Digital control theory normally assumes equidistant sampling intervals and a negligible or constant control delay from sampling to actuation, so called input/output latency. However this can seldom be achieved in practice. In the computer tasks interfere with each other through preemption and blocking when waiting for common resources. The execution time for each task may be data-dependant and the

The ModeGraph library offers improved flexibility of hybrid modelling and incorporates powerful properties of the Mode-Automata semantics. Concepts from Finite State Machines (FSM), Sequential Function Charts (SFC)/Grafcet and Statecharts are efficiently utilised to provide a flexible modelling environment that a broad audience can feel familiar with. Being able to guarantee mutual exclusivity of

In every kind of industry there is a wish to use the resources available in the best way possible. If this can be achieved, both time and money can be saved and profit will be maximized. The problem is to know in which way this can be done. When is a resource used in an optimal way? This question was in focus when Novozymes Biopharma AB was about to expand their batch production. In order to contr

The topic of this master thesis is the development of a new Web based HMI portal for Tetra Aptiva Aseptic. The aim is an open source code project where the basic idea is examined and partly implemented during this master thesis. Through a new technique, developed by Tetra Pak, clients can subscribe on topics of interest, which can be viewed on any trusted and connected computer within the Tetra Pa

Manual tuning of PID controllers can be very time-consuming and that is why automatic tuning was developed. The conventional automatic tuners use a relay instead of controller in a closed loop system to obtain stabile oscillations. The information from a relay experiment is later used to calculate PID control parameters with different tuning rules and there also exist systems that, apart from the

Parameters to the CUSUM algorithm are calculated with the aid of the statistical properties of the input data and change detection theory. It works on Gaussian sequences but not on the data from the measurements. Also an approach called Local CUSUM, which lets detectors act over different intervals of the input data is presented and turned out to give good results. These approaches are compared to

On the packaging machine Tetra Pak A1 a heating box is used to sterilize the packaging material. This is done by passing the material through a bath of hydrogen peroxide and then vaporizing the liquid in the heating box. The heating is done by three resistive elements that pass their energy by convection and radiation to the packaging material. Problems occur due to temperature variations on the w

The automotive cooling system and thermal control strategy are important in order to reduce the pollution emission, extend the life of the components and reduce the fuel consumption. The scope of this thesis is to achieve a minimum model that works properly and a small library with the necessary components that the model could be made with. This will be the base for a future Engine Cooling library

Modeling and parameter identification of the main three of an idustrial robot of the type ABB IRB 2000 is considered. This Master thesis has been done at the Department of Automatic Control, Lund Institute of Technology working with a real robot located in the Robotics Laboratory. The model has been bult using the simulation software called Dymola (Dynamic Modeling laboratory), and the parameter i

As the regulations of pollutant emission is getting more and more strict, models of pollutant formation, as a part of system level models for control design, are needed. In this thesis NOx (nitrogen oxides) formation is modeled. A method is developed to mix equilibrium and non-equilibrium reaction equations to model NOx formation in combustion processes. This algorithm reduces high-index DAE syste

Aim of this thesis is to analyze Dc-Dc converters by using the techniques of Linear Periodic Time varying (LTP) systems to estimate the amount of subharmonics injected in the load. Dc-Dc converters are used to transform a Dc input to a Dc output of different voltage. In this thesis we study in particular the so called "switch mode" converters. In this kind of devices the conversion is ob

In order to improve the security of the vehicles, the car industry focuses more and more on Active Safety. The objective is to introduce embedded electronic control systems to detect dangerous conditions, warn the driver and, in emergency situations, even take actions to avoid crash or at least reduce the violence of the impact. The tire-road friction coefficient which defines the maximum traction

Haldex Traction AB designs and manufactures an all wheel drive system called Haldex Limited Slip Coupling. A slip controller controls the speed differences between the front and rear shafts in the all wheel drive vehicle. The product exists in three generations and a fourth, with some major hardware differences, is under development. The variations in hardware lead to widely different demands on t

Friction is present in all mechanical systems and causes a wide range of problems for control. The development of friction models and methods to account for friction in control has been an active research area for many years. A promising friction model that is capable of describing a wide array of observed friction phenomena is the LuGre model. This thesis deals with the application of friction co

Real time information about the current road surface (friction coefficient) would be of great help for most of the vehicle systems of today. Vehicle stability systems like ABS and ESP would perform considerable better with friction knowledge. Dynamic All Wheel Drive torque distributors would, with friction knowledge, substantially enhance the behavior of the vehicle. In this thesis an enhancement

The eagerness among astronomers to gain deeper knowledge and further understanding of the universe around us sets requirements for future telescopes.Images of more distant stars with higher spatial resolution is desired. Extremely Large Telescopes (ELTs) are being developed for this purpose. An example is a European collaboration that is developing an ELT called the Euro50. To obtain the desired r

In libraries today there is a need to faster and more efficient loan books without the need of clerks. Radio Frequency Identification is used to solve this problem. To make everything automatic and still safe a special system of doors will be used scanning all the angles. A light grid is used to determine when a person wants to leave the library. A connection to the libraries database is establish

Todays, industrial robots don't correspond to the needs of the Small and Medium sized Enterprises (SME). Indeed, industrial robots are in many cases too hard to program or too expensive to be used by this kind of enterprises. In order to respond to this need, a European project was created, regrouping five major European robot manufacturers and five leading research institute and universities,

This work is focused on a system which aims at estimating and attenuating side wind acting on a vehicle. The side wind disturbance is estimated using a disturbance observer. This thesis investigates the robustness towards sensor offset and parameter error. A few possibilities for reducing the effects of sensor offset are presented. A large part of the thesis is dedicated to on line identification

The purpose of this Master's Thesis was to compare and coordinate active chassis systems in a search for new ways of controlling two driving situations; side wind exposure and split friction braking. These situations were to be mastered by three active systems; active steering, brakes and suspension. Examples of how to use the systems were presented for each driving situation. The results from