Proceedings of the NASA Conference on Space Telerobotics, volume 4

Papers presented at the NASA Conference on Space Telerobotics are compiled. The theme of the conference was man-machine collaboration in space. The conference provided a forum for researchers and engineers to exchange ideas on the research and development required for the application of telerobotic technology to the space systems planned for the 1990's and beyond. Volume 4 contains papers related to the following subject areas: manipulator control; telemanipulation; flight experiments (systems and simulators); sensor-based planning; robot kinematics, dynamics, and control; robot task planning and assembly; and research activities at the NASA Langley Research Center

The Design Of A Community-Informed Socially Interactive Humanoid Robot And End-Effectors For Novel Edge-Rolling

This dissertation discusses my work in building an HRI platform called Quori and my once separate now integrated work on a manipulation method that can enable robots like Quori, or any more capable robot, to move large circular cylindrical objects. Quori is a novel, affordable, socially interactive humanoid robot platform for facilitating non-contact human-robot interaction (HRI) research. The design of the system is motivated by feedback sampled from the HRI research community. The overall design maintains a balance of affordability and functionality. Ten Quori platforms have been awarded to a diverse group of researchers from across the United States to facilitate HRI research to build a community database from a common platform. This dissertation concludes with a demonstration of Quori transporting a large cylinder for which Quori does not have the power to lift nor the range of motion to dexterously manipulate. Quori is able to achieve this otherwise insurmountable task through a novel robotic manipulation technique called robotic edge-rolling. Edge-rolling refers to transporting a cylindrical object by rolling on its circular edge, as human workers maneuver a gas cylinder on the ground for example. This robotic edge-rolling is achieved by controlling the object to roll on the bottom edge in contact with the ground, and to slide on the surface of the robot\u27s end-effector. It can thus be regarded as a form of robotic dexterous, in-hand manipulation with nonprehensile grasps. This work mainly addresses the problem of grasp planning for edge-rolling by studying how to design appropriately shaped end-effectors with zero internal mobility and how to find feasible grasps for stably rolling the object with the simple end-effectors

Fourth Annual Workshop on Space Operations Applications and Research (SOAR 90)

The proceedings of the SOAR workshop are presented. The technical areas included are as follows: Automation and Robotics; Environmental Interactions; Human Factors; Intelligent Systems; and Life Sciences. NASA and Air Force programmatic overviews and panel sessions were also held in each technical area

Nonlinear Control Strategies for Outdoor Aerial Manipulators

In this thesis, the design, validation and implementation of nonlinear control strategies for aerial manipulators {i.e. aerial robots equipped with manipulators{ is studied, with special emphasis on the internal coupling of the system and its resilience against external disturbances. For the rst, di erent decentralised control strategies {i.e. using di erent control typologies for each one of the subsystems{ that indirectly take into account this coupling have been analysed. As a result, a nonlinear strategy composed of two controllers is proposed. A higher priority is given to the manipulation accuracy, relaxing the platform tracking, and hence obtaining a solution improving the manipulation capabilities with the surrounding environment. To validate these results, thorough stability and robustness analyses are provided, both theoretically and in simulation. On the other hand, a signi cant e ort has been devoted to improving the response and applicability of robot manipulators used in ight via control. In particular, the design of controllers for lightweight exible manipulators {that reduce the consequences of incidents involving unforeseen contacts{ is analysed. Although their inherent nature perfectly ts for aerial manipulation applications, the added exibility produces unwanted behaviours, such as second-order modes and uncertainties. To cope with them, an adaptable position nonlinear control strategy is proposed. To validate this contribution, the stability of the approach is studied in theory and its capabilities are proven in several experimental scenarios. In these, the robustness of the solution against unforeseen impacts and contact with uncharacterised interfaces is demonstrated. Subsequently, this strategy has been enriched with {multiaxis{ force control capabilities thanks to the inclusion of an outer control loop modifying the manipulator reference. Accordingly, this additional applicationfocused capability is added to the controlled system without loosing the modulated response of the inner-loop position strategy. It is also worth noting that, thanks to the cascade-like nature of the modi cation, the transition between position and force control modes is inherently smooth and automatic. The stability of this expanded strategy has been theoretically analysed and the results validated in a set of experimental scenarios. To validate the rst nonlinear approach with realistic outdoor simulations before its implementation, a computational uid dynamics analysis has been performed to obtain an explicit model of the aerodynamic forces and torques applied to the blunt-body of the aerial platform in ight. The results of this study have been compared to the most common alternative nowadays, being highlighted that the proposed model signi cantly surpasses this option in terms of accuracy. Moreover, it is worth underscoring that this characterisation could be also employed in the future to develop control solutions with enhanced rejection capabilities against wind conditions. Finally, as the focus of this thesis is on the use of novel control strategies on real aerial manipulation outdoors to improve their accuracy while performing complex tasks, a modular autopilot solution to be able to implement them has been also developed. This general-purpose autopilot allows the implementation of new algorithms, and facilitates their theory-to-experimentation transition. Taking into account this perspective, the proposed tool employs the simple and widely-known MAS interface and the highly reliable PX4 autopilot as backup, thus providing a redundant approach to handle unexpected incidents in ight.En esta tesis se ha estudiado el diseño, validación e implementación de estrategias de control no lineales para robots manipuladores aéreos –esto es, robots aéreos equipados con un sistema de manipulación robótica–, dándose especial énfasis a las interacciones internas del sistema y a su resiliencia frente a efectos externos. Para lo primero, se han analizado diferentes estrategias de control descentralizado –es decir, que usan tipologías de control diferentes para cada uno de los subsistemas–, pero que tienen indirectamente en consideración la interacción entre manipulación y vuelo. Como resultado de esta línea, se propone una estretegia de control conformada por dos controladores. Estos se coordinan de tal forma que se le da prioridad a la manipulación sobre el seguimiento de posiciones del vehículo, produciéndose un sistema de control que mejora la precisión de las interacciones entre el sistema manipulador y el entorno. Para validar estos resultados, se ha analizado su estabilidad y robustez tanto teóricamente como mediante simulaciones numéricas. Por otro lado, se ha buscado mejorar la respuesta y aplicabilidad de los manipuladores que se usan en vuelo mediante su control. Dentro de esta tendencia, la tesis se ha centrado en el diseño de controladores para manipuladores ligeros flexibles, ya que estos permiten reducir el peso del sistema completo y reducen el riesgo de incidentes debidos a contactos inesperados. Sin embargo, la flexibilidad de estos produce comportamientos indeseados durante la operación, como la aparición de modos de segundo orden y cierta incentidumbre en su comportamiento. Para reducir su impacto en la precisión de las tareas de manipulación, se ha desarrollado un controlador no lineal adaptable. Para validar estos resultados, se ha analizado la estabilidad del sistema teóricamente y se han desarrollado una serie de experimentos. En ellos, se ha comprobado su robustez ante impactos inesperados y contactos con elementos no caracterizados. Posteriormente, esta estrategia para manipuladores flexibles ha sido ampliada al añadir un bucle externo que posibilita el control en fuerzas en varias direcciones. Esto permite, mediante un único controlador, mantener la suave respuesta de la estrategia. Además cabe destacar que, al contar esta estrategia con un diseño en cascade, la transición entre los segmentos de desplazamiento del brazo y de aplicación de fuerzas es fluida y automática. La estabilidad de esta estrategia ampliada ha sido analizada teóricamente y los resultados han sido validados experimentalmente. Para validar la primera estrategia mediante simulaciones que representen fielmente las condiciones en exteriores antes de su implementación, ha sido necesario realizar un estudio mediante mecánica de fluidos computacional para obtener un modelo explícito de las fuerzas y momentos aerodinámicos a los que se efrenta la plataforma en vuelo. Los resultados de este estudio han sido comparados con la alternativa más empleada actualmente, mostrándose que los avances del método propuesto son sustanciales. Asimismo, es importante destacar que esta caracterización podría también usarse en el futuro para desarrollar controladores con una respuesta mejorada ante perturbaciones aerodinámicas, como en el caso de volar con viento. Finalmente, al ser esta una tesis centrada en las estrategias de control novedosas en sistemas reales para la mejora de su rendimiento en misiones complejas, se ha desarrollado un autopiloto modular fácilmente modificable para implementarlas. Este permite validar experimentalmente nuevos algoritmos y facilita la transición entre teoría y práctica. Para ello, esta herramienta se basa en una interfaz sencilla ampliamente conocida por los investigadores de robótica, Simulink®, y cuenta con un autopiloto de respaldo, PX4, para enfrentarse a los incidentes inesperados que pudieran surgir en vuelo

Human-robot interaction for telemanipulation by small unmanned aerial systems

This dissertation investigated the human-robot interaction (HRI) for the Mission Specialist role in a telemanipulating unmanned aerial system (UAS). The emergence of commercial unmanned aerial vehicle (UAV) platforms transformed the civil and environmental engineering industries through applications such as surveying, remote infrastructure inspection, and construction monitoring, which normally use UAVs for visual inspection only. Recent developments, however, suggest that performing physical interactions in dynamic environments will be important tasks for future UAS, particularly in applications such as environmental sampling and infrastructure testing. In all domains, the availability of a Mission Specialist to monitor the interaction and intervene when necessary is essential for successful deployments. Additionally, manual operation is the default mode for safety reasons; therefore, understanding Mission Specialist HRI is important for all small telemanipulating UAS in civil engineering, regardless of system autonomy and application. A 5 subject exploratory study and a 36 subject experimental study were conducted to evaluate variations of a dedicated, mobile Mission Specialist interface for aerial telemanipulation from a small UAV. The Shared Roles Model was used to model the UAS human-robot team, and the Mission Specialist and Pilot roles were informed by the current state of practice for manipulating UAVs. Three interface camera view designs were tested using a within-subjects design, which included an egocentric view (perspective from the manipulator), exocentric view (perspective from the UAV), and mixed egocentric-exocentric view. The experimental trials required Mission Specialist participants to complete a series of tasks with physical, visual, and verbal requirements. Results from these studies found that subjects who preferred the exocentric condition performed tasks 50% faster when using their preferred interface; however, interface preferences did not affect performance for participants who preferred the mixed condition. This result led to a second finding that participants who preferred the exocentric condition were distracted by the egocentric view during the mixed condition, likely caused by cognitive tunneling, and the data suggest tradeoffs between performance improvements and attentional costs when adding information in the form of multiple views to the Mission Specialist interface. Additionally, based on this empirical evaluation of multiple camera views, the exocentric view was recommended for use in a dedicated Mission Specialist telemanipulation interface. Contributions of this thesis include: i) conducting the first focused HRI study of aerial telemanipulation, ii) development of an evaluative model for telemanipulation performance, iii) creation of new recommendations for aerial telemanipulation interfacing, and iv) contribution of code, hardware designs, and system architectures to the open-source UAV community. The evaluative model provides a detailed framework, a complement to the abstraction of the Shared Roles Model, that can be used to measure the effects of changes in the system, environment, operators, and interfacing factors on performance. The practical contributions of this work will expedite the use of manipulating UAV technologies by scientists, researchers, and stakeholders, particularly those in civil engineering, who will directly benefit from improved manipulating UAV performance

A Control Architecture for Unmanned Aerial Vehicles Operating in Human-Robot Team for Service Robotic Tasks

In this thesis a Control architecture for an Unmanned Aerial Vehicle (UAV) is presented. The aim of the thesis is to address the problem of control a flying robot operating in human robot team at different level of abstraction. For this purpose, three different layers in the design of the architecture were considered, namely, the high level, the middle level and the low level layers. The special case of an UAV operating in service robotics tasks and in particular in Search&Rescue mission in alpine scenario is considered. Different methodologies for each layer are presented with simulated or real-world experimental validation

Development of an Autonomous Robotic Mushroom Harvester

The process of development of a new robot is one of the modern technological arts. This process involves multiple complex steps and recursive approach. In this project, a solution for automatic harvesting of mushrooms is developed. In order to design an effective solution, it is necessary to explore and take into consideration the limitations of grasping very soft and fragile objects (particularly mushrooms). We will elaborate several strategies of picking and analyze each strategy to formulate the design requirements, develop a solution, and finally, evaluate the efficiency of the proposed solution in actual farm conditions for real mushrooms. The mushroom farm used in our study utilizes Dutch shelving systems, which pose stringent space requirements on the construction. The main challenge in this project is the development of a robot with 7 degrees of freedom (DOF), which would fit into the existing infrastructure with no or minimal changes on the existing infrastructure

Pneumatic motion control systems for modular robots

This thesis describes a research study in the design, implementation, evaluation and commercialisation of pneumatic motion control systems for modular robots. The research programme was conducted as part of a collaborative study, sponsored by the Science and Engineering Research Council, between Loughborough University and Martonair (UK) Limited. Microprocessor based motion control strategies have been used to produce low cost pneumatic servo-drives which can be used for 'point-to-point' positioning of payloads. Software based realtime control strategies have evolved which accomplish servo-controlled positioning while compensating for drive system non-linearities and time delays. The application of novel compensation techniques has resulted in a significant improvement in both the static and dynamic performance of the drive. A theoretical foundation is presented based on a linearised model of a pneumatic actuator, servo-valve, and load system. The thesis describes the design and evolution of microprocessor based hardware and software for motion control of pneumatic drives. A British Standards based test-facility has allowed control strategies to be evaluated with reference to standard performance criteria. It is demonstrated in this research study that the dynamic and static performance characteristics of a pneumatic motion control system can be dramatically improved by applying appropriate software based realtime control strategies. This makes the application of computer controlled pneumatic servos in manufacturing very attractive with cost performance ratios which match or better alternative drive technologies. The research study has led to commercial products (marketed by Martonair Ltd), in which realtime control algorithms implementing these control strategy designs are executed within a microprocessor based motion controller