scholarly journals Spacecraft vibration reduction using pulse-width pulse-frequency modulated input shaper

1997 ◽  
Author(s):  
Gangbing Song ◽  
Nick Buck ◽  
Brij Agrawal ◽  
Gangbing Song ◽  
Nick Buck ◽  
...  
Keyword(s):  
Pulse Width ◽  
Vibration Reduction ◽  
Pulse Frequency ◽  
Input Shaper

scholarly journals Spacecraft Vibration Reduction Using Pulse-Width Pulse-Frequency Modulated Input Shaper

1999 ◽  
Vol 22 (3) ◽  
pp. 433-440 ◽  
Author(s):  
Gangbing Song ◽  
Nick V. Buck ◽  
Brij N. Agrawal
Keyword(s):  
Pulse Width ◽  
Vibration Reduction ◽  
Pulse Frequency ◽  
Input Shaper

Pulsed-DC Electrospray for Biopolymer Particle Production

2009 ◽  
Vol 1239 ◽  
Author(s):  
Cho-Hui Lim ◽  
Kiersten R Schierbeek ◽  
Michael E Mullins
Keyword(s):  
Pulse Width ◽  
Particle Production ◽  
Pulse Amplitude ◽  
Pulse Frequency ◽  
Process Conditions ◽  
High Duty Cycle ◽  
Pulsed Dc ◽  
High Pulse ◽  
Long Pulse ◽  
Frequency Pulse

AbstractPLLA microparticles were successfully fabricated via pulsed-DC electrospray. In this study, we investigated the effect of the pulsed voltage characteristics (e.g. pulse frequency, pulse amplitude and pulse width) on the particle’s size. We found that pulse frequency, pulse amplitude, pulse width, and the combinations of these factors had a statistically significant effect on the particle’s size. The process conditions to obtain smaller particles with uniform shape and size are a low pulse frequency, high pulse amplitude, and long pulse width (or a high duty cycle).

Parametric Analysis of Laser Beam Percussion Drilling for Thin Titanium Alloy Sheet Using Yb: Yag Fiber Laser

2021 ◽  
pp. 1-24
Author(s):  
Mohit Singh ◽  
Sanjay Mishra ◽  
Vinod Yadava ◽  
J. Ramkumar
Keyword(s):  
Laser Beam ◽  
Fiber Laser ◽  
Pulse Width ◽  
Peak Power ◽  
Laser Pulses ◽  
Pulse Frequency ◽  
Alloy Sheet ◽  
Power Pulse ◽  
The Individual ◽  
Percussion Drilling

Laser beam percussion drilling (LBPD) can create high density holes in aerospace materials with the repeated application of laser pulses at a single spot. In this study, one-parameter-at-a-time approach has been used to investigate the individual effect of peak power, pulse width and pulse frequency on geometrical accuracy and metallurgical distortion during LBPD of 0.85[Formula: see text]mm thick Ti–6Al–4V sheet using 200[Formula: see text]W Yb:YAG fiber laser. It has been found that the output parameters behave differently at the higher and lower values of a particular input process. The increase of pulse width from 1 to 1.50[Formula: see text]ms increases hole taper by 20% whereas the same corresponding change from 1.50 to 2.00[Formula: see text]ms reduces the taper by 20%. The increase of pulse frequency from 10 to 50[Formula: see text]Hz reduces hole circularity by 40% but the same proportionate change from 50 to 90[Formula: see text]Hz reduces circularity by 79%. Increase of peak power from 1.70 to 2.0[Formula: see text]kW increases hole taper by 8% but the corresponding increase from 2 to 2.30[Formula: see text]kW is 143%.

Design and its Experiments of Micro Electrochemical Machining System

2010 ◽  
Vol 97-101 ◽  
pp. 2505-2508 ◽  
Author(s):  
Yuan Bo Li ◽  
Yong Jun Zhang ◽  
Zhong Ning Guo
Keyword(s):  
High Resolution ◽  
Power Supply ◽  
Pulse Width ◽  
Short Pulse ◽  
Electrochemical Machining ◽  
Pulse Frequency ◽  
Machining Accuracy ◽  
Micro Ecm ◽  
Machining System ◽  
Short Pulse Width

A micro Electrochemical Machining (ECM) system has been developed, and macro/micro complex feed mechanism has been presented in order to achieve high-resolution. A nanosecond pulse power supply for micro-ECM has been developed, and the minimum pulse width can reach 50 ns. Complementary chopper circuit has been designed to avoid waveform distortion, which can achieve higher pulse frequency. A series of ECM experiments using the machining system have been carried out, and results of tests have proved that high-resolution spindle, and high frequency, short pulse width power supply help to achieve better quality surface, higher machining accuracy.

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