Constrained control design for dynamic positioning of marine vehicles with control allocation

In this paper, we address the control design problem of positioning of over-actuated marine vehicles with control allocation. The proposed design is based on a combined position and velocity loops in a multi-variable anti-windup implementation together with a control allocation mapping. The vehicle modelling is considered with appropriate simplifications related to low-speed manoeuvring hydrodynamics and vehicle symmetry. The control design is considered together with a control allocation mapping. We derive analytical tuning rules based on requirements of closed-loop stability and performance. The anti- windup implementation of the controller is obtained by mapping the actuator-force constraint set into a constraint set for the generalized forces. This approach ensures that actuation capacity is not violated by constraining the generalized control forces; thus, the control allocation is simplified since it can be formulated as an unconstrained problem. The mapping can also be modified on-line based on actuator availability to provide actuator-failure accommodation. We provide a proof of the closed-loop stability and illustrate the performance using simulation scenarios for an open-frame underwater vehicle.

Non-formal techniques for early assessment of design ideas for services

Designing systems for multiple stakeholders requires frequent collaboration with multiple stakeholders from the start. In many cases at least some stakeholders lack a professional habit of formal modeling. We report observations from student design teams as well as two case studies, respectively of a prototype for supporting creative communication to design objects, and of stakeholder-involvement in early design. In all observations and case studies we found that non-formal techniques supported strong collaboration resulting in deep understanding of early design ideas, of their value and of the feasibility of solutions.

Control design for positioning of underwater vehicles with control allocation

In this paper, we address the control design problem of positioning of over-actuated underwater vehicles. The proposed design is based on a control architecture with combined position and velocity loops and a control tuning method based on the decoupled models. We derive analytical tuning rules based on requirements of closed-loop stability, positioning performance, and the vehicle velocity dynamic characteristics. The vehicle modelling is considered from force to motion with appropriate simplifications related to low-speed manoeuvring hydrodynamics and vehicle symmetry. The control design is considered together with a control allocation mapping. This approach makes the control tuning independent of the characteristics of the force actuators and provides the basis for control reconfiguration in the presence of actuator failure. We propose an anti-wind-up implementation of the controller, which ensures that the constraints related to actuation capacity are not violated. This approach simplifies the control allocation problem since the actuator constraints are mapped into generalised force constraints.

Design of a robust grid interface system for PMSG-based wind turbine generators

A robust and reliable grid power interface system for wind turbines using a permanent-magnet synchronous generator (PMSG) is proposed in this paper, where an integration of a generator-side three-switch buck-type rectifier and a grid-side Z-source inverter is employed as a bridge between the generator and the grid. The modulation strategy for the proposed topology is developed from space-vector modulation and Z-source network operation principles. Two PMSG control methods, namely, unity-power-factor control and rotor-flux-orientation control (Id = 0), are studied to establish an optimized control scheme for the generator-side three-switch buck-type rectifier. The system control scheme decouples active- and reactive-power control through voltage-oriented control and optimizes PMSG control for the grid- and generator-side converters independently. Maximum power point tracking is implemented by adjusting the shoot-through duty cycles of the Z-source network. The design considerations of the passive components are also provided. The performances and practicalities of the designed architecture have been verified by simulations and experiments.

See to believe : the Center for Tactical Magic’s sleight of hand

The Bay Area’s Center for Tactical Magic has been performing ‘‘magical’’ art interventions since 2000. The Center’s work augments traditional activist techniques by offering new conceptions of what art and activism can entail in a contemporary urban context. This article explores how Jacques Rancie`re’s reconfigured relationship between art and politics can be applied to the Center’s work, providing new distributions of the sensible for participants.

Learning in and out of university : Aboriginal and Torres Strait Islander students’ conceptions and strategies used to learn

Research suggests that students’ approaches to learning and learning outcomes are closely related to their conceptions of learning. This paper describes a phenomenographically inspired investigation into conceptions of formal learning held by 22 Aboriginal and Torres Strait Islander students from three Australian universities in Queensland; experiences of informal learning, reasons for studying and strategies used to learn were also investigated. The attrition rate for these students in tertiary education is higher than that of any other group of students. It was hoped that information gained may delineate factors that contribute to high attrition rates and therefore inform courses of action that may lead to improved teaching and learning practices for these students. Additionally, success in tertiary education for Aboriginal and Torres Strait Islander students may increase their involvement in mainstream society. Results showed that they view and approach university learning in much the same way as other university students. It was also apparent that, generally, the strategies these students used did not match the conceptions of learning they held. An interesting result was the difference between the conceptions of formal learning and explanations of informal learning

Learning in formal and informal contexts : conceptions and strategies of Aboriginal and Torres Strait Islander university students

Research suggests that students' approaches to learning and hence learning outcomes are closely related to their conceptions of learning. This paper describes an investigation into conceptions of formal learning held by 22 Aboriginal and Torres Strait Islander students from three Australian universities in Queensland; categories of informal learning, reasons for studying and strategies used to learn were also investigated. The attrition rate for these students in tertiary education is higher than that of any other group of students. The main aim of this study was to determine their conceptions of learning in order to provide information that might facilitate instruction more suited to their needs in order to address the high attrition rate. Results showed that these students view and approach university learning in much the same way as other university students. It was also apparent that, for the most part, the strategies these students used did not match the conceptions of learning they held. An interesting result was the difference between the conceptions of formal learning and perceptions of informal learning.

The dynamics of expertise acquisition in sport : the role of affective learning design

Objectives The aim of this position paper is to discuss the role of affect in designing learning experiences to enhance expertise acquisition in sport. The design of learning environments and athlete development programmes are predicated on the successful sampling and simulation of competitive performance conditions during practice. This premise is captured by the concept of representative learning design, founded on an ecological dynamics approach to developing skill in sport, and based on the individual-environment relationship. In this paper we discuss how the effective development of expertise in sport could be enhanced by the consideration of affective constraints in the representative design of learning experiences. Conclusions Based on previous theoretical modelling and practical examples we delineate two key principles of Affective Learning Design: (i) the design of emotion-laden learning experiences that effectively simulate the constraints of performance environments in sport; (ii) recognising individualised emotional and coordination tendencies that are associated with different periods of learning. Considering the role of affect in learning environments has clear implications for how sport psychologists, athletes and coaches might collaborate to enhance the acquisition of expertise in sport.

Privacy in the new era of visible and sharable energy-use information

A new era of visible and sharable electricity information is emerging. Where eco-feedback is installed, households can now visualise many aspects of their energy consumption and share this information with others through Internet platforms such as social media. Despite providing users with many affordances, eco-feedback information can make public previously private actions from within the intimate setting of the family home. This paper represents a study focussing specifically on the privacy aspects of nascent ways for viewing and sharing this new stream of personal information. It explores the nuances of privacy related to eco-feedback both within and beyond the family home. While electricity consumption information may not be considered private itself, the household practices which eco-feedback systems makes visible may be private. We show that breaches of privacy can occur in unexpected ways and have the potential to cause distress. The paper concludes with some suggestions for how to realise the benefits of sharing energy consumption information whist effectively maintaining individuals’ conceptions of adequate privacy.

Subtropical values and principles of subtropical design for the South East Queensland region : a report for the Office of Urban Management Queensland Government

The Office of Urban Management recognises that the values which characterise the SEQ region as 'subtropical' are important determinants of form in urban and regional planning. Subtropical values are those qualities on which our regional identity depends. A built environment which responds positively to these values is a critical ingredient for achieving a desirable future for the region. The Centre for Subtropical Design has undertaken this study to identify the particular set of values which characterises SEQ, and to translate theses values into design principals that will maintain and reinforce the value set. The principles not only apply to the overall balance between the natural environment and the built environment, but can be applied by local government authorities to guide local planning schemes and help shape specific built for outcomes.

Contextual constraining of student design practices

Background Engineering design is of significant interest to engineering educators. As yet, how the higher education context shapes student outcomes in engineering design courses remains underexplored. Since design courses are the primary way students are taught the critical topic of design, it is important to understand how the institutional and organizational contexts shape student outcomes and how we could improve design projects, given the context. Purpose We sought to answer two questions: What aspects of the design education process are salient, or important, for students? How do these salient aspects affect their design practices? Design/Method We used a qualitative case study approach to address the research questions because of our emphasis on understanding process-related aspects of design work and developing an interpretive understanding from the students’ perspective. Results Using a nested structuration framework, we show that the context of design practices shaped students’ outcomes by constraining their approach to the project and by providing a framework for their design process. We provide recommendations for design educators to help students overcome impediments to achieving learning objectives for design activities. Our research questions the efficacy of teaching engineering design when a design problem lacks a context beyond the classroom. Conclusions The institutional and organizational contexts influence student design practices. Engineering educators should carefully consider the potential effects of the design projects they implement within a higher education context.

Facilitating sustainable professional part-time work: A question of design?

Despite significant socio-demographic and economic shifts in the contours of work over the past 40 years, there has been surprisingly little change in the way work is designed. Current understandings of the content and structure of jobs are predominantly underpinned by early 20th century theories derived from the manufacturing industry where employees worked independently of each other in stand-alone organisations. It is only in the last 10 years that elaborations and extensions to job/work design theory have been posed, which accommodate some of the fundamental shifts in contemporary work settings, yet these extended frameworks have received little empirical attention. Utilising contemporary features of work design and a sample of professional service workers, the purpose of this study is to examine to what extent and how part-time roles are designed relative to equivalent full-time roles. The findings contribute to efforts to design effective part-time roles that balance organisational and individual objectives.

The role of emotion in product, service and business model design

Designers have become aware of the importance of creating strong emotional experiences intertwined with new tangible products for the past decade, however an increased interest from firms has emerged in developing new service and business models as complimentary forms of emotion-driven innovation. This interdisciplinary study draws from the psychological sciences – theory of emotion – and the management sciences – business model literature to introduce this new innovation agenda. The term visceral hedonic rhetoric (VHR) is defined as the properties of a product, (and in this paper service and business model extensions) that persuasively induce the pursuit of pleasure at an instinctual level of cognition. This research paper lays the foundation for VHR beyond a product setting, presenting the results from an empirical study where organizations explored the possibilities for VHR in the context of their business. The results found that firms currently believe VHR is perceived in either their product and/or services they provide. Implications suggest shifting perspective surrounding the use of VHR across a firm’s business model design in order to influence the outcomes of their product and/or service design, resulting in an overall stronger emotional connection with the customer.

A comparative study of two design charrettes: Implications for codesign and participatory action research

The purpose of this paper is to explore how participatory prototyping, through the use of design charrettes, can advance participatory action research (PAR) approaches and contribute to codesign practices in organisational settings. This will be achieved through the comparison of two varying design charrette experiences from a PAR initiative to redesign spaces in the Auraria Library in Denver, Colorado. Each design charrette followed a three-stage sequence of information sharing, idea generation and prototyping, and prioritisation with each stage building upon the former, both in terms of design concepts and in building up elements of ‘making’. While both charrette structures were similar, leadership and execution varied considerably. Lessons learned from the two design charrette experiences are presented, including the value of participatory prototyping within PAR to support ‘research through design’ activities. In addition, it highlights the value of authentic design participation of ‘designing with’ rather than ‘designing for’ to encourage optimal design outcomes.

Reflecting on Reggio: An evaluation of design intent in an early childhood learning environment

Reggio Emilia is an educational philosophy that encourages teachers, students and their parents to collaborate and actively engage with the environment. This study investigates how the Reggio Emilia design approach was translated architecturally for a kindergarten in an Australian context, and provides insights into the operation of this Reggio kindergarten and the impact that it is now having on the occupants. It evaluates the original architectural design intent of the Reggio Emilia early childhood learning environment against its spatial provision. The relationship that the Reggio Emilia approach facilitates between students and the environment, and the contribution that this approach has on their learning, are also explored. Several key themes emerging from the Reggio values were identified in the literature. These were then used to inform an exploration of the kindergarten spaces and places.. Architects, teachers and a sustainability manager of the kindergarten were interviewed with their experiences constituting the primary data of this study. Using a Grounded Theory methodology, systematic data coding and analysis were then conducted. Themes and concepts that emerged from this process include: differing interpretations of the Reggio Emilia philosophy; motivations for neglect of traditional external structures and play equipment; the impact of education for sustainability; and the positive effects that Reggio Emilia is having on the rest of the institution’s development.