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Friction is present in all mechanical systems and causes a wide range of problems for control. The development of model-based strategies accounting for Friction in the designed control has been a vast area of Research since these last decades. A promising Friction model which received a lot of attention these last years is the so-called LuGre model, which originates in the collaboration between th
The purpose of this Master's Thesis is to investigate how various control methods and failure situations affect the performance of a hydro plant. To make the investigations possible, dynamic models of the main components of a hydro plant are created, including a turbine model, two regulator models, two penstock models, a guidance system that incorporates backlash and friction, and a load model
When using industrial robots in production lines both speed and accuracy is of great importance. This thesis investigates how off-line optimization can be used to create references to a control structure with the aim of traversing a given path in as little time as possible, under given input constraints, without deviating from the path. In this thesis Modelica and Optimica is used to formulate and
Within the EU FP-6 project SMErobotTM a new type of high-performance robots has been developed by ABB Robotics, the Robotics Lab at Lund University and Güdel AG, Switzerland. The new design is based on a parallel configuration of the robot's joints (parallel robots). The main novelty of that concept is its completely new parallel kinematic structure, which allows to exploit all the advantages
In many applications involving mobile devices it is essential to track their position. Moreover, it is usually desired, to perform this localization in a distributed fashion without using a central processing unit. In this case, only distance measurements to reference nodes which are in range can be utilized. It is proposed in this thesis to also use distance measurements to other moving objects,
For variable-frequency drives, the most common way to apply the desired power to an electrical motor is using PWM modulated signals. Due to high-frequency components, those signals give rise to reflections in the motor cables, radiated noise around the cables and acoustic noise in the motor. In order to avoid those problems, NFO Drives AB develops and produces an alternative to PWM modulation call
The thesis work was performed at Tetra Pak where a temperature control system for an external cleaning unit was designed. The external cleaning unit is responsible for the heating and supply of cleaning fluids for an aseptic packaging and filling machine. This thesis presents a least squares estimated model predictive controller that uses an ILC inspired algorithm to predict the process behavior.
The current control strategy in the degassing system in a Gambro AK200S dialysis machine leads to a rather noisy flow upstream in the machine. This is where different concentrates are added to the dialysis fluid and as the control of this adding is rather slow the unsteady flow leads to an unsteady conductivity of the dialysis fluid, which makes it difficult to evaluate the effect of the dialysis
Sharpening knives by hand is both time-consuming and exhausting, and may still not always yield perfect results. This thesis investigates the possibility of sharpening knives with the use of a force-controlled industrial robot, regardless of the knifes shape. The procedure is performed by first identifying the shape of the knife, using Matlab Simulink to simulate the identifiation; two different t
This thesis is divided into two parts. The first part analyzes the asynchronous standard and the synchronous servo motor. Different experiments test the two motors differences to where they would fit the best according to application prerequisites. The second part presents the theory for interpolating two asynchronous standard motors, driving two vertically set linear units, connected by two brace
This thesis proposes a solution to the problem of making an autonomous nonholonomic ground vehicle track a special trajectory while following a reference velocity profile. The proposed strategies have been analyzed, simulated and eventually implemented and verified in Alice, Team Caltech's contribution to the 2007 DARPA Urban Challenge competition for autonomous vehicles. The system architectu
In the last couple of years it has become more and more common to use control theory in computing systems, for instance operating systems, web servers and databases. The reason for this is to make these systems more robust and stable. This is of interest because we today are more dependent on computing systems in our everyday life, and therefore put higher demands on them. A lot of focus has been
Control systems used by manufacturing companies today are often centralized. In such a system, the controller is concentrated to one location. As the production lines in Tetra Pak becomes more and more complex with growing costumer demand, a centralized approach becomes more and more inadequate. Agent-based technology provides a way to implement a desirable, robust and decentralized manufacturing
This thesis deals with the identification of the dynamics of a Parallel Kinematic Manipulator, namely the Gantry-Tau patented by ABB located in the Robotics lav at LTH, Lund. The approach considered for modelling is subspace-based identification of linear models, where measurements from the robot motion are used to estimate the unknown parameters in the models. Rigid body dynamics and flexible bod
In dealing with calorimetry, safety aspects are very important. It is therefore very useful to be able to study a process before carrying out experiments on it. A computer model can then be very useful to save time and money. The purpose of this thesis was to construct a computer model of the Chemisens reaction calorimeter, in the modeling software Dymola. For the purpose of the modeling, a new Dy
The SMErobot$^\texttrademark$ is an EU project aiming at giving small and medium enterprises the benefits of robotic automation. This thesis tries to solve the problem of teaching a robot how to grind a surface. The algorithm presented in this thesis reconstructs a surface by triangulating a point cloud. From this surface a path, covering the whole surface, is computed and translated into a RAPID
A 3G mobile phone must have the ability to control its output power with high precision. A power detector is used to measure the actual power outputted by the power amplifier to the antenna. With higher data rates the traditional implementations with peak detectors have become very difficult to use, which is why true RMS detectors are needed. In this thesis the digital part of a true RMS detector
Genetic regulatory networks are biochemical reaction systems, consisting of a network of interacting genes and associated proteins. The dynamics of genetic regulatory networks contain many complex facets that require careful consideration during the modeling process. The classical modeling approach involves studying systems of ordinary differential equations (ODEs) that model biochemical reactions
This master thesis concerns the current and future development in the area of intelligent houses and home automation. It also describes a system for home automation developed for this thesis. Key words in the design are dynamic behaviour, flexibility, transparency and adaptability. The prototype has been built with a central, Java based, server. To this server, modules handling different communica
To simplify the programming of industrial robots a method called lead-through programming has been developed where the programmer basically leads the robot using his/her hands. The objective of this thesis has been to see how a safety system (protecting the tool from large forces) for a lead-through programming controller could be achieved by using an extra force sensor mounted at the tool. A modi
