# LUP Student Papers

## LUND UNIVERSITY LIBRARIES

### Om regulatorer för maximalekonomisk styrning av fartyg

(1970) In MSc Theses
Department of Automatic Control
Abstract
This paper deals with optimal long-distance steering of large vessels. The purpose of the paper is to design a regulator, that keeps a vessel, when affected by different disturbances, on an economical course. The vessel is supposed to have constant speed forward and therefore the only steering variable is the rudder angle. From a mathematical model of the vessel, the equations of motion are calculated into a linear form. Since the motion of the vessel is studied only in the horizontal plane, the motion-variables of interest are: transversal velocity, angular velocity and angle of heading. A loss-function is described and used to evaluate the quality of different regulators. The disturbances applied to the system are: step-disturbances in... (More)
This paper deals with optimal long-distance steering of large vessels. The purpose of the paper is to design a regulator, that keeps a vessel, when affected by different disturbances, on an economical course. The vessel is supposed to have constant speed forward and therefore the only steering variable is the rudder angle. From a mathematical model of the vessel, the equations of motion are calculated into a linear form. Since the motion of the vessel is studied only in the horizontal plane, the motion-variables of interest are: transversal velocity, angular velocity and angle of heading. A loss-function is described and used to evaluate the quality of different regulators. The disturbances applied to the system are: step-disturbances in only one degree of motion at a time or combinations of step-disturbances in the two degrees of motion: angle of heading and angular velocity. Since the magnitude of the disturbances are not the same in all degrees of motion, an attempt has been made to estimate possible disturbances. As a consequence a scaling of the disturbances is performed. First an optional regulator is calculated, but as the transversal velocity is not measurable the suboptimal regulator is also studied. When different disturbances are applied to the system the loss-function gives an estimation of the quality of the actual regulator. The result of the paper is that an optimal regulator, which can be obtained by reconstruction of the not measurable degree of motion, transversal velocity, is not necessary since proper suboptimal regulator essentially represents as good a steering as an optimal one. Further result is that the feed-back coefficients of the regulator can be determined. (Less)
author
supervisor
organization
year
type
H3 - Professional qualifications (4 Years - )
subject
publication/series
MSc Theses
report number
TFRT-5083
ISSN
0346-5500
language
Swedish
id
8850728
2016-03-29 16:12:32
date last changed
2016-03-29 16:12:32
```@misc{8850728,
abstract     = {This paper deals with optimal long-distance steering of large vessels. The purpose of the paper is to design a regulator, that keeps a vessel, when affected by different disturbances, on an economical course. The vessel is supposed to have constant speed forward and therefore the only steering variable is the rudder angle. From a mathematical model of the vessel, the equations of motion are calculated into a linear form. Since the motion of the vessel is studied only in the horizontal plane, the motion-variables of interest are: transversal velocity, angular velocity and angle of heading. A loss-function is described and used to evaluate the quality of different regulators. The disturbances applied to the system are: step-disturbances in only one degree of motion at a time or combinations of step-disturbances in the two degrees of motion: angle of heading and angular velocity. Since the magnitude of the disturbances are not the same in all degrees of motion, an attempt has been made to estimate possible disturbances. As a consequence a scaling of the disturbances is performed. First an optional regulator is calculated, but as the transversal velocity is not measurable the suboptimal regulator is also studied. When different disturbances are applied to the system the loss-function gives an estimation of the quality of the actual regulator. The result of the paper is that an optimal regulator, which can be obtained by reconstruction of the not measurable degree of motion, transversal velocity, is not necessary since proper suboptimal regulator essentially represents as good a steering as an optimal one. Further result is that the feed-back coefficients of the regulator can be determined.},
author       = {Ekdahl, Kurt Ingvar and Henriksson, Olof},
issn         = {0346-5500},
language     = {swe},
note         = {Student Paper},
series       = {MSc Theses},
title        = {Om regulatorer för maximalekonomisk styrning av fartyg},
year         = {1970},
}

```