Elliptical trainers are prescribed in rehabilitative exercise but difficult to implement in populations with significant functional gait deficits. Typical elliptical machines do not mimic normal gait and therefore require modifications for clinical rehabilitation. This research builds on previous modifications of an elliptical trainer designed to simulate level-surface walking. This design differed from a commercial version. It included articulated footplates and an electromechanically-driven virtual-cam to control footplate position. Ankle dorsiflexion elicited lower-extremity muscle spasticity which produced an unwanted gait variant during stroke patient testing. Spasticity is a hyperexcitable stretch reflex causing inefficient gait. This project’s purpose was to develop an autonomous cam-profile adjustment to optimize the device’s rehabilitation potential. Foot-to-footplate forces were measured in stroke patients and compared to normative data. Greater than normal forces were considered spastic. An embedded controller was designed to reduce footplate forces via real-time cam-profile attenuation. A simulated spastic dorsiflexion load successfully proved the algorithm’s efficacy.

Dans le domaine de l’aéronautique, les systèmes embarqués ont fait leur apparition durant les années 60, lorsque les équipements analogiques ont commencé à être remplacés par leurs équivalents numériques. Dès lors, l’engouement suscité par les progrès de l’informatique fut tel que de plus en plus de fonctionnalités ont été numérisées. L’accroissement permanent de la complexité des systèmes a conduit à la définition d’une architecture appelée Avionique Modulaire Intégrée (IMA pour Integrated Modular Avionics). Cette architecture se distingue des architectures antérieures, car elle est fondée sur des standards (ARINC 653 et ARINC 664 partie 7) permettant le partage des ressources de calcul et de communication entre les différentes fonctions avioniques. Ce type d’architecture est appliqué aussi bien dans le domaine civil avec le Boeing B777 et l’Airbus A380, que dans le domaine militaire avec le Rafale ou encore l’A400M. Pour des raisons de sûreté, le comportement temporel d’un système s’appuyant sur une architecture IMA doit être prévisible. Ce besoin se traduit par un ensemble d’exigences temps réel que doit satisfaire le système. Le problème exploré dans cette thèse concerne la vérification d’exigences temps réel dans les systèmes IMA. Ces exigences s’articulent autour de chaînes fonctionnelles, qui sont des séquences de fonctions. Une exigence spécifie alors une borne acceptable (minimale ou maximale) pour une propriété temporelle d’une ou plusieurs chaînes fonctionnelles. Nous avons identifié trois catégories d’exigences temps réel, que nous considérons pertinentes vis-à-vis des systèmes étudiés. Il s’agit des exigences de latence, de fraîcheur et de cohérence. Nous proposons une modélisation des systèmes IMA, et des exigences qu’ils doivent satisfaire, dans le formalisme du tagged signal model. Nous montrons alors comment, à partir de ce modèle, nous pouvons générer pour chaque exigence un programme linéaire mixte, c’est-à-dire contenant à la fois des variables entières et réelles, dont la solution optimale permet de vérifier la satisfaction de l’exigence / Embedded systems appeared in aeronautics during the 60’s, when the process of replacing analog devices by their digital counterpart started. From that time, the broad thrust of computer science advances make it possible to digitize more and more avionics functionalities. The continual increase of the complexity of these systems led to the definition of a new architecture called Integrated Modular Avionics (IMA). This architecture stands apart from previous architecture because it is based on standards (ARINC 653 and ARINC 664 part 7) which allow the sharing of computation and communication resources among avionics functions. This architecture is implemented in civil aircrafts, with Boeing B777 and Airbus A380, and in military aircrafts, with Rafale or A400M. For safety reason, the temporal behaviour of such a system must be predictable, which is expressed with a set real-time requirements. A real-time requirement specifies an upper or lower bound of a temporal property of one or several functional chains. A functional chain is a sequence of functions. In this thesis, we explore the verification of real-time requirements in IMA systems. We have identified three real-time requirements relevant to our problem : latency, freshness and consistency. We propose a model of IMA systems, and the requirements they must meet, based on the tagged signal model. Then we derive from this model, for each requirement, a mixed integer linear program whose optimal solution allows us to verify the requirement

Embedded systems are ubiquitous in our society, they control vehicles, aircrafts and medical instruments. Some of these systems are distributed, which means they are part of a network and their operation is coordinated. Software development for such systems can be a difficult problem. In this thesis we propose SOFA 2 component system to simplify the software development for distributed embedded systems where the distribution of components is handled entirely by the component system. Lego Mindstorms is proposed as the model of a distributed embedded system. A runtime environment for SOFA 2 and a demo application were developed to evaluate the approach. The proposed approach delivers seamless component distribution. Nevertheless, non-functional requirements such as memory, program size or disk space must be included in the implementation to fully benefit from a component system.

The Orbital Systems Company faces the really important issues such a lack of water, sewerage and even public health infrastructure. Its proposition of the Shower of the Future, which is a high-tech purification system that recycles water was inspired by the NASA, spaceship technology with limited sources of water and can be the solution of these problems. Due to the patented technology, which bases on the special filters, it is possible to reuse water. This idea, which is used in the shower, allows on more than 90% savings in water usage and 80% savings in energy, while producing water that is cleaner than average tap water. The company aims to provide this special technology not only to the hotels or hospitals, but also to the regular house to maintain the sustainability issue and even achieve the economic profit. The Shower of the Future is a new technology still in the developing phase. To achieve the goals of the company, in the software part of the system, two important problems have to be solved. First of them is the management issue. At this moment, three different versions of the showers, which differ in hardware and in software are in used. Much more versions adjusted to the place of destination such as hotel or hospital are planned. To manage the codes and integrate all of the possible version of the shower, the company desires to create one compatible software to control all of them. The mechanisms to integrate the codes by managing the configurable parameters of the system and to auto detect the version of the shower are proposed in the work. The second company’s issue is the improvement of the control system. As performed research and tests show, the temperature control in the Shower of the Future is too slow and inaccurate. To solve this problem, the identification process of the model was conducted and the PID controllers for the heater were designed. Due to specific structure of the shower, which introduce delays and disturbances, a single PID controller is not sufficient to maintain the control system. As a final controller, the switching PID controller created from previously designed PID controllers is proposed. Thanks to it, the temperature rising time is reduced 2 times, the overshoot, which was equal to 5 °C does not appear and the steady state error is diminished. Thanks to improvement of the temperature control system, much less water is wasted and much more energy is saved. The Shower of the Future of the Orbital System, which nevertheless needs improvements and more work, is only the first step in creating a new paradigm for daily water usage. The company and its product seriously consider the sustainability and environment aspect.

Master of Arts / Department of Modern Languages / Emma Betz / Using conversation analytic methodology, this paper examines the self-repair of actions in everyday German conversation, with focus given to the replacement of verbs and the subsequent effect on actions. While study has been done on the function of recycling repair within a turn (Fox, Hayashi, Jesperson, 1996) no research has been done on the function of verb replacement and its effect on talk. This paper shows that verb replacement is a strategy employed by speakers in order to either a) negotiate what type of action is preferred within a particular TCU or b) to invoke external forces to either deflect an action, or to make a particular action available to an interlocutor. This paper concludes by discussing the specific function of this particular type of repair and how it is useful in repairing problematic actions.

Ten years after the Internet revolution are we standing on the brink of another revolution: networked embedded systems that connect the physical world with the computers, enabling new applications ranging from environmental monitoring and wildlife tracking to improvements in health care and medicine. 98% of all microprocessors sold today are used in embedded systems. Those systems have much smaller amounts of memory than PC computers. An embedded system may have as little has a few hundred bytes of memory, which makes programming them a challenge. This thesis focus on three topics regarding programming memory-constrained networked embedded systems: the TCP/IP for memory-constrained networked embedded systems, simplifying event-driven programming of memory-constrained systems, and dynamic loading of program modules in my Contiki operating system for memory-constrained systems. I show that the TCP/IP protocol stack can, contrary to previous belief, be used in memory-constrained embedded systems by implementing two small TCP/IP protocol stacks, lwIP and uIP. I present a novel programming mechanism called protothreads that I show significantly reduce the complexity of event-driven programming for memory-constrained systems. Protothreads provide a conditional blocked wait mechanism on top of event-driven systems with a much smaller memory overhead than full multithreading; each protothread requires only two bytes of memory. I show that dynamic linking of native code in standard ELF object code format is doable and feasible for wireless sensor networks by implementing a dynamic linker in the Contiki operating system. The results show that the energy overhead of dynamic linking of ELF files mainly is due to the ELF file format and not due to the dynamic linking mechanism as such. The impact of the research in this thesis has been and continues to be large. The software I have developed as part of this thesis is currently used by hundreds of companies in embedded devices in such diverse systems as car engines and satellites. The papers in this thesis are included as required reading in advanced courses on networked embedded systems and wireless sensor networks. / Contiki / uIP / Protothreads

Construction equipment such as wheel loaders and dumpers are constantly getting updated with new technology when it comes to performance and fuel consumption. But the interior in the cockpit has not been exposed to any dramatic changes for decades. A modernized cockpit gives the driver a more modern feel of driving a highly technological machine, while at the same time enables for personalization. This thesis work presents a new way of improving the look and feel for displaying relevant information and also relaying information to both the driver of the machine and spectators outside. It includes a way of rerouting CAN-bus signals from a construction machine and displaying it on a tablet. The core idea with the solution is to make it as modular as possible to further improve and be able to use it in any machine available at Volvo's disposal. With this in mind, any machine could use the same software, the same hardware and still be able to fully utilize all the features that have been implemented from the thesis work. The idea and implementational results are designed as partly embedded and partly towards user interface.

A controlled riderless bicycle is desired for the purpose of testing autonomous vehicles ability to detect and recognise cyclists. The bicycle, which is a highly unstable system with complex dynamics have been subject to research for over a century, and in the last decades, controllers have been developed for autonomous bicycles. The controllers are often only evaluated in simulation, but some complex controllers have been developed on real-life bicycles as well. The goal of this work is to validate sensors and subsystems of an instrumented bicycle and to develop a robust controller which can balance a bicycle by using actuation on the steering axis alone. Using an iterative design process, the sensor measuring the lean angle and the steering system are improved and validated. By sensing the lean angle, the handlebar is manipulated to make the bicycle stable. For this purpose, a P, PD, two different PID, an LQR and a fuzzy controller are developed, evaluated and compared. The results show that the bicycle can ride without human interaction on a bicycle roller in different velocities. Additionally, numerous experiments are conducted in an outdoor environment in several different terrains, where the proposed control structure manages to balance and steer the bicycle.

Modern embedded systems development poses new challenges to a designer due to the global reachability of the contemporary market. One product shipped to different countries or customers should satisfy varying conditions, standards and constraints. Variability of a developed system should be taken into account by a designer. In a case of the embedded heterogeneous systems, this problem becomes challenging. Along with the variability heterogeneity of a system introduces new tasks, which should be addressed during design process. In this work, we propose a technology independent design flow. The proposed solution is supported by state-of-the-art tools and takes into account variability, partitioning, interfacing and dependency resolving processes. This thesis is conducted as a case study. We explored a design process of an industrial project, identified existing challenges and drawbacks in the existing solutions. We propose a new approach to a design flow of heterogeneous embedded systems. Also, a tool, supporting the presented solution, is implemented, which would allow a developer to include this approach into everyday design flow in order to increase a development speed and enable a task automation.

No description available.