Authority-Sharing Control of Assistive Robotic Walkers

A recognized consequence of population aging is a reduced level of mobility, which undermines the life quality of several senior citizens. A promising solution is represented by assisitive robotic walkers, combining the benefits of standard walkers (improved stability and physical support) with sensing and computing ability to guarantee cognitive support. In this context, classical robot control strategies designed for fully autonomous systems (such as fully autonomous vehicles, where the user is excluded from the loop) are clearly not suitable, since the user’s residual abilities must be exploited and practiced. Conversely, to guarantee safety even in the presence of user’s cognitive deficits, the responsibility of controlling the vehicle motion cannot be entirely left to the assisted person. The authority-sharing paradigm, where the control authority, i.e., the capability of controlling the vehicle motion, is shared between the human user and the control system, is a promising solution to this problem. This research develops control strategies for assistive robotic walkers based on authority-sharing: this way, we ensure that the walker provides the user only the help he/she needs for safe navigation. For instance, if the user requires just physical support to reach the restrooms, the robot acts as a standard rollator; however, if the user’s cognitive abilities are limited (e.g., the user does not remember where the restrooms are, or he/she does not recognize obstacles on the path), the robot also drives the user towards the proper corridors, by planning and following a safe path to the restrooms. The authority is allocated on the basis of an error metric, quantifying the distance between the current vehicle heading and the desired movement direction to perform the task. If the user is safely performing the task, he/she is endowed with control authority, so that his/her residual abilities are exploited. Conversely, if the user is not capable of safely solving the task (for instance, he/is going to collide with an obstacle), the robot intervenes by partially or totally taking the control authority to help the user and ensure his/her safety (for instance, avoiding the collision). We provide detailed control design and theoretical and simulative analyses of the proposed strategies. Moreover, extensive experimental validation shows that authority-sharing is a successful approach to guide a senior citizen, providing both comfort and safety. The most promising solutions include the use of haptic systems to suggest the user a proper behavior, and the modification of the perceived physical interaction of the user with the robot to gradually share the control authority using a variable stiffness vehicle handling

Master of Science

thesisThis thesis details the development of the Algorithmic Robotics Laboratory, its experimental software environment, and a case study featuring a novel hardware validation of optimal reciprocal collision avoidance. We constructed a robotics laboratory in both software and hardware in which to perform our experiments. This lab features a netted flying volume with motion capture and two custom quadrotors. Also, two experimental software architectures are developed for actuating both ground and aerial robots within a Linux Robot Operating System environment. The first of the frameworks is based upon a single finite state machine program which managed each aspect of the experiment. Concerns about the complexity and reconfigurability of the finite state machine prompted the development of a second framework. This final framework is a multimodal structure featuring programs which focus on these specific functions: State Estimation, Robot Drivers, Experimental Controllers, Inputs, Human Robot Interaction, and a program tailored to the specifics of the algorithm tested in the experiment. These modular frameworks were used to fulfill the mission of the Algorithmic Robotics Lab, in that they were developed to validate robotics algorithms in experiments that were previously only shown in simulation. A case study into collision avoidance was used to mark the foundation of the laboratory through the proving of an optimal reciprocal collision avoidance algorithm for the first time in hardware. In the case study, two human-controlled quadrotors were maliciously flown in colliding trajectories. Optimal reciprocal collision avoidance was demonstrated for the first time on completely independent agents with local sensing. The algorithm was shown to be robust to violations of its inherent assumptions about the dynamics of agents and the ability for those agents to sense imminent collisions. These experiments, in addition to the mathematical foundation of exponential convergence, submits th a t optimal reciprocal collision avoidance is a viable method for holonomic robots in both 2-D and 3-D with noisy sensing. A basis for the idea of reciprocal dance, a motion often seen in human collision avoidance, is also suggested in demonstration to be a product of uncertainty about the state of incoming agents. In the more than one hundred tests conducted in multiple environments, no midair collisions were ever produced

Explaining institutional dynamics within local partnerships: the case of ‘EQUAL II’ and ‘LEADER+’ in Crete

This neo institutional study analyses the dynamic interaction between formal/informal rules and agents’ behaviour inside a political institution, examining these relationships through primary research on local partnerships in Greece. The theoretical assumptions of this analysis derive mainly from normative neo institutionalism but also include insights from rational choice and the historical institutionalism. Consideration is also given to the way in which theories of the structure/agent duality are related to neo institutional propositions on the relationship between rules and agents’ strategic behaviour. The neo institutional approach to local partnerships is also situated in relation to concepts and empirical observations from the literature on urban governance, urban regimes and Europeanisation. This research adopts the critical realism stance which acknowledges a reflexive approach to reality and it applies an embedded case study strategy. The case study consists of two local partnerships in the region of Crete, which were established under the EU Community Initiatives Programmes EQUAL II and LEADER+ and coordinated by the Local Development Agency of Heraklion. A triangulation method is selected, making use of interviews, storytelling, a short questionnaire, direct observation and secondary analysis of documentation. The research data reveal that the formal rules of the partnerships are not indicative of what actually happens. It is the configuration of formal and informal rules that offers a deep understanding of partnership. It is concluded that some formal rules are realised (albeit with deviations along the way), like partnership and programming, while others are remained mostly on paper, like community participation, decentralisation and innovation. In these cases, the informal rules appear to be conflicting with the formal rules, leading to different results than those expected. The research also shows the importance of agents' intentionality in the process of institutional change. Specific actors within the partnership, such as established local leaders and institutional entrepreneurs, select and reinforce particular features of formal rules that restrict partners’ freedom and promote values of efficiency within the partners. Moreover, the findings confirm a gradual changing of local policy making and an increase of local social capital. EQUAL II and LEADER+ partnerships create new possibilities for the empowerment and participation of new actors such as NGOs and vulnerable groups in the local policy-making process. They also promote the establishment of policy networks and enhance the development of collaborative learning processes (trust building and sharing understanding). Finally, they lead to the re-articulation of mayors-chief executives’ relationship inside local authorities and of central state’s position by creating new possibilities for broadening local authorities’ autonomy

4th International Symposium on Ambient Intelligence (ISAmI 2013)

Ambient Intelligence (AmI) is a recent paradigm emerging from Artificial Intelligence (AI), where computers are used as proactive tools assisting people with their day-to-day activities, making everyone’s life more comfortable. Another main concern of AmI originates from the human computer interaction domain and focuses on offering ways to interact with systems in a more natural way by means user friendly interfaces. This field is evolving quickly as can be witnessed by the emerging natural language and gesture based types of interaction. The inclusion of computational power and communication technologies in everyday objects is growing and their embedding into our environments should be as invisible as possible. In order for AmI to be successful, human interaction with computing power and embedded systems in the surroundings should be smooth and happen without people actually noticing it. The only awareness people should have arises from AmI: more safety, comfort and wellbeing, emerging in a natural and inherent way. ISAmI is the International Symposium on Ambient Intelligence and aiming to bring together researchers from various disciplines that constitute the scientific field of Ambient Intelligence to present and discuss the latest results, new ideas, projects and lessons learned, namely in terms of software and applications, and aims to bring together researchers from various disciplines that are interested in all aspects of this area

A qualitative analysis of the networks of tourism SMEs in Germany: managing business networks for knowledge transfer

Theoretically, it is said that social capital encourages individuals and entrepreneurs to engage in business networks. Social capital is the sum of the resource benefits an organisation derives from its network of relationships. These external knowledge sources are particularly relevant for small and medium-sized enterprises (SMEs) because of their lack of internal knowledge stock. Yet, social capital theories have primarily been investigated from a structural perspective to measure benefits through centrality and position in structural holes. To understand the resource benefits, however, it is first necessary to understand what knowledge is available, second the content of the relationship, and third the context and conditions that influence these inter-organisational knowledge transfer relationships. Thus, in this thesis, a relational approach is adopted to generate knowledge on inter-firm relationships at the SME level in order to explore how tourism business networks are operated and managed in such a way that enables the knowledge transfer. This study looks into the business networks in which the SMEs of the tourism industry engage, explains the meaning they ascribe to the knowledge transfer potential among these networks, how they exploit the networks, what knowledge is made available, and the managerial as well as contextual factors that influence the network operation and management. A multi-method qualitative strategy was used to investigate naturally emerging business networks in North-East Germany’s tourism industry. A snowball network sampling procedure was applied, from which two network zones emerged, a closed coordinated small network and the members’ individually built business relationships beyond this network. The research was informed by three rounds of qualitative data generation and collection. In total, 12 first-round interviews were used to enter the field, a second-round workshop and discussion group with 31 participants was used to generate preliminary findings and facilitate access, and in the third round 38 semi-structured qualitative interviews were conducted to generate data for the main empirical study. This qualitative data analysis was complemented and supported with data from informal conversations and observations, collected documents and field notes, as well as a secondary data review. The study contributes to the body of knowledge on tourism SME networks and the availability and transfer of knowledge. Its original contribution is in providing a greater knowledge and understanding of the cognitive and relational component of social capital, particularly in the formation of a network. It further adds to both literature and theory on network coordinators by unpacking and circumscribing their boundaries. The study also theorises the cult of personality in a network context. In addition, it contributes to the understanding of the role of regional tourism organisations (RTO) in that it explored how different strategies lead to a collaborative environment, effective communication and member exchange. Thus, this research contributes to the conversation of SMEs, tourism business networks, coordination, and knowledge transfer

Explaining institutional dynamics within local partnerships: the case of ‘EQUAL II’ and ‘LEADER+’ in Crete

This neo institutional study analyses the dynamic interaction between formal/informal rules and agents’ behaviour inside a political institution, examining these relationships through primary research on local partnerships in Greece. The theoretical assumptions of this analysis derive mainly from normative neo institutionalism but also include insights from rational choice and the historical institutionalism. Consideration is also given to the way in which theories of the structure/agent duality are related to neo institutional propositions on the relationship between rules and agents’ strategic behaviour. The neo institutional approach to local partnerships is also situated in relation to concepts and empirical observations from the literature on urban governance, urban regimes and Europeanisation. This research adopts the critical realism stance which acknowledges a reflexive approach to reality and it applies an embedded case study strategy. The case study consists of two local partnerships in the region of Crete, which were established under the EU Community Initiatives Programmes EQUAL II and LEADER+ and coordinated by the Local Development Agency of Heraklion. A triangulation method is selected, making use of interviews, storytelling, a short questionnaire, direct observation and secondary analysis of documentation. The research data reveal that the formal rules of the partnerships are not indicative of what actually happens. It is the configuration of formal and informal rules that offers a deep understanding of partnership. It is concluded that some formal rules are realised (albeit with deviations along the way), like partnership and programming, while others are remained mostly on paper, like community participation, decentralisation and innovation. In these cases, the informal rules appear to be conflicting with the formal rules, leading to different results than those expected. The research also shows the importance of agents' intentionality in the process of institutional change. Specific actors within the partnership, such as established local leaders and institutional entrepreneurs, select and reinforce particular features of formal rules that restrict partners’ freedom and promote values of efficiency within the partners. Moreover, the findings confirm a gradual changing of local policy making and an increase of local social capital. EQUAL II and LEADER+ partnerships create new possibilities for the empowerment and participation of new actors such as NGOs and vulnerable groups in the local policy-making process. They also promote the establishment of policy networks and enhance the development of collaborative learning processes (trust building and sharing understanding). Finally, they lead to the re-articulation of mayors-chief executives’ relationship inside local authorities and of central state’s position by creating new possibilities for broadening local authorities’ autonomy