Assistive control for non-contact machining of random shaped contours

Recent achievements in robotics and automation technology has opened the door towards different machining methodologies based on material removal. Considering the non force feedback nature of non-contact machining methods, careful attention on motion control design is a primary requirement for successful achievement of precise cutting both in machining and in surgery processes. This thesis is concerned with the design of pre-processing methods and motion control techniques to provide both automated and human-assistive non-contact machining of random and complex shaped contours. In that sense, the first part of the thesis focuses on extraction of contours and generation of reference trajectories or constraints for the machining system. Based on generated trajectories, two different control schemes are utilized for high precision automated machining. In the first scheme, preview control is adopted for enhancing the tracking performance. In the second scheme, control action is generated based on direct computation of contouring error in the operational space by introducing a new coordinate frame moving with the reference contour. Further, non-contact machining is extended for realization in a master/slave telerobotic framework to enable manual remote cutting by a human operator. With the proposed approach, the human operator (i.e. a surgeon) is limited to conduct motion within a desired virtual constraint and is equipped with the ability of adjusting the cutting depth over a that contour providing advantage for laser surgery applications. The proposed framework is experimentally tested and results of the experiments prove the applicability of proposed motion control schemes and show the validity of contributions made in the context of thesis

Virtual reality systems in the management of technology-based organizations

The introduction of virtual reality media into engineering or technology-based organizations is investigated and a taxonomy for identifying determinants for successful introduction of such media, is developed in the form of a taxonometric planning framework. The research addresses the continuing convergence and integration of digital electronic media, in particular, virtual reality technology and systems, as an exemplary application of new media. This is addressed as a strategic and potentially radical and disruptive innovation. The proposed taxonomy framework is intended as a means of aiding organizations to determine their preparedness or potential adaptability to meet, manage and use new media technology to optimal affect and to manage effectively the demands and impacts of potentially disruptive, technological change. The thesis itself explores and develops the theme that communicative media entail a specific lexicon or language of use that continually evolves, and to be effective, must be understood, at least within its community of practice. In turn, the cultural impact of using virtual reality technology and systems, and the use of virtual representation and virtual world modelling as reflecting events or behaviours and desired outcomes in the real world, is discussed throughout the thesis from a socio-technical perspective. Overall, the taxonomy represents a ‘new way of thinking’ about the introduction and implementation of new media and virtual reality based systems. An adaptation of Checkland & Scholes (1990) Soft-Systems Methodology (SSM) is the core research methodology implemented throughout the research program. Research activity has incorporated use of advanced visualization systems in the Virtual Reality Centre of RMIT University’s Interactive Information Institute (I3), development of a Virtual Reality Users Survey and associated analysis instrument, and a meta-analysis of secondary sources. Collectively, these form the core data collection strategies. The research is characterized by a strongly interdisciplinary approach, exploring the potentialities for and impact of new media and virtual reality systems on the management of technology-based organizations. The taxonomy is a step towards developing a theory of the dynamics of complex technology-based organizations and the various transformations that can occur with the introduction of new and potentially disruptive technology. It is asserted that effective alignment of strategic information and communications technologies with organizational strategic goals and a range of sociological factors, can lead to successful introduction of potentially disruptive technology (in this case: new media based virtual reality) in engineering and technology management environments. It is argued further that the transformative effect of introducing new media technology such as virtual reality, can be catalytic toward producing and driving paradigmatic transformation within an organization