Singularity-free path planning for the Stewart platform manipulator

This paper addresses the problem of singularity-free path planning for the six-degree-of-freedom parallel manipulator known as the Stewart platform manipulator. Unlike serial manipulators, the Stewart platform possesses singular configurations within the workspace where the manipulator is uncontrollable. An algorithm has been developed to construct continuous paths within the workspace of the manipulator by avoiding singularities and ill-conditioning. Given two end-poses of the manipulator, the algorithm finds out safe (well-conditioned) via points and plans a continuous path from the initial pose to the final one. When the two end-poses belong to different branches and no singularity-free path is possible, the algorithm indicates the impossibility of a valid path. A numerical example has also been presented as illustration of the path planning strategy.

The ultimate edge: The case for planning media for sustaining space communities

Governments and intergovernmental organisations have long recognised that space communities – the ultimate ‘settlements at the edge’ – will exist one day and have based their first plans for these on another region ‘at the edge’, the Antarctic. United States President Eisenhower proposed to the United Nations in 1960 that the principles of the Antarctic Treaty be applied to outer space and celestial bodies (State Department, n.d.). Three years later the UN adopted the Declaration of Legal Principles Governing the Activities of States in the Exploration and Use of Outer Space and in 1967 that became the Outer Space Treaty. According to the UN Office for Outer Space Affairs, ‘the Treaty was opened for signature by the three depository Governments (the Russian Federation, the United Kingdom and the United States of America) in January 1967, and it entered into force in October 1967’ (Office for Outer Space Affairs, n.d). The status of the treaty (at time of writing) was 89 signatories and 102 parties (Office for Disarmament Affairs, n.d.). Other related instruments include the Rescue Agreement, the Liability Convention, the Registration Convention and the Moon Agreement (Office for Outer Space Affairs, n.d.-a). Jumping to the present, a newsagency reported in July 2014 (Reuters, 2014) that the British Government had shortlisted eight aerodromes in its search for a potential base for the UK’s first spaceplane flights which Ministers want to happen by 2018 (UK Space Agency, 2014). The United States already has a spaceport, in New Mexico (Cokley, Rankin, Heinrich, & McAuliffe, 2013)...

An automated emergency landing system for fixed-wing aircraft: Planning and control

A number of hurdles must be overcome in order to integrate unmanned aircraft into civilian airspace for routine operations. The ability of the aircraft to land safely in an emergency is essential to reduce the risk to people, infrastructure and aircraft. To date, few field-demonstrated systems have been presented that show online re-planning and repeatability from failure to touchdown. This paper presents the development of the Guidance, Navigation and Control (GNC) component of an Automated Emergency Landing System (AELS) intended to address this gap, suited to a variety of fixed-wing aircraft. Field-tested on both a fixed-wing UAV and Cessna 172R during repeated emergency landing experiments, a trochoid-based path planner computes feasible trajectories and a simplified control system executes the required manoeuvres to guide the aircraft towards touchdown on a predefined landing site. This is achieved in zero-thrust conditions with engine forced to idle to simulate failure. During an autonomous landing, the controller uses airspeed, inertial and GPS data to track motion and maintains essential flight parameters to guarantee flyability, while the planner monitors glide ratio and re-plans to ensure approach at correct altitude. Simulations show reliability of the system in a variety of wind conditions and its repeated ability to land within the boundary of a predefined landing site. Results from field-tests for the two aircraft demonstrate the effectiveness of the proposed GNC system in live operation. Results show that the system is capable of guiding the aircraft to close proximity of a predefined keyhole in nearly 100% of cases.

Planning, development and management of sustainable cities: A commentary from the guest editors

Cities are the most dramatic manifestations of human activities on the surface of the earth. These human-dominated organisms—i.e., cities—degrade natural habitats, simplify species composition, disrupt hydrological systems, and modify energy flow and nutrient cycling. Today, these consequential impacts of human activities, originated from population increase, rapid urbanization, high private motor vehicle dependency, deregulated industrialization and mass livestock production, are increasing exponentially and causing great deal of environmental, social, and economic challenges both at global and local scales. In such a situation, establishment of sustainable cities, through sustainable urban development practices, is seen as a potential panacea to combat these challenges responsibly, effectively, and efficiently. This paper offers a critical review of the key literature on the issues relating to planning, development and management of sustainable cities, introduces the contributions from the Special Issue, and speculates on the prospective research directions to place necessary mechanisms to secure a sustainable urban future for all.

Population health planning and health promotion: Opportunities and challenges to improve social determinants

Complex social factors and health issues challenge equitable health outcomes for many people, in particular those living in marginalised communities. Primary health care promises solutions through population health and health promotion approaches to improve social conditions (determinants) affecting health with emphasis on change at systems levels. Yet short-term efficiency focus policy decisions without long-term planning can undermine the effectiveness of primary health care. The workshop goal is to explore opportunities and share ideas about population health planning in Primary Health Networks and other community health care settings, so as to draw out opportunities, challenges and forward thinking health planning and health promotion strategies.

Governance and regional planning outcomes: Using governance indicators to support a policy implementation approach

Regional planning faces numerous decision making uncertainties related to the complex interdependencies between urban and regional centres. Questions about how to achieve sustainable planning solutions across regions are a key uncertainty and relate to a lack of information about the actual achievement of outcomes as proposed by the objectives of a plan. Regional plan implementation and its impact on environmental, social and economic outcomes have been little explored within Australian urban and regional planning research. Despite a desire to improve the conditions across Australian regions, ambiguity persists regarding the results of regional planning efforts. Of the variables affecting regional planning, scholars argue that governance has a significant impact on achieving outcomes (see Pahl-Wostl 2009). In order to better analyse the impact of governance, we propose a set of governance indicators to examine decisions across regional planning institutions and apply this to governance models across Queensland’s regions. We contend that these governance indicators can support a more rigorous assessment of the impacts of governance models on plan implementation and outcomes. We propose that this is a way to better understand the relationship between planning and outcomes across urban and regional areas.

A critical evaluation of literature on robot path planning in dynamic environment

Robot Path Planning (RPP) in dynamic environments is a search problem based on the examination of collision-free paths in the presence of dynamic and static obstacles. Many techniques have been developed to solve this problem. Trapping in a local minima and maintaining a Real-Time performance are known as the two most important challenges that these techniques face to solve such problem. This study presents a comprehensive survey of the various techniques that have been proposed in this domain. As part of this survey, we include a classification of the approaches and identify their methods.

Submission to the External Independent Review of the United Nations Response to Allegations of Sexual Exploitation and Abuse and Other Serious Crimes by Members of Foreign Military Forces Not Under United Nations Command in the Central African Republic

In 2015 the UN Secretary-General established an External Independent Review to review how the United Nations has responded to allegations of child sexual exploitation and child sexual abuse, and to make recommendations concerning how the United Nations should respond to allegations in the future. This submission to the Review Panel draws on literature regarding children's rights, the nature of child sexual abuse, international instruments and policy, the nature of institutional child sexual abuse, and the CAR case itself. It makes recommendations for reform of UN protocols and procedures to better prevent child sexual abuse, and to improve responses to future occurrences.

A Jacobian-Based Algorithm for Planning Attitude Maneuvers Using Forward and Reverse Rotations

Algorithms for planning quasistatic attitude maneuvers based on the Jacobian of the forward kinematic mapping of fully-reversed (FR) sequences of rotations are proposed in this paper. An FR sequence of rotations is a series of finite rotations that consists of initial rotations about the axes of a body-fixed coordinate frame and subsequent rotations that undo these initial rotations. Unlike the Jacobian of conventional systems such as a robot manipulator, the Jacobian of the system manipulated through FR rotations is a null matrix at the identity, which leads to a total breakdown of the traditional Jacobian formulation. Therefore, the Jacobian algorithm is reformulated and implemented so as to synthesize an FR sequence for a desired rotational displacement. The Jacobian-based algorithm presented in this paper identifies particular six-rotation FR sequences that synthesize desired orientations. We developed the single-step and the multiple-step Jacobian methods to accomplish a given task using six-rotation FR sequences. The single-step Jacobian method identifies a specific FR sequence for a given desired orientation and the multiple-step Jacobian algorithm synthesizes physically feasible FR rotations on an optimal path. A comparison with existing algorithms verifies the fast convergence ability of the Jacobian-based algorithm. Unlike closed-form solutions to the inverse kinematics problem, the Jacobian-based algorithm determines the most efficient FR sequence that yields a desired rotational displacement through a simple and inexpensive numerical calculation. The procedure presented here is useful for those motion planning problems wherein the Jacobian is singular or null.

The story of … the military jacket

Fashion and war don’t seem an obvious pairing, but the military jacket is a fashion staple. It may take the form of a double-breasted dress uniform with brass buttons and epaulettes, trimmed in rock star braid, or it may be a khaki combat jacket, worn with Doc Martens and a scowl. Here I explore how these two forms of the military jacket were frogmarched into fashion...

Analysis of governance for sustainability planning in the Cairns Region

The relationship between governance arrangements and sustainability planning outcomes in complex governance systems remains poorly understood, despite significant discussions of governance in the environmental management literature emerging in the last decade. In order to analyse and examine the relationship between the health of sustainability planning governance and decision-making outcomes, this paper applies the Governance Systems Analysis framework (GSA) in the Cairns region. This paper analyses the sustainability planning governance arrangements in the Cairns region by exploring the capacity, connectivity and knowledge use of institutions in the region to deliver desired sustainability planning outcomes. The paper finds that the planning for sustainability in the Cairns region is on a knife’s edge, and could fail or succeed to deliver its intended decision-making outcomes. The paper concludes with recommendations for governance reform for sustainability in the Cairns region.

A dosimetric retrospective planning study comparing volumetric arc therapy (VMAT) and stereotactic body radiotherapy (SBRT) treatment plans for non-small cell lung cancer (NSCLC)

Purpose A retrospective planning study comparing volumetric arc therapy (VMAT) and stereotactic body radiotherapy (SBRT) treatment plans for non-small cell lung cancer (NSCLC). Methods and materials Five randomly selected early stage lung cancer patients were included in the study. For each patient, four plans were created: the SBRT plan and three VMAT plans using different optimisation methodologies. A total of 20 different plans were evaluated. The dose parameters of dose conformity results and the target dose constraints results were compared for these plans. Results The mean planning target volume (PTV) for all the plans (SBRT and VMAT) was 18·3 cm3, with a range from 15·6 to 20·1 cm3. The maximum dose tolerance to 1 cc of all the plans was within 140% (84 Gy) of the prescribed dose, and 95% of the PTV of all the plans received 100% of the prescribed dose (60 Gy). In all the plans, 99% of the PTV received a dose >90% of the prescribed dose, and the mean dose in all the plans ranged from 67 to 72 Gy. The planning target dose conformity for the SBRT and the VMAT (0°, 15° collimator single arc plans and dual arc) plans showed the tightness of the prescription isodose conformity to the target. Conclusions SBRT and VMAT are radiotherapy approaches that increase doses to small tumour targets without increasing doses to the organs at risk. Although VMAT offers an alternative to SBRT for NSCLC and the potential advantage of VMAT is the reduced treatment times over SBRT, the statistical results show that there was no significant difference between the SBRT and VMAT optimised plans in terms of dose conformity and organ-at-risk sparing.

A lesson from cyclone Larry: An untold story of the success of good coastal planning

When tropical cyclone Larry crossed the Queensland coast on 20 March 2006, commercial, recreational and naval vessels in the port of Cairns, 60 km north of the eye of the cyclone and others closer to the eye, were protected from the destructive winds by sheltering in deep mangrove creeks in Trinity Inlet and off other coastal rivers. The Trinity Inlet mangroves are protected under the comprehensive multi-use Trinity Inlet Management Plan, agreed by the local and state government agencies (Cairns City Council, the Cairns Port Authority and the Queensland Government). Using this Australian example and one from the town of Palompon in Leyte province, central Philippines, we show how long-term mangrove habitat protection resulting from well-conceived coastal planning can deliver important economic and infrastructure benefits.

Supporting mindful planners in a mindless system: Limitations to the emotional turn in planning practice

Despite widespread acknowledgment within planning scholarship that emotion – both present in knowledge and a form of knowledge – is integral to lived experience and the judgement of planners, it is often sidelined within planning practice. The extent to which mainstream planning has been able or willing to accommodate emotions remains constrained and the emotions of planners and the public remain an unacknowledged but pervasive presence. Antonio Ferreira recently highlighted in this journal the importance of attending to emotions at the level of the individual planner through the concept of mindfulness. We argue this approach must be complemented by an acknowledgement of the structural and institutional limitations of including emotions in planning practice. Drawing from the emotional geographies literature to describe a social-spatial conceptualisation of emotion, we highlight ontological and practical tensions associated with the achievement of the ‘emotional turn’ and advance a more purposeful engagement with emotion in mainstream planning practice.