Numerical Investigation on the Selection of the System Outputs for Feedback Vibration Control of a Smart Blade Section

2016 ◽  
Vol 138 (3) ◽  
Author(s):  
Nailu Li ◽  
Mark J. Balas ◽  
Hua Yang ◽  
Wei Jiang
Keyword(s):  
Vibration Control ◽  
Feedback System ◽  
Vibration Modes ◽  
Torsional Mode ◽  
Aerodynamic Model ◽  
Attached Flow ◽  
Blade Section ◽  
Section Model ◽  
Effective Output ◽  
Equations Of Motions

This study presents the possible and effective output signals for the feedback vibration control of the smart blade section undergoing different aerodynamic conditions. Equations of motions of the smart blade section are described by a typical wing section model, leading to three vibration modes (flapwise mode, edgewise mode, and torsional mode). The aerodynamics is described by an unsteady aerodynamic model and aerodynamic effects of the microtab installed on the trailing-edge of the blade section. The equations of the aeroservoelastic model are summarized into state-space equation for analysis of output choice in the feedback system. All vibration modes are proved to be fully controllable with the microtab actuation. The numerical results show that the most effective output signal is the combination of flapwise velocity and torsional velocity for the system undergoing the attached flow and the combination of all three-mode velocities for the system undergoing the stall flow. In addition, the output choice for different microtab configurations is also analyzed. The effectiveness of the proposed output signals in vibration control is confirmed by the simulation results.

scholarly journals Numerical Investigation of Flapwise-Torsional Vibration Model of a Smart Section Blade with Microtab

2015 ◽  
Vol 2015 ◽  
pp. 1-11 ◽  
Author(s):  
Nailu Li ◽  
Mark J. Balas ◽  
Hua Yang ◽  
Wei Jiang ◽  
Kaman T. Magar
Keyword(s):  
Torsional Vibration ◽  
Numerical Data ◽  
Vibration Modes ◽  
Aerodynamic Model ◽  
Aeroelastic Model ◽  
Vibration Model ◽  
Divergence Instability ◽  
Blade Section ◽  
Control Capability ◽  
Control Study

This study presents a method to develop an aeroelastic model of a smart section blade equipped with microtab. The model is suitable for potential passive vibration control study of the blade section in classic flutter. Equations of the model are described by the nondimensional flapwise and torsional vibration modes coupled with the aerodynamic model based on the Theodorsen theory and aerodynamic effects of the microtab based on the wind tunnel experimental data. The aeroelastic model is validated using numerical data available in the literature and then utilized to analyze the microtab control capability on flutter instability case and divergence instability case. The effectiveness of the microtab is investigated with the scenarios of different output controllers and actuation deployments for both instability cases. The numerical results show that the microtab can effectively suppress both vibration modes with the appropriate choice of the output feedback controller.

scholarly journals Vibration Control of Blade Section Based on Sliding Mode PI Tracking Method and OPC Technology

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Tingrui Liu
Keyword(s):  
Vibration Control ◽  
Sliding Mode ◽  
Engineering Application ◽  
Control Input ◽  
Pi Method ◽  
Opc Technology ◽  
Practical Engineering ◽  
Blade Section ◽  
The Stability ◽  
And Control

Vibration control of the blade section of a wind turbine is investigated based on the sliding mode proportional-integral (SM-PI) method, i.e., sliding mode control (SMC) based on a PI controller. The structure is modeled as a 2D pretwisted blade section integrated with calculation of structural damping, which is subjected to flap/lead-lag vibrations of instability. To facilitate the hardware implementation of the control algorithm, the SM-PI method is applied to realize tracking for limited displacements and velocities. The SM-PI algorithm is a novel SMC algorithm based on the nominal model. It combines the effectiveness of the sliding mode algorithm for disturbance control and the stability of PID control for practical engineering application. The SM-PI design and stability analysis are discussed, with superiority and robustness and convergency control demonstrated. An experimental platform based on human-computer interaction using OPC technology is implemented, with position tracking for displacement and control input signal illustrated. The platform verifies the feasibility and effectiveness of the SM-PI algorithm in solving practical engineering problems, with online tuning of PI parameters realized by applying OPC technology.

scholarly journals A Decoupled Unified Observation Method of Stochastic Multidimensional Vibration for Wind Tunnel Models

Sensors ◽  
2020 ◽  
Vol 20 (17) ◽  
pp. 4694
Author(s):  
Mengde Zhou ◽  
Wei Liu ◽  
Qinqin Wang ◽  
Bing Liang ◽  
Linlin Tang ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Vibration Control ◽  
Active Vibration Control ◽  
Inertial Force ◽  
Vibration Monitoring ◽  
Vibration Modes ◽  
Wind Tunnel Tests ◽  
Stochastic Vibration ◽  
Active Vibration ◽  
Observation Method

Active vibration control is the most effective method for stochastic multidimensional vibration in wind tunnel tests, in which vibration monitoring is the core foundation. Vibrations are induced by the disturbances of several complex air flow instabilities under extreme test conditions with high attack angles. Here, a decoupled unified observation method is proposed in order to fully monitor stochastic multidimensional vibration. First, stochastic multidimensional vibration is explained using the Cartesian coordinate system. Then, the multidimensional vibration decoupling of the pitch plane and the yaw plane is realized according to the proposed decoupling design principle of the long cantilever sting. A unified observation method is presented, based on inertial force theory, to observe multidimensional vibration due to acceleration in each decoupling plane. Verification experiments were conducted in lab and a transonic wind tunnel, using an established real-time monitoring system. The results of lab experiments indicate that, in the frequency region of 0–120 Hz, three vibration modes of a selected stochastic vibration can be decoupled and observed through the vibration components in pitch plane and yaw plane. In addition, wind tunnel tests were carried out according to the working conditions (α = −4~10° with γ = 45°) at Ma = 0.6 and Ma = 0.7, respectively. The results show that six vibration modes of two selected stochastic vibrations can be decoupled and observed through the vibration components in pitch plane and yaw plane. The experimental results prove that stochastic vibration can be fully monitored in multiple dimensions through the vibration components in pitch plane and yaw plane using the proposed decoupled unified observation method. Therefore, these results lay the foundation for active vibration control.

Motion and Vibration Control of Three Dimensional Flexible Shaking Table Using LQI Control Approach

2001 ◽  
Author(s):  
Hidefumi Hiramatsu ◽  
Daijiro Fuji ◽  
Kazuto Seto ◽  
Toru Watanabe
Keyword(s):  
Vibration Control ◽  
Three Dimensional ◽  
Design Procedure ◽  
Equation System ◽  
State Equation ◽  
Shaking Table ◽  
System Model ◽  
Vibration Modes ◽  
Control Approach ◽  
Control Forces

Abstract This paper deals with a design procedure of control system for a three-dimensional flexible shaking table. The shaking table should be less weighted so that actuators require less control forces and higher fidelity to control commands. However, as the weight of shaking table is reduced, the natural frequencies of vibration modes of the table appear on operating frequency region. Such vibration modes get into problem that may cause spillover instability. So, the research purpose is to control such vibration and motion by using the modeling method presented by Seto [1]. Utilizing the model, state equation system model including integrator is composed and feedback controller is designed by using LQI control law. As the system model both includes the multi-degree-of -freedom-structure model and integrator, the designed controller achieves simultaneous motion and vibration control. Computer simulation and control experiments are carried out and the effectiveness of the presented procedure is investigated.

Development of a Multi-DOF Tuned Dynamic Absorber for Reducing Hand Vibrations on an Off-Highway Vehicle

2020 ◽  
Author(s):  
Hongan Xu ◽  
David Clark ◽  
Marlin Zeis ◽  
Mike Hill ◽  
Tony Zambito
Keyword(s):  
Vibration Control ◽  
Safety Issue ◽  
Control Measures ◽  
Steering Wheel ◽  
Bench Test ◽  
Vibration Modes ◽  
Quality And Safety ◽  
Important Quality ◽  
Dynamic Absorber

Abstract A variety of off-highway vehicles are subject to significant steering wheel vibrations during operation. Typical examples of such machines are vibratory asphalt and soil compactors. Large compacting forces, while essential for the proper compacting operation, will inevitably cause undesired effects such as severe vibrations of steering wheels. Traditional vibration control measures are often found either impractical or less effective in reducing the level of hand vibrations which is considered an important quality and safety issue in compacter design and sales. In this paper, an advanced concept of reducing hand vibrations is presented in the context of Multi-degree-of-freedom Tuned Dynamic Absorbers (MTDA). The MTDA essentially represents an assembly of simple dynamic absorbers individually tuned to different targeted vibration modes in different degree of freedoms. While the design concept and associated parameters are numerically determined by FEA, the prototype is fine tuned to the desired vibration modes through a bench test. The effectiveness of the MTDA is experimentally verified in-situ through a sequence of tests which are carefully designed to adequately reflect its performance under field conditions.

Theoretical modeling and vibration control for pre-twisted composite blade based on LLI controller

2019 ◽  
Vol 42 (7) ◽  
pp. 1255-1270
Author(s):  
Ting-Rui Liu ◽  
Ai-Ling Gong
Keyword(s):  
Vibration Control ◽  
Theoretical Modeling ◽  
Linear Quadratic ◽  
Linear Quadratic Gaussian ◽  
Flutter Suppression ◽  
Hamilton Variational Principle ◽  
Composite Blade ◽  
Loop Transfer Recovery ◽  
Blade Section ◽  
Blade Tip

Theoretical modeling and vibration control for divergent motion of thin-walled pre-twisted wind turbine blade have been investigated based on “linear quadratic Gaussian (LQG) controller using loop transfer recovery (LTR) at plant input” (LLI). The blade section is a single-celled composite structure with symmetric layup configuration of circumferentially uniform stiffness (CUS), exhibiting displacements of vertical/lateral bending coupling. Flutter suppression for divergent instability is investigated, with blade driven by nonlinear aerodynamic forces. Theoretical modeling of CUS-based structure is implemented based on Hamilton variational principle of elasticity theory. The discretization of aeroelastic equations is solved by Galerkin method, with blade tip responses demonstrated. The LLI controller is characterized by LTR at the plant input. The effects of LLI controller are achieved and illustrated by displacement responses, controller responses and frequency spectrum analysis, respectively.

Shake Table Test of Complex High-Rise Building Equipped with Torsional Vibration Control Device

2012 ◽  
Vol 446-449 ◽  
pp. 3889-3893
Author(s):  
Bin Zhao ◽  
Juan He ◽  
Hui Gao ◽  
Xu Gang Chen
Keyword(s):  
Vibration Control ◽  
Torsional Vibration ◽  
Shake Table Test ◽  
Scale Model ◽  
Shake Table ◽  
Test Results ◽  
Torsional Mode ◽  
High Rise ◽  
High Rise Building ◽  
Local Space

For many high-rising buildings, large local space is very useful for its special function needs, such as conference hall and hotel lobby. The shake table test results of a high-rising building with large local space show that the dynamic characteristics of such structure are complex and the torsional mode becomes the first mode, while the torsional responses under earthquake excitation, especially of the floor just above the large local space, are very remarkable. In this paper, the bidirectional Tuned Mass Damper (TMD) is employed for reducing the torsional vibration of such complex high-rise building structure. A reduced-scale model is design and constructed. A series of shake table tests are carried out and the test results indicate that the TMD system is very effective in torsional vibration control of structural system.

Method to Calculate Aircraft VNAV Trajectory Cost Using a Performance Database

2014 ◽  
Author(s):  
Alejandro Murrieta-Mendoza ◽  
Ruxandra Botez
Keyword(s):  
Trajectory Optimization ◽  
Calculated Data ◽  
Optimization Methods ◽  
Fast Method ◽  
Computing Power ◽  
Flight Plan ◽  
Aerodynamic Model ◽  
The Given ◽  
Equations Of Motions ◽  
A Performance

Vertical Navigation (VNAV) trajectory optimization has been identified as a means to reduce fuel consumption. Due to the computing power limitations of devices such as Flight Management Systems (FMSs), it is very desirable to implement a fast method for calculating trajectory cost using optimization algorithms. Conventional trajectory optimization methods solve a set of differential equations called the aircraft equations of motions to find the optimal flight profile. Many FMSs do not use these equations, but rather a set of lookup tables with experimental, or pre-calculated data, called a Performance Database (PDB). This paper proposes a method to calculate a full trajectory flight cost using a PDB. The trajectory to be calculated is composed of climb, acceleration, cruise, descent and deceleration flight phases. The influence of the crossover altitude during climb and step climbs in cruise were considered for these calculations. Since the PDB is a set of discrete data, Lagrange linear interpolations were performed within the PDB to calculate the required values. Given a takeoff weight, the initial and final coordinates and the desired flight plan, the trajectory model provides the Top of Climb coordinates, the Top of Descent coordinates, the fuel burned and the flight time needed to follow the given flight plan. The accuracy of the trajectory costs calculated with the proposed method was validated for two aircraft; one with an aerodynamic model in FlightSIM, software developed by Presagis, and the other using the trajectory generated by the reference FMS.

scholarly journals Design of a Maglev Inertial Actuator with High Mass Power Ratio for Lateral Vibration Control of Propulsion Shafting

Actuators ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 315
Author(s):  
Qianqian Wu ◽  
Zhihui Liu ◽  
Fengyan An ◽  
Bilong Liu
Keyword(s):  
Vibration Control ◽  
Magnetic Circuit ◽  
High Mass ◽  
Good Effect ◽  
Power Ratio ◽  
Lateral Vibration ◽  
Control Effect ◽  
Output Force ◽  
Inertial Actuator ◽  
Effective Output

The maglev inertial actuators with high power and mass maybe effective for lateral vibration control of a propulsion shafting. But the mass power ratio of the actuators currently in use is too small to meet the requirements. In the paper, a maglev inertial actuator was innovatively designed with high mass power ratio. The structure of the magnetic circuit assembly and the suspending assembly were designed and optimized. To verify the property of the proposed maglev inertial actuator, a prototype with mass less than 8 kg was developed and tests were carried out. The minimum effective output force can reach 200 N within the frequency band of 20–300 Hz. A lateral vibration of a propulsion shafting system was constructed and the active control effect was tested. The experimental results show that the proposed maglev inertial actuator has a good effect on lateral vibration control of shafting.

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