the technique of active vibration suppression for vibration reduction of flexible structures during slew operations. The control object is a flexible composite beam driven by a high torque DC motor with the presence of nonlinearities such as backlash and stick-slip type of friction. Two piezoelectric patches are bonded on the surface of the flexible beam near its cantilevered end and are used as the smart actuator and the smart sensor respectively. In this new approach, the method of command input shaping is used to modify the existing command so that less vibration will be caused by the command itself. To overcome the nonlinearities associated with the DC motor, an extended shaper is designed. The technique of active vibration suppression using smart materials is used to actively control the vibration during and after the slew. With this pair of smart actuator and smart sensor, a strain rate feedback (SRF) controller is designed for active vibration suppression. With the extended Zero Vibration Derivative (ZVD) shaper and the SRF controller, the proposed new approach can effectively reduce the vibration of the flexible beam during slew operations.

Vibration suppression for large-scale flexible structures based on cable-driven parallel robots

2020 ◽  
pp. 107754632096194
Author(s):  
Haining Sun ◽  
Xiaoqiang Tang ◽  
Senhao Hou ◽  
Xiaoyu Wang
Keyword(s):  
Large Scale ◽  
Vibration Suppression ◽  
Control Method ◽  
External Disturbance ◽  
Flexible Structures ◽  
Parallel Robot ◽  
Parallel Robots ◽  
Lyapunov Theory ◽  
Normal Operation ◽  
Control Methods

Specific satellites with ultralong wings play a crucial role in many fields. However, external disturbance and self-rotation could result in undesired vibrations of the flexible wings, which affect the normal operation of the satellites. In severe cases, the satellites would be damaged. Therefore, it is imperative to conduct vibration suppression for these flexible structures. Utilizing fuzzy-proportional integral derivative control and deep reinforcement learning (DRL), two active control methods are proposed in this article to rapidly suppress the vibration of flexible structures with quite small controllable force based on a cable-driven parallel robot. Inspired by the output law of DRL, a new control method named Tang and Sun control is innovatively presented based on the Lyapunov theory. To verify the effectiveness of these three control methods, three groups of simulations with different initial disturbances are implemented for each method. Besides, to enhance the contrast, a passive pretightening scheme is also tested. First, the dynamic model of the cable-driven parallel robot which comprises four cables and a flexible structure is established using the finite element method. Then, the dynamic behavior of the model under the controllable cable force is analyzed by the Newmark-ß method. Finally, these control methods are implemented by numerical simulations to evaluate their performance, and the results are satisfactory, which validates the controllers’ ability to suppress vibrations.

Optimal Vibration Control of Membrane Structures with In-Plane Polyvinylidene Fluoride Actuators

2020 ◽  
Vol 20 (08) ◽  
pp. 2050095
Author(s):  
Yifan Lu ◽  
Qi Shao ◽  
Fei Yang ◽  
Honghao Yue ◽  
Rongqiang Liu
Keyword(s):  
Vibration Control ◽  
Polyvinylidene Fluoride ◽  
Vibration Suppression ◽  
Flexible Structures ◽  
Control Force ◽  
Membrane Structures ◽  
Optimization Criteria ◽  
High Flexibility ◽  
And Control ◽  
Actuator Placement

Different kinds of membrane structures have been proposed for future space exploration and earth observation. However, due to the low stiffness, high flexibility, and low damping properties, membrane structures are likely to generate large-amplitude (compared to the thickness) vibrations, which may lead to the degradation of their working performance. In this work, the governing equations are established at first, taking into account the modal control force induced by the polyvinylidene fluoride (PVDF) actuator. The optimal vibration control of the membrane structure is explored subsequently. A square PVDF actuator is attached on the membrane to achieve the vibration suppression. The influence of actuator position and control gains on the vibration control performance are studied. The optimal criteria for actuator placement and energy allocation are developed. Several case studies are numerically simulated to demonstrate the validity of the proposed optimization criteria. The analytical results in this study can serve as guidelines for optimal vibration control of membrane structures. Additionally, the proposed optimization criteria can be applied to active control of different flexible structures.

Sliding Mode Control of a Gossamer Structure Using Smart Materials

2004 ◽  
Vol 10 (8) ◽  
pp. 1199-1220 ◽  
Author(s):  
Akhilesh K. Jha ◽  
Daniel J. Inman
Keyword(s):  
Smart Materials ◽  
Polyvinylidene Fluoride ◽  
Vibration Suppression ◽  
Sliding Mode ◽  
Fiber Composite ◽  
Piezoelectric Actuators ◽  
System Structure ◽  
Mode Shapes ◽  
Space Applications ◽  
Piezoelectric Actuators And Sensors

Gossamer structures have been a subject of renewed interest for space applications because of their low weights, on-orbit deploying capabilities, and minimal stowage volumes. In this study, vibration suppression of an inflated structure using piezoelectric actuators and sensors has been attempted. These actuators and sensors can be suitably used for gossamer structures since they can conform to curved surfaces and provide distributed actuation and sensing capabilities. Using the natural frequencies and mode shapes of the system (structure, actuators, and sensors), a state-space model is derived. For designing a robust vibration controller, we used a sliding mode technique. The derivations of the sliding model controller and observer are presented in details. Finally, by means of numerical analysis, the method was demonstrated for an inflated torus considering Macro-Fiber Composite (MFC™) as actuators and Polyvinylidene Fluoride (PVDF) as sensors. The simulation studies show that the piezoelectric actuators and sensors are suitable for vibration suppression of an inflatable torus. The robustness properties of the controller and observer against the parameter uncertainty and disturbances are also studied.

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