Propeller Synchrophase Angle Optimization of Turboprop-Driven Aircraft—An Experimental Investigation

2014 ◽  
Vol 136 (11) ◽  
Author(s):  
Xianghua Huang ◽  
Long Sheng ◽  
Yangyang Wang
Keyword(s):  
Interior Noise ◽  
Noise Model ◽  
Experimental Platform ◽  
Limited Success ◽  
Sampling Condition ◽  
Phase Optimization ◽  
And Control ◽  
Phase Angles ◽  
Optimization Search ◽  
Minimum Noise

Propeller synchrophasing is an effective way of reducing interior noise and vibration of turboprop-driven aircraft. However, synchrophasing has achieved limited success in practice for the reason that the predetermined phase angles are not acoustically optimized for maximum noise reduction during all flight conditions. An investigation has been conducted out which includes two folds: first, the noise vector based on laboratory experimental data has been modeled and second, optimal phase to acquire minimum noise is obtained via optimization search. An improved identification method of vector noise model which can be less dependent to noise phase message is presented. Compared with traditional methods, this method can greatly reduce the real-time requirement between phase optimization model and control model or sound acquiring model, so it can eliminate the influence which communication delay brings on identification precision. A synchrophasing experimental platform is established to verify the vector noise modeling. It adopts two propellers-driven servo motors to simulate the interior noise environment of the aircraft. The influence of the date sampling condition on identification is also researched. Ant colony optimization with two improvements is applied to phase optimization of four propellers. Simulation results show that the improved algorithm requires much less calculation.

Investigation of Impact Profile and Isolation Effect in Automated Impact Device Design and Control for Operational Modal Analysis

2015 ◽  
Vol 137 (9) ◽  
Author(s):  
Z. C. Ong ◽  
C. C. Lee
Keyword(s):  
Modal Analysis ◽  
Isolation Effect ◽  
Time Averaging ◽  
Impact Device ◽  
Lack Of Information ◽  
Analysis Technique ◽  
And Control ◽  
Phase Angles ◽  
Synchronous Time

A novel modal analysis technique called impact-synchronous modal analysis (ISMA) was introduced in previous research. With the utilization of impact-synchronous time averaging (ISTA), this modal analysis can be performed in presence of ambient forces whereas the conventional analysis method requires machines to be totally shut down. However, lack of information of phase angles with respect to impact in ISMA has caused it to be labor-intensive and time-consuming. An automated impact device (AID) is introduced in this study in the effort to replace the manually operated impact hammer and prepare it to be used in the current practice of ISMA on the purpose of enhancing its effectiveness and practicability. Impact profile and isolation effect are noted to be the contributing parameters in this study. This paper devoted on calibrating and controlling of the AID which gives the desired impact profiles as compared to the manual impact hammer. The AID is found effective in the determination of dynamic characteristics when the device is isolated from the boundary condition of the test structure.

scholarly journals Development of Accurate BSIM4 Noise Parameters for CMOS 0.13-µm Transistors in Below 3-GHz LNA Application

2018 ◽  
Vol 10 (3) ◽  
pp. 925
Author(s):  
Asmaa Nur Aqilah Zainal Badri ◽  
Norlaili Mohd Noh ◽  
Shukri Bin Korakkottil Kunhi Mohd ◽  
Asrulnizam Abd Manaf ◽  
Arjuna Marzuki ◽  
...  
Keyword(s):  
Thermal Noise ◽  
Noise Figure ◽  
Noise Model ◽  
Ic Design ◽  
Noise Parameters ◽  
Specific Frequency ◽  
Minimum Noise ◽  
Minimum Noise Figure ◽  
Selection Of

Accurate transistor thermal noise model is crucial in IC design as it allows accurate selection of transistors for specific frequency application. The accuracy of the model is represented by the similarity between the simulated and the measured noise parameters (NPs). This work was based on a problem faced by a foundry concerning the dissimilarities between the measured and simulated NPs, especially minimum noise figure (NF<sub>min</sub>) for frequencies below 3 GHz.

Additive Gaussian noise model and Kalman filter to enhance controllability of gesture-controlled teleoperated soft actuators

2020 ◽  
pp. 095440542094100
Author(s):  
PDSH Gunawardane ◽  
APTD Pathirana ◽  
REA Pallewela ◽  
Nimali T Medagedara
Keyword(s):  
Kalman Filter ◽  
Gaussian Noise ◽  
Noise Model ◽  
The Internet ◽  
Linear Calibration ◽  
Spherical Object ◽  
Gesture Control ◽  
Soft Actuators ◽  
Human Finger ◽  
And Control

Soft actuators are used in bilateral systems as slave-side actuators. To broaden the applications and usage of these soft actuators in teleoperated applications required high accuracy and control. This article focuses on the improvement and control of the soft actuators operated through the Internet using a glove-based gesture control system. A hand-worn sensor glove (a glove with flex sensors and accelerometers) is used to detect hand gestures (specifically bending angle and force generated in a finger while gripping a spherical object) of an operator. The operator’s finger movements are mimicked in a remote location, through the Internet, in a soft actuator. The bending angles of the human finger have converted into the pressure variations inside the actuator using a linear calibration technique. A vertically mounted actuator and a spherical object are used to demonstrate the gripping action. The main problems that occurred during the controlling of this setup are noise and delays. Electronic noise (line noise and circuit noise), mechanical noise (vibration, nonuniformities in actuator fabrication, wear, and tear), elastic effect (energy absorbed during the state transformation), communication delays (delays occurred due to geography, telecommunication infrastructure, and round trip transmission), and other noises (other environmental effects) degraded the performance. This article considered a Brownian motion model, an additive Gaussian noise model, and a Kalman filter to solve these problems. The experimentations are performed in three different locations (to demonstrate the teleoperation) and the recorded improvement in the performance is approximately 17%.

scholarly journals Design, Implementation and Control of a Fish Robot with Undulating Fins

10.5772/50898 ◽  
2011 ◽  
Vol 8 (5) ◽  
pp. 60 ◽  
Author(s):  
Mohsen Siahmansouri ◽  
Ahmad Ghanbari ◽  
Mir Masoud Seyyed Fakhrabadi
Keyword(s):  
Field Trials ◽  
Robotic Fish ◽  
Propulsive Force ◽  
Fish Robot ◽  
Revolution Speed ◽  
The Individual ◽  
And Control ◽  
Phase Angles ◽  
The Relationship ◽  
Undulating Fin

Biomimetic robots can potentially perform better than conventional robots in underwater vehicle designing. This paper describes the design of the propulsion system and depth control of a robotic fish. In this study, inspired by knife fish, we have designed and implemented an undulating fin to produce propulsive force. This undulating fin is a segmental anal fin that produces sinusoidal wave to propel the robot. The relationship between the individual fin segment and phase angles with the overall fin trajectory has also been discussed. This propulsive force can be adjusted and directed for fish robot manoeuvre by a mechanical system with two servomotors. These servomotors regulate the direction and depth of swimming. A wireless remote control system is designed to adjust the servomotors which enables us to control revolution, speed and phase differences of neighbor servomotors of fins. Finally, Field trials are conducted in an outdoor pool to demonstrate the relationship between robotic fish speed and fin parameters like phase difference, the number of phase and undulatory amplitude.

Ecosystem Approach to the Simulation and Control of an Oil Refinery Waste Treatment Facility

1976 ◽  
Vol 98 (1) ◽  
pp. 20-29 ◽  
Author(s):  
G. D. Martin ◽  
R. J. Mulholland ◽  
K. W. Thornton
Keyword(s):  
System Performance ◽  
Waste Treatment ◽  
Biological Indicators ◽  
Ecosystem Approach ◽  
Oil Refinery ◽  
State Variable ◽  
Model Response ◽  
Computer Optimization ◽  
And Control ◽  
Optimization Search

Ecosystems of a series of linked treatment ponds for oil refinery effluent are modeled by state variable techniques and simulated using a digital computer. The model response verifies the observed behavior of the pond series. A control philosophy, using pond series flow rate and feedback aeration, and a measure of system performance, using biological indicators, are both developed. A computer optimization search is conducted in order to maximize system performance.

scholarly journals Warning Effect Evaluation and Control for Vehicle Turn Signal Sound

2021 ◽  
Vol 26 (2) ◽  
pp. 171-178
Author(s):  
Yunfeng Xiang ◽  
Yansong He ◽  
Zhifei Zhang ◽  
Zhongming Xu
Keyword(s):  
Subjective Evaluation ◽  
Hearing Threshold ◽  
Objective Evaluation ◽  
Interior Noise ◽  
Vehicle Interior ◽  
Turn Signal ◽  
Time Frequency ◽  
Vehicle Interior Noise ◽  
And Control ◽  
Warning Effect

The sound quality of a turn signal sound is directly related to the driving safety and influences comfort during driving. A turn signal sound and interior noise always exist simultaneously while driving. However, none of the studies are performed to observe and control the change of a turn signal sound when the vehicle interior noise was changed. Therefore, this paper develops a method to evaluate and control the warning effect of a turn signal sound masked by vehicle interior noise. First, the turn signal sound and the vehicle interior noise at different speeds are measured and the time-frequency characteristics of the turn signal sound is analyzed. Second, the pairwise comparison method is applied to subjectively evaluate the warning effect of the sounds and the warning effect of the turn signal sound at 6~speeds relative to that at 40~km/h was obtained. Third, a new hearing threshold evaluating the warning effect is developed and used as a sound metric. This metric is employed to evaluate objectively the warning effect of warning sounds at different speeds. The subjective evaluation results are consistent with the objective evaluation results, which confirms the validity of objective evaluation. To keep the warning effect of the warning sound during the driving, two methods of controlling the turn signal sound are proposed and will be researched further in the future.

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