Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Instrumentation and estimation for high temperature control
Högskolan Väst, Institutionen för ingenjörsvetenskap, Avd för automation och datateknik. (PTW)ORCID-id: 0000-0002-2824-0271
2013 (Engelska)Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
Abstract [en]

Within a variety of industrially relevant high temperature production processes such as welding, heat treatment and metal deposition, the quality of the manufactured component is largely affected by how well parameters can be controlled during processing. These parameters might be, in the case of metal deposition, power input, material feed, or a parameter which is common for all of the aforementioned processes: material temperature. The ability to correctly measure, or in other ways estimate process parameters is vital in order to successfully control high temperature processes such as above 700 degrees Celsius. In this work, instrumentation and estimation solutions adapted to high temperature control are proposed and implemented with a focus on the laser metal wire deposition process. Special attention is given to temperature measurements on specimens with varying emissivity as commonly found in high temperature processes. A calibration procedure for a single-wavelength pyrometer is also presented together with a general discussion on limitations of such a system for measurands with varying emissivity. A new method for non-contact emissivity compensated temperature estimations using a spectrometer is presented. Simulations and industrially relevant experiments have been carried out validating the method. The theoretical framework for the developed method will be further investigated in the future together with additional experimental validation. In addition to temperature measurements, a method for real-time process control of laser metal wire deposition has been developed and implemented with good results. This control scheme estimates and controls the tool-to-workpiece distance based on resistance measurements. Such measurements allow for placement of instruments outside of the processing chamber and easy integration into existing equipment. Future work will be directed towards incorporation of resistance measurements into an iterative learning control scheme. Also, improvement on the resistance-distance model and further investigation into suitable signal processing methods for the resistance signal will be pursued.

Ort, förlag, år, upplaga, sidor
Göteborg: Chalmers Reproservice , 2013. , s. 156
Serie
R - Department of Signals and Systems, Chalmers University of Technology, ISSN 1403-266x ; R017
Nyckelord [en]
Additive Manufacturing, Automation, Emissivity, Emissivity Compensated Spectral Pyrometry, Laser Metal Wire Deposition, Metal Deposition, Pyrometry, Resistance Feedback Control, Thermometry, Varying Emissivity
Nationell ämneskategori
Robotteknik och automation
Forskningsämne
TEKNIK, Produktions- och materialteknik; TEKNIK, Fysik
Identifikatorer
URN: urn:nbn:se:hv:diva-5602OAI: oai:DiVA.org:hv-5602DiVA, id: diva2:649272
Presentation
2013-09-25, C118, Högskolan Väst, Trollhättan, 09:25 (Engelska)
Opponent
Handledare
Forskningsfinansiär
EU, FP7, Sjunde ramprogrammet, 266271Tillgänglig från: 2013-09-25 Skapad: 2013-09-18 Senast uppdaterad: 2016-02-08Bibliografiskt granskad
Delarbeten
1. Emissivity estimation for high temperature radiation pyrometry on Ti–6Al–4V
Öppna denna publikation i ny flik eller fönster >>Emissivity estimation for high temperature radiation pyrometry on Ti–6Al–4V
2013 (Engelska)Ingår i: Measurement, ISSN 0263-2241, E-ISSN 1873-412X, Vol. 46, nr 2, s. 871-880Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

The paper demonstrates a versatile procedure suitable for industrial implementation of temperature measurement on a hot titanium alloy. The driving force has been the need for an accurate temperature measurement during additive manufacturing using laser welding technology where Ti–6Al–4V-wire is melted. The challenges consider both industrial constraints and the varying emissivity of the surface. Measurements makes use of a narrow bandwidth spot radiation pyrometer and a calibration procedure for estimation of the surface temperature through spectral emissivity estimation. The theoretical results are validated through experiments. A number of difficulties in radiation temperature measurements for metals with varying surface properties are discussed; especially the case of surface oxidation. The uncertainty in temperature reading due to the uncertainty in the emissivity estimate is established along with a model that qualitatively describes surface oxidation. The procedure is expected to be useful for several manufacturing applications where it is important to control high temperatures.

Nyckelord
Ti-6Al-4V; Temperature; Emissivity; Radiation pyrometer; Laser metal deposition; Calibration, WIL, Work-integrated Learning
Nationell ämneskategori
Övrig annan teknik
Forskningsämne
TEKNIK, Fysik; Arbetsintegrerat lärande
Identifikatorer
urn:nbn:se:hv:diva-4856 (URN)10.1016/j.measurement.2012.10.019 (DOI)000314428600004 ()2-s2.0-84870711131 (Scopus ID)
Forskningsfinansiär
EU, FP7, Sjunde ramprogrammet, 266271
Tillgänglig från: 2012-12-06 Skapad: 2012-12-06 Senast uppdaterad: 2019-04-30Bibliografiskt granskad
2. Automatic detection of material phase transitions from spectroscopic data
Öppna denna publikation i ny flik eller fönster >>Automatic detection of material phase transitions from spectroscopic data
2013 (Engelska)Ingår i: Proceedings of the IECON 2013: 39th Annual Conference of the IEEE Industrial Electronics Society, IEEE, 2013, s. 2384-2389Konferensbidrag, Publicerat paper (Refereegranskat)
Abstract [en]

When using a temperaturemeasurementmethod which utilizes spectral information for measuring the temperature of varying emissivity measurands, there is a need for a temperature reference at some point in time. In this work, such a reference is created from the spectral radiance data already used by the temperature measurement method. A method of using knowledge of the measurand material's phase transitions and spectral radiance data as a temperature reference is presented. Through automatical identification of phase transitions from radiance spectra employing signal processing, the temperature is known at a certain instance in time, just like required by the temperature measurement method. Three methods for automatic identification of material phase transitions from spectroscopic data are examined and evaluated. The methods are, based on derivatives, steady-state identification and cross correlation respectively. They are introduced and evaluated using experimental data collected from a solidifying copper sample. All methods proved to identify the phase transitions correctly. The addition of automatic phase transition identification supplements the existing temperature measurement method such that it becomes a stand alone, reference free method for measuring the true absolute temperature of a measurand with varying emissivity.

Ort, förlag, år, upplaga, sidor
IEEE, 2013
Serie
Proceedings of the Annual Conference of the IEEE Industrial Electronics Society, ISSN 1553-572X
Nyckelord
materialphase transitions, spectroscopic data, WIL, Work-integrated Learning, AIL
Nationell ämneskategori
Robotteknik och automation
Forskningsämne
TEKNIK, Produktions- och materialteknik; Arbetsintegrerat lärande
Identifikatorer
urn:nbn:se:hv:diva-5609 (URN)10.1109/IECON.2013.6699504 (DOI)2-s2.0-84893523136 (Scopus ID)978-1-4799-0223-1 (ISBN)
Konferens
IECON 2013. 39th Annual Conference of the IEEE Induistrial Electronics Society. In conjunction with ICELIE 2013, IWIES 2013. Vienna, Austria 10-13 November 2013
Anmärkning

 Article number 6699504

Tillgänglig från: 2013-09-18 Skapad: 2013-09-18 Senast uppdaterad: 2018-08-09Bibliografiskt granskad
3. Resistance measurements for control of laser metal wire deposition
Öppna denna publikation i ny flik eller fönster >>Resistance measurements for control of laser metal wire deposition
2014 (Engelska)Ingår i: Optics and lasers in engineering, ISSN 0143-8166, E-ISSN 1873-0302, Vol. 54, nr March, s. 62-67Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

A method for controlling robotized laser metal wire deposition online by electrical resistance metering is proposed. The concept of measuring the combined resistance of the wire and the weld pool is introduced and evaluated for automatic control purposes. Droplet formation, detachment of the wire from the weld pool and stubbing can be hard to avoid during processing due to the sensitive process and short reaction times needed for making on-line adjustments. The implemented system shows a possible route for automatic control of the process wherein such problems can be avoided automatically. The method proves to successfully adjust the distance between the tool and the workpiece through controlling the robot height position, thus increasing stability of the laser metal wire deposition process.

Nyckelord
Laser metal wire deposition;Automatic control ;Resistance ; Additive manufacturing
Nationell ämneskategori
Robotteknik och automation
Forskningsämne
TEKNIK, Produktions- och materialteknik
Identifikatorer
urn:nbn:se:hv:diva-5610 (URN)10.1016/j.optlaseng.2013.10.010 (DOI)000328720700010 ()2-s2.0-84887089320 (Scopus ID)
Forskningsfinansiär
EU, FP7, Sjunde ramprogrammet, 266271
Tillgänglig från: 2013-09-18 Skapad: 2013-09-18 Senast uppdaterad: 2019-05-10Bibliografiskt granskad
4. Emissivity compensated spectral pyrometry-algorithm and sensitivity analysis
Öppna denna publikation i ny flik eller fönster >>Emissivity compensated spectral pyrometry-algorithm and sensitivity analysis
2014 (Engelska)Ingår i: Measurement science and technology, ISSN 0957-0233, E-ISSN 1361-6501, Vol. 25, nr 2, s. 025011-Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

In order to solve the problem of non-contact temperature measurements on an object with varying emissivity, a new method is herein described and evaluated. The method uses spectral radiance measurements and converts them to temperature readings. It proves to be resilient towards changes in spectral emissivity and tolerates noisy spectral measurements. It is based on an assumption of continuous changes in emissivity and uses historical values of spectral emissivity and temperature for estimating current spectral emissivity.

The algorithm, its constituent steps and accompanying parameters are described and discussed. A thorough sensitivity analysis of the method is carried out through simulations. No rigorous instrument calibration is needed for the presented method and is therefore industrially tractable.

Nyckelord
Spectral pyrometry
Nationell ämneskategori
Robotteknik och automation
Forskningsämne
TEKNIK, Produktions- och materialteknik
Identifikatorer
urn:nbn:se:hv:diva-5608 (URN)10.1088/0957-0233/25/2/025011 (DOI)000332697800011 ()2-s2.0-84892836708 (Scopus ID)
Tillgänglig från: 2013-09-18 Skapad: 2013-09-18 Senast uppdaterad: 2019-05-10Bibliografiskt granskad
5. Emissivity compensated spectral pyrometry for varying emissivity metallic measurands
Öppna denna publikation i ny flik eller fönster >>Emissivity compensated spectral pyrometry for varying emissivity metallic measurands
2014 (Engelska)Ingår i: Measurement science and technology, ISSN 0957-0233, E-ISSN 1361-6501, Vol. 25, nr 2, s. 025010-Artikel i tidskrift (Refereegranskat) Published
Abstract [en]

A novel method for converting electromagnetic spectral radiance information into emperature measurements is presented. It allows for varying spectral emissivity of the metallic measurand during the course of the measurement. Such variations are due to e.g. thermal oxidation or temperature dependent emissivity. Based on the assumption that emissivity changes with time and temperature in a continuous manner, it is further assumed that an emissivity estimate at one sample instance can be derived from the estimated emissivity found at the previous samples together with updated spectral information. This leads to successive recalculations of spectral emissivity together with corresponding temperature values. The proposed algorithm has been proven to give accurate temperature estimates from a measurement based on data captured by a standard UV-Vis spectrophotometer even for an oxidizing Ti-6Al-4V specimen in a temperature range between 900K and 1400K. The method however, is not limited to these wavelength- or temperature-ranges.

Nyckelord
Emissivity Compensated Spectral Pyrometry
Nationell ämneskategori
Robotteknik och automation
Forskningsämne
TEKNIK, Produktions- och materialteknik
Identifikatorer
urn:nbn:se:hv:diva-5607 (URN)10.1088/0957-0233/25/2/025010 (DOI)000332697800010 ()2-s2.0-84892898937 (Scopus ID)
Anmärkning

Del av lic.  

Tillgänglig från: 2013-09-18 Skapad: 2013-09-18 Senast uppdaterad: 2019-05-10Bibliografiskt granskad

Open Access i DiVA

Fulltext saknas i DiVA

Övriga länkar

Länk till Chalmers post

Personposter BETA

Hagqvist, Petter

Sök vidare i DiVA

Av författaren/redaktören
Hagqvist, Petter
Av organisationen
Avd för automation och datateknik
Robotteknik och automation

Sök vidare utanför DiVA

GoogleGoogle Scholar

urn-nbn

Altmetricpoäng

urn-nbn
Totalt: 253 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf