Aircraft Cabin Tonal Noise Alleviation Through Fuselage Skin Embedded Piezoelectric Actuators

2011 ◽  
Vol 133 (5) ◽  
Author(s):  
C. Testa ◽  
G. Bernardini ◽  
M. Gennaretti
Keyword(s):  
Piezoelectric Actuators ◽  
Point Sources ◽  
General Aviation ◽  
Sound Waves ◽  
Control Approach ◽  
System A ◽  
Cabin Noise ◽  
Fuselage Skin ◽  
And Control ◽  
General Aviation Aircraft

An integrated spectral-integral formulation is applied for prediction and active control of the noise generated by propellers inside the cabin of a general aviation aircraft. It consists of a multidisciplinary approach that involves interaction among exterior noise field, elastic fuselage dynamics, interior acoustics, and control system. A fuselage skin embedding piezoelectric elements is supposed to be impinged by external sound waves generated by propellers. An optimal harmonic control approach is applied for the actuation of the piezoelectric patches, aimed at alleviating the corresponding cabin noise. The aeroacoustoelastic plant model considered in the control problem is obtained by combining modal approaches for the description of cabin acoustic field and fuselage shell dynamics, with a boundary element method scattering formulation for the prediction of exterior pressure disturbances. Considering the fuselage of a general aviation aircraft impinged by noise generated by a couple of pulsating point sources moving with it, numerical results examine the effectiveness of the control approach applied to several configurations of piezoelectric actuators.

Cabin Noise Levels in Single Engine General Aviation Aircraft

1986 ◽  
Vol 30 (14) ◽  
pp. 1381-1385 ◽  
Author(s):  
Stanley T. Hughes ◽  
Jefferson Koonce
Keyword(s):  
Flight Time ◽  
Sound Level ◽  
General Aviation ◽  
Noise Levels ◽  
High Noise ◽  
Cabin Noise ◽  
Run Up ◽  
Loss Of Hearing ◽  
Aviation Pilots ◽  
General Aviation Aircraft

Sound level measurements were made on several of the most popular general aviation aircraft produced. Measurements were taken at various flight milestones such as; run up, taxi, climb, cruise power and descent. For each of the aircraft a time weighted mission sound level was obtained, using three different mission scenarios, varying only in flight time. For each of the three scenarios, and for all aircraft, the time weighted noise values obtained were an or exceeded the 85 dBA limit recommended by NIOSH. The results of this study indicate that a substantial percentage of general aviation pilots will show some loss of hearing due to the high noise levels present in their cabins. Recommendations are made for protection of occupants of general aviation aircraft.

Resistance Monitor and Control for Vacuum Evaporation of Metals and Carbon

1976 ◽  
Vol 34 ◽  
pp. 572-573
Author(s):  
Russell L. Steere ◽  
Eric F. Erbe ◽  
J. Michael Moseley
Keyword(s):  
Electronic Device ◽  
Point Sources ◽  
High Contrast ◽  
Variable Resistor ◽  
Quality Of Results ◽  
Low Contrast ◽  
Evaporation Source ◽  
And Control ◽  
At Will

We have designed and built an electronic device which compares the resistance of a defined area of vacuum evaporated material with a variable resistor. When the two resistances are matched, the device automatically disconnects the primary side of the substrate transformer and stops further evaporation.This approach to controlled evaporation in conjunction with the modified guns and evaporation source permits reliably reproducible multiple Pt shadow films from a single Pt wrapped carbon point source. The reproducibility from consecutive C point sources is also reliable. Furthermore, the device we have developed permits us to select a predetermined resistance so that low contrast high-resolution shadows, heavy high contrast shadows, or any grade in between can be selected at will. The reproducibility and quality of results are demonstrated in Figures 1-4 which represent evaporations at various settings of the variable resistor.

Modeling human-like longitudinal driver model for intelligent vehicles based on reinforcement learning

2021 ◽  
pp. 095440702098357
Author(s):  
Ju Xie ◽  
Xing Xu ◽  
Feng Wang ◽  
Haobin Jiang
Keyword(s):  
Reinforcement Learning ◽  
Comprehensive Evaluation ◽  
Path Following ◽  
Intelligent Vehicles ◽  
Driver Model ◽  
Control Center ◽  
Training Performance ◽  
Learning Agents ◽  
System A ◽  
And Control

The driver model is the decision-making and control center of intelligent vehicle. In order to improve the adaptability of intelligent vehicles under complex driving conditions, and simulate the manipulation characteristics of the skilled driver under the driver-vehicle-road closed-loop system, a kind of human-like longitudinal driver model for intelligent vehicles based on reinforcement learning is proposed. This paper builds the lateral driver model for intelligent vehicles based on optimal preview control theory. Then, the control correction link of longitudinal driver model is established to calculate the throttle opening or brake pedal travel for the desired longitudinal acceleration. Moreover, the reinforcement learning agents for longitudinal driver model is parallel trained by comprehensive evaluation index and skilled driver data. Lastly, training performance and scenarios verification between the simulation experiment and the real car test are performed to verify the effectiveness of the reinforcement learning based longitudinal driver model. The results show that the proposed human-like longitudinal driver model based on reinforcement learning can help intelligent vehicles effectively imitate the speed control behavior of the skilled driver in various path-following scenarios.

Sign in / Sign up

Export Citation Format

Share Document