Change search
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Navigation Strategies for Improved Positioning of Autonomous Vehicles
Linköping University, Department of Electrical Engineering, Automatic Control.
2019 (English)Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
Abstract [en]

This report proposes three algorithms using model predictive control (MPC) in order to improve the positioning accuracy of an unmanned vehicle. The developed algorithms succeed in reducing the uncertainty in position by allowing the vehicle to deviate from a planned path, and can also handle the presence of occluding objects. To achieve this improvement, a compromise is made between following a predefined trajectory and maintaining good positioning accuracy.

Due to the recent development of threats to systems using global navigation satellite systems to localise themselves, there is an increased need for methods of localisation that can function without relying on receiving signals from distant satellites. One example of such a system is a vehicle using a range-bearing sensor in combination with a map to localise itself. However, a system relying only on these measurements to estimate its position during a mission may get lost or gain an unacceptable level of uncertainty in its position estimates. Therefore, this thesis proposes a selection of algorithms that have been developed with the purpose of improving the positioning accuracy of such an autonomous vehicle without changing the available measurement equipment. These algorithms are:

  • A nonlinear MPC solving an optimisation problem.
  • A linear MPC using a linear approximation of the positioning uncertainty to reduce the computational complexity.
  • A nonlinear MPC using a linear approximation (henceforth called the approximate MPC) of an underlying component of the positioning uncertainty in order to reduce computational complexity while still having good performance.

The algorithms were evaluated in two different types of simulated scenarios in MATLAB. In these simulations, the nonlinear, linear and approximate MPC algorithms reduced the root mean squared positioning error by 20-25 %, 14-18 %, and 23-27 % respectively, compared to a reference path. It was found that the approximate MPC seems to have the best performance of the three algorithms in the examined scenarios, while the linear MPC may be used in the event that this is too computationally costly. The nonlinear MPC solving the full problem is a reasonable choice only in the case when computing power is not limited, or when the approximation used in the approximate MPC is too inaccurate for the application.

Place, publisher, year, edition, pages
2019. , p. 54
Keywords [en]
MPC, positioning, nonlinear, linear, approximation, error, navigation, control, improved, covariance
National Category
Control Engineering
Identifiers
URN: urn:nbn:se:liu:diva-159830ISRN: LiTH-ISY-EX--19/5255--SEOAI: oai:DiVA.org:liu-159830DiVA, id: diva2:1345095
External cooperation
FOI
Subject / course
Automatic Control
Presentation
2019-08-19, Systemet, Linköping, 10:00 (Swedish)
Supervisors
Examiners
Available from: 2019-08-26 Created: 2019-08-22 Last updated: 2019-08-26Bibliographically approved

Open Access in DiVA

fulltext(1573 kB)25 downloads
File information
File name FULLTEXT01.pdfFile size 1573 kBChecksum SHA-512
084a8e5ee636e359e7c06997391d68958017d8f5191ad29ce379df391598ed9b5d0a313651db72004f30460d5d85d03cfa98806056d575587100fc826db80bd0
Type fulltextMimetype application/pdf

Search in DiVA

By author/editor
Sandmark, David
By organisation
Automatic Control
Control Engineering

Search outside of DiVA

GoogleGoogle Scholar
Total: 25 downloads
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

urn-nbn

Altmetric score

urn-nbn
Total: 38 hits
CiteExportLink to record
Permanent link

Direct link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf