Real-time Software Engineering Research Articles

A Model-Driven Co-Design Framework for Fusing Control and Scheduling Viewpoints.

Model-Driven Engineering (MDE) is widely applied in the industry to develop new software functions and integrate them into the existing run-time environment of a Cyber-Physical System (CPS). The design of a software component involves designers from various viewpoints such as control theory, software engineering, safety, etc. In practice, while a designer from one discipline focuses on the core aspects of his field (for instance, a control engineer concentrates on designing a stable controller), he neglects or considers less importantly the other engineering aspects (for instance, real-time software engineering or energy efficiency). This may cause some of the functional and non-functional requirements not to be met satisfactorily. In this work, we present a co-design framework based on timing tolerance contract to address such design gaps between control and real-time software engineering. The framework consists of three steps: controller design, verified by jitter margin analysis along with co-simulation, software design verified by a novel schedulability analysis, and the run-time verification by monitoring the execution of the models on target. This framework builds on CPAL (Cyber-Physical Action Language), an MDE design environment based on model-interpretation, which enforces a timing-realistic behavior in simulation through timing and scheduling annotations. The application of our framework is exemplified in the design of an automotive cruise control system.

NSTX-U Control System Upgrades

The National Spherical Tokamak Experiment (NSTX) is undergoing a wealth of upgrades (NSTX-U). These upgrades, especially including an elongated pulse length, require broad changes to the control system that has served NSTX well. A new fiber serial Front Panel Data Port input and output (I/O) stream will supersede the aging copper parallel version. Driver support for the new I/O and cyber security concerns require updating the operating system from Redhat Enterprise Linux (RHEL) v4 to RedHawk (based on RHEL) v6. While the basic control system continues to use the General Atomics Plasma Control System (GA PCS), the effort to forward port the entire software package to run under 64-bit Linux instead of 32-bit Linux included PCS modifications subsequently shared with GA and other PCS users. Software updates focused on three key areas: (1) code modernization through coding standards (C99/C11), (2) code portability and maintainability through use of the GA PCS code generator, and (3) support of 64-bit platforms. Central to the control system upgrade is the use of a complete real time (RT) Linux platform provided by Concurrent Computer Corporation, consisting of a computer (iHawk), an operating system and drivers (RedHawk), and RT tools (NightStar). Strong vendor support coupled with an extensive RT toolset influenced this decision. The new real-time Linux platform, I/O, and software engineering will foster enhanced capability and performance for NSTX-U plasma control.

ARINC Specification 653 Based Real-Time Software Engineering

This paper reports successive steps of a real-time avionic pitch control application creation. The application structure follows a new real-time systems development profile published in ARINC specification 653. The paper mentions some main ARINC specification 653 features and shows the subsequent application creation levels: control system units distribution, timing requirements definition, application implementation and tests. It describes the author’s experience gained during an avionic hard real-time system development and focuses on real-time software engineering details of the application creation.

Publishing in International Journal of Automation Technology

Automation technology is created by integrating mechanical design, dynamics, control, sensors, actuators, electronics and real time software engineering knowledge into a single system. While there are a number of journals which focus on the individual subjects, a sole journal like IJAT which presents the integration of disciplines to create automation products has been missing. Although automation covers rather a large spectrum, we encourage the authors to submit their articles with the details of technology integration. While mathematical details of a position control of a single axis machine may be more suitable to be presented in a pure control journal, the integration of mechanical drives, motors, sensors, control law, trajectory generation and real time software modules constitutes an excellent example for an automation technology. Similarly, while an image processing algorithm would be narrow, integration of image processing, timing, coordination with moving machinery, hardware and software lay out describes an automation technology. The aim of the journal is to bring theory, design and integration together which leads to the creation of a novel automation technology. The journal is expected to be a key resource for automation engineers in industry and academia while disseminating archival academic knowledge to the society.

Performance Support System for$hbox I^125$Monitoring in the McMaster University Nuclear Reactor

The purpose of this paper is to present a design methodology that can be employed to develop computerized radiation monitoring systems for technology insertion into non-computerized human-machine systems. The methodology seeks to hybridize and exploit the benefits of several diverse disciplines including nuclear engineering, computer science, health physics, real-time system design, human-machine interaction, computer-human interface, and software engineering, in the realization of a Performance Support System (PSS). The focus for combining these disciplines is on the implementation of a specific application: The Iodine Monitoring and Advising System (IMAS), a computerized embedded system for the MNR (McMaster Nuclear Reactor) I <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">125</sup> production facility. IMAS uses radiation monitoring techniques and human factor concepts to provide nuclear reactor operators with a computerized monitoring alarm facility. The migration from a crude and inflexible spill detector to an intelligent performance support system is documented

Surfing the net for software engineering notes

Building real-time applications can be one of the most difficult jobs facing today's software engineers. With all the talk about Web services and Web based applications we sometimes forget that there is a large community of practice engaged in the construction of hard real-time systems. Real-time software engineering has been around for several decades. Typical real-time applications can be found in the areas of communications, avionics, process control, and other specialized applications such as signaling and switching systems.

Evaluating real-time software specification languages

In recent years, many notations and methods in real-time software engineering have been proposed. However, thorough experimentation to evaluate these notations and methods has not been carried out. This paper focuses on real-time software engineering specification languages: Unified Modeling Language (UML), Real-Time Object-Oriented Modeling Language (ROOM), Modecharts, statecharts, Mealy and Moore machines, finite state machines, classical logic, Z, ASTRAL, temporal logic, FNLOG, linear logic, Timed Communicating Sequential Processes (TCSP), Temporal Calculus of Communicating Systems (TCCS), ρ1, and Multilevel Specification. The basis for evaluating these software engineering specification languages is by using the Turing machines and Interaction machines. We classify them based on their computational capabilities.

Ada, model railroading, and real-time software engineering education (keynote address)

Ada, model railroading, and real-time software engineering education (keynote address)

Real-Time Computing Education: Responding to a Challenge of the Next Century

This paper summarizes the discussion held among members of the IFAC TC on Real-Time Software Engineering on the distinctive features of real-time computing. It discusses the internal and external factors that characterize real-time computing as an area of science and presents some ideas about the balance between theory, abstraction, and design in the process of instruction. It also attempts to answer the question whether realtime computing is a fundamental or an applied subject area.

Conceptual model for process control software specification

The paper presents a method for software specification in the domain of industrial process control. As a result of ever more demanding applications, particularly in the area of PLC based control, there is an emerging need for introducing methods that include an appropriate conceptual model and define the specification process. An approach to the method development is presented, based on an architectural extension of the Ward–Mellor structured real time software engineering method. The core of the method is a conceptual model of the equipment control specification, which consists of two essential parts: the first is that of process equipment entities, and the second is the functional part. The former is further decomposed in relation to two aspects of the process equipment entities: the structural aspect and the classification aspect. In order to make the conceptual model more clear some segments of the real process control application dealing with the hydrolysis process in the production of TiO 2 are given.

Recommendations for a Real Time Systems Curriculum

An outline of a syllabus for the education of real time systems engineers is given. This comprises the treatment of basic concepts, real time software engineering and programming in high level real time languages, real time operating systems with special emphasis to such topics as task scheduling, hardware architectures and especially distributed automation structures, process interfacing, system reliability and fault tolerance, and finally integrated project development support systems. Accompanying course material and laboratory work are outlined, such as suggestions for establishing a laboratory with advanced, but low-cost, hardware and software are provided.

The Ontaryo Hydro/AECL approach to real-time software engineering standards

Abstract Software is increasingly becoming a component of many systems within CANDU nuclear generating stations, including special safety systems. There are no widely accepted standards to which software may be engineered that provide adequate assurance that the software will be of acceptable quality. Ontario Hydro, AECL CANDU and AECL Research have initiated a joint development program to establish standards, methods and tools for software engineering to be used in control, protective and monitoring systems. This paper describes the need for standards, the framework for the set of standards under development and how the standards are to be applied to a specific project. The result of the standards development work will be a set of standards to define the requirements on acceptable software processes and products, and a definition ot the methodology that will be used by Ontario Hydro and AECL. The benefits of the standards development program and its relationship to national and international standards is discussed. This paper provides details on the initiatives and the status of the joint Ontario Hydro and AECL work program.

Predicting and Improving Response-Times of Perfect-Models

PERFECT (Programming EnviRonment For Expertsystems Constrained in reasoning Time) aims at supporting knowledge engineers during the development of real-time knowledge based systems (RTKBS). It provides support at the knowledge level (Newell, 1981) in offering guidance in modeling complex industrial processes, and in supplying ways to use this knowledge model during problem solving. Apart from support in modeling, PERFECT also provides support at the level of (real-time) software engineering by means of an analyzer that predicts the response-time of the knowledge model at run-time. In case the response-times are not as required, the analyzer proposes an alternative structure for the knowledge model.

Predicting and improving response-times of perfect-models

PERFECT (Programming EnviRonment For Expertsystems Constrained in reasoning Time) aims at supporting knowledge engineers during the development of real-time knowledge based systems (RTKBS). It provides support at the knowledge level (Newell, 1981) in offering guidance in modeling complex industrial processes, and in supplying ways to use this knowledge model during problem solving. Apart from support in modeling, PERFECT also provides support at the level of (real-time) software engineering by means of an analyzer that predicts the response-time of the knowledge model at run-time. In case the response-times are not as required, the analyzer proposes an alternative structure for the knowledge model.

The Use of AI-methods in the Implementation of Realtime Software Products

Expert systems used for diagnosis or monitoring in industrial applications need real time response behavior in many cases. Not only man-machine interaction has to be handled but also online data input from sensors.Based on experience in the implementation of engine diagnosis systems, network monitoring systems and medical expert systems the pros and cons of real time software engineering methodologies combining classical and AI-related approaches are discussed. We cover the implementation of fast and reliable knowledge bases (including relational databases), the evaluation of expert system shells vs. special inference modules written in ADA and the topic of integration of different tools.

A curriculum for real-time computer and control systems engineering

An outline of a syllabus for the education of real-time-systems engineers is given. This comprises the treatment of basic concepts, real-time software engineering, and programming in high-level real-time languages, real-time operating systems with special emphasis on such topics as task scheduling, hardware architectures, and especially distributed automation structures, process interfacing, system reliability and fault-tolerance, and integrated project development support systems. Accompanying course material and laboratory work are outlined, and suggestions for establishing a laboratory with advanced, but low-cost, hardware and software are provided. How the curriculum can be extended into a second semester is discussed, and areas for possible graduate research are listed. The suitable selection of a high-level real-time language and supporting operating system for teaching purposes is considered.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Real-time scheduling theory and Ada

Rate monotonic scheduling theory puts real-time software engineering on a sound analytical footing. The authors review the theory and its implications for Ada.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Finite state machines for real-time software engineering

Finite state machines have a fundamental importance for realtime software development. A comparison of the Mealy and Moore models for finite state machines indicates certain advantages of the Moore model over the almost industry-standard Mealy model. A refinement of the Moore model is proposed that distinguishes between continuous activities taken while the system is in a specific state, and those required at the transitions into and out of the state. Methods for using FSMs in the design model of a real-time system are discussed.

Education of real-time systems engineers

An outline of a syllabus for the education of real-time systems engineers is given. This comprises the treatment of basic concepts, real-time software engineering and programming in high-level real-time languages, real-time operating systems with special emphasis to some topics like task scheduling, hardware architectures and especially distributed automation structures, process interfacing, system reliability and fault-tolerance, and finally integrated project development support systems. Accompanying course materials and laboratory work are outlined and suggestions for establishing a laboratory with very advanced, but low-cost, hardware and software are provided. It is described how the curriculum can be extended into a second semester and areas for possible graduate research are listed. The paper closes with considerations about a suitable selection of a high-level real-time language and a supporting operating system for teaching purposes.

Real-time programming and its support environment

A real-time programming course is described that provides both an understanding of real-time applications and a basis for designing systems using modern system concepts. Design is based on concurrent interacting tasks and modules sharing common resources. Specification of the real-time system is based on real-time software engineering concepts. Emphasis is on detailed testing and verification of the resulting concurrent programs. Programming is done on personal computers using a real-time operating system. Testing and verification are aided by an event-tracing facility. It is concluded that the teaching of real-time programming can be greatly facilitated by the use of realistic examples and assignments, a simple method for specifying the overall design for classwide evaluation, and the provision of a support environment that permits debugging and verification of the student's design. >