Active Control of a Circular Membrane to Reduce Transient Noise Transmission

1995 ◽  
Vol 117 (3A) ◽  
pp. 252-258 ◽  
Author(s):  
J. L. van Niekerk ◽  
B. H. Tongue
Keyword(s):  
Feedback Control ◽  
Active Control ◽  
Sliding Mode ◽  
Control Strategies ◽  
Circular Membrane ◽  
Velocity Feedback ◽  
Circular Duct ◽  
Control Approach ◽  
Noise Transmission

An active control approach that reduces transient noise transmission through a membrane in a circular duct is presented. Discrete sections of piezo-electrical film, PVDF, are used as actuators to adjust the tension of the membrane. Different control strategies, such as optimal, sliding mode and velocity feedback control, are investigated analytically and then implemented experimentally. It is shown that velocity feedback control is the more effective, stable controller for this application.

Predictive Time-Based Feedback Control Approach for Managing Freeway Incidents

2000 ◽  
Vol 1710 (1) ◽  
pp. 79-84 ◽  
Author(s):  
Omar B. Sawaya ◽  
Dung L. Doan ◽  
Athanasios K. Ziliaskopoulos
Keyword(s):  
Feedback Control ◽  
Traffic Management ◽  
Control Strategies ◽  
Compliance Rate ◽  
Dynamic Control ◽  
Route Guidance ◽  
Control Approach ◽  
Real Time Traffic ◽  
Freeway Incidents ◽  
Alternate Routes

A feedback control approach is introduced that produces dynamic control strategies in the form of alternate routes around freeway incidents and in response to the prevailing traffic conditions. The approach is based on the equalization of predictive travel times on alternate routes. The methodology is intended to be used as a decision-aid tool for real-time traffic management applications, more specifically for route guidance via variable message signs. The approach is implemented and tested computationally on an example network in a simulated environment under various scenarios of system disturbances. The results indicate that the performance of this approach is fairly robust to uncertainties in demand, compliance rate, and incident severity. It also performs better than an anticipatory approach and an instantaneous time–based feedback control approach.

The Use of Optimally Shaped Piezo-electric Film Sensors in the Active Control of Free Field Structural Radiation, Part 2: Feedback Control

1996 ◽  
Vol 118 (1) ◽  
pp. 112-121 ◽  
Author(s):  
S. D. Snyder ◽  
N. Tanaka ◽  
Y. Kikushima
Keyword(s):  
Feedback Control ◽  
Control Strategies ◽  
Free Field ◽  
Low Frequency ◽  
Acoustic Power ◽  
State Equations ◽  
Subsequent Increase ◽  
Low Frequencies ◽  
Control Approach ◽  
Iir Filters

Feedback control of free field structural radiation is considered. State equations are formulated with a transformation which decouples the acoustic power error criterion. Using the resultant equations, expressed in terms of “transformed mode” states, the order of the state equations can be significantly reduced at low frequencies. Two experimental implementations of feedback control strategies using shaped piezoelectric polymer film sensors to measure the transformed system states are described. The first of these is a simple analog implementation. The second implementation is in discrete time, where an adaptive algorithm for optimizing the weights of IIR filters for practical use is described. It is shown that by using the outlined control approach significant levels of low frequency acoustic power attenuation can be obtained with no control spillover and subsequent increase in higher frequency acoustic power output.

Novel design of an optimized synergetic control for dual stator induction motor

2019 ◽  
Vol 38 (6) ◽  
pp. 1828-1845
Author(s):  
Hossine Guermit ◽  
Katia Kouzi ◽  
Sid Ahmed Bessedik
Keyword(s):  
Induction Motor ◽  
Sliding Mode ◽  
Optimal Parameter ◽  
Control Strategies ◽  
Pso Algorithm ◽  
Operating Conditions ◽  
Content Type ◽  
Control Approach ◽  
Simulation Results ◽  
Synergetic Control

Purpose This paper aims to present a contribution to improve the performance of vector control scheme of double star induction motor drive (DSIM) by using an optimized synergetic control approach. The main advantage of synergetic control is that it supports all parametric and nonparametric uncertainties, which is not the case in several control strategies. Design/methodology/approach The suggested controller is developed based on the synergistic control theory and the particle swarm optimization (PSO) algorithm which allow to obtain the optimal parameter of suggested controller to improve the performance of control system. Findings To show the benefits of proposed controller, a comparative simulation results between conventional PI controller, sliding mode controller and suggested controller were carried out. Originality/value The obtained simulation results illustrate clearly that synergetic controller ensures a rapid response, asymptotic stability of the closed-loop system in the all range operating condition and system robustness in presence of parameter variation in all range of operating conditions.

Nonlinear Active Rollover Prevention Control Strategies for a 5-Axle Tractor/Semitrailer

2001 ◽  
Author(s):  
A. Scott Lewis ◽  
Moustafa El-Gindy
Keyword(s):  
Active Control ◽  
Load Transfer ◽  
Sliding Mode ◽  
Control Strategies ◽  
Lateral Load ◽  
Lateral Acceleration ◽  
Computer Simulation Model ◽  
Parameter Uncertainties ◽  
Transfer Ratio ◽  
Vehicle Rollover

Abstract This paper presents new active control strategies to prevent heavy vehicle rollover and focuses mainly on cases of maneuver-induced rollover such as rollover in cornering and lane-change maneuvers. Two performance measures as control strategies are explored: the lateral load transfer ratio and the trailer lateral acceleration. A nonlinear 75,000 pound 5-axle tractor/semitrailer computer simulation model has been used to demonstrate the effectiveness of the proposed active control system. A new non-linear sliding mode controller has been designed and found to be effective in improving the dynamic performance and roll stability, regardless of parameter uncertainties, such as tires or suspension characteristics. The controller torque requirement is limited by the differential dynamic braking forces that the tractor drive axles are able to produce as a function of the applied dynamic loads and road surface condition. The results show that with this new controller, the vehicle lateral acceleration can be controlled to prevent rollover without significant change of the vehicle trajectory when active yaw torque is applied to the tractor drive axles. Also, simulation results indicate that the vehicle rollover might be prevented using either the lateral load transfer ratio or the lateral acceleration at the trailer centre of gravity as control strategies.

Sub-Scale Demonstration of the Active Feedback Control of Gas-Turbine Combustion Instabilities

2000 ◽  
Vol 122 (2) ◽  
pp. 262-268 ◽  
Author(s):  
Stanley S. Sattinger ◽  
Yedidia Neumeier ◽  
Aharon Nabi ◽  
Ben T. Zinn ◽  
David J. Amos ◽  
...  
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Gas Turbine ◽  
Active Control ◽  
Combustion Instabilities ◽  
Engine Operation ◽  
Turbine Engine ◽  
Control Approach ◽  
Active Feedback ◽  
Active Feedback Control

Described are sub-scale tests that successfully demonstrate active feedback control as a means of suppressing damaging combustion oscillations in natural-gas-fueled, lean-premix combustors. The control approach is to damp the oscillations by suitably modulating an auxiliary flow of fuel injected near the flame. The control system incorporates state observer software that can ascertain the frequency, amplitude, and phase of the dominant modes of combustion oscillation, and a sub-scale fuel flow modulator that responds to frequencies well above 1 kHz. The demonstration was conducted on a test combustor that could sustain acoustically coupled combustion instabilities at preheat and pressurization conditions approaching those of gas-turbine engine operation. With the control system inactive, two separate instabilities occurred with combined amplitudes of pressure oscillations exceeding 70 kPa (10 psi). The active control system produced four-fold overall reduction in these amplitudes. With the exception of an explainable control response limitation at one frequency, this reduction represented a major milestone in the implementation of active control. [S0742-4795(00)00702-X]

Integrated active control of independently rotating wheels on rail vehicles via observers

2016 ◽  
Vol 231 (3) ◽  
pp. 295-305 ◽  
Author(s):  
Zheng-Gang Lu ◽  
Xiao-Jie Sun ◽  
Jun-Qi Yang
Keyword(s):  
Active Control ◽  
Sliding Mode ◽  
Stability Control ◽  
Wheel Pair ◽  
Control Approach ◽  
Active Steering ◽  
Reduced Order Observer ◽  
Stability Control System ◽  
The One ◽  
Yaw Angle

As the well-known difficulties are that feedback signals are not easy and economical measurement in practice for active control, this paper presents a study of state estimation for active control of independently rotating wheels (IRW) based on observers. The reduced-order observer and high-order sliding mode observer are used to provide reliable and accurate estimations of the wheel pair state and track curvature using practical sensors. This proposed method uses less sensors than the one of previous studies. Furthermore, lateral accelerator and yaw velocity sensors (gyros) are economical and available for active steering and stability control system to obtain the required feedback signals. The wheels’ relative rotational speed, track curvature and yaw angle of wheelsets are the feedback signals for IRW active control approach. Computer simulations are used to verify the effectiveness of proposed methods and assess control performance in stability and negotiation.

Time Delayed Negative Velocity Feedback Design for Active Control of Structures

2005 ◽  
Author(s):  
Phailaung Phohomsiri ◽  
Firdaus E. Udwadia
Keyword(s):  
Feedback Control ◽  
Active Control ◽  
Time Delays ◽  
Control Design ◽  
System Stability ◽  
Ground Acceleration ◽  
Velocity Feedback ◽  
Significant Time ◽  
Control Methodology ◽  
Delayed Control Systems

In this paper, we present velocity feedback control design with significant time delays for the active control of structures. Because of the presence of significant time delays, we study the infinite dimensionality of the system with time-delayed control and introduce the concept of the so-called non-system poles. Analytical results related to performance and stability analysis of the new control design are provided. The non-system poles are shown to influence both system stability and system performance and cannot therefore be ignored in time-delayed control systems. We then apply the time delayed negative velocity feedback control methodology to a single-degree-of-freedom system subjected to random ground acceleration. The numerical results show good stability characteristics and effective behavior of the proposed control methodology.

scholarly journals Sub-Scale Demonstration of the Active Feedback Control of Gas-Turbine Combustion Instabilities

1998 ◽  
Author(s):  
Stanley S. Sattinger ◽  
Yedidia Neumeier ◽  
Aharon Nabi ◽  
Ben T. Zinn ◽  
David J. Amos ◽  
...  
Keyword(s):  
Control System ◽  
Feedback Control ◽  
Gas Turbine ◽  
Active Control ◽  
Combustion Instabilities ◽  
Engine Operation ◽  
Turbine Engine ◽  
Control Approach ◽  
Active Feedback ◽  
Active Feedback Control

Described are sub-scale tests that successfully demonstrate active feedback control as a means of suppressing damaging combustion oscillations in natural-gas-fueled, lean-premix combustors. The control approach is to damp the oscillations by suitably modulating an auxiliary flow of fuel injected near the flame. The control system incorporates state observer software that can ascertain the frequency, amplitude, and phase of the dominant modes of combustion oscillation, and a sub-scale fuel flow modulator that responds to frequencies well above 1 kHz. The demonstration was conducted on a test combustor that could sustain acoustically coupled combustion instabilities at preheat and pressurization conditions approaching those of gas-turbine engine operation. With the control system inactive, two separate instabilities occurred with combined amplitudes of pressure oscillations exceeding 70 kPa (10 psi). The active control system produced four-fold overall reduction in these amplitudes. With the exception of an explainable control response limitation at one frequency, this reduction represented a major milestone in the implementation of active control.

Experimental investigations on active control of multifrequency helicopter vibrations using discrete model predictive sliding mode control

2017 ◽  
Vol 232 (15) ◽  
pp. 2898-2909
Author(s):  
Xunjun Ma ◽  
Yang Lu ◽  
Fengjiao Wang
Keyword(s):  
Active Control ◽  
Discrete Model ◽  
Sliding Mode ◽  
Structural Response ◽  
Test System ◽  
Experimental Investigations ◽  
Least Mean Square ◽  
Single Input Single Output ◽  
Control Approach ◽  
Practical Applications

The presented experimental results illustrate the recent advances in the reduction of multifrequency vibrations of helicopter fuselage using an active control of structural response system. Recently, to cancel the multifrequency helicopter vibrations, a hybrid control approach has been proposed combining the filtered-x least mean square algorithm with a discrete model predictive sliding mode controller. To verify its effectiveness and self-adaptability, a set of active control experiments of structural response are conducted on a free–free elastic beam, which simulates a helicopter in flight. Considering that the helicopter vibrations in practical applications are much more complex, the further experiments of real-time active control are performed using a model helicopter test system. Higher discrete frequency components, which are actually of concern, are selected as the control objectives during the tests. The algorithm’s control effects are sufficiently checked by single-input single-output and multiple-input multiple-output tests under different excitation conditions. For many cases the attenuation of measured response exceed level of 20 dB, with maximum reduction reaching 34.1 dB. These two sets of tests confirm that the active control system is practical for canceling the multifrequency helicopter vibrations.

Time-Delayed Positive Velocity Feedback Control Design for Active Control of Structures

2006 ◽  
Vol 132 (6) ◽  
pp. 690-703 ◽  
Author(s):  
Phailaung Phohomsiri ◽  
Firdaus E. Udwadia ◽  
Hubertus F. von Bremen
Keyword(s):  
Feedback Control ◽  
Active Control ◽  
Control Design ◽  
Velocity Feedback
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