scholarly journals The laser radiation parameters control method based on the digital video system registration

2021 ◽  
Vol 2131 (5) ◽  
pp. 052091
Author(s):  
A Shepelev ◽  
A Antipov ◽  
A Putilov ◽  
A Osipov ◽  
S Arakelian
Keyword(s):  
Laser Radiation ◽  
Laser Beam ◽  
High Speed ◽  
Control Method ◽  
Digital Processing ◽  
Beam Radiation ◽  
Video System ◽  
Measure Methods ◽  
Spatial Parameters ◽  
Parameters Analysis

Abstract The paper describes a method of a beam radiation parameters analysis. Such analysis bases on the laser beam registration in the plane of a diffusely reflecting screen and digital processing of the registered image. The algorithm of the laser beam spatial parameters determination is presented and realized programmatically. The experiment was carried out using a digital high-speed video system and a solid-state pulsed periodic laser based on a Cr3+: BeAl2O4 alexandrite crystal. A comparison of the proposed method with a standardized method based on the registration of radiation by a matrix photodetector is presented. The development of measure methods of the laser radiation parameters is necessary due to the appearance of new sources of laser radiation and their use in various applications.

scholarly journals Semiconductor Physics, Quantum Electronics & Optoelectronics, 23 (1), P. 71-74 (2020). DOI: https://doi.org/10.15407/spqeo23.01.071 Pyroelectric USB-joulemeters of pulsed laser radiation V.B. Samoylov, L.V. Levash, O.A. Rosnovskiy, M.Yu. Vedula, V.S. Rad'ko Institute of Physics, NAS of Ukraine, 46, prospect Nauky, 03680 Kyiv, Ukraine E-mail: [email protected] Abstract. The general arrangement, principle of operation and basic parameters of pyroelectric USB-meters of energy of pulsed laser radiation have been described. A smart head of the meter converts the signal from the pyroelectric sensor and immediately transfers it to PC using a high-speed USB 2.0 connection. The device consists of two circuit panels located in the common package. The pyroelectric sensitive element and preamplifier are mounted on the sensor panel. Output of the preamplifier is connected with input of the preliminary digital processing panel. The meter is connected with host computer that performs further processing, storage and monitoring of data. Sensor panel can be produced in two modifications, dependently on the pulse energy. Sensitive elements on the base of LiNbO3 or LiTaO3 with absorbing coatings are used for measuring the low-energy pulses, whereas the transparent sensitive elements with a small intrinsic absorption is used for measurements of high-energy radiation pulses. The pulse rate and pulse energy can vary from single pulses up to 2 kHz and from 0.1 μJ up to 0.5 J, respectively. Keywords: laser, impulse radiation, joulemeter, detector, pyroelectric. Full Text (PDF) Back to Volume 23 N1 Creative Commons License This work is licensed under a Creative Commons Attribution-NoDerivatives 4.0 International License.

2020 ◽  
Vol 23 (1) ◽  
pp. 71-74
Author(s):  
V.B. Samoylov ◽  
◽  
L.V. Levash ◽  
O.A. Rosnovskiy ◽  
M.Yu. Vedula ◽  
...  
Keyword(s):  
Laser Radiation ◽  
Pulse Energy ◽  
High Speed ◽  
Pulsed Laser ◽  
Digital Processing ◽  
High Energy ◽  
Pulsed Laser Radiation ◽  
Semiconductor Physics ◽  
Creative Commons ◽  
Laser Impulse

scholarly journals A Critical Review of Supersonic Flow Control for High-Speed Applications

2021 ◽  
Vol 11 (15) ◽  
pp. 6899
Author(s):  
Abdul Aabid ◽  
Sher Afghan Khan ◽  
Muneer Baig
Keyword(s):  
Supersonic Flow ◽  
Flow Control ◽  
Active Control ◽  
Critical Review ◽  
High Speed ◽  
Passive Control ◽  
Control Method ◽  
Sudden Expansion ◽  
Control Approach ◽  
Cost Efficient

In high-speed fluid dynamics, base pressure controls find many engineering applications, such as in the automobile and defense industries. Several studies have been reported on flow control with sudden expansion duct. Passive control was found to be more beneficial in the last four decades and is used in devices such as cavities, ribs, aerospikes, etc., but these need additional control mechanics and objects to control the flow. Therefore, in the last two decades, the active control method has been used via a microjet controller at the base region of the suddenly expanded duct of the convergent–divergent (CD) nozzle to control the flow, which was found to be a cost-efficient and energy-saving method. Hence, in this paper, a systemic literature review is conducted to investigate the research gap by reviewing the exhaustive work on the active control of high-speed aerodynamic flows from the nozzle as the major focus. Additionally, a basic idea about the nozzle and its configuration is discussed, and the passive control method for the control of flow, jet and noise are represented in order to investigate the existing contributions in supersonic speed applications. A critical review of the last two decades considering the challenges and limitations in this field is expressed. As a contribution, some major and minor gaps are introduced, and we plot the research trends in this field. As a result, this review can serve as guidance and an opportunity for scholars who want to use an active control approach via microjets for supersonic flow problems.

scholarly journals Design and validation of an MPC controller for CMG-based testbed

2021 ◽  
Author(s):  
Matteo Facchino ◽  
Atsushi Totsuka ◽  
Elisa Capello ◽  
Satoshi Satoh ◽  
Giorgio Guglieri ◽  
...  
Keyword(s):  
Predictive Control ◽  
Attitude Control ◽  
High Speed ◽  
Control Method ◽  
Input Constraints ◽  
Virtual Reference ◽  
Control Moment ◽  
Pyramidal Configuration ◽  
Actuation Systems ◽  
Constraints Satisfaction

AbstractIn the last years, Control Moment Gyros (CMGs) are widely used for high-speed attitude control, since they are able to generate larger torque compared to “classical” actuation systems, such as Reaction Wheels . This paper describes the attitude control problem of a spacecraft, using a Model Predictive Control method. The features of the considered linear MPC are: (i) a virtual reference, to guarantee input constraints satisfaction, and (ii) an integrator state as a servo compensator, to reduce the steady-state error. Moreover, the real-time implementability is investigated using an experimental testbed with four CMGs in pyramidal configuration, where the capability of attitude control and the optimization solver for embedded systems are focused on. The effectiveness and the performance of the control system are shown in both simulations and experiments.

Multimode Adaptive Control for Tank Gun Control System Based on Tracking Differentiator

2011 ◽  
Vol 383-390 ◽  
pp. 79-85
Author(s):  
Dong Yuan ◽  
Xiao Jun Ma ◽  
Wei Wei
Keyword(s):  
Adaptive Control ◽  
Control System ◽  
High Speed ◽  
Control Method ◽  
Reference Model ◽  
Gun Control ◽  
Math Model ◽  
Tracking Differentiator ◽  
Switch Control ◽  
Model Reference Adaptive

Aiming at the problems such as switch impulsion, insurmountability for influence caused by nonlinearity in one tank gun control system which adopts double PID controller to realize the multimode switch control between high speed and low speed movement, the system math model is built up; And then, Model Reference Adaptive Control (MRAC) method based on nonroutine reference model is brought in and the adaptive gun controller is designed. Consequently, the compensation of nonlinearity and multimode control are implemented. Furthermore, the Tracking Differentiator (TD) is affiliated to the front of controller in order to restrain the impulsion caused by mode switch. Finally, the validity of control method in this paper is verified by simulation.

Laser beam welding quality monitoring system based in high-speed (10 kHz) uncooled MWIR imaging sensors

2015 ◽  
Author(s):  
Rodrigo Linares ◽  
German Vergara ◽  
Raúl Gutiérrez ◽  
Carlos Fernández ◽  
Víctor Villamayor ◽  
...  
Keyword(s):  
Laser Beam ◽  
Monitoring System ◽  
High Speed ◽  
Laser Beam Welding ◽  
Quality Monitoring ◽  
Welding Quality ◽  
Imaging Sensors

scholarly journals Long-Stroke Nanopositioning Stage Driven by Piezoelectric Motor

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Yong Wang ◽  
Fujun Sun ◽  
Junhui Zhu ◽  
Ming Pang ◽  
Changhai Ru
Keyword(s):  
High Speed ◽  
Control Method ◽  
Laser Vibrometer ◽  
Piezoelectric Motor ◽  
Backward Error ◽  
Positioning Control ◽  
Ac Drive ◽  
Variable Friction ◽  
Long Stroke ◽  
Speed Characteristic

This paper reported a biaxial nanopositioning stage single-driven by piezoelectric motor. The employed piezoelectric motor can perform two different driving modes, namely, AC drive mode to drive in long-stroke and at high-speed and DC scanning mode with the high-resolution of several nanometers, which satisfies the requirements of both long-stroke and nanoresolution. To compensate for the effects of the variable friction force and some unpredictable disturbances, a novel backward error compensation (BEC) positioning control method integrated of the two driving modes and a double closed-loop PID controller system are proposed to obtain a high-accuracy positional motion. The experiment results demonstrate that the nanopositioning stage with large travel range of 300 mm × 300 mm has a fine speed characteristic and resolution is 5 nm. In the experiments of different travels up to 15 mm, calibrated by a commercial laser vibrometer, the positioning accuracy is proved within 55 nm inx-axis and 40 nm iny-axis with standard deviation less than 40 nm inx-axis and 30 nm iny-axis and the final position locking can be limited to 10 nm, meeting the requirements of micromanipulation technology.

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