scholarly journals Dynamic Observer Modeling and Minimum-Variance Self-Tuning Control of EDM Interelectrode Gap

2018 ◽  
Vol 8 (9) ◽  
pp. 1443 ◽  
Author(s):  
Bin Xin ◽  
Shujuan Li ◽  
Xincheng Yin ◽  
Xiong Lu
Keyword(s):  
Real Time ◽  
Physical Model ◽  
Short Circuit ◽  
Single Crystal Silicon ◽  
Minimum Variance ◽  
Machining Process ◽  
Crystal Silicon ◽  
Interelectrode Gap ◽  
Self Tuning ◽  
The Time Domain

The electric discharge machining (EDM) interelectrode gap directly determines the discharge state, which affects the machining efficiency, workpiece surface quality, and the tool wear rate. The measurement of the real-time varying interelectrode gap during machining is extremely difficult, and so obtaining an accurate mathematical model of the dynamic interelectrode gap will make EDM gap control possible. Based on p-type single-crystal silicon EDM, a flat-plate capacitance model is introduced to analyze the time-domain characteristics of the inter-electrode voltage in the breakdown delay phase. Further, we theoretically established a physical model of the interelectrode spacing d and the charging time constant τ of the plate capacitor. The least-squares fitting of the experimental data was used to determine the model coefficients, and in combination with the actual machining process, a minimum-variance self-tuning controller was designed to control the interelectrode gap in real time. The experimental verification results show that the established physical model can correctly predict the interelectrode gap in the actual machining process. The minimum-variance self-tuning controller improves machining stability, and eliminates the occurrence of the short-circuit state.

scholarly journals Modeling of Interelectrode Gap in Electric Discharge Machining and Minimum Variance Self-Tuning Control of Interelectrode Gap

2020 ◽  
Vol 2020 ◽  
pp. 1-20
Author(s):  
Bin Xin ◽  
Ming Gao ◽  
Shujuan Li ◽  
Bin Feng
Keyword(s):  
Electric Discharge ◽  
Removal Rate ◽  
Short Circuit ◽  
Minimum Variance ◽  
Machining Process ◽  
Electric Discharge Machining ◽  
Precise Control ◽  
Interelectrode Gap ◽  
Machining System ◽  
P Type

In the electric discharge machining system, the determination of the gap between the anode and the cathode is a difficult point of this kind of machining approach. An accurate mathematical model of interelectrode gap is obtained, and the precise control of the gap is achieved on this basis. In this paper, based on the example of discharge machining of P-type single crystal Si, the theoretical analysis proved that the discharge channel can be equivalent to pure resistance, and the physical model of the interelectrode gap and voltage and current was established. The order and parameters of the EDM system model were determined by adopting the system identification theory. We designed the minimum variance self-correcting controller to accurately control the interelectrode gap in combination with the actual machining process. Experimental results show that the interelectrode gap model can correctly reflect the interelectrode gap in the actual machining process; the minimum variance self-correcting controller eliminates the short circuit phenomenon during processing and can stably track different desired gaps; the material removal rate and the surface roughness decrease with the increase of the interelectrode gap.

Study on the Illumination Characteristics of Solar Photovoltaic Battery

2015 ◽  
Vol 1092-1093 ◽  
pp. 91-95
Author(s):  
Zhen Yong Liu ◽  
Jian Qi Sun ◽  
Zhi Chun Ma
Keyword(s):  
Light Intensity ◽  
Short Circuit ◽  
Maximum Output Power ◽  
Cell Sheet ◽  
Single Crystal Silicon ◽  
Short Circuit Current ◽  
Open Circuit ◽  
Maximum Output ◽  
Solar Panels ◽  
Crystal Silicon

Effects of solar panels must be taken into account by the light intensity of its output characteristics in practical application, especially solar panels placed outdoor. So the light intensity coefficient is an important parameter to be considered. In this paper,we took the light intensity characteristics of single crystal silicon solar cell as the research object. Also,through transforming the illumination intensity which are 777.60W/m2,996.97 W/m2 and 1224.88 W/m2, we would finish researching the characteristics of the cell sheet, which included battery plate volt ampere characteristic, open circuit voltage, short circuit current and maximum output power. Also, we’ve got the relationship of Uoc-T, Isc-T and Pm-T, respectively and Put forward the better intensity theory. It would lay a solid foundation of practice for the further study on how to improve the rate of light conversion.

SCREAM’03: A Single Mask Process for High-Q Single Crystal Silicon MEMS

2004 ◽  
Author(s):  
Wenhua Zhang ◽  
Weibin Zhang ◽  
Kimberly Turner ◽  
Peter G. Hartwell
Keyword(s):  
Single Crystal ◽  
Single Crystal Silicon ◽  
Silicon On Insulator ◽  
Machining Process ◽  
Laser Vibrometer ◽  
Crystal Silicon ◽  
Wet Process ◽  
Whole Process ◽  
Microelectromechanical Devices ◽  
Electrically Actuated

We present a single-mask single-crystal silicon (SCS) process for the fabrication of suspended MicroElectroMechanical devices (MEMS). This is a bulk micro-machining process that uses Deep Reactive Ion Etch (DeepRIE) of a silicon-on-insulator (SOI) substrate with highly doped device layer to fabricate movable single-crystal silicon MEMS structures, which can be electrically actuated without metal deposition. The buried oxide layer is not removed afterwards and no wet process release is involved in the whole process sequence, which makes this process different from others works based on SOI wafer. Several MEMS oscillators have been made using this process. Dynamic behavior is characterized using a laser vibrometer. Quality factor is improved by more than 1 order compared to the same oscillator made using SCREAM process.

Single Point Diamond Turning of Single Crystal Silicon Carbide: Molecular Dynamic Simulation Study

2011 ◽  
Vol 496 ◽  
pp. 150-155 ◽  
Author(s):  
Saurav Goel ◽  
Xi Chun Luo ◽  
R.L. Reuben ◽  
Waleed Bin Rashid ◽  
Ji Ning Sun
Keyword(s):  
Silicon Carbide ◽  
Single Crystal ◽  
Molecular Dynamic ◽  
Single Point ◽  
Single Crystal Silicon ◽  
Diamond Turning ◽  
Machining Process ◽  
Crystal Silicon ◽  
Molecular Dynamic Simulation Study ◽  
Machining Properties

Silicon carbide can meet the additional requirements of operation in hostile environments where conventional silicon-based electronics (limited to 623K) cannot function. However, being recent in nature, significant study is required to understand the various machining properties of silicon carbide as a work material. In this paper, a molecular dynamic (MD) simulation has been adopted, to simulate single crystal β-silicon carbide (cubic) in an ultra precision machining process known as single point diamond turning (SPDT). β-silicon carbide (cubic), similar to other materials, can also be machined in ductile regime. It was found that a high magnitude of compression in the cutting zone causes a sp3- sp2 order-disorder transition which appears to be fundamental cause of wear of diamond tool during the SPDT process.

Study on Mechanical Properties of Single-Crystal Silicon Carbide by Nanoindentation

2016 ◽  
Vol 1136 ◽  
pp. 549-554 ◽  
Author(s):  
Mitsuhiro Matsumoto ◽  
Hirofumi Harada ◽  
Koichi Kakimoto ◽  
Ji Wang Yan
Keyword(s):  
Mechanical Properties ◽  
Silicon Carbide ◽  
Single Crystal ◽  
Loading Rate ◽  
Single Crystal Silicon ◽  
Maximum Load ◽  
Indentation Load ◽  
Machining Process ◽  
Crystal Silicon ◽  
Sic Wafer

In order to clarify the mechanical properties of single-crystal silicon carbide (SiC), nanoindentation was performed on a 4H-SiC wafer. The change of hardness with the angle between the wafer orientation flat and the indenter edge, the maximum load and the loading rate were investigated. The hardness reached maximum at an indentation load of 12 mN in the range of 3-50 mN. Hardness decreased under two conditions: when the edge of the indenter tip is parallel to the [11-20] direction, and when a very low loading rate was used. Transmission electron microscopy was used to observe dislocations and cracks under the indents. It was demonstrated that the deformation process of SiC involved three steps with respect to the increase of the indentation load. These results provide information for improving ductile machining process of single crystal SiC.

Real-Time and Full-Field Deflection Measurement of Thin Films Electroplated on the Single Crystal Silicon Wafers

2006 ◽  
Vol 306-308 ◽  
pp. 1289-1294
Author(s):  
Xi De Li ◽  
Cheng Wei
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Mechanical Properties ◽  
Single Crystal ◽  
Sample Size ◽  
Real Time ◽  
Single Crystal Silicon ◽  
Crystal Silicon ◽  
Full Field ◽  
Young’S Moduli

A special speckle microinterferometer has been developed to test the mechanical properties of thin films electroplated on the single crystal silicon wafer. A piezo-actuated micro-loading unit is synchronized with the microinterfermeter to measure thin film deflection in bending with an accuracy of sub-micrometers. All of the film specimens were microfabricated to be the type of microbridge samples. They are made of Cu and NiFe, the sizes from 1102.9µm to 213.7µm long, 491.0µm to 9.7µm wide. The corresponding thicknesses are 9.4µm and 7.6µm, respectively. Deflections of the microbradge samples can be measured full-field and real-time by using the microinterferometer and no patterning or marking of the specimen surface is needed. The loading force is directly measured using a miniature load cell. The Young’s moduli are calculated for both material and sample size from the load-deflection curves. Test techniques, procedures and factors which affect on the deflection measurements are briefly presented along with detailed analyzes of the results.

Research on Real-Time Stress Damage of Millisecond Laser Irradiation on Single-Crystal Silicon

2016 ◽  
Vol 36 (2) ◽  
pp. 0219002
Author(s):  
李贺 Li He ◽  
蔡继兴 Cai Jixing ◽  
谭勇 Tan Yong ◽  
马遥 Ma Yao ◽  
郭明 Guo Ming ◽  
...  
Keyword(s):  
Single Crystal ◽  
Real Time ◽  
Laser Irradiation ◽  
Single Crystal Silicon ◽  
Crystal Silicon ◽  
Time Stress ◽  
Stress Damage ◽  
Millisecond Laser

scholarly journals Investigation into the characteristics of silicon photovoltaic converters of solar batteries in case of overheating

2018 ◽  
pp. 14-20 ◽  
Author(s):  
A. V. Ivanchenko ◽  
S. V. Mazurik ◽  
A. S. Tonkoshkur
Keyword(s):  
Single Crystal ◽  
Functional Properties ◽  
Elevated Temperatures ◽  
Short Circuit ◽  
Single Crystal Silicon ◽  
Photovoltaic System ◽  
Polymeric Nanocomposites ◽  
Dark Mode ◽  
Crystal Silicon ◽  
Solar Batteries

Recently, solar panels have become one of the most desirable sources of renewable electrical energy, and thus the requirements for their reliability, in particular to maintain the basic functional properties at elevated temperatures, are increasing. The basic element of solar batteries is photovoltaic converter. Until now, the degree of degradation and ways to protect photovoltaic converters during overheating corresponding to real situations during their exploitation, are not sufficiently studied. In this paper, the authors study one of the important problems arising during the development of circuit-technical devices for the protection of the photovoltaic converters against electrothermal overloads, namely, the problem of the effect of overheating of photovoltaic converters on their functional properties. Primarily, this is important in connection with the perspective of using functional electronics to improve the reliability of the photovoltaic system of the solar battery. In particular, resettable fuses based on polymeric nanocomposites with carbon fillers are such elements of the electronics. One of the difficulties of direct application of the resettable fuses is that they have a switching temperature that exceeds the standard operating temperature range of the modern photovoltaic converters. The paper presents investigations results of the current-voltage and volt-watt characteristics of the single-crystal silicon photovoltaic converters of the solar batteries, which have undergone heat treatment at elevated temperature (up to 150°C) at different time intervals (up to 6 hours) under lighting conditions and in dark mode in open- and short-circuited states. The method based on fixing the deviations of the functional parameters (i.e., open-circuit voltage, short-circuit current and maximum power) of the converters from their nominal values was used for their analysis. It has been established that in the investigated temperature and time ranges there are no significant changes of the main functional characteristics and parameters of the photovoltaic converters based on single-crystal silicon.

scholarly journals Laser Grinding of Single-Crystal Silicon Wafer for Surface Finishing and Electrical Properties

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 262
Author(s):  
Xinxin Li ◽  
Yimeng Wang ◽  
Yingchun Guan
Keyword(s):  
Single Crystal ◽  
Silicon Wafer ◽  
Photoelectron Spectroscopy ◽  
Laser Scanning ◽  
Single Crystal Silicon ◽  
Machining Process ◽  
Surface Finishing ◽  
Crystal Silicon ◽  
Single Crystal Silicon Wafer ◽  
X Ray

In this paper, we first report the laser grinding method for a single-crystal silicon wafer machined by diamond sawing. 3D laser scanning confocal microscope (LSCM), X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS), laser micro-Raman spectroscopy were utilized to characterize the surface quality of laser-grinded Si. Results show that SiO2 layer derived from mechanical machining process has been efficiently removed after laser grinding. Surface roughness Ra has been reduced from original 400 nm to 75 nm. No obvious damages such as micro-cracks or micro-holes have been observed at the laser-grinded surface. In addition, laser grinding causes little effect on the resistivity of single-crystal silicon wafer. The insights obtained in this study provide a facile method for laser grinding silicon wafer to realize highly efficient grinding on demand.

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