| 1. |
- Lednicki, Luka
(författare)
-
Software and hardware models in component-based development of embedded systems
- 2015
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- As modern embedded systems grow in complexity component-based development is an increasingly attractive approach to make the development of such systems simpler and less error prone. In this approach software systems are built by composing them out of prefabricated software components. One of the challenges for applying component-based development to embedded systems is the tight coupling between the software and the hardware platform. To take full advantage of the component-based approach in the embedded domain, the development process has to provide support for describing and handling this coupling.The goal of this thesis is to provide advancements in development of embedded component-based systems by using a combination of software and hardware models. To achieve the overall research goal, three different aspects are investigated: (i) how to provide support for integration of sensors and actuators in component-based development, (ii) how to utilize a combination of software and hardware models in development of distributed systems, and (iii) how to analyze extra-functional system properties using models of both software and hardware. The thesis goal is addressed by following contributions: (i) a component-based model which allows describing sensors and actuators, and how they are connected to the processing nodes and software components, (ii) a method for automatic synthesis of code for communication with sensors and actuators, (iii) a framework for automatic generation of distributed communication in component-based models and (iv) a compositional model-level analysis of timing and processing node utilization for component-based applications. These contributions are evaluated in separation, by applying prototype tools to either example systems, case-studies, or test scenarios.
|
|
| 2. |
- Maras, Josip, 1986-
(författare)
-
Automating Reuse in Web Application Development
- 2014
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Web applications are one of the fastest growing types of software systems today. Structurally, they are composed out of two parts: the server-side, used for data-access and business logic, and the client-side used as a user-interface. In recent years, thanks to fast, modern web browsers and advanced scripting techniques, developers are building complex interfaces, and the client-side is playing an increasingly important role.From the user's perspective, the client-side offers a number of features. A feature is an abstract notion representing a distinguishable part of the system behavior. Similar features are often used in a large number of web applications, and facilitating their reuse would offer considerable benefits. However, the client-side technology stack does not offer any widely used structured reuse method, and code responsible for a feature is usually copy-pasted to the new application. Copy-paste reuse can be complex and error prone - usually it is hard to identify exactly the code responsible for a certain feature and introduce it into the new application without errors.The primary focus of the research described in this PhD thesis is to provide methods and tools for automatizing reuse in client-side web application development. This overarching problem leads to a number of sub-problems: i) how to identify code responsible for a particular feature; ii) how to include the code that implements a feature into an already existing application without breaking neither the code of the feature nor of the application; and iii) how to automatically generate sequences of user actions that accurately capture the behavior of a feature? In order to tackle these problems we have made the following contributions: i) a client-side dependency graph that is capable of capturing dependencies that exist in client-side web applications, ii) a method capable of identifying the exact code and resources that implement a particular feature, iii) a method that can introduce code from one application into another without introducing errors, and iv) a method for generating usage scenarios that cause the manifestation of a feature. Each contribution was evaluated a suite of web applications, and the evaluations have shown that each method is capable of performing its intended purpose.
|
|
| 3. |
- Feljan, Juraj, 1985-
(författare)
-
Task Allocation Optimization for Multicore Embedded Systems
- 2015
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Modern embedded systems are becoming increasingly performance intensive, since, on the one hand, they include more complex functionality than before, and one the other hand, the functionality that was typically realized with hardware is often moved to software. Multicore technology, previously successfully used for general-purpose systems, is penetrating into the domain of embedded systems. While it does increase the performance capacity, it also introduces the problem of how to allocate software tasks to the cores of the hardware platform, as different allocations exhibit different extra-functional properties. An intuitive example is allocating too many tasks to a core --- the core will be overloaded and tasks will miss their deadlines.This thesis addresses the issue of task allocation in multicore embedded systems. The overall goal of the thesis is to advance the way soft real-time multicore systems are developed, by providing new methods and tools that enable deciding already at design-time which task to run on which core, with respect to a number of timing-related extra-functional properties. To achieve this goal, we developed a model-based framework for task allocation optimization. The framework uses model simulation in order to obtain performance predictions for particular task allocations. This in turn enables testing a large number of allocation candidates in search for one that exhibits good timing-related performance. Apart from defining and implementing the framework, three additional contributions are provided, each tackling a particular aspect of the framework: the influence of task allocation on communication duration is studied and interpreted in the context of design-time model-based analysis; a novel heuristic for guiding task allocation optimization is defined; and finally, a novel optimization method combining performance prediction and performance measurement is defined.
|
|
| 4. |
- Land, Rikard, 1975-
(författare)
-
Software Systems In-House Integration : Observations and Guidelines Concerning Architecture and Process
- 2006
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Software evolution is a crucial activity for software organizations. A specifc type of software evolution is the integration of previously isolated systems. The need for integration is often a consequence of different organizational changes, including merging of previously separate organizations. One goal of software integration is to increase the value to users of several systems by combining their functionality, another is to reduce functionality overlap. If the systems are completely owned and controlled in-house, there is an additional advantage in rationalizing the use of internal resources by decreasing the amount of software with essentially the same purpose. Despite in-house integration being common, this topic has received little attention from researchers. This thesis contributes to an increasing understanding of the problems associated with in-house integration and provides guidelines to the more efficient utilization of the existing systems and the personnel.In the thesis, we combine two perspectives: software architecture and processes. The perspective of software architecture is used to show how compatibility analysis and development of integration alternatives can be performed rapidly at a high level of abstraction. The software process perspective has led to the identification of important characteristics and practices of the integration process. The guidelines provided in the thesis will help those performing future in-house integration to make well-founded decisions timely and efficiently.The contributions are based on several integration projects in industry, which have been studied systematically in order to collect, evaluate and generalize their experiences.
|
|
| 5. |
- Lüders, Frank, 1971-
(författare)
-
An Evolutionary Approach to Software Components in Embedded Real-Time Systems
- 2006
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Component-based software engineering denotes the practice of building software from pre-existing smaller products, in particular when this is done using standardized software component models. The main expected benefits of this practice over traditional software engineering approaches are increased productivity and timeliness of development projects. While the use of software component models has become common for desktop and server-side software, this is not the case in the domain of embedded real-time systems, presumably due to the special requirements such systems have to meet with respect to predictable timing and limited use of resources. Much research exists that aims to define new component models for this domain, typically focusing on source code components, static system configuration, and relatively narrow application domains.This dissertation explores the alternative approach of using components based on binary code, allowing dynamic configuration, and targeting a broader domain. A study of a general purpose component model shows that the model is compatible with real-time requirements, although putting some restrictions on its use may be necessary to ensure predictability. A case study demonstrates how the model has been used with advantage in an industrial control system. The dissertation furthermore proposes an approach for extending the component model with run-time services for embedded real-time systems. It presents a prototype tool for supporting such services, along with two empirical studies to evaluate the approach and the tool as well as the component model itself. One study shows that both the component model and the services provided by the tool result in very modest and predictable run-time overheads. The other study, evaluating the effects on productivity and quality of using the approach in a software development project, did not produce quantitative evidence, but concludes that the approach is promising and identifies possible adjustments to it and opportunities for further studies.
|
|
| 6. |
- Sentilles, Séverine
(författare)
-
Managing Extra-Functional Properties in Component-Based Development of Embedded Systems
- 2012
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The continuously increasing complexity of embedded systems is a major issue for their development, which, in addition, must also consider specific extra-functional requirements and constraints, such as limited and shared resources, distribution, timing, and dependability. Thus, embedded systems call for development solutions that can efficiently and predictably cope with these issues. Component-based software engineering is a proven paradigm to handle complexity. Yet, for efficiently managing extra-functional properties, a component model needs to have dedicated mechanisms that provide a suitable support for their management. The objective of this thesis is to build this support. We have performed a systematic analysis of existing component models and identified challenges of applying a component-based approach to embedded system development. Based on these challenges we have advanced the current state-of-the-art by developing a new component model, called ProCom, that accommodates the specifics of embedded systems through its well-defined execution semantics and layered structure. Centered around ProCom, we have also developed PRIDE, the ProCom Integrated Development Environment. PRIDE supports the development from early specification to synthesis and deployment, providing the means to aggregate various analysis and verification tools. The main contribution of the thesis is in the design and implementation of an extra-functional property management framework that enables to seamlessly specify, manage and integrate multi-valued context-aware extra-functional properties of component-based embedded systems. Properties can be attached to architectural elements of component models and their values can be compared and refined during the development process. In particular, having multiple context-aware values allows values from different sources to be compared. The proposed concepts have been demonstrated on several representative example systems.
|
|
| 7. |
- Vulgarakis, Aneta, 1982-
(författare)
-
A Resource-Aware Framework for Designing Predictable Component-Based Embedded Systems
- 2012
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Managing complexity is an increasing challenge in the development of embedded systems (ES). Some of the factors contributing to the increase in complexity are the growing complexity of hardware and software, and the increased pressure to deliver full-featured products with reduced time-to-market. An attractive approach to manage the software complexity, reduce time-to-market and decrease development costs lies in the adoption of component-based development that has been proven as a successful approach in other domains. Another raising challenge, due to complexity increase, in ES, is predictability, i.e., the ability to anticipate the behavior of a system at run-time. The particular predictability requirements of ES call for a development framework equipped with techniques and tools that can be applied to deal with requirements, such as timing, and resource utilization, already at early-stage of development. Modeling and formal analysis play increasingly important roles in achieving predictability, since they can help us to understand how systems function, validate the design and verify some important properties. In this thesis, we present a resource-aware framework for designing predictable component-based ES. The proposed framework consists of (i) the formally specified ProCom component model that takes into account the characteristics of control-intensive ES, and (ii) the resource-aware timed behavioral language - REMES for modeling and reasoning about components’ and systems’ functional and extra-functional behavior that includes relevant resource types for ES, associated analysis techniques for various resource-wise properties, and a set of associated tools. To demonstrate the potential application of our framework, we present a number of case studies, out of which one is an industrial research prototype, where ProCom and REMES are applied.
|
|
| 8. |
- Behere, Sagar, 1981-
(författare)
-
Architecting Autonomous Automotive Systems : With an emphasis on Cooperative Driving
- 2013
-
Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The increasing usage of electronics and software in a modern automobile enables realization of many advanced features. One such feature is autonomous driving. Autonomous driving means that a human driver’s intervention is not required to drive the automobile; rather, theautomobile is capable of driving itself. Achieving automobile autonomyrequires research in several areas, one of which is the area of automotive electrical/electronics (E/E) architectures. These architectures deal with the design of the computer hardware and software present inside various subsystems of the vehicle, with particular attention to their interaction and modularization. The aim of this thesis is to investigate how automotive E/E architectures should be designed so that 1) it ispossible to realize autonomous features and 2) a smooth transition canbe made from existing E/E architectures, which have no explicit support for autonomy, to future E/E architectures that are explicitly designed for autonomy.The thesis begins its investigation by considering the specific problem of creating autonomous behavior under cooperative driving condi-tions. Cooperative driving conditions are those where continuous wireless communication exists between a vehicle and its surroundings, which consist of the local road infrastructure as well as the other vehicles in the vicinity. In this work, we define an original reference architecture for cooperative driving. The reference architecture demonstrates how a subsystem with specific autonomy features can be plugged into an existing E/E architecture, in order to realize autonomous driving capabilities. Two salient features of the reference architecture are that it isminimally invasive and that it does not dictate specific implementation technologies. The reference architecture has been instantiated on two separate occasions and is the main contribution of this thesis. Another contribution of this thesis is a novel approach to the design of general, autonomous, embedded systems architectures. The approach introduces an artificial consciousness within the architecture, that understands the overall purpose of the system and also how the different existing subsystems should work together in order to meet that purpose.This approach can enable progressive autonomy in existing embedded systems architectures, over successive design iterations.
|
|
| 9. |
- Behere, Sagar, 1981-
(författare)
-
Reference Architectures for Highly Automated Driving
- 2016
-
Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Highly automated driving systems promise increased road traffic safety, as well as positive impacts on sustainable transportation by means of increased traffic efficiency and environmental friendliness. The design and development of such systems require scientific advances in a number of areas. One area is the vehicle's electrical/electronic (E/E) architecture. The E/E architecture can be presented using a number of views, of which an important one is the functional view. The functional view describes the decomposition of the system into its main logical components, along with the hierarchical structure, the component inter-connections, and requirements. When this view captures the principal ideas and patterns that constitute the foundation of a variety of specific architectures, it may be termed as a reference architecture. Two reference architectures for highly automated driving form the principal contribution of this thesis. The first reference architecture is for cooperative driving. In a cooperative driving situation, vehicles and road infrastructure in the vicinity of a vehicle continuously exchange wireless information and this information is then used to control the motion of the vehicle. The second reference architecture is for autonomous driving, wherein the vehicle is capable of driver-less operation even without direct communication with external entities. The description of both reference architectures includes their main components and the rationale for how these components should be distributed across the architecture and its layers. These architectures have been validated via multiple real-world instantiations, and the guidelines for instantiation also form part of the architecture description. A comparison with similar architectures is also provided, in order to highlight the similarities and differences. The comparisons show that in the context of automated driving, the explicit recognition of components for semantic understanding, world modeling, and vehicle platform abstraction are unique to the proposed architecture. These components are not unusual in architectures within the Artificial Intelligence/robotics domains; the proposed architecture shows how they can be applied within the automotive domain. A secondary contribution of this thesis is a description of a lightweight, four step approach for model based systems engineering of highly automated driving systems, along with supporting model classes. The model classes cover the concept of operations, logical architecture, application software components, and the implementation platforms. The thesis also provides an overview of current implementation technologies for cognitive driving intelligence and vehicle platform control, and recommends a specific setup for development and accelerated testing of highly automated driving systems, that includes model- and hardware-in-the-loop techniques in conjunction with a publish/subscribe bus. Beyond the more "traditional" engineering concepts, the thesis also investigates the domain of machine consciousness and computational self-awareness. The exploration indicates that current engineering methods are likely to hit a complexity ceiling, breaking through which may require advances in how safety-critical systems can self-organize, construct, and evaluate internal models to reflect their perception of the world. Finally, the thesis also presents a functional architecture for the brake system of an autonomous truck. This architecture proposes a reconfiguration of the existing brake systems of the truck in a way that provides dynamic, diversified redundancy, and an increase in the system reliability and availability, while meeting safety requirements.
|
|
| 10. |
|
|
