Closed-Loop Trailing-Edge Separation Control System Using Empirical Mode Decomposition

AIAA Journal ◽  
2018 ◽  
Vol 56 (1) ◽  
pp. 121-131 ◽  
Author(s):  
Rohit Gupta ◽  
Phillip J. Ansell
Keyword(s):  
Control System ◽  
Empirical Mode Decomposition ◽  
Closed Loop ◽  
Separation Control ◽  
Trailing Edge ◽  
Mode Decomposition ◽  
Edge Separation

Development of a MEMS-Based Active Control System for Flow Separation in the Transonic Regime

2000 ◽  
Author(s):  
Steve Tung ◽  
Brant Maines ◽  
Fukang Jiang ◽  
Tom Tsao
Keyword(s):  
Shear Stress ◽  
Control System ◽  
Wind Tunnel ◽  
Flow Separation ◽  
Control Flow ◽  
Separation Control ◽  
Sensors And Actuators ◽  
Trailing Edge ◽  
Flow Separation Control ◽  
Mach Numbers

Abstract A MEMS-based active system is currently under development for flow separation control in the transonic regime. The system consists of micro shear stress sensors for flow sensing and micro balloon actuators for separation control. We have successfully completed the first phase of the program in which the micro sensors and actuators were fabricated and tested in a wind tunnel facility. In the test, the sensors and actuators were flush mounted on a 3D model, which is representative of the upper surface of a wing with a deflected trailing edge flap. The model was installed in the wind tunnel and tested at a series of Mach numbers between 0.2 and 0.6. For all Mach numbers, the sensor output indicates that flow separates over the trailing edge when the micro balloons are in the ‘down’ position. When the micro balloons are inflated, the shear stress level on the trailing edge increases substantially, indicating an improvement of the separation characteristics. This result demonstrates the feasibility of using MEMS sensors and actuators to control flow separation. It is the first step toward the development of a revolutionary closed loop flow control system applicable to existing and future aircraft to enhance aerodynamic performance.

scholarly journals sEMG based Classification of Hand Gestures using EMD Algorithm and its Application on Control System

2019 ◽  
Vol 8 (11S) ◽  
pp. 1103-1105
Keyword(s):  
Support Vector Machine ◽  
Control System ◽  
Empirical Mode Decomposition ◽  
Time Domain ◽  
Support Vector ◽  
Hand Gestures ◽  
Mode Decomposition ◽  
Single Sensor ◽  
Mean Variance

Single sensor is employed for classifying four hand gestures from flexor carpum ulnaris. The first three IMFs that are obtained as a result of Empirical Mode Decomposition are taken into consideration. Time domain features like mean, variance, skewness, etc are taken for each IMFs. Support Vector Machine was used for classification task and the extracted model is used for making predictions

Psychoacoustic active noise control system based on empirical mode decomposition

2019 ◽  
Vol 67 (5) ◽  
pp. 332-349
Author(s):  
Yonghong Nie ◽  
Yu Liu ◽  
Guofeng Li ◽  
Ganqing Zhang
Keyword(s):  
Control System ◽  
Noise Reduction ◽  
Empirical Mode Decomposition ◽  
Noise Control ◽  
Active Noise Control ◽  
Peak Frequency ◽  
Least Mean Square ◽  
Shaping Filter ◽  
Active Noise ◽  
Mode Decomposition

A psychoacoustic active noise control (ANC) system based on empirical mode decomposition (EMD) is proposed and implemented to improve the noise reduction performance of the control system. The noise source signal is decomposed by EMD, and the psychoacoustic parameter â–œloudnessâ–? of each intrinsic mode function (IMF) is initially calculated in such a system. Thereafter, the high-pass psychoacoustic weighting filter used to shape the error and reference signals is designed adaptively and automatically according to the loudness, peak frequency, and amplitude of each IMF. Three different ANC systems are simulated, and the sound pressure levels and loudness of their residual error signals are compared. The results demonstrate that the filter designed using this method can restrain the components of noise sources with small loudness better than the A-weighting shaping filter, so that the proposed control system can improve the noise reduction compared to those of the filtered-x least mean square and A-weighting shaping filters. Finally, the computational complexity of the three ANC systems is analyzed and compared.

Flow-separation-control system operating in feedback closed loop

2019 ◽  
Vol 91 (3) ◽  
pp. 498-508
Author(s):  
Wienczyslaw Stalewski ◽  
Andrzej Krzysiak
Keyword(s):  
Flow Separation ◽  
Closed Loop ◽  
Pressure Sensors ◽  
The Self ◽  
Experimental Investigations ◽  
Separation Control ◽  
Trailing Edge ◽  
High Lift ◽  
Content Type ◽  
Flow Separation Control

Purpose The purpose of this study is to develop the concept of self-adapting system which would be able to control a flow on the wing-high-lift system and protect the flow against strong separation. Design/methodology/approach The self-adapting system has been developed based on computational approach. The computational studies have been conducted using the URANS solver. The experimental investigations have been conducted to verify the computational results. Findings The developed solution is controlled by closed-loop-control (CLC) system. As flow actuators, the main-wing trailing-edge nozzles are proposed. Based on signals received from the pressure sensors located at the flap trailing edge, the CLC algorithm changes the amount of air blown from the nozzles. The results of computational simulations confirmed good effectiveness and reliability of the developed system. These results have been partially confirmed by experimental investigations. Research limitations/implications The presented research on an improvement of the effectiveness of high-lift systems of modern aircraft was conducted on the relatively lower level of the technology readiness. However, despite this limitation, the results of presented studies can provide a basis for developing innovative self-adaptive aerodynamic systems that potentially may be implemented in future aircrafts. Practical implications The studies on autonomous flow-separation control systems, operating in a closed feedback loop, are a great hope for significant advances in modern aeronautical engineering, also in the UAV area. The results of the presented studies can provide a basis for developing innovative self-adaptive aerodynamic systems at a higher level of technological readiness. Originality/value The presented approach is especially original and valuable in relation to the innovative concept of high-lift system supported by air-jets blown form the main-wing-trailing-edge nozzles; the effective and reliable flow sensors are the pressure sensors located at the flap trailing edge, and the effective and robust algorithm controlling the self-adapting aerodynamic system – original especially in respect to a strategy of deactivation of flow actuators.

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