Ship Motion Control : Course Keeping and Roll Stabilisation Using Rudder and Fins

Motion control systems have a significant impact on the performance of ships and marine structures allowing them to perform tasks in severe sea states and during long periods of time. Ships are designed to operate with adequate reliability and economy, and in order to achieve this, it is essential to control the motion. For each type of ship and operation performed (transit, landing a helicopter, fishing, deploying and recovering loads, etc.), there are not only desired motion settings, but also limits on the acceptable (undesired) motion induced by the environment. The task of a ship motion control system is therefore to act on the ship so it follows the desired motion as closely as possible. This book provides an introduction to the field of ship motion control by studying the control system designs for course-keeping autopilots with rudder roll stabilisation and integrated rudder-fin roll stabilisation. These particular designs provide a good overview of the difficulties encountered by designers of ship motion control systems and, therefore, serve well as an example driven introduction to the field. The idea of combining the control design of autopilots with that of fin roll stabilisers, and the idea of using rudder induced roll motion as a sole source of roll stabilisation seems to have emerged in the late 1960s. Since that time, these control designs have been the subject of continuous and ongoing research. This ongoing interest is a consequence of the significant bearing that the control strategy has on the performance and the issues associated with control system design. The challenges of these designs lie in devising a control strategy to address the following issues: underactuation, disturbance rejection with a non minimum phase system, input and output constraints, model uncertainty, and large unmeasured stochastic disturbances. To date, the majority of the work reported in the literature has focused strongly on some of the design issues whereas the remaining issues have been addressed using ad hoc approaches. This has provided an additional motivation for revisiting these control designs and looking at the benefits of applying a contemporary design framework, which can potentially address the majority of the design issues.

Total energy shaping of a class of underactuated Port-Hamiltonian Systems using a new set of closed-loop potential shape variables

This paper proposes a method for designing set-point regulation controllers for a class of underactuated mechanical systems in Port-Hamiltonian System (PHS) form. A new set of potential shape variables in closed loop is proposed, which can replace the set of open loop shape variables-the configuration variables that appear in the kinetic energy. With this choice, the closed-loop potential energy contains free functions of the new variables. By expressing the regulation objective in terms of these new potential shape variables, the desired equilibrium can be assigned and there is freedom to reshape the potential energy to achieve performance whilst maintaining the PHS form in closed loop. This complements contemporary results in the literature, which preserve the open-loop shape variables. As a case study, we consider a robotic manipulator mounted on a flexible base and compensate for the motion of the base while positioning the end effector with respect to the ground reference. We compare the proposed control strategy with special cases that correspond to other energy shaping strategies previously proposed in the literature.

A multi-hierarchical motorway ramp signalling strategy

Ramp signalling is an access control for motorways, in which a traffic signal is placed at on-ramps to regulate the rate of vehicles entering the motorway and thus to preserve the motorway capacity. In general, ramp signalling algorithms fall into two categories: local control and coordinated control by their effective scope. Coordinated ramp signalling strategies make use of measurements from the entire motorway network to operate individual ramp signals for the optimal performances at the network level. This study proposes a multi-hierarchical strategy for coordinated ramp signalling. The strategy is structured in two layers. At the higher layer with a longer update interval, coordination group is assembled and disassembled based on the location of high-risk breakdown flow. At the lower layer with a shorter update interval, individual ramps are hired to serve the coordination and are also released based on the prevailing congestion level on the ramp. This strategy is modelled and applied to the northbound Pacific Motorway micro-simulation platform (AIMSUN). The simulation results show an effective congestion mitigation of the proposed strategy.

Revolving kaleidoscope : site-specificity and the part object in contemporary installation art

This practice-led research project explores the possibilities for restaging and reconfiguring contemporary art installations in multiple and different locations. By exploring ideas and art that demonstrate a kaleidoscopic approach to creative practice, this project examines how analysing artists' particular processes can achieve new understandings and experiences of installation art. This project achieves this through reflection on, and analysis of creative works made throughout the research, and a critical examination of contemporary art practices.

Using Participatory Design (PD) as youth engagement strategy to inform design and development of evidence-based wellbeing e-tools

The paper presents a participatory design research framework as a primary method for structuring youth engagement, participation and contribution to the design, development and usability evaluation of three evidencebased e-tools for wellbeing, which include smart phone mobile apps as well as e-health websites. The three projects are part of a series of six e-tools part of Safe and Supportive program under Young and Well CRC. The participatory design method, developed by Zelenko (2012) for application in design of online health promoting technologies, was further piloted in partnership with Inspire USA for specific application within the CRC, deploying a combination of creative design workshops and speculative design activities in developing e-tool prototypes with young people. This paper presents the resulting participatory research framework as it was implemented across the e-tool projects to facilitate active youth participation in co-designing the e-tools and ensuring the final designs are relevant to young people and deliver health messages in engaging ways. The principles of Participatory Design (PD) that inform the new framework include a high degree of participant agency in creative decisionmaking and a commitment to the process of co-designing, with young people working alongside designers and developers. The paper will showcase how the PD framework was applied across three projects to increase young people’s contribution to final design outcome.

A new distributed control strategy to coordinate multiple dstatcoms in LV network

Voltage rise is the main issue which limits the capacity of Low Voltage (LV) network to accommodate more Renewable Energy (RE) sources. In addition, voltage drop at peak load period is a significant power quality concern. This paper proposes a new robust voltage support strategy based on distributed coordination of multiple distribution static synchronous compensators (DSTATCOMs). The study focuses on LV networks with PV as the RE source for customers. The proposed approach applied to a typical LV network and its advantages are shown comparing with other voltage control strategies.

Contemporary cultures of service delivery to families : implications for music therapy

Family-centred and early intervention and prevention programs are a strong focus of current policy objectives within Australia, and a significant area of practice within the music therapy community. Recent shifts in the culture of policy and practice increasingly reflect ecological understandings by focussing on integrated and place-based approaches to service delivery. Further, current funding opportunities are strongly concerned with the extent to which interventions are able to reach out to highly vulnerable families that typically do not engage with services easily. Music therapy holds unique promise within these cultural shifts and thus advocates must develop a solid understanding of the concepts and related language in order to confidently engage with both funding and service systems. This paper uses an integrative review to first define and summarise current knowledge in three key areas relevant to contemporary Australian policy and practice: hard-to-reach families, home visiting as assertive outreach, and integrated or place-based service delivery. Evidence for the effectiveness of music therapy in relation to these key themes is then presented. Finally, the paper discusses the implications for the future of music therapy within the current Australian early intervention and prevention policy context and makes recommendations for moving forward on both practice and research fronts. While there is growing evidence and theory to suggest that music therapy may be uniquely efficacious in this area, greater Australian Journal of Music Therapy Vol 25, 2014 149 advocacy, documentation, research and adjustment of practices and language will further cement the position of the industry.

Directing experience : an exploration of active analysis and visual cognition theory in the training of contemporary directors

The focus of this research is the creation of a stage-directing training manual on the researcher's site at the National Institute of Dramatic Art. The directing procedures build on the work of Stanislavski's Active Analysis and findings from present-day visual cognition studies. Action research methodology and evidence-based data collection are employed to improve the efficacy of both the directing procedures and the pedagogical manual. The manual serves as a supplement to director training and a toolkit for the more experienced practitioner. The manual and research findings provide a unique and innovative contribution to the field of theatre directing.

Contemporary public spaces in urban knowledge precincts : observations from Brisbane, Australia

The advanced era of knowledge-based urban development has led to an unprecedented increase in mobility of people and the subsequent growth in the new typology of agglomerated enclaves of knowledge such as urban knowledge precincts. A new role has been assigned to contemporary public spaces of these precincts to attract and retain the mobile knowledge workforce for long by creating a sense of place for them. This paper sheds light over the place making in the globalised knowledge economy world which develops a sense of permanence spatio-temporally to knowledge workers displaying a set of particular characteristics and simultaneously is process-dependent getting developed by the internal and external flows and contributing substantially in the development of the broader context it stands in relation with. The paper highlights the observations from Australia’s new world city Brisbane to outline the application of urban design as a tool to create and sustain this bipartite place making in urban knowledge precincts, which caters diverse range of social, cultural and democratic needs. It seeks to analyse the modified permeable typology of public spaces that makes it more viable and adaptive as per the changing needs of the contemporary globalised or in other words knowledge society. This research has taken an overall process-based approach reflecting how urban design is an assemblage of the encompassing processes that underlay the resultant place making. It explores how the permeable design typology of these contemporary precincts in Brisbane develops a progressive sense of place that makes them stimulating, effervescent and vibrant.

Topological design and modulation strategy for buck-boost three-level inverters

To date, designed topologies for DC-AC inversion with both voltage-buck and boost capabilities are mainly focused on two-level circuitries with extensions to three-level possibilities left nearly unexplored. Contributing to this area of research, this paper presents the design of a number of viable buck-boost three-level inverters that can also support bidirectional power conversion. The proposed front-end circuitry is developed from the Cuk-derived buck-boost two-level inverter, and by using the "alternative phase opposition disposition" (APOD) modulation scheme, the buck-boost three-level inverters can perform distinct five-level line voltage and three-level phase voltage switching by simply controlling the active switches located in the designed voltage boost section of the circuits. As a cost saving option, one active switch can further be removed from the voltage-boost section of the circuits by simply re-routing the gating commands of the remaining switches without influencing the ac output voltage amplitude. To verify the validity of the proposed inverters, Matlab/PLECS simulations were performed before a laboratory prototype was implemented for experimental testing.

Topological design and modulation strategy for buck-boost three-level inverters

To date, designed topologies for DC-AC inversion with both voltage buck and boost capabilities are mainly focused on two-level circuitries with extensions to three-level possibilities left nearly unexplored. Contributing to this area of research, this paper presents the design of a number of viable buck-boost three-level inverters that can also support bidirectional power conversion. The proposed front-end circuitry is developed from the Cuk-derived buck-boost two-level inverter, and by using the ldquoalternative phase opposition dispositionrdquo modulation scheme, the buck-boost three-level inverters can perform distinct five-level line voltage and three-level phase voltage switching by simply controlling the active switches located in the designed voltage boost section of the circuits. As a cost saving option, one active switch can further be removed from the voltage boost section of the circuits by simply rerouting the gating commands of the remaining switches without influencing the AC output voltage amplitude. To verify the validity of the proposed inverters, MATLAB/PLECS simulations were performed before a laboratory prototype was implemented for experimental testing.

Lower partial moment and information entropy-based dynamic electricity purchasing strategy

In the electricity market environment, load-serving entities (LSEs) will inevitably face risks in purchasing electricity because there are a plethora of uncertainties involved. To maximize profits and minimize risks, LSEs need to develop an optimal strategy to reasonably allocate the purchased electricity amount in different electricity markets such as the spot market, bilateral contract market, and options market. Because risks originate from uncertainties, an approach is presented to address the risk evaluation problem by the combined use of the lower partial moment and information entropy (LPME). The lower partial moment is used to measure the amount and probability of the loss, whereas the information entropy is used to represent the uncertainty of the loss. Electricity purchasing is a repeated procedure; therefore, the model presented represents a dynamic strategy. Under the chance-constrained programming framework, the developed optimization model minimizes the risk of the electricity purchasing portfolio in different markets because the actual profit of the LSE concerned is not less than the specified target under a required confidence level. Then, the particle swarm optimization (PSO) algorithm is employed to solve the optimization model. Finally, a sample example is used to illustrate the basic features of the developed model and method.

Food safety strategy template : supporting information

A strategy sets out the actions an organisation intends to take to achieve a particular goal, such as improved food safety practices. The development of a strategy allows the organisation to review and improve their existing operations, identify and implement new strategies, prioritise actions and strategically allocate resources to maximise efficiency and effectiveness. Implementing a holistic food safety strategy will help local governments continually improve their performance in this area. To support local governments develop a holistic food safety strategy a customisable template has been developed as part of the research project ‘Food Safety: Maximising Impact by Understanding the Food Business Context’ (more information about the research project is available online at www.acelg.org.au/foodsafety).

A ramp metering strategy for rapid congestion recovery

Recurrent congestion caused by high commuter traffic is an irritation to motorway users. Ramp metering (RM) is the most effective motorway control means (M Papageorgiou & Kotsialos, 2002) for significantly reducing motorway congestion. However, given field constraints (e.g. limited ramp space and maximum ramp waiting time), RM cannot eliminate recurrent congestion during the increased long peak hours. This paper, therefore, focuses on rapid congestion recovery to further improve RM systems: that is, to quickly clear congestion in recovery periods. The feasibility of using RM for recovery is analyzed, and a zone recovery strategy (ZRS) for RM is proposed. Note that this study assumes no incident and demand management involved, i.e. no re-routing behavior and strategy considered. This strategy is modeled, calibrated and tested in the northbound model of the Pacific Motorway, Brisbane, Australia in a micro-simulation environment for recurrent congestion scenario, and evaluation results have justified its effectiveness.

Food safety strategy template

A customisable template for councils developing a food safety strategy.