Bearing-only SLAM : a vision-based navigation system for autonomous robots

To navigate successfully in a previously unexplored environment, a mobile robot must be able to estimate the spatial relationships of the objects of interest accurately. A Simultaneous Localization and Mapping (SLAM) sys- tem employs its sensors to build incrementally a map of its surroundings and to localize itself in the map simultaneously. The aim of this research project is to develop a SLAM system suitable for self propelled household lawnmowers. The proposed bearing-only SLAM system requires only an omnidirec- tional camera and some inexpensive landmarks. The main advantage of an omnidirectional camera is the panoramic view of all the landmarks in the scene. Placing landmarks in a lawn field to define the working domain is much easier and more flexible than installing the perimeter wire required by existing autonomous lawnmowers. The common approach of existing bearing-only SLAM methods relies on a motion model for predicting the robot’s pose and a sensor model for updating the pose. In the motion model, the error on the estimates of object positions is cumulated due mainly to the wheel slippage. Quantifying accu- rately the uncertainty of object positions is a fundamental requirement. In bearing-only SLAM, the Probability Density Function (PDF) of landmark position should be uniform along the observed bearing. Existing methods that approximate the PDF with a Gaussian estimation do not satisfy this uniformity requirement. This thesis introduces both geometric and proba- bilistic methods to address the above problems. The main novel contribu- tions of this thesis are: 1. A bearing-only SLAM method not requiring odometry. The proposed method relies solely on the sensor model (landmark bearings only) without relying on the motion model (odometry). The uncertainty of the estimated landmark positions depends on the vision error only, instead of the combination of both odometry and vision errors. 2. The transformation of the spatial uncertainty of objects. This thesis introduces a novel method for translating the spatial un- certainty of objects estimated from a moving frame attached to the robot into the global frame attached to the static landmarks in the environment. 3. The characterization of an improved PDF for representing landmark position in bearing-only SLAM. The proposed PDF is expressed in polar coordinates, and the marginal probability on range is constrained to be uniform. Compared to the PDF estimated from a mixture of Gaussians, the PDF developed here has far fewer parameters and can be easily adopted in a probabilistic framework, such as a particle filtering system. The main advantages of our proposed bearing-only SLAM system are its lower production cost and flexibility of use. The proposed system can be adopted in other domestic robots as well, such as vacuum cleaners or robotic toys when terrain is essentially 2D.

Community engagement and groundwater investigation in a rural/peri urban basaltic aquifier system, Tamborine Mountain, South East Queensland

The Tamborine Mt area is a popular residential and tourist area in the Gold Coast hinterland, SE Qld. The 15km2 area occurs on elevated remnant Tertiary Basalts of the Beechmont Group, which comprise a number of mappable flow units originally derived from the Tweed volcanic centre to the south. The older Albert Basalt (Tertiary), which underlies the Beechmont Basalt at the southern end of the investigation area, is thought to be derived from the Focal Peak volcanic centre to the south west. The Basalts contain a locally significant ‘un-declared’ groundwater resource, which is utilised by the Tamborine Mt community for: • domestic purposes to supplement rainwater tank supplies, • commercial scale horticulture and • commercial export off-Mountain for bottled water. There is no reticulated water supply, and all waste water is treated on-site through domestic scale WTPs. Rainforest and other riparian ecosystems that attract residents and tourist dollars to the area, are also reliant on the groundwater that discharges to springs and surface streams on and around the plateau. Issues regarding a lack of compiled groundwater information, groundwater contamination, and groundwater sustainability are being investigated by QUT, utilising funding provided by the Federal Government’s ‘Caring for our Country’ programme through SEQ Catchments Ltd. The objectives of the two year project, which started in April 2009, are to: • Characterise the nature and condition of groundwater / surface water systems in the Tamborine Mountain area in terms of the issues being raised; • Engage and build capacity within the community to source local knowledge, encourage participation, raise awareness and improve understanding of the impacts of land and water use; • Develop a stand-alone 3D Visualisation model for dissemination into the community and use as a communication tool.

Linking the fifth pillar to the first in the UN Decade of Action

The UN Decade of Action outlines five pillars of activity within a safe system framework to achieve the goal of slowing and then reversing the global growth in road traffic fatalities, especially in low-income and middle-income countries. The first four pillars - road safety management, safer roads and mobility, safer vehicles, and safer road users – have a strong focus on prevention of road traffic crashes and mitigation of energy exchange when a crash occurs. The fifth pillar – post-crash response – is far more specific, focusing only on crash victims in the event of a safe system failure. The victims appear to be relevant to the first four pillars only insofar as their numbers can be used to evaluate the success of road safety programs and identify the target groups and contributing factors. This paper argues that a better understanding of the lived experience of long term disability from traffic crashes has the potential to provide a feedback loop from the fifth pillar to the first. Research conducted in Thailand with male crash victims with spinal injury demonstrates that patterns of attribution and social and cultural factors have important implications for road safety management and for interventions aimed at influencing behaviour. In addition, the mobility constraints experienced by people with long term disability can point to systemic issues that might otherwise go unnoticed. The UN Decade of Action can benefit from a more thorough exploration of the experiences and circumstances of people with long term disability as the result of a road traffic crash. Rather than being evidence of the failure of the safe system, they can inform the development of more effective road safety management on low-income and middle-income countries.

Selection et controle de modes de deplacement pour un robot mobile autonome en environnements naturels

Autonomous navigation and locomotion of a mobile robot in natural environments remain a rather open issue. Several functionalities are required to complete the usual perception/decision/action cycle. They can be divided in two main categories : navigation (perception and decision about the movement) and locomotion (movement execution). In order to be able to face the large range of possible situations in natural environments, it is essential to make use of various kinds of complementary functionalities, defining various navigation and locomotion modes. Indeed, a number of navigation and locomotion approaches have been proposed in the literature for the last years, but none can pretend being able to achieve autonomous navigation and locomotion in every situation. Thus, it seems relevant to endow an outdoor mobile robot with several complementary navigation and locomotion modes. Accordingly, the robot must also have means to select the most appropriate mode to apply. This thesis proposes the development of such a navigation/locomotion mode selection system, based on two types of data: an observation of the context to determine in what kind of situation the robot has to achieve its movement and an evaluation of the behavior of the current mode, made by monitors which influence the transitions towards other modes when the behavior of the current one is considered as non satisfying. Hence, this document introduces a probabilistic framework for the estimation of the mode to be applied, some navigation and locomotion modes used, a qualitative terrain representation method (based on the evaluation of a difficulty computed from the placement of the robot's structure on a digital elevation map), and monitors that check the behavior of the modes used (evaluation of rolling locomotion efficiency, robot's attitude and configuration watching. . .). Some experimental results obtained with those elements integrated on board two different outdoor robots are presented and discussed.

Unspeakably present: The (un)acknowledgment of diverse sexuality and gender human rights in Australian youth justice systems

A number of international human rights frameworks protect the rights of young people in contact with the criminal justice system in states parties, including Australia. These frameworks inform youth justice policy in Australia’s jurisdictions. While the frameworks protect young people’s right to non-discrimination on the grounds of ‘race’, religion and political opinion, the rights of young people to non-discrimination on the grounds of sexuality and gender diversity are not explicitly protected. This is problematic given that lesbian, gay, bisexual, trans, intersex and queer (LGBTIQ) young people appear over-represented in youth justice systems. This article argues that the exclusion of this group from human rights frameworks has an important flow-on effect: the marginalisation of the right of LGBTIQ young people to non-discrimination in policy and discourse that is informed by international human rights frameworks. After outlining the relevant frameworks, this article examines the evidence about LGBTIQ young people’s interactions with youth justice agencies, particularly police. The evidence indicates that the human rights of LGBTIQ young people are frequently breached in these interactions. We conclude by arguing that it is timely to consider how best to protect the human rights of LBGTIQ young people and keep their rights on the agenda.

Designing a quality health information system: Case study analysis of maternal and child health in Papua New Guinea

Papua New Guinea (PNG) is facing what must seem like an insurmountable challenge to deliver quality healthcare servicesfor women living in both rural and urban areas. Glo bal governing bodies and donor agencies including WHO and UN have indicated that PNG does not have an appropriate health information system. Although there are some systems in place, to date, little research has been conducted on improving or resolving the data integrity and integration issues of the existing health information systems and automating the capture of women and newborns information in PNG. This current research study concentrates on the adoption of eHealth, as an innovative tool to strengthen the health information systems in PNG to meet WHO standards. The research targets maternal and child health focussing on child birth records asan exemplar...

A preliminary analysis of the impact of UN MDGs and RIO+20 on corporate social accountability practices

This chapter explores the impact of UN Millennium Development Goals (MDGs) and Rio + 20 in improving Corporate Social Responsibility (CSR) practices. While MDGs and Rio + 20 have suggested additive guidelines for improving CSR practices, they do not provide a strong legislative mandate. We find both MDGs and Rio + 20 have had limited cumulative effect on CSR practices and discourses within the corporate reports. UN bodies should bring a new policy and regulatory framework that addresses limitations in the principles espoused in the MDGs and Rio + 20. An independent monitoring system (a social compliance audit mechanism) can be mandated in an attempt to make incremental substantive change.