Functional model-based design of embedded systems with UniTi

Advancing the field of embedded systems requires a rigorous approach to their design. This is because embedded systems are complex, diverse and challenging. Although many tools exist, none support the following four essential features: (i) the modelling of multiple domains, (ii) accurate inclusion of time, (iii) mathematical definitions, and (iv) model transformations. In addition, such a tool must underlie a sound design flow that adequately supports the complexity of designing embedded systems.\ud \ud In this thesis we propose a design flow and a modelling and simulation framework called UniTi that manages complexity in a top-down fashion; a problem is split up into sub-problems that are solved individually and then combined. This design flow and framework is based on model-based design, i.e. a single reference model is iteratively and incrementally developed and refined during the design process. Our approach is a functional approach, not only because it is practical and useful, but also because it has a mathematical basis supported by a functional language, i.e. computations are considered as evaluations of mathematical functions.\ud \ud In this work we specialise the design for the application domain of beamforming applications, for which we propose a generic platform. Two adaptive algorithms for tracking are developed in the context of this platform. A tiled reconfigurable architecture is used, as the tiles provide scalability and reconfigurability provides flexibility. The environment and analogue hardware are represented in the continuous time (CT) domain, while digital hardware is represented in the discrete time (DT) domain and software in the dataflow (DF) domain.\ud \ud We formally define the CT, DT, and DF domains for UniTi. It also supports exact time delays in the CT domain by representing signals as functions of time. Model components, represented as signal transformations, are composed using function composition instead of value-passing, with unified sequential, parallel and feedback composition by re-defining the dataflow model to match with CT and DT components and signals. As a consequence, mixed-domain models are executable for simulation. Finally, UniTi provides support for model transformations.\ud \ud The result of this work is a functional model-based design approach for designing, modelling, and simulation of embedded systems

Integrated Design and Implementation of Embedded Control Systems with Scilab

Embedded systems are playing an increasingly important role in control engineering. Despite their popularity, embedded systems are generally subject to resource constraints and it is therefore difficult to build complex control systems on embedded platforms. Traditionally, the design and implementation of control systems are often separated, which causes the development of embedded control systems to be highly time-consuming and costly. To address these problems, this paper presents a low-cost, reusable, reconfigurable platform that enables integrated design and implementation of embedded control systems. To minimize the cost, free and open source software packages such as Linux and Scilab are used. Scilab is ported to the embedded ARM-Linux system. The drivers for interfacing Scilab with several communication protocols including serial, Ethernet, and Modbus are developed. Experiments are conducted to test the developed embedded platform. The use of Scilab enables implementation of complex control algorithms on embedded platforms. With the developed platform, it is possible to perform all phases of the development cycle of embedded control systems in a unified environment, thus facilitating the reduction of development time and cost.Comment: 15 pages, 14 figures; Open Access at http://www.mdpi.org/sensors/papers/s8095501.pd

UNICS - An Unified Instrument Control System for Small/Medium Sized Astronomical Observatories

Although the astronomy community is witnessing an era of large telescopes, smaller and medium sized telescopes still maintain their utility being larger in numbers. In order to obtain better scientific outputs it is necessary to incorporate modern and advanced technologies to the back-end instruments and to their interfaces with the telescopes through various control processes. However often tight financial constraints on the smaller and medium size observatories limit the scope and utility of these systems. Most of the time for every new development on the telescope the back-end control systems are required to be built from scratch leading to high costs and efforts. Therefore a simple, low cost control system for small and medium size observatory needs to be developed to minimize the cost and efforts while going for the expansion of the observatory. Here we report on the development of a modern, multipurpose instrument control system UNICS (Unified Instrument Control System) to integrate the controls of various instruments and devices mounted on the telescope. UNICS consists of an embedded hardware unit called Common Control Unit (CCU) and Linux based data acquisition and User Interface. The Hardware of the CCU is built around the Atmel make ATmega 128 micro-controller and is designed with a back-plane, Master Slave architecture. The Graphical User Interface (GUI) has been developed based on QT and the back end application software is based on C/C++. UNICS provides feedback mechanisms which give the operator a good visibility and a quick-look display of the status and modes of instruments. UNICS is being used for regular science observations since March 2008 on 2m, f/10 IUCAA Telescope located at Girawali, Pune India.Comment: Submitted to PASP, 10 Pages, 5 figure

Anticipating user eXperience with a desired product: The AUX framework

Positive user experience (UX) has become a key factor in designing interactive products. It acts as a differentiator which can determine a product’s success on the mature market. However, current UX frameworks and methods do not fully support the early stages of product design and development. During these phases, assessment of UX is challenging as no actual user-product interaction can be tested. This qualitative study investigated anticipated user experience (AUX) to address this problem. Using the co-discovery method, participants were asked to imagine a desired product, anticipate experiences with it, and discuss their views with another participant. Fourteen sub-categories emerged from the data, and relationships among them were defined through co-occurrence analysis. These data formed the basis of the AUX framework which consists of two networks which elucidate 1) how users imagine a desired product and 2) how they anticipate positive experiences with that product. Through this AUX framework, important factors in the process of imagining future products and experiences were learnt, including the way in which these factors interrelate. Focusing on and exploring each component of the two networks in the framework will allow designers to obtain a deeper understanding of the required pragmatic and hedonic qualities of product, intended uses of product, user characteristics, potential contexts of experience, and anticipated emotions embedded within the experience. This understanding, in turn, will help designers to better foresee users’ underlying needs and to focus on the most important aspects of their positive experience. Therefore, the use of the AUX framework in the early stages of product development will contribute to the design for pleasurable UX