A Programming System for Distributed Real-Time Applications

A distributed programming system designed to support the construction and execution of a real-time distributed program is presented. The system is to facilitate the construction of a distributed program from sequential programs written in different programming languages and to simplify the loading and execution of the distributed program. The system is based on a distributed configuration language. The language is used to write the configuration of a distributed program, which includes resource requirements, process declarations, port connections, real-time constraints, process assignment constraints, and process control statements

A Petri net-occam based methodology for the development of dependable distributed control software.

Analysis of flexible manufacturing cells (FMCs) shows their requirement for flexible, correct, reliable, safe and distributed control. A comparison of the state of the art in software engineering for parallel systems, and an examination of safety related systems, reveal a need for formal and rigorous techniques at all stages in the software life cycle. However, parallel software, safety related software and formal techniques are complex. It is better to avoid faults rather than eliminate or tolerate them, and although less flexible, avoidance is often simpler to implement. There is a need for a tool which overcomes many of these complexities, and this thesis discusses and defines such a tool in the form of a methodology. The novelty of the work is in the combination of the core goals to manage these issues, and how the strategies guide the user to a solution which will not deadlock and which is comprehensible. Place-transition Petri nets are an ideal representation for designing and modelling the interaction of concurrent (and distributed) processes. Occam is a high level real time parallel language designed to execute on one or a network of transputers. Transputers are processing, memory and communication building blocks, and, together with occam, are shown to be suitable for controlling and communicating the control as the DCS in FMCs. The methodology developed in this thesis adopts the mathematically based tools of Petri nets, occam and transputers, and, by exploiting their structural similarities, incorporates them in a steps and tasks to improve the development of correct, reliable and hence safe occam code. The four steps: identify concurrent and sequential operations, produce Petri net graphs for all controllers, combine controller Petri net graphs and translate Petri net graphs into occam; are structured around three core goals: Petri net/occam equivalence, comprehensibility and pro-activity; which are manifest in four strategies: output-work-backwards, concurrent and sequential actions, structuralise and modularise, and deadlock avoidance. The methodology assists in all stages of the software development life cycle, and is applicable to small DCSs such as an FMC. The methodology begins by assisting in the creation of DCS requirements from the manufacturing requirements of the FMC, and guides the user to the production of dependable occam code. Petri nets allow the requirements to be specified as they are created, and the methodology's imposed restrictions enable the final Petri net design to be translated directly into occam. Thus the mathematics behind the formal tools is hidden from the user, which should be attractive to industry.The methodology is successfully applied to the example FMC, and occam code to simulate the FMC is produced. Due to the novelty of the research, many suggestions for further work are given

Integrating sensors and actuators for robotic assembly

This thesis addresses the problem of integrating sensors and actuators for closed-loop control of a robotic assembly cell. In addition to the problems of interfacing the physical components of the work-cell, the difficulties of representing sensory feedback at a high level within the robot control program are investigated. A new level of robot programming, called sensor-level programming, is introduced. In this, the movements of the actuators are not given explicitly, but rather are inferred by the programming system to achieve new sensor conditions given by the programmer.Control of each sensor and actuator is distributed through a master-slave hierarchy, with each sensor and actuator having its own slave controller. A protocol for information interchange between each controller and the master is defined. If possible, the control of the kinematics of a robot arm is achieved through the manufacturer's existing control system. Under these circumstances, the actuator slave would be acting as aninterface between the generic command codes issued from the central controller, and the syntax of the corresponding control instructions required by the commercial system.Sensor information is preprocessed in the sensor slaves and a set of high-level descriptors, called attributes, are sent to the central controller. Closed-loop control is achieved on the basis of these attributes.The processing of sensor information which is corrupted by noise is investigated. Sources of sensor noise are identified and new algorithms are developed to quantify the noise based on information obtained from the closed-loop servoing. Once the relative magnitudes of the system andmeasurement noise have been estimated, a Kalman filter is used to weight the sensor information and hence reduce the credibility given to noisy sensors; in the limit ignoring the information completely. The improvements in system performance by processing the sensor information in this way are demonstrated.The sensor-level representation and automatic error processing are embedded in a software control system, which can be used to interface commercial systems as well as purpose-built devices. An'industrial research project associated with the lay-up of carbon-fibre provides anexample of its operation.A list of publications resulting from the work in this thesis is given in Appendix E

Three solutions for a robot arm controller using Pascal-Plus, occam and edison

Three currently available concurrent language systems, Pascal‐Plus, occam and Edison, are used to implement a controller for a robot arm. The robot arm allows real parallelism of operation within the movements of the arm. The feasibility and restrictions placed upon the resultant solution for each of the language systems is then analysed and discussed. A Petri‐net solution is also presented for the generalized problem and it is shown that each of the solutions is a different folding of the general net

Bibliography of Lewis Research Center technical publications announced in 1993

This compilation of abstracts describes and indexes the technical reporting that resulted from the scientific and engineering work performed and managed by the Lewis Research Center in 1993. All the publications were announced in the 1993 issues of STAR (Scientific and Technical Aerospace Reports) and/or IAA (International Aerospace Abstracts). Included are research reports, journal articles, conference presentations, patents and patent applications, and theses

Dictionary of World Biography

Jones, Barry Owen (1932– ). Australian politician, writer and lawyer, born in Geelong. Educated at Melbourne University, he was a public servant, high school teacher, television and radio performer, university lecturer and lawyer before serving as a Labor MP in the Victorian Parliament 1972–77 and the Australian House of Representatives 1977–98. He took a leading role in reviving the Australian film industry, abolishing the death penalty in Australia, and was the first politician to raise public awareness of global warming, the ‘post-industrial’ society, the IT revolution, biotechnology, the rise of ‘the Third Age’ and the need to preserve Antarctica as a wilderness. In the Hawke Government, he was Minister for Science 1983–90, Prices and Consumer Affairs 1987, Small Business 1987–90 and Customs 1988–90. He became a member of the Executive Board of UNESCO, Paris 1991–95 and National President of the Australian Labor Party 1992–2000, 2005–06. He was Deputy Chairman of the Constitutional Convention 1998. His books include Decades of Decision 1860– (1965), Joseph II (1968), Age of Apocalypse (1975), and he edited The Penalty is Death (1968). Sleepers, Wake!: Technology and the Future of Work was published by Oxford University Press in 1982, became a bestseller and has been translated into Chinese, Japanese, Korean, Swedish and braille. The fourth edition was published in 1995. Knowledge Courage Leadership, a collection of speeches and essays, appeared in 2016. He received a DSc for his services to science in 1988 and a DLitt in 1993 for his work on information theory. Elected FTSE (1992), FAHA (1993), FAA (1996) and FASSA (2003), he is the only person to have become a Fellow of four of Australia’s five learned Academies. Awarded an AO in 1993, named as one of Australia’s 100 ‘living national treasures’ in 1998, he was elected a Visiting Fellow Commoner of Trinity College, Cambridge in 1999. His autobiography, A Thinking Reed, was published in 2006 and The Shock of Recognition, about music and literature, in 2016. In 2014 he received an AC for services ‘as a leading intellectual in Australian public life