This diploma thesis deals with complete designing and implementation of local navigation of a robot which travels according to set GPS. This work contains a study of contemporary used principles of the sensors which can be used as the components of the robot. There are sensors for measuring the surroundings of the robot and orientation of the robot in the environs. The equipment includes an instructing control unit with the ATmega8 microcontroller. This equipment collects data from the sensors and transfers them to the other systems of the robot. The following part of the thesis deals with the draft of the buses and communication protocols, which are necessary for connection between the sensors and the control unit. The I2C and RS232 buses were chosen as the most suitable. The communication protocol was borrowed from the semester project written by Bc. Michal Sitta. The main task of this control unit is reading out the data which have been measured from connected sensors. The realization of interface between the sensor bus and the major system is another core goal of the control unit. The system for a local navigation is designed with the approach which allows the widest range of extensibility. During the designing of the control unit the future possibility of insertion other sensors was taken into consideration.

La détection, localisation d'obstacles et la reconstruction de carte d'occupation 2D sont des fonctions de base pour un robot navigant dans un environnement intérieure lorsque l'intervention avec les objets se fait dans un environnement encombré. Les solutions fondées sur la vision artificielle et couramment utilisées comme SLAM (simultaneous localization and mapping) ou le flux optique ont tendance a être des calculs intensifs. Ces solutions nécessitent des ressources de calcul puissantes pour répondre à faible vitesse en temps réel aux contraintes. Nous présentons une architecture matérielle pour la détection, localisation d'obstacles et la reconstruction de cartes d'occupation 2D en temps réel. Le système proposé est réalisé en utilisant une architecture de vision sur FPGA (field programmable gates array) et des capteurs d'odométrie pour la détection, localisation des obstacles et la cartographie. De la fusion de ces deux sources d'information complémentaires résulte un modèle amelioré de l'environnement autour des robots. L'architecture proposé est un système à faible coût avec un temps de calcul réduit, un débit d'images élevé, et une faible consommation d'énergie / Obstacle detection, localization and occupancy map reconstruction are essential abilities for a mobile robot to navigate in an environment. Solutions based on passive monocular vision such as simultaneous localization and mapping (SLAM) or optical flow (OF) require intensive computation. Systems based on these methods often rely on over-sized computation resources to meet real-time constraints. Inverse perspective mapping allows for obstacles detection at a low computational cost under the hypothesis of a flat ground observed during motion. It is thus possible to build an occupancy grid map by integrating obstacle detection over the course of the sensor. In this work we propose hardware/software system for obstacle detection, localization and 2D occupancy map reconstruction in real-time. The proposed system uses a FPGA-based design for vision and proprioceptive sensors for localization. Fusing this information allows for the construction of a simple environment model of the sensor surrounding. The resulting architecture is a low-cost, low-latency, high-throughput and low-power system.

MSc (Mathematics) / Department of Mathematics and Applied Mathematics / See the attached abstract below

The most advanced ports as of writing of this report are at least somewhat autonomous. Whether discussing the transporters between crane and stack (temporary storage) or cranes, the ports are shifting into a completely autonomous system. This ultimate goal presents a challenge in regards to unloading and loading cargo ships in the harbour. How do you achieve unloading of a ship without human intervention while still guaranteeing secure trajectories for the containers? ABB Ports in collaboration with the Division of Vehicular Systems at Linköping University have developed a simulation that utilises a simple control model to investigate the behaviour, limitations and capabilities of such an autonomous crane. Specifically, this simulation utilises a model of the dynamics of a Ship-to-Shore crane (STS), which has the task of unloading a ship. In order to set the crane model in context of realistic scenarios, some additions to the simulation are needed. One of these additions is obstacles. Before this thesis work, the model enjoyed an empty simulation environment to freely optimise how quickly the containers could be transported off of the ship. The addition of obstacles in the form of other containers on the cargo ship as well as the physical presence of the crane’s legs presents new challenges for the optimiser used to solve the optimal control problems formulated through the model in the simulation. The implementation of obstacles is one of the objectives for this thesis. This addition was implemented by modeling the obstacle dimensions and ship limitations by looking at the largest container ships in the world. Due to the simulation not containing obstacles previous to this thesis work, the initial guess provided to the solver initialised the solving in an area of convergence that is unfair to the solver, This rendered the simulation useless, as any obstacle presented to the solver would generate an infeasible solution. Another functionality needed for the obstacle implementation to be meaningful is a solution for guaranteeing safe trajectories for the containers from ship to shore. The solution utilised to reach this goal was to combine a convex hull and safety conditions where the convex hull covers the obstacles, including some padding to prevent collisions between the container carried (load) and obstacles. The safety conditions however calculates the potential positions of the load when an emergency stop occurs, and therefore can prevent the load from swinging into obstacles if there is an emergency stop. These implementations however changes the usefulness and performance of the simulation because of how they shrink the area of convergence for the solver and making some problems non-solvable. When considering both a convex hull and safety conditions, the usability of the simulations is harmed, but can still be utilised to learn about autonomous performance of the simulation. The optimal solutions include some interesting characteristics that can learn crane operators about how the control systems can be utilised. Such a simulation would benefit from continuous development in order to investigate further technologies and features that could improve both performance and usability. Areas such as homotopy, modelling ropes, comparison between simple and nuanced model would be truly interesting for future areas of investigation.

We adress an obstacle problem for (graphical) mean curvature flow with Dirichlet boundary conditions. Using (an adapted form of) the standard implicit time-discretization scheme we derive the existence of distributional solutions satisfying an appropriate variational inequality. Uniqueness of this flow and asymptotic convergence towards the stationary solution is proven.

During the last decade, potential theory and p-harmonic functions have been developed in the setting of doubling metric measure spaces supporting a p-Poincar´e inequality. This theory unifies, and has applications in several areas of analysis, such as weighted Sobolev spaces, calculus on Riemannian manifolds and Carnot groups, subelliptic differential operators and potential theory on graphs. In this thesis we investigate the double obstacle problem for p-harmonic functions on metric spaces. We show the existence and uniqueness of solutions and their continuity when the obstacles are continuous. Moreover the solution is p-harmonic in the open set where it does not touch the continuous obstacles. The boundary regularity of the solutions is also studied. Furthermore we study two kinds of convergence problems for the solutions. First we let the obstacles vary and fix the boundary values and show the convergence of the solutions. Second we consider an increasing sequence of open sets, with union Ω, and fix the obstacles and the boundary values. We show that the solutions of the obstacle problems in these sets converge to the solution of the corresponding problem in Ω. / Låt oss börja med att betrakta följande situation: Vi vill förflytta oss från en plats vid ena sidan av en äng till en viss punkt på andra sidan ängen. På båda sidor om ängen finns skogsområden som vi inte får gå in i. Ängen är tyvärr inte homogen utan består av olika sorters mark som vi har noggrant beskrivet på en karta. Vi vill göra förflyttningen på smidigast sätt, men då ängen inte är homogen ska vi förmodligen inte gå rakaste vägen utan ska anpassa vägen optimalt efter terrängen. Detta är ett exempel på ett dubbelhinderproblem där hindren är skogsområdena på sidorna som vi måste hålla oss utanför. Mer abstrakt vill man minimiera energin hos funktioner som tar vissa givna randvärden (de givna start- och slutpunkterna i exemplet ovan) och som håller sig mellan ett undre och ett övre hinder. I denna avhandling studeras detta dubbelhinderproblem i väldigt allmänna situationer. För att kunna lösa hinderproblemet krävs det att vi tillåter ickekontinuerliga lösningar och då visas i avhandlingen att hinderproblemet är entydigt lösbart. Ett huvudresultat i avhandlingen är att om våra hinder är kontinuerliga så blir även lösningen kontinuerlig. Vidare visas diverse konvergenssatser som visar hur lösningarna varierar när hindren eller området i vilket problemet löses varierar. Hinderproblem har utöver eget intresse viktiga tillämpningar i potentialteorin, bland annat för att studera motsvarande energiminimeringsproblem utan hinder. / <p>Incorrect series title in colophon.</p>

This thesis deals with the general problem of robot motion planning and control. It proposes the hypothesis that it should bepossible to create a generic software framework capable of dealing with all robot motion planning and control problems, independent of the robot being used, the task being solved, the workspace obstacles or the algorithms employed. The thesis work then consisted of identifying the requirements and creating a design and implementation of such a framework. This report motivates and documents the entire process. The framework developed was tested on two different robot arms under varying conditions. The testing method and results are also presented.The thesis concludes that the proposed hypothesis is indeed valid.

Self-driving cars have recently become a challenging research topic, with the aim of making transportation safer and more efficient. Current advanced driving assistance systems (ADAS) allow cars to drive autonomously by following lane markings, identifying road signs and detecting pedestrians and other vehicles. In this thesis work we improve the robustness of autonomous cars by designing an on-road obstacle detection system. The proposed solution consists on the low-level fusion of radar and lidar through the occupancy grid framework. Two inference theories are implemented and evaluated: Bayesian probability theory and Dempster-Shafer theory of evidence. Obstacle detection is performed through image processing of the occupancy grid. Last, the Dempster-Shafer additional features are leveraged by proposing a sensor performance estimation module and performing advanced conflict management. The work has been carried out at Volvo Car Corporation, where real experiments on a test vehicle have been performed under different environmental conditions and types of objects. The system has been evaluated according to the quality of the resulting occupancy grids, detection rate as well as information content in terms of entropy. The results show a significant improvement of the detection rate over single-sensor approaches. Furthermore, the Dempster-Shafer implementation may slightly outperform the Bayesian one when there is conflicting information, although the high computational cost limits its practical application. Last, we demonstrate that the proposed solution is easily scalable to include additional sensors.

This thesis presents two simulations of a heavy hybrid vehicle, the first part of the thesis is focused on the specifications of the vehicle designed in accordance with the requirements based on the literature study of the soils where the vehicle will travel. The second part presents the study of the vehicle through two simulations. The first simulation is oriented on the dynamical behavior of the vehicle. The second simulation focuses on the energy management of the vehicle. The presented thesis is a multi-disciplinary study, combining knowledge on vehicle dynamics, hydraulic suspensions and hybrid systems. The dynamical simulation of the vehicle has been performed with Matlab/Simulink and the third party program Delft-Tire for the tire modelling. Specials features of Matlab have been used; SimMechanics for the modelling of the parts, links and joints of the vehicle, and SimHydraulics for the modelling of the hydraulic suspensions. The principal tests performed on the vehicle by the dynamical simulation are the tests defined by the NATO - STANAG standards as AVTP 03-170. The tests are a crossing obstacle test and different sine wave roads. The obstacle of the obstacle crossing test is an APG-10 obstacle, an 10 inch high step with vertical edges. The objective of this simulation is to verify the design of the suspension and to observe the forces created in each link of the suspension system in order to design the chassis and the suspension system. The sine wave driving tests are performed to highlight the influence of the different hydraulic connections. Finally the slalom test presents the influence of the hydraulic anti-roll bar. The results show that the vehicle suspension verifies the STANAG standard. The results show also that the forces applied at the wheel by the obstacle crossing defined in the AVTP 03- 170 are directly related to the diameter and the stiffness of the tire. The maximum forces encountered at the wheel corresponds to 2.5 G vertically and 1.5 G longitudinally. The sine wave driving and the slalom test are showing the benefits and the need for advanced hydraulic suspensions. The second simulation is the modelling of the hybrid power management of the vehicle. The simulation has been performed with the objectives to create a tool for sizing series hybrid powertrain. This simulation has also been performed with Matlab/Simulink and the Simscape Library. The tool created show that when, the vehicle is equipped with 150 kW of power generation and 300 kW of battery would be able to drive at a constant speed of 10 km/h with the terrain inputs evaluated from the literature study, but to create sufficient result the input parameters of the tools need to have a better definition.

BakgrundTrycksår är en vanlig vårdskada som förekommer hos patienterna i slutenvården. Det går att förhindra uppkomsten av trycksår med hjälp av beprövade metoder och evidensbaserade åtgärder. Det förekommer dock hinder som motverkar sjuksköterskor från att arbeta förebyggande mot trycksår. Det är viktigt att dessa hinder förhindras för att utveckla sjukvården och minska vårdskador.SyfteSyftet med litteraturöversikten är identifiera vilka hinder som påverkar sjuksköterskans preventionsarbete för trycksår.MetodStudien utformades som en litteraturöversikt. För att besvara syftet valdes artiklar med kvantitativa och kvalitativa metoder från CINAHL och PubMed.ResultatResultatet beskrevs under sex teman. Sjuksköterskorna upplevde flera hinder som försvårar deras arbete för att förebygga trycksår som kunskapsbrist, tidsbrist, personalbrist, sjuksköterskans inställningar, avsaknad av riktlinjer och att riskbedömning inte görs i praktiken.SlutsatsKunskapsbrist, tidsbrist, personalbrist, sjuksköterskans inställningar, avsaknad av riktlinjer och riskbedömningar som inte görs i praktiken är allvarliga hinder som motverkar sjuksköterskans arbete. För att kunna förbättra vården behöver dessa hinder åtgärdas. / BackgroundPressure ulcers are common healthcare injuries that occurs in patients in inpatient care. It is possible to prevent the occurrence of pressure ulcers with the help of proven methods and evidence-based measures. There are obstacles that prevent nurses from working to prevent pressure ulcers. It is important that these obstacles are counteracted in order to develop healthcare and reduce healthcare injuries.PurposeThe purpose of the literature review is to identify the obstacles that affect the nurse's prevention work for pressure ulcers.MethodThe study was designed as a literature review. To answer the purpose, quantitative and qualitative articles from CINAHL and PubMed were selected.ResultsThe result was described under six themes. The nurses experienced several obstacles that counteract their work to prevent pressure ulcers, such as lack of knowledge, lack of time, lack of staff, the nurse's attitudes, lack of guidelines and that risk assessment is not done in practice.ConclusionLack of knowledge, lack of time, lack of staff, the nurse's attitudes, lack of guidelines and risk assessments that are not made in practice are serious obstacles that counteract the nurse's work. In order to improve care, these obstacles need to be addressed.