An Extended Kalman Filter Based Method for Fast In-Situ Etch Rate Measurements

1995 ◽  
Vol 406 ◽  
Author(s):  
T. L. Vincent ◽  
P. P. Khargonekar ◽  
F. L. Terry
Keyword(s):  
Kalman Filtering ◽  
High Speed ◽  
Etch Rate ◽  
Rate Measurement ◽  
Extended Kalman Filtering ◽  
Control Applications ◽  
Suitable Candidate ◽  
Multiple Wavelength ◽  
Speed Advantage

AbstractThe goal of this paper is the presentation of a new algorithm for determining etch rate from single or multiple wavelength reflectometry data. This algorithm is based on techniques from recursive nonlinear estimation theory — Extended Kalman Filtering. A major advantage of our algorithm is extremely high speed. Consequently, it can be used in real-time feedback control applications. The speed advantage also makes it a suitable candidate for full wafer high speed etch rate measurement.

In-Situ Temperature Estimation in Rapid Thermal Processing Systems using Extended Kalman Filtering

1991 ◽  
Vol 224 ◽  
Author(s):  
Y.M. Cho ◽  
C.D. Schaper ◽  
T. Kailath
Keyword(s):  
Kalman Filtering ◽  
Thermal Processing ◽  
Closed Loop ◽  
Rapid Thermal Processing ◽  
Measurement Equipment ◽  
Heat Transfer Characteristics ◽  
Extended Kalman Filtering ◽  
Temperature Estimation ◽  
Systems Models

AbstractAn Extended Kalman Filter (EKF) is developed to provide an improved pyrometer-based estimate of temperature in rapid thermal processing systems. Models of the heat transfer characteristics, emissivity variations, and temperature measurement equipment, are used in formulating an EKF as a closed-loop observer to filter out noise, lessen the effects of processing variations, and to infer temperature at locations where no measurements are available. Extensive simulations are conducted to analyze the robustness of the EKF.

Application of extended Kalman filtering to tracking of airborne high‐speed broadband acoustic sources

2001 ◽  
Vol 110 (5) ◽  
pp. 2739-2740
Author(s):  
William G. Frazier ◽  
Chad M. Williams ◽  
Jay E. Williams ◽  
Kenneth E. Gilbert
Keyword(s):  
Kalman Filtering ◽  
High Speed ◽  
Extended Kalman Filtering ◽  
Acoustic Sources

scholarly journals Upgraded Kalman Filtering of Cutting Forces in Milling

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5397 ◽  
Author(s):  
Giovanni Totis ◽  
Zoltan Dombovari ◽  
Marco Sortino
Keyword(s):  
Kalman Filtering ◽  
High Speed ◽  
State Of The Art ◽  
Force Measurement ◽  
Frequency Bandwidth ◽  
Force Estimation ◽  
Extended Kalman Filtering ◽  
Force Application Point ◽  
Cutting Force Measurement ◽  
Identification Phase

Advanced piezoelectric dynamometers with a wide frequency bandwidth are required for cutting force measurement in high-speed milling and micromilling applications. In many applications, the signal bandwidth is limited by the dynamic response of the mechanical system, thus compensation techniques are necessary. The most effective compensation techniques for a full 3D force correction require an accurate and complex identification phase. Extended Kalman filtering is a better alternative for input force estimation in the presence of unknown dynamic disturbances. The maximum bandwidth that can be currently achievable by Kalman filtering is approximately 2 kHz, due to crosstalk disturbances and complex dynamometer’s dynamics. In this work, a novel upgraded Kalman filter based on a more general model of dynamometer dynamics is conceived, by also taking into account the influence of the force application point. By so doing, it was possible to extend the frequency bandwidth of the device up to more than 5 kHz along the main directions and up to more than 3 kHz along the transverse directions, outperforming state-of-the-art methods based on Kalman filtering.

ISERM: in-situ etch rate measurement system

2016 ◽  
Author(s):  
S. Gürtler ◽  
M. Georges ◽  
C. Schikora
Keyword(s):  
Measurement System ◽  
Etch Rate ◽  
Rate Measurement

An atomic-resolution microscope study of Al contracts on GaAs

1986 ◽  
Vol 44 ◽  
pp. 726-727
Author(s):  
Z. Liliental-Weber ◽  
C. Nelson ◽  
R. Ludeke ◽  
R. Gronsky ◽  
J. Washburn
Keyword(s):  
High Speed ◽  
Schottky Contacts ◽  
Detailed Knowledge ◽  
The Past ◽  
Semiconductor Interfaces ◽  
Deposited Metal ◽  
Microwave Applications ◽  
Free Interfaces ◽  
Potential Use

The properties of metal/semiconductor interfaces have received considerable attention over the past few years, and the Al/GaAs system is of special interest because of its potential use in high-speed logic integrated optics, and microwave applications. For such materials a detailed knowledge of the geometric and electronic structure of the interface is fundamental to an understanding of the electrical properties of the contact. It is well known that the properties of Schottky contacts are established within a few atomic layers of the deposited metal. Therefore surface contamination can play a significant role. A method for fabricating contamination-free interfaces is absolutely necessary for reproducible properties, and molecularbeam epitaxy (MBE) offers such advantages for in-situ metal deposition under UHV conditions

scholarly journals Spatially Resolved Experimental Modal Analysis on High-Speed Composite Rotors Using a Non-Contact, Non-Rotating Sensor

Sensors ◽  
2021 ◽  
Vol 21 (14) ◽  
pp. 4705
Author(s):  
Julian Lich ◽  
Tino Wollmann ◽  
Angelos Filippatos ◽  
Maik Gude ◽  
Juergen Czarske ◽  
...  
Keyword(s):  
High Speed ◽  
Natural Frequencies ◽  
Mode Shapes ◽  
Fiber Reinforced ◽  
Structural Dynamic ◽  
Spatially Resolved ◽  
Glass Fiber Reinforced ◽  
Vibration Responses ◽  
And Performance

Due to their lightweight properties, fiber-reinforced composites are well suited for large and fast rotating structures, such as fan blades in turbomachines. To investigate rotor safety and performance, in situ measurements of the structural dynamic behaviour must be performed during rotating conditions. An approach to measuring spatially resolved vibration responses of a rotating structure with a non-contact, non-rotating sensor is investigated here. The resulting spectra can be assigned to specific locations on the structure and have similar properties to the spectra measured with co-rotating sensors, such as strain gauges. The sampling frequency is increased by performing consecutive measurements with a constant excitation function and varying time delays. The method allows for a paradigm shift to unambiguous identification of natural frequencies and mode shapes with arbitrary rotor shapes and excitation functions without the need for co-rotating sensors. Deflection measurements on a glass fiber-reinforced polymer disk were performed with a diffraction grating-based sensor system at 40 measurement points with an uncertainty below 15 μrad and a commercial triangulation sensor at 200 measurement points at surface speeds up to 300 m/s. A rotation-induced increase of two natural frequencies was measured, and their mode shapes were derived at the corresponding rotational speeds. A strain gauge was used for validation.

Enhanced Grain Refinement of W18Cr4V High‐Speed Steel using in situ TiN‐Nb‐Cr@Graphene/Fe Nanocomposite Inoculant

2021 ◽  
Author(s):  
Lina Bai ◽  
Chunxiang Cui ◽  
Jianjun Zhang ◽  
Lichen Zhao ◽  
Guixing Zheng ◽  
...  
Keyword(s):  
Grain Refinement ◽  
High Speed ◽  
High Speed Steel

scholarly journals Influence of Hydrogeochemistry on Tunnel Drainage in Evaporitic Formations: El Regajal Tunnel Case Study (Aranjuez, Spain)

2021 ◽  
Vol 13 (3) ◽  
pp. 1505
Author(s):  
Ignacio Menéndez Pidal ◽  
Jose Antonio Mancebo Piqueras ◽  
Eugenio Sanz Pérez ◽  
Clemente Sáenz Sanz
Keyword(s):  
High Speed ◽  
Civil Engineering ◽  
Saturation Index ◽  
The Subject ◽  
Under Construction ◽  
Underground Flow ◽  
Very High ◽  
Over Time

Many of the large number of underground works constructed or under construction in recent years are in unfavorable terrains facing unusual situations and construction conditions. This is the case of the subject under study in this paper: a tunnel excavated in evaporitic rocks that experienced significant karstification problems very quickly over time. As a result of this situation, the causes that may underlie this rapid karstification are investigated and a novel methodology is presented in civil engineering where the use of saturation indices for the different mineral specimens present has been crucial. The drainage of the rock massif of El Regajal (Madrid-Toledo, Spain, in the Madrid-Valencia high-speed train line) was studied and permitted the in-situ study of the hydrogeochemical evolution of water flow in the Miocene evaporitic materials of the Tajo Basin as a full-scale testing laboratory, that are conforms as a whole, a single aquifer. The work provides a novel methodology based on the calculation of activities through the hydrogeochemical study of water samples in different piezometers, estimating the saturation index of different saline materials and the dissolution capacity of the brine, which is surprisingly very high despite the high electrical conductivity. The circulating brine appears unsaturated with respect to thenardite, mirabilite, epsomite, glauberite, and halite. The alteration of the underground flow and the consequent renewal of the water of the aquifer by the infiltration water of rain and irrigation is the cause of the hydrogeochemical imbalance and the modification of the characteristics of the massif. These modifications include very important loss of material by dissolution, altering the resistance of the terrain and the increase of the porosity. Simultaneously, different expansive and recrystallization processes that decrease the porosity of the massif were identified in the present work. The hydrogeochemical study allows the evolution of these phenomena to be followed over time, and this, in turn, may facilitate the implementation of preventive works in civil engineering.

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