1.1 1428 info:srw/schema/1/mods-v3.3xml studentPublicationsH3 Måns Engfors author professor Charlotta Johnsson supervisor Rickard Nilsson supervisor Department of Automatic Control v1000253 department As commercial mobile devices grow more powerful their field of application expands. A mobile device that looks more and more like a computer can also be used like one, even in a industrial context. There are many different commercial mobile software and hardware platforms on the market today. Companies in the process of incorporating such mobile platforms in their systems stand before a difficult decision. This thesis evaluates the most popular platforms today from a case companies industrial point of view and shine light on the most important questions that arise in the platform decision process. This entails defining an industrial context, identifying relevant user scenarios and compiling a requirement specification that<br /> evidently leads to a platform recommendation. The first step in doing this is to determine company-specific requirements, gather data by<br /> conducting interviews and examine the existing company specific systems. This is followed by evaluation of the available mobile<br /> platforms on the market today; Android, Symbian, IPhone, Blackberry and Windows Mobile. The purpose of this thesis is primarily to guide<br /> the company in this platform-decision process, but it can also be used as reference in future mobile development processes. Android is<br /> pointed out as the most suitable platform for future development and two prototypes are implemented fulfilling the most relevant user<br /> scenarios. The company is recommended to place as much functionality as possible in web solutions, since they are portable and often<br /> accessible from any platform. http://lup.lub.lu.se/student-papers/record/3024856/file/3024859.pdf application/pdf 650932 no 2011 eng Technology and Engineering 0280-5316 ISRN LUTFD2/TFRT--5881--SE http://lup.lub.lu.se/student-papers/record/3024856/file/3024861.pdf application/pdf no 3024856 2012-08-22T13:54:23+02:00 2012-08-22T14:21:16+02:00 2012-08-22T14:03:01+02:00 1 info:srw/schema/1/mods-v3.3xml studentPublicationsH3 Klaudius Werber author Anders Robertsson supervisor Department of Automatic Control v1000253 department This student thesis is part of the ROSETTA project that examines the possibilities of future manufacturing based on close human-robot interaction. <br /> In this report, the capabilities of a robot system that is controlled by the Kinect sensor of the Microsoft XBOX-360 are tested. A setup including two Kinect devices and one robot is presented. Applications for calibration of two Kinect sensors, robot workspace surveillance, face detection and shadowing the user&#39;s arm are introduced and evaluated concerning their effectiveness. Finally, the compatibility of the introduced setup with the objectives of the ROSETTA project is evaluated. It proves that the Kinect can strongly support developing solutions for these objectives. The thesis work was conducted at the Department of Automatic Control at LTH at Lund University, Sweden, in collaboration with the Institute of Integrated Sensor Systems at University of Kaiserslautern, Germany. http://lup.lub.lu.se/student-papers/record/2198971/file/2214422.pdf application/pdf 1459963 no 2011 eng Technology and Engineering 0280-5316 ISRN LUTFD2/TFRT--5888--SE key=5888 month=August 2198971 2011-10-25T13:19:23+02:00 2011-11-24T16:02:40+01:00 2011-10-25T13:41:07+02:00 2 info:srw/schema/1/mods-v3.3xml studentPublicationsH3 Peter Larsson author Anders Robertsson supervisor Peter Valdt supervisor Department of Automatic Control v1000253 department This thesis describes methods for treating servo-induced vibrations in<br /> robotics. The focus lies on portal robots (also called linear robots) that<br /> partially consist of hardware manufactured by Bernecker &amp; Rainer<br /> Industrie-Elektronik Ges.m.b.H. It is of interest in many industrial<br /> applications that there is some kind of vibration treatment in the control<br /> strategy. The main reason for this is that it can be time consuming having<br /> to wait for transient vibrations to fade. Another reason is that<br /> mechanical wear increases if there are vibrations present in the<br /> application. Emphasis lies on how to prevent servo-induced vibrations,<br /> however, active vibration damping through simple model based feedback is<br /> also briefly investigated. A comparison is also conducted between the<br /> derived preventive solution and an already existing one in the servo drive<br /> systems at hand. http://lup.lub.lu.se/student-papers/record/2204788/file/2221658.pdf application/pdf 2787549 no 2011 eng Technology and Engineering 0280-5316 ISRN LUTFD2/TFRT--5889--SE http://lup.lub.lu.se/student-papers/record/2204788/file/2214421.pdf application/pdf Populärvetenskaplig sammanfattning no key=5889 2204788 2011-11-16T13:47:58+01:00 2011-11-30T13:20:30+01:00 2011-11-16T14:26:39+01:00 3 info:srw/schema/1/mods-v3.3xml studentPublicationsH3 Gustav Henriks author Joachim Ferreau supervisor Pontus Giselsson supervisor Anders Robertsson supervisor Department of Automatic Control v1000253 department With a steady development of technology, the use of Model Predictive Control (MPC) has become more and more popular since the computation time has gone down. With this increase, a need for determining which MPC algorithm is good for solving a certain type of MPC problem has occurred which would facilitate the choice of algorithm and also could increase the performance. One of the determining aspects is if a solver has the possibility to terminate early (stop the algorithm before it has performed all of its iterations), for example if it is placed on an embedded system with strict real-time bounds. With the use of an MPC Benchmarking suite available at ABB Corporate Research Switzerland, the early termination of MPC algorithms has been investigated. With the usage of 19 benchmarks and 3 different solvers that uses Interior point method, Gradient descent and Active-set method a large number of results have been looked through with the help of different Machine Learning methods. The result has been classified as good or bad performance when terminated early and different models have been fitted to predict this data. From this a group of key-features have been attempted to get extracted to see if there is a possibility on beforehand to tell if a control problem and a certain solver can be early terminated. Important features that were found were mostly concerning whether the control input u was under constraint or not. Good results were especially achieved for a machine learning model based on the Active-set solver qpOASES which could give good indications on whether a certain problem could get early terminated or not. http://lup.lub.lu.se/student-papers/record/8896087/file/8896088.pdf application/pdf 536337 no 2016 eng Technology and Engineering 0280-5316 TFRT-6023 http://lup.lub.lu.se/student-papers/record/8896087/file/8896090.pdf application/pdf no 8896087 2016-12-15T08:46:38+01:00 2016-12-16T13:58:41+01:00 2016-12-16T13:58:41+01:00 4 info:srw/schema/1/mods-v3.3xml studentPublicationsH3 Sebastian Brand author Niklas Nilsson author Martin Holmstrand supervisor Anders Robertsson supervisor Rolf Johansson supervisor Department of Automatic Control v1000253 department Today’s industrial robots are highly repeatable, but need to be calibrated to improve their absolute accuracy. This calibration can be done on many of the robot properties such as kinematic parameters, joint friction or bending stiffness. This thesis explores a calibration procedure for the kinematic parameters, that use a specialized piece of<br /> hardware - the double ball-bar.<br /> The double ball-bar restricts the motion of the robot to a spherical surface. Sensors were added to the ball-bar joints, which made it possible to use the forward kinematic homogeneous transformation matrix from both the robot side and the ball-bar side, the matrices can be compared to each other and the parameters of the robot can be identified using a non-linear least-squares minimization algorithm.<br /> The calibration proved promising in simulations and showed an increased robustness to error sources such as white noise and fluctuations of the gear ratio found in cycloid drives. It also provided an improved identification of the robot parameters compared to the calibration done using the sensor-less double ball-bar.<br /> In experiments the identification showed some improvement in the identification over using the sensor-less double ball-bar, but also that the method needs to be further improved to be able to produce satisfactory calibration results. http://lup.lub.lu.se/student-papers/record/8898906/file/8898907.pdf application/pdf 16608700 no 2016 eng Technology and Engineering 0280-5316 TFRT-6017 http://lup.lub.lu.se/student-papers/record/8898906/file/8898909.pdf application/pdf no 8898906 2017-01-13T11:05:29+01:00 2017-01-16T13:39:10+01:00 2017-01-16T13:39:10+01:00 5 info:srw/schema/1/mods-v3.3xml studentPublicationsH3 Rebecka Erntell author Mats Iderup supervisor Björn Strandmark supervisor Noroz Akhlagi supervisor Martina Maggio supervisor Anders Robertsson supervisor Department of Automatic Control v1000253 department The aim of this thesis was to explore and evaluate current methods for building tiny, low-power audio recording systems for wireless applications. Short audio clips should be recorded, transferred to a smartphone and played back. Optimization of the different parts should be explored and a prototype for usage in battery powered devices with limited space should be built.<br /> System requirements were defined in terms of audio quality, physical size and energy consumption. Additionally, the price should be kept low and the system should be reliable and stable, without notable delays.<br /> The system was divided into six focus areas; microphones, preamplifiers, signal processing, transmission, software design and energy consumption feedback. Each of those was explored theoretically and by practical prototyping, testing and tuning.<br /> Low energy consumption mainly proved to compromise audio quality, system speed and development time. Signal processing and transmission, especially range, speed and protocol overhead, played major roles.<br /> Size constraints did not affect performance very much, except for reduced battery capacity and microphone positioning options. Decent sound quality could be achieved with small size and low cost and signal processing could do much to keep energy consumption down and the perceived sound quality up. http://lup.lub.lu.se/student-papers/record/8898949/file/8898952.pdf application/pdf 4180408 no 2016 eng Technology and Engineering 0280-5316 TFRT-6024 http://lup.lub.lu.se/student-papers/record/8898949/file/8898954.pdf application/pdf no 8898949 2017-01-13T14:08:33+01:00 2017-01-16T13:46:42+01:00 2017-01-16T13:46:42+01:00 6 info:srw/schema/1/mods-v3.3xml studentPublicationsH3 Farid Alijani author Martin Karlsson supervisor Björn Olofsson supervisor Anders Robertsson supervisor Department of Automatic Control v1000253 department Docking of mobile robots requires precise position measurements in relation to the docking platform to accomplish the task successfully. Besides, the pose estimation of the robot with the sensors in an indoor environment should be accurate enough for localization and navigation toward the docking platform. However, the sensor measurements are entitled to disturbances and measurement uncertainties. In this thesis, sensor integration is exploited to decrease the measurement errors and increase the accuracy of the docking.<br /> The first approach in the autonomous docking of a mobile robot considered in this thesis is to use the already built-in laser scanner sensor to examine the feasibility of the precise docking with several experiments employing different markers.<br /> The second approach is a vision-based control method with a marker mounted on the docking platform, identified as the target. The vision-feedback control system evaluates the current position of the robot relative to the target in real time to compute the velocity commands for the actuators to reach the docking platform. The versatility of the markers is investigated in this method.<br /> The final approach is a Reinforcement Learning (RL) framework to investigate and compare the optimality of the docking with the vision-based control method. In the RL approach training is handled in a simulation environment with the reward distribution.<br /> The obtained results of the approaches are evaluated in experiments based on the desired docking behavior with respect to the trajectory and time. The control design with a real-time vision system demonstrates the capabilities of this approach to conduct accurate docking of the mobile robot starting in different configurations. http://lup.lub.lu.se/student-papers/record/8898960/file/8898961.pdf application/pdf 1783412 no 2017 eng Technology and Engineering 0280-5316 TFRT-6018 http://lup.lub.lu.se/student-papers/record/8898960/file/8898963.pdf application/pdf no 8898960 2017-01-13T14:42:57+01:00 2017-01-16T13:48:20+01:00 2017-01-16T13:48:20+01:00 7 info:srw/schema/1/mods-v3.3xml studentPublicationsH3 Marcus Greiff author Fredrik Bagge Carlson supervisor Anders Robertsson supervisor Professor Bo Bernhardsson supervisor Department of Automatic Control v1000253 department The master thesis seeks to develop a control system for the Crazyflie 2.0 unmanned aerial vehicle to enable aggressive and autonomous flight. For this purpose, different rigid-body models are considered, differing primarily in their parametrisation of rotation. The property of differential flatness is explored and several means of parametrising trajectories in at output space are implemented. A new method of rotor control with parameter estimation is developed and geometric controllers are implemented for rigid-body control. Finally, state estimation is accomplished through a scalar-update extended Kalman filter, where information from the internal measurement unit is fused with positional information from camera systems, ultra-wide band systems, optical flow measurements and laser ranging measurements. Capable of sustaining flight with any combination of the previously mentioned sensors, the real-time implementation is showcased using polynomial motion-planning to avoid known obstacles. http://lup.lub.lu.se/student-papers/record/8905295/file/8905299.pdf application/pdf 6635965 no 2017 eng Technology and Engineering 0280-5316 TFRT-6026 http://lup.lub.lu.se/student-papers/record/8905295/file/8905301.pdf application/pdf no 8905295 2017-03-31T13:15:26+02:00 2017-05-24T11:56:43+02:00 2017-05-24T11:56:43+02:00 8 info:srw/schema/1/mods-v3.3xml studentPublicationsH3 Staffan Hedström author Dr Per Petersson supervisor Professor Bo Bernhardsson supervisor Rolf Johansson supervisor Department of Automatic Control v1000253 department In adaptive deep brain stimulation, a treatment for motor symptoms in Parkinson’s disease, the target of the stimulus is usually in the sub-thalamic nucleus or the globus pallidus. In this thesis, a new stimulus target called reticular thalamus is investigated in a rat model of Parkinson’s disease. The responses to the stimulus were recorded from both local field potentials and action potentials from neurons in a live animal implanted with an electrode array and stimulus electrode. The local field potentials were used to investigate the state of a rat, to categorise healthy, parkinsonian and dyskinetic states, to create a response to the stimulus used for investigating the effects of the new stimulus target and to try find the transfer function (turns input into output) to the brain of a rat model of Parkinson’s disease with the Markov parameter realisation algorithm. The new stimulus target showed interesting and clear visual responses from the rat and set the structures in the basal ganglia in a 5-10 Hz ringing for half a second as revealed by a peristimulus time histogram. A power spectral density diagram revealed characteristics previously shown to be correlated with Parkinson’s disease. The transfer function created from the responses was not able to predict the responses to other stimulation protocols other than the one used to build the transfer function, possibly due to the fact that the stimulus target was more effectively inhibited by the higher frequency stimulus protocols, so that the biological properties changed the system. http://lup.lub.lu.se/student-papers/record/8882067/file/8882069.pdf application/pdf 3286908 no 2016 eng Technology and Engineering 0280-5316 TFRT-5993 http://lup.lub.lu.se/student-papers/record/8882067/file/8882074.pdf application/pdf no 8882067 2016-06-16T10:41:24+02:00 2016-06-17T09:13:21+02:00 2016-06-17T09:13:21+02:00 9 info:srw/schema/1/mods-v3.3xml studentPublicationsH3 Santiago Antonio Castro Chans author Mohammed Adlouni supervisor Richard Pates supervisor Professor Bo Bernhardsson supervisor Department of Automatic Control v1000253 department This project discusses the effects of recycle streams on the dynamics and performance of chemical plants. The questions addressed are: can the current industry standard tuning methods still be applied to systems with recycle, and if not, how can they be modified? This is approached by analysing the arrest time tuning method when applied to an integrating process with and without recycle. The results show that the integrating model does not capture all the relevant dynamics of the integrating process with recycle. Consequently a new model, and an easy tuning method for the industry standard controllers, is proposed. http://lup.lub.lu.se/student-papers/record/8883196/file/8883199.pdf application/pdf 2030915 no 2016 eng Technology and Engineering 0280-5316 TFRT-6007 http://lup.lub.lu.se/student-papers/record/8883196/file/8883201.pdf application/pdf no 8883196 2016-06-20T09:07:37+02:00 2016-08-17T09:28:48+02:00 2016-08-17T09:28:48+02:00 10 info:srw/schema/1/mods-v3.3xml studentPublicationsH3 Måns Fällman author Michael Pettersson supervisor Professor Tore Hägglund supervisor Prof Karl-Erik Årzén supervisor Department of Automatic Control v1000253 department The purpose of this thesis was to reduce the start-up and restart time of a hemodialysis machine by targeting time consuming control loops. This was done by investigating different techniques of modelling to find the best combination of versatility and conformity to the process. Finding the best controller was done by evaluating different controllers in simulations with the model in MATLAB/Simulink by comparing closed loop performance and robustness. The results were verified by implementing the controller on a LabView realtime hardware setup. http://lup.lub.lu.se/student-papers/record/8883967/file/8883969.pdf application/pdf 1040802 no 2016 eng Technology and Engineering 0280-5316 TFRT-5992 http://lup.lub.lu.se/student-papers/record/8883967/file/8883971.pdf application/pdf no 8883967 2016-06-21T14:13:57+02:00 2016-08-17T09:30:20+02:00 2016-08-17T09:30:20+02:00 11 info:srw/schema/1/mods-v3.3xml studentPublicationsH3 Henning Larsson author Pontus Giselsson supervisor professor Anders Rantzer supervisor Department of Automatic Control v1000253 department In this thesis, a methodology for aggregating district heating networks for use in dynamic optimization with the JModelica.org platform is investigated. Several methodologies for this network reduction are reviewed, and one, based on a detailed physical model of the system, is presented in greater detail. This method is implemented along with an abstract network representation and Modelica code generation to automate as much as possible of the workflow from network data to simulation and optimization models.<br /> Experiments are presented both for aggregation for typical cases with 3–4 conusmers in a sub-network, and for a full district heating network. The tests on the smaller networks are mostly accurate, and while the results from the full network show the need for further improvement of the method, a likely source for the error is presented, along with solution proposals. http://lup.lub.lu.se/student-papers/record/7373316/file/7373327.pdf application/pdf 1721950 no 2015 eng Technology and Engineering 0280-5316 ISRN LUTFD2/TFRT--5975--SE http://lup.lub.lu.se/student-papers/record/7373316/file/7373329.pdf application/pdf no 7373316 2015-06-18T16:10:09+02:00 2015-06-22T09:55:31+02:00 2015-06-22T09:55:31+02:00 12 info:srw/schema/1/mods-v3.3xml studentPublicationsH3 Christopher Dahlin Rodin author Professor Bo Bernhardsson supervisor professor Anders Rantzer supervisor Department of Automatic Control v1000253 department Radars used for detecting objects with a positive elevation, such as other vehicles, are common in autonomous parking and braking systems in modern vehicles. Detecting objects with a negative elevation, such as ditches and holes, is however more troublesome. A common approach is to use a lidar, but a lidar is very costly and fragile compared to a radar. In this thesis, two two-dimensional radars are attached above the windshield of a truck and aimed down towards the ground.<br /> At first the geometrical limitations of detecting ditches is analyzed in order to find which mounting angles of the radars are viable. Data is then collected from the radars, with the determined angles, a Global Positioning System (GPS) unit, and Inertial Measurement Unit (IMU) by driving the truck in a real world terrain. Data from a lidar is also recorded for reference.<br /> Combined with a GPS and IMU, the radar detections are first transformed from the radar coordinate system, the a truck coordinate system, and finally to global Universal Transverse Mercator (UTM) coordinates. The global position of each detection is filtered, and finally used to create an elevation map of the environment. A similar map is also created from the lidar detections.<br /> The resulting radar elevation map accurately maps the terrain near the vehicle, including the ditches next to the road. The radars appear to miss small objects, and the density of the detections is quite low for the radar mount angles used.<br /> In order to improve the accuracy, the vertical position of the radar detection needs to be determined. A higher density of detections would also improve the mapping, which could be aquired by decreasing the pitch angle of the radars. http://lup.lub.lu.se/student-papers/record/7373365/file/7373366.pdf application/pdf 2937362 no 2015 eng Technology and Engineering 0280-5316 ISRN LUTFD2/TFRT--5970--SE http://lup.lub.lu.se/student-papers/record/7373365/file/7373373.pdf application/pdf no 7373365 2015-06-18T16:29:58+02:00 2015-06-22T09:53:04+02:00 2015-06-22T09:53:04+02:00 13 info:srw/schema/1/mods-v3.3xml studentPublicationsH3 Sofia Finnved author Sebastian Nöbbelin author Rolf Johansson supervisor Prof Karl-Erik Årzén supervisor Department of Automatic Control v1000253 department Automatic brake functions in trucks and cars can save lives but may heat the brakes to dangerous temperature levels. Various types of models for temperature estimation in a disc brake have been evaluated. A homogeneous temperature inside the disc was assumed and this simplification gave adequate modeling results. The implementation was done in Simulink.<br /> One model estimated the heat generation based on the kinetic energy difference during a brake event. The difficulty of estimating driving resistance coefficients and the sensitivity to the driver’s behavior made this model less suitable for generalization. More promising models used the brake cylinder pressure as input. The brake cylinder pressure was used to derive a braking force at the periphery of each wheel. The braking force could be determined in different ways, each one with their own advantages and disadvantages. The common disadvantage was that the brake force depends on the load over each wheel. It was assumed that the load over each wheel be known. A simple, exponential model for cooling gave sufficiently good results. A model based on the sum of convection and radiation gave better results.<br /> The brake pressure model was used in a short study on steady state temperatures, while the vehicle was pulse braked. No conclusions was drawn from these simulations, but the results were promising, thus opening up for future research. http://lup.lub.lu.se/student-papers/record/7397831/file/7397842.pdf application/pdf 6626173 no 2015 eng Technology and Engineering 0280-5316 ISRN LUTFD2/TFRT--5966--SE http://lup.lub.lu.se/student-papers/record/7397831/file/7397846.pdf application/pdf no 7397831 2015-06-22T13:00:18+02:00 2015-06-26T13:03:02+02:00 2015-06-26T13:03:02+02:00 14 info:srw/schema/1/mods-v3.3xml studentPublicationsH3 Ida Synnøve Jönsson author Josefin Berner supervisor professor Anders Rantzer supervisor Department of Automatic Control v1000253 department HVAC systems are widely used to provide a good indoor air quality in buildings. Buildings stand for a substantial part of the total energy consumption in developed countries, and with an increased focus on cost reductions and energy savings, it is necessary to use intelligent and energy-efficient controllers. <br /> Accurate models describing the dynamics of the building system is a good basis for intelligent control. In countries like Sweden there are large seasonal variations in the outdoor climate, and these variations interfere with the indoor condition and thus affects the control. In this thesis the seasonal variations are investigated, and the aim is to determine how these differences affect identified models for control of temperature and relative humidity in buildings. Two MISO (Multiple Input-Single Output) systems and one MIMO (Multiple Input-Multiple Output) system is used to describe the mean room temperature and relative humidity in a selected room in the Q-building at KTH, Stockholm. The models are identified following the black-box approach, and data from four different months during 2014, representing the winter, spring, summer and autumn season respectively, are collected and preprocessed.<br /> The validation of the identified models for the humidity and temperature, shows that it is possible to use identical orders and input delays for all seasons, with good results. Based on the results one would not recommend using models with the same model parameters throughout the year, since the conditions varies too much from season to season. http://lup.lub.lu.se/student-papers/record/7440340/file/7440346.pdf application/pdf 2132563 no 2015 eng Technology and Engineering 0280-5316 ISRN LUTFD2/TFRT--5976--SE http://lup.lub.lu.se/student-papers/record/7440340/file/7440350.pdf application/pdf no 7440340 2015-06-23T11:10:06+02:00 2015-06-26T13:04:55+02:00 2015-06-26T13:04:55+02:00 15 info:srw/schema/1/mods-v3.3xml studentPublicationsH3 Martin Djup author Elias Allar author Johan Nilsson supervisor Professor Tore Hägglund supervisor Anders Robertsson supervisor Department of Automatic Control v1000253 department In this master thesis we have studied the possibilities of implementing and controlling the speed of a brushless DC motor in an hydraulic application developed by BorgWarner TorqTransfer Systems AB. The hydraulic application is a coupling that give vehicles intelligent all-wheel drive.<br /> <br /> Today, the hydraulic application uses hydraulic pressure controlled by an ordinary DC motor to produce the all-wheel drive. The purpose of this thesis was to test if the DC motor could be substituted to a brushless variant by looking at different ways of controlling the speed of the brushless motor and evaluate its possibilities. The controllers were tested and evaluated by constructing a model of the brushless DC motor, together with different controllers, in Simulink.<br /> <br /> Two kinds of controllers were implemented and tested in Simulink. The first one was field-oriented control with field weakening, and the second one was sixstep commutation. Field-oriented control is a very computationally heavy method compared to the six-step commutation which is one of the simplest ways to control a brushless DC motor.<br /> What makes the control implementation a little bit harder is that there can be no angle- or speed sensors involved, so both control methods need to be sensorless. The field-oriented control with field weakening was made sensorless with a sliding mode observer and the six-step commutation was made sensorless via back-EMF sensing.<br /> <br /> The results show that the alternative that seems to have the upper hand is the field-oriented control, even if it may be harder to implement. It also shows that if some more work is put on the control design, the six-step commutation may also be a good candidate. Overall, this thesis shows that it is theoretically possible to implement a brushless DC motor in the hydraulic application. http://lup.lub.lu.se/student-papers/record/7442408/file/7442410.pdf application/pdf 2591556 no 2015 eng Technology and Engineering 0280-5316 ISRN LUTFD2/TFRT--5979--SE http://lup.lub.lu.se/student-papers/record/7442408/file/7442412.pdf application/pdf no 7442408 2015-06-23T16:31:53+02:00 2015-07-02T17:02:40+02:00 2015-06-26T13:09:49+02:00 16 info:srw/schema/1/mods-v3.3xml studentPublicationsH3 Sara Gustafzelius author Simon Yngve supervisor Erik Bylow supervisor Anders Robertsson supervisor Prof Karl-Erik Årzén supervisor Department of Automatic Control v1000253 department In this thesis an RGB-D camera was used with the goal to perform dynamic path planning in an initially unknown environment. Depth data from an RGB-D camera together with a discretizising algorithm is continuously used for maintaining an obstacle map of the environment which within the path planning algorithm D* Lite [S. Koening, 2005] is performed on the flight.<br /> <br /> Experiments were conducted on two different systems, on Combine’s hexacopter and on a Gantry Tau robot at the Robot Lab of the Department of Automatic Control, LTH. On Combine’s hexacopter different tracking algorithms such as ICP, Translation Approximation and SDF where evaluated for 3D positioning while the robots internal positioning where used on the Gantry Tau robot.<br /> <br /> For discretization purposes we compare the use of Box Approximation and Signed Distance Function (SDF) for creating the obstacle map. http://lup.lub.lu.se/student-papers/record/7442930/file/7442931.pdf application/pdf 4773214 no 2015 eng Technology and Engineering 0280-5316 ISRN LUTFD2/TFRT--5980--SE http://lup.lub.lu.se/student-papers/record/7442930/file/7442933.pdf application/pdf no 7442930 2015-06-24T08:45:23+02:00 2015-07-03T09:34:22+02:00 2015-07-03T09:34:22+02:00 17 info:srw/schema/1/mods-v3.3xml studentPublicationsH3 Mattias Fält author Lucas Jimbergsson author Pontus Giselsson supervisor Professor Bo Bernhardsson supervisor Department of Automatic Control v1000253 department Model Predictive control (MPC) has been studied extensively because of its ability to handle constraints and its great properties in terms of stability and performance [Mayne et al., 2000]. We have in this thesis focused on MPC of Hybrid Systems, i.e. systems with both continuous and discrete dynamics. More specifically, we look at problems that can be cast as Mixed Integer Quadratic Programming (MIQP) problems which we are solving using a Branch and Bound technique. The problem is in this way reduced to solving a large number of constrained quadratic problems. However, the use in real time systems puts a requirement on the speed and efficiency of the optimization methods used. Because of its low computational cost, there have recently been a rising interest in the Alternating Direction Method of Multiplies (ADMM) for solving constrained optimization problems. We are in this thesis looking at how the different properties of ADMM can be used and improved for these problems, as well as how the Branch and Bound solver can be tailored to accompany ADMM. We have two main contributions to ADMM that mitigate some of the downsides with the often ill-conditioned problems that arise from Hybrid Systems. Firstly, a technique for greatly improving the conditioning of the problems, and secondly, a method to perform fast line search within the solver. We show that these methods are very efficient and can be used to solve problems that are otherwise hard or impossible to precondition properly. http://lup.lub.lu.se/student-papers/record/7445552/file/7446199.pdf application/pdf 1122995 no 2015 eng Technology and Engineering 0280-5316 ISRN LUTFD2/TFRT--5981--SE http://lup.lub.lu.se/student-papers/record/7445552/file/7446201.pdf application/pdf no 7445552 2015-06-24T13:31:27+02:00 2015-07-03T09:38:34+02:00 2015-07-03T09:38:34+02:00 18 info:srw/schema/1/mods-v3.3xml studentPublicationsH3 Tor Larsson author Toivo Henningsson supervisor Björn Olofsson supervisor Prof Karl-Erik Årzén supervisor Department of Automatic Control v1000253 department In this thesis a Moving Horizon Estimator (MHE) has been implemented for the JModelica.org platform. JModelica.org is an open-source software platform for simulation and optimization of systems described in the modeling language Modelica. MHE is an optimization-based strategy for state estimation where, at each time step, a finite horizon optimization problem is solved to generate an estimate of the current state values. The goal has been to implement an MHE that works with many already existing Modelica models and that has an intuitive user interface. The performance of the implemented MHE is evaluated using both linear and nonlinear systems in a series of simulation examples. The results indicate that the MHE performs well. http://lup.lub.lu.se/student-papers/record/7447367/file/7447384.pdf application/pdf 2589618 no 2015 eng Technology and Engineering 0280-5316 ISRN LUTFD2/TFRT--5982--SE http://lup.lub.lu.se/student-papers/record/7447367/file/7447391.pdf application/pdf no 7447367 2015-06-24T14:50:03+02:00 2015-07-03T09:41:24+02:00 2015-07-03T09:41:24+02:00 19 info:srw/schema/1/mods-v3.3xml studentPublicationsH3 Stefan Oros author Rolf Johansson supervisor Anders Robertsson supervisor Department of Automatic Control v1000253 department The main objective for the thesis project is to find a suitable mathematical model of the velocity dependent friction force that arises between the nip roller and the carton material in the laminator at slip, in order to enable realistic simulations of the nip in the laminator. Theoretically, the LuGre model is found to contain the necessary physical properties for the actual situation. Experiments are conducted measuring friction between a rubber sample and carton samples in order to find an expansion and validation of the model. The model is found to produce a satisfactory low-magnitude residual in relation to the experiments for the range that varies with velocity. During the low velocities high-amplitude friction induced oscillations appear making the measurements highly inaccurate. It is known, however, that the slip will never reach these low velocities so this source of error is disregarded. Also, the measurement instrument is found not to be entirely ideal for this project. An instrument that can continuously change the velocity would be better. This model is good for most of the nip cases. However, further investigations are needed for the boundary effects that arise due to the cylindrical shape of the rollers and also a way to identify the dynamical parameters and thus expand from a steady-state model to a dynamical model. http://lup.lub.lu.se/student-papers/record/7448451/file/7448460.pdf application/pdf 2613210 no 2015 eng friction LuGre modelling Stribeck sliding carton Technology and Engineering 0280-5316 ISRN LUTFD2/TFRT--5968--SE http://lup.lub.lu.se/student-papers/record/7448451/file/7448462.pdf application/pdf no 7448451 2015-06-25T09:15:47+02:00 2015-07-03T09:44:33+02:00 2015-07-03T09:44:33+02:00 20 1.1issn any "1401-9191 0280-5316 0280-5316"issnany1401-9191 0280-5316 0280-5316