The task in this thesis is the steering of one of Saab Bofors Dynamics robots using Sliding Mode Control, a method they never used before. The robot constitutes a system which in addition to perturbations and uncertainties due to modeling imprecision, hold the difficulty of being highly time variant. In order to be able to keep required performance with uncertainties and modeling imprecision present, the use of robust control methods like Sliding Mode Control is necessary. SMC is based on the states of the system being forced to stay on or in the direct vicinity of a hyper plane in the state space which is chosen in a way that gives the system dynamics desired properties. Other advantages with sliding mode are reduced order dynamics on the switching surface and total insensitivity to some uncertainties and perturbations.

Jämtkraft AB which is a power production company in Sweden has bought two newhydro power units to their station in Hissmofors. The two new generators are using aconcept with sliding stator feet to handle the thermal expansion.The concept with sliding stator feet on hydro electric generators has not beenworking satisfactory on many hydro power stations in Sweden and has caused a lot ofcosts due to long downtimes.The new station in Hissmofors is very important for Jämtkraft AB, and therefore theywant to know how to make sure that the sliding stator feet are working as theyshould. According to theories and a simplified model of the generator the stator feetdisplacement should be around 1 -1,6 mm.The generators are delivered with a surveillance system that will measure thedisplacement of the sliding stator feet. The signal from the system isn?t accessible forJämtkraft AB but it will alarm when the sliding stator feet are malfunctioning.To secure the function of the sliding feet a logger for the surveillance system or adifferent measurement system must be used; if both systems are used Jämtkraft cansecure the function of the surveillance system..

Jämtkraft AB has recently modernized its hydropower station at Hissmofors by replacing four older worn out units with two new units. The generators uses a concept with sliding stator feet to deal with the thermal movements that occur in the stator during operation when the unit is operating intermittently. At other sites, this method revealed shortcomings in the reliability. This has made Jämtkraft AB feel uncertainty about its function and therefore want to investigate it during an early stage. The generators have a built-in monitoring system for the sliding stator feet and by using data from there the function of the sliding stator feet has been investigated. The study focused on how the different stator feet move relative to each other and how the eccentricity and deviation from roundness changed during operation. The results show that there are several indications that the function of the sliding stator feet is not satisfactory.

A detailed dam safety evaluation (in Sweden called FDU) was performed in 2009 by WSP where stability control was performed for Långströmmen power plant with associated spillways. This evaluation concluded that stability could not be ensured, and risk of sliding occurred. The evaluation is based entirely on the recommendations outlined in RIDAS, the power companies guidelines for dam safety, and it is clear that extensive renovations are necessary to stabilize the dam.In this work, the stability will also be checked with guidance through new proposals on guidelines for concrete dams sliding stability, ELFORSK?s report 08:59. This report considered the guidelines in RIDAS as oversimplified, both from an international perspective, but also with regard to the current state of knowledge regarding dam safety.

As a consequence of increasing wind power installations in the Nordic grid the last years, the need for regulating power has become larger. In the Nordic grid, regulating power is mainly provided by hydro power. One part of the regulating power is called frequency control, which ensures that the grid frequency is stable and close to 50 Hz.However, setting the turbine into frequency controlled operation may cause stress and wear of the components in the mechanical control system. Frequency controlling implies large and frequent servo forces and longer travelling distance of the sliding bearings in the Kaplan turbine.Based on one selected Kaplan turbine, Selsfors G1, measurements and MATLAB calculations have been performed in order to determine forces and movements of the linkage system. With these forces and movements as input, stresses and fatigue have been determined as well as sliding distances, bearing pressures and wear of bearings during a typical lifetime of 40 years.The results indicate that no severe wear exists on the bearings during 40 years of service.

The Swedish Transport Administration manage nearly 4,000 railway bridges in different condition and age around the country. These bridges is in constant need of maintenance and requires continuous inspections. This thesis is designed as a damage investigation on a single-track railway bridge south of Solvarbo in Säter municipality. The railway bridge is in operation and serves over 10,000 trains a year, everything from speed trains to freight trains. The bridge is built as a beam bridge, simply supported over a road.

The Swedish Transport Administration manage nearly 4,000 railway bridges in different condition and age around the country. These bridges is in constant need of maintenance and requires continuous inspections. This thesis is designed as a damage investigation on a single-track railway bridge south of Solvarbo in Säter municipality. The railway bridge is in operation and serves over 10,000 trains a year, everything from speed trains to freight trains. The bridge is built as a beam bridge, simply supported over a road.

Hägglunds Drives in Mellansel, Sweden, manufacture radial piston hydraulic motors foremostwithin applications in the industry. These motors have several sliding contacts, one of these, isthe contact between piston ring and cylinder bore. The radial piston hydraulic motors advantageis to produce high torque in very low rotation velocity, this result in that the maximum slidingvelocity between piston ring and cylinder bore, during the whole stroke, is very low. Theconsequence of this low sliding velocity is that the contact between piston ring and cylinderbore, during the whole stroke, is bound to the boundary lubrication regime. This result in, thatthe piston ring is exposed to wear, thus affect the service life of the complete hydraulic motor.To minimize wear of piston ring, it is essential to determine the oil film thickness between thepiston ring and cylinder bore.

The objective with this project was to design a new lifting aid connected to toilet chair.A questionnaire distributed at three homes for aged people indicated that there was an interest in a mechatronic lifting device.Since existing products have limited tilting functionality, the new design was chosen to introduce lifting by motorised tilting of the sitting platform. The mechanical construction was analyzed based on a maximum load caused by a person with weight 160 kg. Two linear actuators were used to control the tilting/lifting of the sit ?place, making standing-up easer.Finally, 28 persons tested the new lifting device and gave their impressions. Many appreciated the safe, stable lifting speed.

In industrial control systems PID-control remains the prevalent strategy, also for processes that would benefit from model based control. The purpose of this thesis is to evaluate whether model based control can be readily implemented in an industrial control system. To this end a simulated surge tank with a simulated industrial control system is studied. For evaluation two scenarios with specified objectives are selected.Following a review of LQR and versions of MPC, Predictive Functional Control (PFC) is considered the most suitable for implementation. PFC is a form of MPC developed with industrial applications in mind and therefore has several advantages for implementation in an industrial control system.

Title: Co-operative, prevent or complement? - An essay on the relationships between control systems. Authors: Kim Eriksson and Victoria KarlssonPurpose: The essay aims to describe the relations between control systems and how they related to each other, based on an operationalization of the control systems. Research question: What are the control systems relations to each other? With regards whether control systems co-operative, prevents and/or complement each other.Theoretical framework: The essays theoretical framework is based on Malmi and Browns (2008) description of five different control systems and control mechanisms associated with each control system.   Research methodology: The method was based on three different data collection methods. These methods were observations, documentation, and semi-structured interviews.Conclusions: It is concluded that the control systems has comprehensive relations. Control systems have more, than one, relation to each other..

The secondary control must be part of the production plan, since the capacity will bedeployed in advance, just as the primary control. The activation of the new frequencycontrol should be preformed in Vattenfall's operations centers (DC) to minimizecommunication delay. Vattenfall needs to work towards a more holistic optimizationsystem. The main issue for Vattenfall Generation is not how we produce but ratherwhen, which is done with creation of bids. This is where there is the mostopportunity for improvement.

Studier har visat att det finns ett samband mellan syskonplacering och locus of control, medan andra studier inte funnit något samband. Syftet med denna studie är att undersöka relationen mellan syskonplacering, kön och locus of control ur ett hälsoperspektiv hos gymnasieelever i årskurs 3. I undersökningen deltog 147 gymnasielever ifrån fem skolor i Kronobergs län. Resultatet visade att kön och syskonplacering samvarierade med intern health locus of control (F= 3,01;p< 0,03; ES= 6,2) och att syskonplacering och kön tillsammans inte visade någon signifikant inverkan på extern health locus of control (F= 2,20;p=<0,09; ES= 4,6). Fyndet kan indikera att manliga mellanbarn i större utsträckning strävar efter en intern health locus of control än kvinnliga mellanbarn.Nyckelord: Syskonplacering, health locus of control, intern- och extern locus of control, kön..

This thesis aims to develop a control system for measuring electromagnetic compability (EMC). This has meant that a controller designed around an ATmega8 microcontroller has been manufactured and programmed. It has also meant the development of a comprehensive control software in the program MATLAB. The control system has been tested with satisfactory results and can now, monitor and control measurements of the EMC-type..

Title: Co-operative, prevent or complement? - An essay on the relationships between control systems. Authors: Kim Eriksson and Victoria KarlssonPurpose: The essay aims to describe the relations between control systems and how they related to each other, based on an operationalization of the control systems. Research question: What are the control systems relations to each other? With regards whether control systems co-operative, prevents and/or complement each other.Theoretical framework: The essays theoretical framework is based on Malmi and Browns (2008) description of five different control systems and control mechanisms associated with each control system.   Research methodology: The method was based on three different data collection methods. These methods were observations, documentation, and semi-structured interviews.Conclusions: It is concluded that the control systems has comprehensive relations. Control systems have more, than one, relation to each other..