Motion planning and stochastic control with experimental validation on a planetary rover

Motion planning for planetary rovers must consider control uncertainty in order to maintain the safety of the platform during navigation. Modelling such control uncertainty is difficult due to the complex interaction between the platform and its environment. In this paper, we propose a motion planning approach whereby the outcome of control actions is learned from experience and represented statistically using a Gaussian process regression model. This model is used to construct a control policy for navigation to a goal region in a terrain map built using an on-board RGB-D camera. The terrain includes flat ground, small rocks, and non-traversable rocks. We report the results of 200 simulated and 35 experimental trials that validate the approach and demonstrate the value of considering control uncertainty in maintaining platform safety.

Enhanced locomotion control for a planetary rover

This article presents an approach to improve and monitor the behavior of a skid-steering rover on rough terrains. An adaptive locomotion control generates speeds references to avoid slipping situations. An enhanced odometry provides a better estimation of the distance travelled. A probabilistic classification procedure provides an evaluation of the locomotion efficiency on-line, with a detection of locomotion faults. Results obtained with a Marsokhod rover are presented throughout the paper

Symptom control and quality of life in lux-lung 3 : a phase III study of afatinib or cisplatin/pemetrexed in patients with advanced lung adenocarcinoma with EGFR mutations

Purpose Patient-reported symptoms and health-related quality of life (QoL) benefits were investigated in a randomized, phase III trial of afatinib or cisplatin/pemetrexed. Patients and Methods Three hundred forty-five patients with advanced epidermal growth factor receptor (EGFR) mutation-positive lung adenocarcinoma were randomly assigned 2:1 to afatinib 40 mg per day or up to six cycles of cisplatin/pemetrexed. Lung cancer symptoms and health-related QoL were assessed every 21 days until progression using the European Organisation for Research and Treatment of Cancer Quality of Life Questionnaire C30 and Lung Cancer-13 questionnaires. Analyses of cough, dyspnea, and pain were preplanned, including percentage of patients who improved on therapy, time to deterioration of symptoms, and change in symptoms over time. Results Questionnaire compliance was high. Compared with chemotherapy, afatinib significantly delayed the time to deterioration for cough (hazard ratio [HR], 0.60; 95% CI, 0.41 to 0.87; P = .007) and dyspnea (HR, 0.68; 95% CI, 0.50 to 0.93; P = .015), but not pain (HR, 0.83; 95% CI, 0.62 to 1.10; P = .19). More patients on afatinib (64%) versus chemotherapy (50%) experienced improvements in dyspnea scores (P lt; .010). Differences in mean scores over time significantly favored afatinib over chemotherapy for cough (P lt; .001) and dyspnea (P = .001). Afatinib showed significantly better mean scores over time in global health status/QoL (P = .015) and physical (P = .001), role (P = .004), and cognitive (P lt; .007) functioning compared with chemotherapy. Fatigue and nausea were worse with chemotherapy, whereas diarrhea, dysphagia, and sore mouth were worse with afatinib (all P = .01). Conclusion In patients with lung adenocarcinoma with EGFR mutations, first-line afatinib was associated with better control of cough and dyspnea compared with chemotherapy, although diarrhea, dysphagia, and sore mouth were worse. Global health status/QoL was also improved over time with afatinib compared with chemotherapy.

Cross-layer design for traffic management in wireless networked control systems

Wireless networked control systems (WNCSs) have been increasingly deployed in industrial applications. As they require timely data packet transmissions, it is difficult to make efficient use of the limited channel resources, particularly in contention based wireless networks in the layered network architecture. Aiming to maintain the WNCSs under critical real-time traffic condition at which the WNCSs marginally meet the real-time requirements, a cross-layer design (CLD) approach is presented in this paper to adaptively adjust the control period to achieve improved channel utilization while still maintaining effective and timely packet transmissions. The effectiveness of the proposed approach is demonstrated through simulation studies.

Mobility and out-of-home activities of older people living in suburban environments : ‘Because I'm a driver, I don't have a problem'

Governments are challenged by the need to ensure that ageing populations stay active and engaged as they age. Therefore, it is critical to investigate the role of mobility in older people's engagement in out-of-home activities, and to identify the experiences they have within their communities. This research investigates the use of transportation by older people and its implications for their out-of-home activities within suburban environments. The qualitative, mixed-method approach employs data collection methods which include a daily travel diary (including a questionnaire), Global Positioning System (GPS) tracking and semi-structured interviews with older people living in suburban environments in Brisbane, Australia. Results show that older people are mobile throughout the city, and their car provides them with that opportunity to access desired destinations. This ability to drive allows older people to live independently and to assist others who do not drive, particularly where transport alternatives are not as accessible. The ability to transport goods and other people is a significant advantage of the private car over other transport options. People with no access to private transportation who live in low-density environments are disadvantaged when it comes to participation within the community. Further research is needed to better understand the relationship between transportation and participation within the community environment, to assist policy makers and city and transportation planners to develop strategies for age-friendly environments within the community.

Recasting the theory of mosquito-borne pathogen transmission dynamics and control

Mosquito-borne diseases pose some of the greatest challenges in public health, especially in tropical and sub-tropical regions of theworld. Efforts to control these diseases have been underpinned by a theoretical framework developed for malaria by Ross and Macdonald, including models, metrics for measuring transmission, and theory of control that identifies key vulnerabilities in the transmission cycle. That framework, especially Macdonald’s formula for R0 and its entomological derivative, vectorial capacity, are nowused to study dynamics and design interventions for many mosquito-borne diseases. A systematic review of 388 models published between 1970 and 2010 found that the vast majority adopted the Ross–Macdonald assumption of homogeneous transmission in a well-mixed population. Studies comparing models and data question these assumptions and point to the capacity to model heterogeneous, focal transmission as the most important but relatively unexplored component in current theory. Fine-scale heterogeneity causes transmission dynamics to be nonlinear, and poses problems for modeling, epidemiology and measurement. Novel mathematical approaches show how heterogeneity arises from the biology and the landscape on which the processes of mosquito biting and pathogen transmission unfold. Emerging theory focuses attention on the ecological and social context formosquito blood feeding, themovement of both hosts and mosquitoes, and the relevant spatial scales for measuring transmission and for modeling dynamics and control.

A pilot randomised trial of Medilixir cream shows some promising results, but control treatment may have been inappropriate

Aim To test the efficacy of Medilixir [cream] against the standard treatment of aqueous cream in the provision of relief from the symptoms of postburn itch. Design RCT with two parallel arms. Setting Professor Stuart Pegg Adult Burns Centre, Royal Brisbane and Women's Hospital, Brisbane, Australia. Participants Fifty-two patients aged between 18 and 80 years, admitted directly to the burns centre between 10 March and 22 July 2008, were able to provide informed consent, and had shown no allergic reaction to a patch test with the study medication, were randomised. Patients admitted from intensive care or high dependency were excluded. Main results Effect estimates and confidence intervals were not reported for any of the outcomes; only group means/proportions and P-values from hypothesis testing were provided. More patients in the intervention group reported itch reduction compared to comparison treatment (91 vs. 82%, P=0.001). Itch recurrence after cream application occurred later in the intervention group compared to the control group (P<0.001). Use of antipruritic medication was significantly greater in the control group (P=0.023). There was no difference in sleep disturbance between groups (not quantified). On average, Medilixir took longer to apply than aqueous cream (157s for Medilixir vs. 139s for aqueous cream; mean difference 17s), but authors noted that the groups did not differ significantly (CI for mean difference and P-values were not reported).

Power sharing control with frequency droop in a hybrid microgrid

A microgrid may contain a large number of distributed generators (DGs). These DGs can be either inertial or non-inertial, either dispatchable or non-dispatchable. Moreover, the DGs may operate in plug and play fashion. The combination of these various types of operation makes the microgrid control a challenging task, especially when the microgrid operates in an autonomous mode. In this paper, a new control algorithm for converter interfaced (dispatchable) DG is proposed which facilitates smooth operation in a hybrid microgrid containing inertial and non-inertial DGs. The control algorithm works satisfactorily even when some of the DGs operate in plug and play mode. The proposed strategy is validated through PSCAD simulation studies.

A distributed control based coordination scheme of household PV systems for overvoltage prevention

This paper presents a distributed communication based active power curtailment (APC) control scheme for grid connected photovoltaic (PV) systems to address voltage rise. A simple distribution feeder model is presented and simulated using MATLAB. The resource sharing based control scheme proposed is shown to be effective at reducing voltage rise during times of peak generation and low load. Simulations also show the even distribution of APC using simple communications. Simulations demonstrate the versatility of the proposed control method under major communication failure conditions. Further research may lead to possible applications in coordinated electric vehicle (EV) charging.

Older driver safety and mobility : where to from here?

The older adult population (65 years and over) represents a rapid growing segment of the population in many developed countries. Unlike earlier cohorts of older drivers that included many who were familiar with public transportation, the present cohort of older drivers historically has a greater reliance on the private automobile as their main form of transportation. Recent studies of older adults’ travel patterns reported automobile to be responsible for over 80% of the total number of hours spent on all trips. While older drivers, as a group, does not demonstrate a particular road risk, the evident demographic change and the increased physical fragility and severity of crash-related injuries makes older driver safety a prevalent public health issue. This study systematically reviewed the safety and mobility outcomes of existing strategies used internationally to manage older driver safety, with a specific focus on age-based testing (ABT), license restriction and self-regulation (i.e. voluntary limiting driving in potentially hazardous situations). ABT remains the most commonly adopted strategy by licensing authorities both within Australia and internationally. Heterogeneity in the development of functional declines, and in driving behaviours within the older driver population, makes age an unreliable index of driving capacity. Given the counter-productive safety and mobility outcomes of ABT strategies, their continued popularity within both the legislative and public domains remains problematic. Self-regulation may provide greater potential for reducing older drivers’ crash risk while maintaining their mobility and independence. The current body of literature on older drivers’ self-regulation is systematically reviewed. Despite being promoted by researchers and licensing authorities as a strategy to maintain older driver safety and mobility, the proportion of older drivers who self-regulate, and exactly how they do so, remains unclear. Future research on older drivers’ adoption of self-regulation, particularly the underlying psychological factors that underlies this process, is needed in order to promote its use within the older driver community.

Terms of engagement : consensus or control in remote Australian resource management?

Public engagement is a defining feature of collaborative approaches to environmental management (Petts 2006, Whelan and Oliver 2005). Public engagement in this context is focused on incorporating residents and communities of interest in activities like ecological restoration, catchment management, and environmental conservation in a wide range of situations (Nelson and Pettit 2004, Petts 2007). Some authors consider public engagement to be a sign of healthy democratic functioning in society (Skocpol and Fiorina 1999). Others draw attention to overcoming widely noted practical limitations of top-down mechanisms, emphasising that public engagement results in programs being implemented more effectively (Broderick 2005, Leach et al. 1999).

Seeds of cosmopolitan future? Young people and their aspirations for future mobility

Mobility across space is an exemplary characteristic of the global era and an important aspect of the cultural experience of many people in advanced industrialised nations. Mobility evokes powerful images that effectively counter any illusion of stationary life and provide a break from the insularity of the local and parochial. High levels of mobility are simultaneously a fact, a necessity and a cultural aspiration. In recent times, debates about mobility in social theory have considered the relationship between mobility and cosmopolitan culture and identities (Hannerz, 1990, Urry, 1990, 2000, Beck, 2006). Against this backdrop, this paper also draws on some of the more recent discussions about the emergence of globalised and cosmopolitan identities among young people (Beck and Beck-Gernsheim, 2009). Using data from a longitudinal study of young people in Queensland, this paper provides an insight into young people’s aspirations about future mobility. The data affirm Skeggs’ (2004) comment that mobility is an unequal resource, and demonstrate that aspirations of future mobility reflect numerous social, economic and cultural realities of young people’s lives. This inevitably leads us to problematise the established, and often abstract, nexus between cosmopolitanism and mobility in contemporary debates about cosmopolitanism.

Wide-area control of aggregated power systems

This paper proposes a new method for stabilizing disturbed power systems using wide area measurement and FACTS devices. The approach focuses on both first swing and damping stability of power systems following large disturbances. A two step control algorithm based on Lyapunov Theorem is proposed to be applied on the controllers to improve the power systems stability. The proposed approach is simulated on two test systems and the results show significant improvement in the first swing and damping stability of the test systems.

Control, operation and power sharing among parallel converter-interfaced DERs in a microgrid in the presence of unbalanced and harmonic loads

This paper demonstrates power management and control of DERs in an autonomous MG. The paper focuses on the control and performance of converter-interfaced DERs in voltage controlled mode. Several case studies are considered for a MG based on the different types of loads supplied by the MG (i.e. balanced three-phase, unbalanced, single-phase and harmonic loads). DERs are controlled by adjusting the voltage magnitude and angle in their converter output through droop control, in a decentralized concept. Based on this control method, DERs can successfully share the total demand of the MG in the presence of any type of loads. This includes proper total power sharing, unbalanced power sharing as well as harmonic power sharing, depending on the load types. The efficacy of the proposed power control, sharing and management among DERs in a microgrid is validated through extensive simulation studies using PSCAD/EMTDC.

Voltage regulation, power balancing and battery storage discharge control by smart demand side management and multi-objective decision making

A novel intelligent online demand side management system is proposed for peak load management. The method also regulates the network voltage, balances the power in three phases and coordinates the battery storage discharge within the network. This method uses low cost controllers with low bandwidth two-way communication installed in costumers' premises and at distribution transformers to manage the peak load while maximizing customer satisfaction. A multi-objective decision making process is proposed to select the load(s) to be delayed or controlled. The efficacy of the proposed control system is verified through an event-based developed simulation in Matlab.