People that have driven a car with a trailer at high speed know that the trailer can begin to oscillate. This oscillation is known as snake behavior. How much the car and trailer starts to oscillate depends on how the trailer is loaded. An empty trailer does not tend to oscillate, while a heavy loaded trailer, with the load centered over the trailer axle, oscillates more easily. For a normal perso

This thesis presents an implementation of a positioning and navigation system for a mobile robot using ultrasonic pulses and passive sensors that are part of a sensor network. The system uses the Telos Tmote Sky sensor-boards running Contiki. In addition to the Tmote Sky the mobile robot consists of a number of processors and is equipped with position encoders for the wheels in order to be able to

This thesis presents an implementation of a positioning and navigation system for a mobile robot using ultrasonic pulses and passive sensors that are part of a sensor network. The system uses the Telos Tmote Sky sensor-boards running Contiki. In addition to the Tmote Sky the mobile robot consists of a number of processors and is equipped with position encoders for the wheels in order to be able to

The balancing act of an inverted pendulum with a robotic manipulator is a classical benchmark for testing modern control strategies in conjunction with fast sensor-guided movements. From the control design perspective, it presents a challenging and difficult problem as the system is open-loop unstable and includes nonlinear effects in the actuators, such as friction, backlash, and elasticity. In a

This thesis addresses the issue of Information Systems (IS) security in pharmaceutical manufacturing which is closely related to the ISA 99 standard. The ISA 99 'Security for industrial Automation and Control Systems' standard is focused on the work for securing process automation systems from IS security threats. The main thought behind the ISA 99 standard is that a high level of IS secur

In this thesis simple vehicle models are compared to more advanced models. The parameters in the simple models have to be chosen in such a way, that the model behaviour is as close to the advanced model as possible. This parameter optimisation is done with help of The Optimica Compiler, wich generates AMPL files that solves the problems. To run a successful parameter estimation there is a need for

Optimal paths are useful when testing the performances of vehicles. In this thesis, optimal paths for vehicle models created in Modelica have been obtained. The optimal paths have been obtained by applying the theory of optimal control. The optimal control problem has been formulated with the Optimica language and has been solved with AMPL and IPOPT. Two approaches for finding optimal paths have b

The aim of the thesis is to model engine physics and dynamics and to design controllers based on the physical model. By implementing equations and solving them it's possible to describe the major phenomena in a four stroke engine running in HCCI mode. To describe the cycle-tocycle connection in the model a wall temperature model was introduced. This wall model is used to simulate the engine dy

TrueTime is a MATLAB/Simulink-based simulator for real-time control systems that has been developed at the Department of Automatic Control, LTH. The aim of this thesis is to port the TrueTime kernel block to the open-source Scilab/Scicos simulation environment. The original kernel block is a variable-step, discrete S-function written in C++. In this work, the Scicos engine should replace the Simul

In the process industry general TITO systems, i.e. systems with two inputs and two outputs, are usually assumed to be two separate systems. If the system is strongly coupled, the performance is generally poor, but usually nothing is done about this since there are no automatic means to improve it. The aim of this master's thesis is to develop a module with a completely automated design procedu

More than 90 % of all computers are embedded in different types of systems, for example mobile phones and industrial robots. Some of these systems are real-time systems; they have to produce their output within certain time constraints. They can also be safety critical; if something goes wrong, there is a risk that a great deal of damage is caused. Industrial Extended Automation System 800xA, deve

This Master's Thesis presents the development of methods for improved GPS navigation on Wayfinder Navigator, a mobile phone based navigation system developed by Wayfinder Systems. Focus has been put on off track detection, i.e. to detect a user diverging from the route given by the navigation system, and how the GPS position is presented to the user by the application. Improving off track dete

As a part of the RUNES project a robot has been developed and it has as a part of this theses been improved with an obstacle avoidance component. Work has also been done to make room for additional components on the Tmote sky (one of the micro controllers mounted on the robot) such as a power control component developed at KTH. Attempts has also been made to try to enhance the performance of the r

In many process industries samples are taken and analyzed in laboratories to monitor and ensure proper production conditions. If the analysis result is not within specification limits measures are taken to correct errors. It has proved to be hard to take the appropriate measures. The problem description fits into the confines of control theory and the aim is to make a fairly simple solution to a v

Most vehicles today use some kind of hydraulic brake system in order to stop the vehicle. There are other techniques that will not only decrease the stop length, but also create a more stable vehicle; an example of such system is the Electromechanical braking system. The problem with such a system is that the requirements of data transmission and reliability are different from the system that is u

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