Radiation Power Control of the Industrial CO2 Laser Excited by а Nonself-Sustained Glow Discharge by Changing the Frequency of Ionization Pulses

2020 ◽  
Vol 21 (4) ◽  
pp. 224-231
Author(s):  
A. N. Shemyakin ◽  
M. Yu. Rachkov ◽  
N. G. Solov’ev ◽  
M. Yu. Yakimov
Keyword(s):  
Laser Radiation ◽  
Glow Discharge ◽  
Power Control ◽  
Laser Power ◽  
Control Method ◽  
Radiation Power ◽  
Capacitively Coupled ◽  
Wide Range ◽  
Direct Regression ◽  
Confidence Estimates

The article describes radiation power control of industrial CO2 lasers of Lantan series excited by а nonself-sustained glow discharge in the automatic mode. These lasers are closed-cycle fast gas-transport lasers excited by a nonself-sustained glow discharge with ionization by periodic-pulsed capacitively coupled auxiliary discharge. In this case, ionization and conductivity are provided by periodic-pulsed capacitively coupled discharge. The energy contribution to molecular oscillations is provided by the passage of the main discharge current through the plasma with electron density given by ionization. This permits easy laser power control, provides excellent optical homogeneity and stability of an active volume together with high laser efficiency. A system of a nonself-sustained glow discharge with ionization by periodic-pulsed capacitively coupled auxiliary discharge, the stages of creation and brief characteristics of the Lantan series lasers is presented. The method of controlling the power of laser radiation by changing the frequency of the ionization pulses is determined. This control method allows operating of the laser in continuous and in pulse-periodic modes with adjustable pulse ratio and pulse duration, and also provides switching from one mode to another. In the continuous mode, the radiation power is controlled by changing the frequency of ionization pulses, which are high voltage pulses with duration of 100 ns, given with the frequency of 1-5 kHz. Pulse-periodic radiation control is performed by modulating ionization pulses that consists of pulses being delivered in batches. The frequency of the pulses in a batch determines the radiation power in a pulse. The frequency of the batches following is the frequency of the pulse mode, and the length of the batch determines the pulses duration. Based on the experimental data, the dependence of the radiation power on the ionization pulses frequency was determined. An experimental system is presented and the measuring accuracy of the laser radiation power and the frequency of ionization pulses is determined. Data acquiring and processing of experimental results were performed using the NI 6008 USB data acquisition device in the LabVIEW programs of National Instruments. To study the dependence of the laser power on Мехатроника, автоматизация, управление, Том 21, № 4, 2020 231 the frequency of the ionization pulses, a regression analysis method was applied. Studies have shown that the dependence of the laser power on the ionization pulses frequency is linear in a wide range of parameters. The equation of the direct regression is calculated. The confidence estimates of the coefficients of the direct regression and the confidence estimates of the deviation of the theoretical direct regression from the empirical one are calculated with a confidence level of 95%. 

Radiation power control of the industrial CO 2 lasers excited by a nonself-sustained glow discharge with regard to dissociation in a working gas mixture

2018 ◽  
Vol 98 ◽  
pp. 198-204
Author(s):  
Andrey N. Shemyakin ◽  
Michael Yu. Rachkov ◽  
Nikolay G. Solovyov ◽  
Mikhail Yu. Yakimov
Keyword(s):  
Glow Discharge ◽  
Power Control ◽  
Radiation Power ◽  
Gas Mixture

Recording laser power control method based on wobble signal amplitude detection

1999 ◽  
Author(s):  
Kenji Nagashima ◽  
Seiji Nishiwaki ◽  
Toshiya Akagi ◽  
Atsushi Miyazaki ◽  
Hiroyuki Yamaguchi ◽  
...  
Keyword(s):  
Power Control ◽  
Laser Power ◽  
Control Method ◽  
Signal Amplitude

scholarly journals CONTROL OF CO2 LASER POWER BY ACOUSTIC FIELDS

2019 ◽  
pp. 27-34
Author(s):  
A.S. Abrahamyan ◽  
R.Yu. Chilingaryan
Keyword(s):  
Laser Radiation ◽  
Co2 Laser ◽  
Discharge Current ◽  
Laser Power ◽  
Modulation Depth ◽  
Radiation Power ◽  
Three Dimensional ◽  
Laser Radiation Power ◽  
Current Frequency ◽  
Current Modulation

The present study investigates the optimization of the operation of the CO2 laser in the acoustoplasma mode (i.e., dependence of the laser radiation power on the composition of the working mixture, pressure, value of the direct component of the discharge current, frequency, and modulation depth). A three-dimensional dependence on the frequency and modulation depth of the discharge current is experimentally obtained for the normalized efficiency of the conversion of the electric power supplied to the discharge tube into laser power. The maximum gain when transition to the acoustoplasma mode exceeds 2.5 times. The optimum depth of the discharge current modulation is 0.5–0.7. The laser radiation power modulation caused by the discharge current modulation is measured. Laser power is not modulated at modulation frequencies of current >1 kHz. Meanwhile, at current modulation frequencies <0.5 kHz, the modulation depth of the laser radiation power nonlinearly depends on the modulation depth of the discharge current and has a threshold character. The modulation depth of the laser radiation power is associated with the creation of an acoustoplasma and not simply with the discharge current modulation.

Software system for numerical simulation of broadband laser gas analysis of the atmosphere

2018 ◽  
pp. 66-73 ◽  
Author(s):  
S. A. Sadovnikov
Keyword(s):  
Numerical Simulation ◽  
Laser Radiation ◽  
Gas Analysis ◽  
Modular System ◽  
Software System ◽  
Transmission Spectra ◽  
Molecular Absorption ◽  
Molecular Scattering ◽  
Atmospheric Transmission ◽  
Wide Range

Introduction: Successful monitoring of environmental parameters requires the development of flexible software complexes with evolvable calculation functionality. Purpose: Developing a modular system for numerical simulation of atmospheric laser gas analysis. Results: Based on differential absorption method, a software system has been developed which provides the calculation of molecular absorption cross-sections, molecular absorption coefficients, atmospheric transmission spectra, and lidar signals. Absorption line contours are calculated using the Voigt profile. The prior information sources are HITRAN spectroscopic databases and statistical models of the distribution of temperature, pressure and gas components in the atmosphere. For modeling lidar signals, software blocks of calculating the molecular scattering coefficient and aerosol absorption/scattering coefficients were developed. For testing the applicability of various laser sources in the problems of environmental monitoring of the atmosphere, a concentration reconstruction error calculation block was developed for the atmospheric gas components, ignoring the interfering absorption of laser radiation by foreign gases. To verify the correct functioning of the software, a program block was developed for comparing the results of the modeling of atmospheric absorption and transmission spectra by using the standard SPECTRA information system. The discrepancy between the calculation of the atmospheric transmission spectra obtained using the developed system as compared to the SPECTRA results is less than 1%. Thus, a set of the presented program blocks allows you to carry out complex modeling of remote atmospheric gas analysis. Practical relevance: The software complex allows you to rapidly assess the possibilities of using a wide range of laser radiation sources for the problems of remote gas analysis.

scholarly journals Extended Permanent Magnet Synchronous Motors Speed Range Based on the Active and Reactive Power Control of Inverters

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3549
Author(s):  
Pham Quoc Khanh ◽  
Viet-Anh Truong ◽  
Ho Pham Huy Anh
Keyword(s):  
Power Control ◽  
Permanent Magnet ◽  
Reactive Power ◽  
Control Method ◽  
Speed Control ◽  
Torque Ripple ◽  
Current Control ◽  
Permanent Magnet Synchronous Motors ◽  
Synchronous Motors ◽  
Speed Range

The paper proposes a new speed control method to improve control quality and expand the Permanent Magnet Synchronous Motors speed range. The Permanent Magnet Synchronous Motors (PMSM) speed range enlarging is based on the newly proposed power control principle between two voltage sources instead of winding current control as the conventional Field Oriented Control method. The power management between the inverter and PMSM motor allows the Flux-Weakening obstacle to be overcome entirely, leading to a significant extension of the motor speed to a constant power range. Based on motor power control, a new control method is proposed and allows for efficiently reducing current and torque ripple caused by the imbalance between the power supply of the inverter and the power required through the desired stator current. The proposed method permits for not only an enhanced PMSM speed range, but also a robust stability in PMSM speed control. The simulation results have demonstrated the efficiency and stability of the proposed control method.

scholarly journals Laser beam calibration for wood surface colour treatment

2021 ◽  
Author(s):  
M. Jurek ◽  
R. Wagnerová
Keyword(s):  
Laser Beam ◽  
Power Control ◽  
Wood Surface ◽  
Laser Power ◽  
Production Quality ◽  
Chemical Processes ◽  
Continuous Control ◽  
Calibration System ◽  
Laser Engraving ◽  
Wood Surfaces

AbstractLaser engraving of photographs on wood surfaces is a challenging task. To optimize the outcome and production quality it is necessary to control every aspect of the laser engraving process. Most of the production machines and technologies overall are mainly focused on laser power control. However, with other systems and deeper knowledge of the wood characteristics it is possible to achieve even better quality. This paper deals with enlarging the number of achievable shades of burned wood and its optimization. A calibration system was developed to control colour shades of engraved wood with a combination of laser power and optic focus. With this approach it is possible to widen achievable palette of engraved shades by continuous control of chemical processes of laser and wood interaction. The production is divided into wood burning and wood carbonization by variation of laser beam focus.

scholarly journals Improving Energy Efficiency Fairness of Wireless Networks: A Deep Learning Approach

Energies ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 4300 ◽  
Author(s):  
Hoon Lee ◽  
Han Seung Jang ◽  
Bang Chul Jung
Keyword(s):  
Energy Efficiency ◽  
Wireless Networks ◽  
Deep Learning ◽  
Power Control ◽  
Control Method ◽  
Optimal Solution ◽  
Control Policy ◽  
Maximization Problem ◽  
Optimization Approach ◽  
Conventional Optimization

Achieving energy efficiency (EE) fairness among heterogeneous mobile devices will become a crucial issue in future wireless networks. This paper investigates a deep learning (DL) approach for improving EE fairness performance in interference channels (IFCs) where multiple transmitters simultaneously convey data to their corresponding receivers. To improve the EE fairness, we aim to maximize the minimum EE among multiple transmitter–receiver pairs by optimizing the transmit power levels. Due to fractional and max-min formulation, the problem is shown to be non-convex, and, thus, it is difficult to identify the optimal power control policy. Although the EE fairness maximization problem has been recently addressed by the successive convex approximation framework, it requires intensive computations for iterative optimizations and suffers from the sub-optimality incurred by the non-convexity. To tackle these issues, we propose a deep neural network (DNN) where the procedure of optimal solution calculation, which is unknown in general, is accurately approximated by well-designed DNNs. The target of the DNN is to yield an efficient power control solution for the EE fairness maximization problem by accepting the channel state information as an input feature. An unsupervised training algorithm is presented where the DNN learns an effective mapping from the channel to the EE maximizing power control strategy by itself. Numerical results demonstrate that the proposed DNN-based power control method performs better than a conventional optimization approach with much-reduced execution time. This work opens a new possibility of using DL as an alternative optimization tool for the EE maximizing design of the next-generation wireless networks.

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