liu.seSök publikationer i DiVA
Ändra sökning
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • 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
Model-Based Design, Development and Control of an Underwater Vehicle
Linköpings universitet, Institutionen för systemteknik, Reglerteknik.
Linköpings universitet, Institutionen för systemteknik, Reglerteknik.
2016 (Engelska)Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)Alternativ titel
Modellbaserad design, utveckling och reglering av ett undervattensfordon (Svenska)
Abstract [en]

With the rising popularity of ROVs and other UV solutions, more robust and high performance controllers have become a necessity. A model of the ROV or UV can be a valuable tool during control synthesis. The main objective of this thesis was to use a model in design and development of controllers for an ROV.

In this thesis, an ROV from Blue Robotics was used. The ROV was equipped with 6 thrusters placed such that the ROV was capable of moving in 6-DOFs. The ROV was further equipped with an IMU, two pressure sensors and a magnetometer. The ROV platform was further developed with EKF-based sensor fusion, a control system and manual control capabilities.

To model the ROV, the framework of Fossen (2011) was used. The model was estimated using two different methods, the prediction-error method and an EKF-based method. Using the prediction-error method, it was found that the initial states of the quaternions had a large impact on the estimated parameters and the overall fit to validation data. A Kalman smoother was used to estimate the initial states. To circumvent the problems with the initial quaternions, an \abbrEKF was implemented to estimate the model parameters. The EKF estimator was less sensitive to deviations in the initial states and produced a better result than the prediction-error method. The resulting model was compared to validation data and described the angular velocities well with around 70 % fit.

The estimated model was used to implement feedback linearisation which was used in conjunction with an attitude controller and an angular velocity controller. Furthermore, a depth controller was developed and tuned without the use of the model. Performance of the controllers was tested both in real tests and simulations. The angular velocity controller using feedback linearisation achieved good reference tracking. However, the attitude controller could not stabilise the system while using feedback linearisation. Both controllers' performance could be improved further by tuning the controllers' parameters during tests.

The fact that the feedback linearisation made the ROV unstable, indicates that the attitude model is not good enough for use in feedback linearisation. To achieve stability, the magnitude of the parameters in the feedback linearisation were scaled down. The assumption that the ROV's center of rotation coincides with the placement of the ROV's center of gravity was presented as a possible source of error.

In conclusion, good performance was achieved using the angular velocity controller. The ROV was easier to control with the angular velocity controller engaged compared to controlling it in open loop. More work is needed with the model to get acceptable performance from the attitude controller. Experiments to estimate the center of rotation and the center of gravity of the ROV may be helpful when further improving the model.

Ort, förlag, år, upplaga, sidor
2016. , s. 101
Nyckelord [en]
Model, Design, Development, Control, Underwater, Underwater vehicle, BlueROV, ROV, Fossen, Modelling, Parameter Estimation, Prediction-error method, Extended Kalman filter, EKF, Feedback linearisation, Attitude controller, Angular velocity controller
Nationell ämneskategori
Reglerteknik
Identifikatorer
URN: urn:nbn:se:liu:diva-129437ISRN: LiTH-ISY-EX--16/4979--SEOAI: oai:DiVA.org:liu-129437DiVA, id: diva2:939494
Externt samarbete
Combine Control Systems
Ämne / kurs
Examensarbete i Reglerteknik
Handledare
Examinatorer
Tillgänglig från: 2016-06-20 Skapad: 2016-06-19 Senast uppdaterad: 2016-06-20Bibliografiskt granskad

Open Access i DiVA

fulltext(29615 kB)2824 nedladdningar
Filinformation
Filnamn FULLTEXT01.pdfFilstorlek 29615 kBChecksumma SHA-512
56f2d5ec512e098359b4bb654ad94e7100998680cc3567c07aea11fcfe39bb1f1fa2483bd80bd16ada028fd8f3e7bef11ebe18fb7fa04832fb9c966ad78bfdbe
Typ fulltextMimetyp application/pdf

Sök vidare i DiVA

Av författaren/redaktören
Aili, AdamEkelund, Erik
Av organisationen
Reglerteknik
Reglerteknik

Sök vidare utanför DiVA

GoogleGoogle Scholar
Totalt: 2824 nedladdningar
Antalet nedladdningar är summan av nedladdningar för alla fulltexter. Det kan inkludera t.ex tidigare versioner som nu inte längre är tillgängliga.

urn-nbn

Altmetricpoäng

urn-nbn
Totalt: 2884 träffar
RefereraExporteraLänk till posten
Permanent länk

Direktlänk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • oxford
  • 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