106,105 research outputs found
PhyNetLab: An IoT-Based Warehouse Testbed
Future warehouses will be made of modular embedded entities with
communication ability and energy aware operation attached to the traditional
materials handling and warehousing objects. This advancement is mainly to
fulfill the flexibility and scalability needs of the emerging warehouses.
However, it leads to a new layer of complexity during development and
evaluation of such systems due to the multidisciplinarity in logistics,
embedded systems, and wireless communications. Although each discipline
provides theoretical approaches and simulations for these tasks, many issues
are often discovered in a real deployment of the full system. In this paper we
introduce PhyNetLab as a real scale warehouse testbed made of cyber physical
objects (PhyNodes) developed for this type of application. The presented
platform provides a possibility to check the industrial requirement of an
IoT-based warehouse in addition to the typical wireless sensor networks tests.
We describe the hardware and software components of the nodes in addition to
the overall structure of the testbed. Finally, we will demonstrate the
advantages of the testbed by evaluating the performance of the ETSI compliant
radio channel access procedure for an IoT warehouse
CAN Fieldbus Communication in the CSP-based CT Library
In closed-loop control systems several realworld entities are simultaneously communicated to through a multitude of spatially distributed sensors and actuators. This intrinsic parallelism and complexity motivates implementing control software in the form of concurrent processes deployed on distributed hardware architectures. A CSP based occam-like architecture seems to be the most convenient for such a purpose. Many, often conflicting, requirements make design and implementation of distributed real-time control systems an extremely difficult task. The scope of this paper is limited to achieving safe and real-time communication over a CAN fieldbus for an\ud
existing CSP-based framework
A distributed Real-Time Java system based on CSP
CSP is a fundamental concept for developing software for distributed real time systems. The CSP paradigm constitutes a natural addition to object orientation and offers higher order multithreading constructs. The CSP channel concept that has been implemented in Java deals with single- and multi-processor environments and also takes care of the real time priority scheduling requirements. For this, the notion of priority and scheduling has been carefully examined and as a result it was reasoned that priority scheduling should be attached to the communicating channels rather than to the processes. In association with channels, a priority based parallel construct is developed for composing processes: hiding threads and priority indexing from the user. This approach simplifies the use of priorities for the object oriented paradigm. Moreover, in the proposed system, the notion of scheduling is no longer connected to the operating system but has become part of the application instead
Building Blocks for Control System Software
Software implementation of control laws for industrial systems seem straightforward, but is not. The computer code stemming from the control laws is mostly not more than 10 to 30% of the total. A building-block approach for embedded control system development is advocated to enable a fast and efficient software design process.\ud
We have developed the CTJ library, Communicating Threads for JavaÂż,\ud
resulting in fundamental elements for creating building blocks to implement communication using channels. Due to the simulate-ability, our building block method is suitable for a concurrent engineering design approach. Furthermore, via a stepwise refinement process, using verification by simulation, the implementation trajectory can be done efficiently
Enabling High-Level Application Development for the Internet of Things
Application development in the Internet of Things (IoT) is challenging
because it involves dealing with a wide range of related issues such as lack of
separation of concerns, and lack of high-level of abstractions to address both
the large scale and heterogeneity. Moreover, stakeholders involved in the
application development have to address issues that can be attributed to
different life-cycles phases. when developing applications. First, the
application logic has to be analyzed and then separated into a set of
distributed tasks for an underlying network. Then, the tasks have to be
implemented for the specific hardware. Apart from handling these issues, they
have to deal with other aspects of life-cycle such as changes in application
requirements and deployed devices. Several approaches have been proposed in the
closely related fields of wireless sensor network, ubiquitous and pervasive
computing, and software engineering in general to address the above challenges.
However, existing approaches only cover limited subsets of the above mentioned
challenges when applied to the IoT. This paper proposes an integrated approach
for addressing the above mentioned challenges. The main contributions of this
paper are: (1) a development methodology that separates IoT application
development into different concerns and provides a conceptual framework to
develop an application, (2) a development framework that implements the
development methodology to support actions of stakeholders. The development
framework provides a set of modeling languages to specify each development
concern and abstracts the scale and heterogeneity related complexity. It
integrates code generation, task-mapping, and linking techniques to provide
automation. Code generation supports the application development phase by
producing a programming framework that allows stakeholders to focus on the
application logic, while our mapping and linking techniques together support
the deployment phase by producing device-specific code to result in a
distributed system collaboratively hosted by individual devices. Our evaluation
based on two realistic scenarios shows that the use of our approach improves
the productivity of stakeholders involved in the application development
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