Developing a 3-DOF Compliant Perching Arm for a Free-Flying Robot on the International Space Station

This paper presents the design and control of the 3-DOF compliant perching arm for the free-flying Astrobee robots that will operate inside the International Space Station (ISS). The robots are intended to serve as a flexible platform for future guest scientists to use for zero-gravity robotics research - thus, the arm is designed to support manipulation research. It provides a 1-DOF underactuated tendon-driven gripper capable of enveloping a range of objects of different shapes and sizes. Co-located RGB camera and LIDAR sensors provide perception. The Astrobee robots will be capable of grasping each other in flight, to simulate orbital capture scenarios. The arm's end-effector module is swappable on-orbit, allowing guest scientists to add upgraded grippers, or even additional arm degrees of freedom. The design of the arm balances research capabilities with Astrobee's operational need to perch on ISS handrails to reduce power consumption. Basic arm functioning and grip strength were evaluated using an integrated Astrobee prototype riding on a low-friction air bearing

Thermal Design of Astrobee Perching Arm

This paper presents the thermal design of actuators in the perching arm of Astrobee robot that will operate inside the International Space Station (ISS) starting in 2019. Since the crew's safety is of the utmost importance on the ISS, all materials used in the Astrobee robot should meet the touch temperature requirements according to the ISS safety standards to protect crew from skin burns by controlling the exposure temperature. The Astrobee perching arm consists of 2-DOF (Degrees-of-Freedom)- arm servo motors and 1-DOF gripper DC motor, which are capable of overheating in the stalled condition. Thermal properties of two types of actuators are verified by monitoring the touch temperature in worst-case operations with no thermal protection. Then, the proper thermal protection designs have been conducted and installed to guarantee the safety in all conditions

Astrobee: A New Platform for Free-Flying Robotics on the International Space Station

The Astrobees are next-generation free-flying robots that will operate in the interior of the International Space Station (ISS). Their primary purpose is to provide a flexible platform for research on zero-g freeflying robotics, with the ability to carry a wide variety of future research payloads and guest science software. They will also serve utility functions: as free-flying cameras to record video of astronaut activities, and as mobile sensor platforms to conduct surveys of the ISS. The Astrobee system includes two robots, a docking station, and a ground data system (GDS). It is developed by the Human Exploration Telerobotics 2 (HET-2) Project, which began in Oct. 2014, and will deliver the Astrobees for launch to ISS in 2017. This paper covers selected aspects of the Astrobee design, focusing on capabilities relevant to potential users of the platform

Thermal Design of Astrobee Perching Arm

This paper presents the thermal design of actuators in the perching arm of Astrobee robot that will operate inside the International Space Station (ISS) in starting 2019. Since the crew's safety is of the utmost importance on the ISS, all materials used in the Astrobee robot should meet the touch temperature requirements according to the ISS safety standards to protect crew from skin burns. The Astrobee perching arm consists of 2-DOF arm servo motors and 1-DOF gripper DC motor, which are capable of overheating when stalled, particularly given the lack of gravity-driven thermal convection in the ISS zero-gee environment. Thermal properties of two types of actuators are verified by monitoring the touch temperature in worst-case operations with no thermal protection. Then, the proper thermal protection designs have been conducted and installed to guarantee the safety in all conditions

Enabling technologies for precise aerial manufacturing with unmanned aerial vehicles

The construction industry is currently experiencing a revolution with automation techniques such as additive manufacturing and robot-enabled construction. Additive Manufacturing (AM) is a key technology that can o er productivity improvement in the construction industry by means of o -site prefabrication and on-site construction with automated systems. The key bene t is that building elements can be fabricated with less materials and higher design freedom compared to traditional manual methods. O -site prefabrication with AM has been investigated for some time already, but it has limitations in terms of logistical issues of components transportation and due to its lack of design exibility on-site. On-site construction with automated systems, such as static gantry systems and mobile ground robots performing AM tasks, can o er additional bene ts over o -site prefabrication, but it needs further research before it will become practical and economical. Ground-based automated construction systems also have the limitation that they cannot extend the construction envelope beyond their physical size. The solution of using aerial robots to liberate the process from the constrained construction envelope has been suggested, albeit with technological challenges including precision of operation, uncertainty in environmental interaction and energy e ciency. This thesis investigates methods of precise manufacturing with aerial robots. In particular, this work focuses on stabilisation mechanisms and origami-based structural elements that allow aerial robots to operate in challenging environments. An integrated aerial self-aligning delta manipulator has been utilised to increase the positioning accuracy of the aerial robots, and a Material Extrusion (ME) process has been developed for Aerial Additive Manufacturing (AAM). A 28-layer tower has been additively manufactured by aerial robots to demonstrate the feasibility of AAM. Rotorigami and a bioinspired landing mechanism demonstrate their abilities to overcome uncertainty in environmental interaction with impact protection capabilities and improved robustness for UAV. Design principles using tensile anchoring methods have been explored, enabling low-power operation and explores possibility of low-power aerial stabilisation. The results demonstrate that precise aerial manufacturing needs to consider not only just the robotic aspects, such as ight control algorithms and mechatronics, but also material behaviour and environmental interaction as factors for its success.Open Acces

A survey of single and multi-UAV aerial manipulation

Aerial manipulation has direct application prospects in environment, construction, forestry, agriculture, search, and rescue. It can be used to pick and place objects and hence can be used for transportation of goods. Aerial manipulation can be used to perform operations in environments inaccessible or unsafe for human workers. This paper is a survey of recent research in aerial manipulation. The aerial manipulation research has diverse aspects, which include the designing of aerial manipulation platforms, manipulators, grippers, the control of aerial platform and manipulators, the interaction of aerial manipulator with the environment, through forces and torque. In particular, the review paper presents the survey of the airborne platforms that can be used for aerial manipulation including the new aerial platforms with aerial manipulation capability. We also classified the aerial grippers and aerial manipulators based on their designs and characteristics. The recent contributions regarding the control of the aerial manipulator platform is also discussed. The environment interaction of aerial manipulators is also surveyed which includes, different strategies used for end-effectors interaction with the environment, application of force, application of torque and visual servoing. A recent and growing interest of researchers about the multi-UAV collaborative aerial manipulation was also noticed and hence different strategies for collaborative aerial manipulation are also surveyed, discussed and critically analyzed. Some key challenges regarding outdoor aerial manipulation and energy constraints in aerial manipulation are also discussed

Modelling and control of aerial manipulators

Hace unos años, dentro de la robótica aérea, surgió la manipulación aérea como campo de investigación. Desde su nacimiento, su impacto ha ido incrementándose poco a poco debido, sobretodo, al gran número de aplicaciones que podrían llevarse a cabo con este tipo de sistemas. Un manipulador aéreo puede definirse como una plataforma aérea la cual ha sido equipada con uno o varios brazos robóticos. Este nuevo concepto ha abierto un mundo de posibilidades para este tipo de robots aéreos. Además, gracias a la posibilidad de este tipo de robots aéreos de interactuar con su entorno, podrían llevar a cabo inspecciones de estructuras civiles o incluso, tareas de ensamblaje de estructuras y todo ello, por supuesto, de forma autónoma. Esta tesis se centra en el estudio e implementación de sistemas de manipulación aérea y, en particular, en el diseño de estrategias de control para la plataforma aérea. Este estudio comienza con el cáculo de las ecuaciones que representan la dinámica del sistema, y que nos permite analizar su comportamiento y la influencia del movimiento de los brazos robóticos en la estabilidad de la plataforma.El análisis de estas ecuaciones nos permite diseñar de esquemas de control tales como los basados en Backstepping. Pero el objetivo de esta tesis no es solo el diseño sino también la implementación de estas técnicas de control en sistemas de manipulación aérea reales y con capacidad de llevar a cabo tareas de manipulación en escenarios al aire libre. La principales contribuciones de esta tesis son el cálculo de los modelos dinámicos para cada uno de los tipos de manipuladores aéreos estudiados he implementados durante el desarrollo de la tesis. Además del uso de estas modelos para la diseño de una estrategia de control adaptable a cada una de las plataformas. También se ha diseñado un mecanismo “compliant” que ha sido integrado en un manipulador parallevar a cabo tareas de inspección estructuras por contacto, además de un control de fuerza-posición. Cada manipulador aéreo implementado durante esta tesis, excepto el en caso del helicóptero, va unido a un estudio de las especificaciones hardware necesarias para la realización de una validación del sistema mediante experimentos de vuelo en escenarios al aire libre, y en el caso de los manipuladores aéreos para inspección de estructuras, en un puente real. Cada experimento realizado ha sido analizado en detalle para corregir errores, además de para adaptar o agregar cualquier modificación estructural o de hardware necesaria

A Human-Embodied Drone for Dexterous Aerial Manipulation

Current drones perform a wide variety of tasks in surveillance, photography, agriculture, package delivery, etc. However, these tasks are performed passively without the use of human interaction. Aerial manipulation shifts this paradigm and implements drones with robotic arms that allow interaction with the environment rather than simply sensing it. For example, in construction, aerial manipulation in conjunction with human interaction could allow operators to perform several tasks, such as hosing decks, drill into surfaces, and sealing cracks via a drone. This integration with drones will henceforth be known as dexterous aerial manipulation. Our recent work integrated the worker’s experience into aerial manipulation using haptic technology. The net effect was such a system could enable the worker to leverage drones and complete tasks while utilizing haptics on the task site remotely. However, the tasks were completed within the operator’s line-of-sight. Until now, immersive AR/VR frameworks has rarely been integrated in aerial manipulation. Yet, such a framework allows the drones to embody and transport the operator’s senses, actions, and presence to a remote location in real-time. As a result, the operator can both physically interact with the environment and socially interact with actual workers on the worksite. This dissertation presents a human-embodied drone interface for dexterous aerial manipulation. Using VR/AR technology, the interface allows the operator to leverage their intelligence to collaboratively perform desired tasks anytime, anywhere with a drone that possesses great dexterity