New simulation-based approach for the profile control in a process chamber: Fluid, thermal, and plasma profile

2015 ◽  
Vol 231 (3) ◽  
pp. 565-580 ◽  
Author(s):  
Dong Xiang ◽  
Huanxiong Xia ◽  
Wang Yang ◽  
Peng Mou
Keyword(s):  
Chemical Vapor ◽  
Control Mode ◽  
Error Feedback ◽  
Profile Error ◽  
Loop Control ◽  
Profile Control ◽  
Simulation Based ◽  
Feedback Method ◽  
Chamber Fluid ◽  
Plasma Profile

Process chamber is the core unit of chemical vapor deposition and etching, and the physical fields in it have fatal effect on process quality. It is significant and difficult for improving the process performance to regulate the fields’ profiles finely. Two design solutions for the profile regulation are proposed: controllable type and resistance type. A novel profile error feedback method is presented, and a simulation-based auto-design framework is established. The profile error feedback method is in a quasi-closed-loop-control mode. It starts from an initial guessed sequence of the design/control variables and predicts a better sequence via feedback of the profile error between the output-targeted profile and the expected one. It never stops until the profile error is narrowed in the preset tolerance. Three kinds of numerical experiments about the regulation of the thermal, fluid, and plasma profile are set to test the effectiveness and feasibility of the profile error feedback method and the two kinds of design schemes.

Closed-loop control of a laser assisted carbon nanotube growth process for interconnects in flexible electronics

2011 ◽  
Vol 1365 ◽  
Author(s):  
Yoeri van de Burgt ◽  
Yves Bellouard ◽  
Rajesh Mandamparambil ◽  
Andreas Dietzel
Keyword(s):  
Carbon Nanotube ◽  
Flexible Electronics ◽  
Iron Catalyst ◽  
Chemical Vapor ◽  
Catalyst Layer ◽  
Deposition Process ◽  
Loop Control ◽  
Aluminum Oxide Layer ◽  
Carbon Nanotube Forests ◽  
Carbon Nanotube Growth

ABSTRACTA feedback control mechanism based on infrared radiation monitoring coupled with reflectivity information was developed to control the temperature of a laser assisted chemical vapor deposition process for the growth of carbon nanotube forests. An infrared laser operating at 808 nm is focused on a silicon substrate containing a 20 nm-aluminum-oxide layer and a 1.5 nm-iron catalyst layer. The growth takes place in an argon/ hydrogen/ ethylene gaseous environment. SEM and Raman spectroscopy analysis show that good controllability and reproducibility is achieved over multiple experiments.

Design of Portable On-Board Charger

2012 ◽  
Vol 229-231 ◽  
pp. 837-840
Author(s):  
Deng Liang Cheng ◽  
Wei Rong Jiang ◽  
Jian Wei Mei
Keyword(s):  
Pulse Width ◽  
Parallel Machines ◽  
Pulse Width Modulation ◽  
Control Mode ◽  
Constant Current ◽  
System Control ◽  
Single Chip ◽  
Battery Charging ◽  
Loop Control ◽  
Bus Voltage

To solve the key technology of automotive lithium battery charging system, a new kind of smart portable on-board charger is developed. This battery charger takes single-chip machine of freescale as system control chip, realizes closed-loop control of bus voltage by the voltage pulse width modulation chip TL494, realizes charger output with constant voltage, constant current and switch without disturbances by the current pulse width modulation chip UC3846, achieves master-slave control mode for multi–parallel machines through the CAN bus technology. In addition, the microcontroller program realizes the process monitoring and fuzzy PID regulation, the charging process has multiple intelligent protection and external regulatory functions. The experimental results show that with dual regulations of the software and hardware, the charger has the advantages of stable reliability, flexible operation and precise intelligence, an effective exploration of the battery charging technology is carried out.

Research on Control Strategy of Integrated Gasification Humid Air Turbine Cycle

2018 ◽  
Vol 140 (11) ◽  
Author(s):  
Tingting Wei ◽  
Dengji Zhou ◽  
Di Huang ◽  
Shixi Ma ◽  
Wang Xiao ◽  
...  
Keyword(s):  
Control System ◽  
Control Strategy ◽  
Design Method ◽  
Control Mode ◽  
Humid Air ◽  
Loop Control ◽  
System A ◽  
Air Turbine ◽  
Integrated Gasification ◽  
Strategy Design

Integrated gasification humid air turbine (IGHAT) cycle is an advanced power generation system, combining gasification technology and humid air turbine (HAT) cycle. It draws great attention in the energy field considering its high specific power, high efficiency, and low emission. There are only a few HAT cycle plants and IGHAT cycle is still on the theory research stage. Therefore, the study on control strategies of IGHAT cycle has great significance in the future development of this system. A design method of control strategy is proposed for the unknown gas turbine systems. The control strategy design is summarized after IGHAT control strategy and logic is designed based on the dynamic simulation results and the operation experience of gas turbine power station preliminarily. Then, control logic is configured and a virtual control system of IGHAT cycle is established on the Ovation distribution control platform. The model-in-loop control platform is eventually set up based on the interaction between the simulation model and the control system. A case study is implemented on this model-in-loop control platform to demonstrate its feasibility in the practical industry control system. The simulation of the fuel switching control mode and the power control mode is analyzed. The power in IGHAT cycle is increased by 24.12% and 32.47%, respectively, compared to the ones in the simple cycle and the regenerative cycle. And the efficiency of IGHAT cycle is 1.699% higher than that of the regenerative cycle. Low component efficiency caused by off-design performance and low humidity caused by high pressure are the main limits for system performance. The results of case study show the feasibility of the control strategy design method proposed in this paper.

scholarly journals On Stability of Open-Loop Operation without Rotor Information for Brushless DC Motors

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Zhong Wu ◽  
Haotun Lyu ◽  
Yongli Shi ◽  
Di Shi
Keyword(s):  
Theoretical Analysis ◽  
Operation Mode ◽  
Open Loop ◽  
Control Mode ◽  
Open Loop Control ◽  
Brushless Dc Motors ◽  
Loop Control ◽  
Rotor Position ◽  
Brushless Dc ◽  
Dc Motors

Open-loop operation mode is often used to control the Brushless DC Motors (BLDCMs) without rotor position sensors when the back electromotive force (EMF) is too weak due to the very low rotor velocity. The rotor position information is not necessary in this mode and the stator windings are supplied with voltages under a certain ratio of the amplitude to the frequency. However, the rotor synchronization will be destroyed once if the commutation instant is inappropriate. In order to improve the reliability of the open-loop operation mode, a dynamic equation is established to represent the synchronization error between the rotor and the stator. Thereafter, the stability of the open-loop control mode is analyzed by using Lyapunov indirect method. Theoretical analysis indicates that the open-loop control mode is asymptotically stable only when the commutation instant of the stator current lags behind the ideal one suitably. Finally, theoretical analysis is verified through the experimental results of a certain BLDCM.

Research on Error Compensation by Semi-Closed Loop Control for a 3-UPS Parallel Machine Tool

2012 ◽  
Vol 461 ◽  
pp. 272-276
Author(s):  
Jian Ye Guo ◽  
Jia Shun Shi ◽  
Liang Zhao
Keyword(s):  
Machine Tool ◽  
Error Compensation ◽  
Closed Loop ◽  
Parallel Machine ◽  
Control Mode ◽  
Closed Loop Control ◽  
Kinematics Analysis ◽  
Compensation Strategy ◽  
Loop Control ◽  
Parallel Machine Tool

This paper took a 3-UPS Parallel Machine Tool (PMT) as the object of research; it mainly introduced the process of establishing the compensation strategy for this PMT. Firstly the kinematics equations on driving chain and constraint chain was established on the basis of kinematics analysis. Then according to the structural characteristics and the results of kinematics analysis, the error compensation strategy of feedback correction type with the semi-closed loop control mode was used in the error compensation for this PMT by the method of installing respectively the encoders on the each joint of parallelogram mechanism, namely the compensation way of “parallel driving and series feedback” was adopted. Finally this paper has also deduced the theoretical model of error compensation. The research results in this paper provided a theoretical basis for realizing error compensation of this PMT, and had important practical significance for improving machining precision of PMT

scholarly journals Closed-loop control of laser assisted chemical vapor deposition growth of carbon nanotubes

2012 ◽  
Vol 112 (3) ◽  
pp. 034904 ◽  
Author(s):  
Yoeri van de Burgt ◽  
Yves Bellouard ◽  
Rajesh Mandamparambil ◽  
Miro Haluska ◽  
Andreas Dietzel
Keyword(s):  
Carbon Nanotubes ◽  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Closed Loop ◽  
Chemical Vapor ◽  
Closed Loop Control ◽  
Chemical Vapor Deposition Growth ◽  
Loop Control

Dynamic Modeling Analysis for Control of Chemical Vapor Deposition

1998 ◽  
Vol 120 (2) ◽  
pp. 164-169 ◽  
Author(s):  
M. A. Gevelber ◽  
M. Bufano ◽  
M. Toledo-Quin˜ones
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Control Volume ◽  
Chemical Vapor ◽  
Nonlinear Dynamic Model ◽  
Loop Control ◽  
Closed Loop Control System ◽  
Loop Control System ◽  
Fluid Transients ◽  
Variable Equation

A nonlinear dynamic model of the chemical vapor deposition (CVD) process has been developed to aid design of a closed-loop control system. A lumped control volume analysis is used to capture important mass and fluid transients and spatial affects, while a simplified single variable equation is used to represent the complex reaction chemistry. Steady-state experimental results and model predictions are compared and the control implications of the process dynamics are discussed.

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