1,385 research outputs found
Automated sequence and motion planning for robotic spatial extrusion of 3D trusses
While robotic spatial extrusion has demonstrated a new and efficient means to
fabricate 3D truss structures in architectural scale, a major challenge remains
in automatically planning extrusion sequence and robotic motion for trusses
with unconstrained topologies. This paper presents the first attempt in the
field to rigorously formulate the extrusion sequence and motion planning (SAMP)
problem, using a CSP encoding. Furthermore, this research proposes a new
hierarchical planning framework to solve the extrusion SAMP problems that
usually have a long planning horizon and 3D configuration complexity. By
decoupling sequence and motion planning, the planning framework is able to
efficiently solve the extrusion sequence, end-effector poses, joint
configurations, and transition trajectories for spatial trusses with
nonstandard topologies. This paper also presents the first detailed computation
data to reveal the runtime bottleneck on solving SAMP problems, which provides
insight and comparing baseline for future algorithmic development. Together
with the algorithmic results, this paper also presents an open-source and
modularized software implementation called Choreo that is machine-agnostic. To
demonstrate the power of this algorithmic framework, three case studies,
including real fabrication and simulation results, are presented.Comment: 24 pages, 16 figure
An Omnidirectional Aerial Manipulation Platform for Contact-Based Inspection
This paper presents an omnidirectional aerial manipulation platform for
robust and responsive interaction with unstructured environments, toward the
goal of contact-based inspection. The fully actuated tilt-rotor aerial system
is equipped with a rigidly mounted end-effector, and is able to exert a 6
degree of freedom force and torque, decoupling the system's translational and
rotational dynamics, and enabling precise interaction with the environment
while maintaining stability. An impedance controller with selective apparent
inertia is formulated to permit compliance in certain degrees of freedom while
achieving precise trajectory tracking and disturbance rejection in others.
Experiments demonstrate disturbance rejection, push-and-slide interaction, and
on-board state estimation with depth servoing to interact with local surfaces.
The system is also validated as a tool for contact-based non-destructive
testing of concrete infrastructure.Comment: Accepted submission to Robotics: Science and Systems conference 2019.
9 pages, 12 figure
Path and Motion Planning for Autonomous Mobile 3D Printing
Autonomous robotic construction was envisioned as early as the ‘90s, and yet, con-
struction sites today look much alike ones half a century ago. Meanwhile, highly
automated and efficient fabrication methods like Additive Manufacturing, or 3D
Printing, have seen great success in conventional production. However, existing
efforts to transfer printing technology to construction applications mainly rely on
manufacturing-like machines and fail to utilise the capabilities of modern robotics.
This thesis considers using Mobile Manipulator robots to perform large-scale
Additive Manufacturing tasks. Comprised of an articulated arm and a mobile base,
Mobile Manipulators, are unique in their simultaneous mobility and agility, which
enables printing-in-motion, or Mobile 3D Printing. This is a 3D printing modality,
where a robot deposits material along larger-than-self trajectories while in motion.
Despite profound potential advantages over existing static manufacturing-like large-
scale printers, Mobile 3D printing is underexplored. Therefore, this thesis tack-
les Mobile 3D printing-specific challenges and proposes path and motion planning
methodologies that allow this printing modality to be realised. The work details
the development of Task-Consistent Path Planning that solves the problem of find-
ing a valid robot-base path needed to print larger-than-self trajectories. A motion
planning and control strategy is then proposed, utilising the robot-base paths found
to inform an optimisation-based whole-body motion controller. Several Mobile 3D
Printing robot prototypes are built throughout this work, and the overall path and
motion planning strategy proposed is holistically evaluated in a series of large-scale
3D printing experiments
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
The Use of Tactile Sensors in Oral and Maxillofacial Surgery: An Overview
Background: This overview aimed to characterize the type, development, and use of haptic technologies for maxillofacial surgical purposes. The work aim is to summarize and evaluate current advantages, drawbacks, and design choices of presented technologies for each field of application in order to address and promote future research as well as to provide a global view of the issue. Methods: Relevant manuscripts were searched electronically through Scopus, MEDLINE/PubMed, and Cochrane Library databases until 1 November 2022. Results: After analyzing the available literature, 31 articles regarding tactile sensors and interfaces, sensorized tools, haptic technologies, and integrated platforms in oral and maxillofacial surgery have been included. Moreover, a quality rating is provided for each article following appropriate evaluation metrics. Discussion: Many efforts have been made to overcome the technological limits of computed assistant diagnosis, surgery, and teaching. Nonetheless, a research gap is evident between dental/maxillofacial surgery and other specialties such as endovascular, laparoscopic, and microsurgery; especially for what concerns electrical and optical-based sensors for instrumented tools and sensorized tools for contact forces detection. The application of existing technologies is mainly focused on digital simulation purposes, and the integration into Computer Assisted Surgery (CAS) is far from being widely actuated. Virtual reality, increasingly adopted in various fields of surgery (e.g., sino-nasal, traumatology, implantology) showed interesting results and has the potential to revolutionize teaching and learning. A major concern regarding the actual state of the art is the absence of randomized control trials and the prevalence of case reports, retrospective cohorts, and experimental studies. Nonetheless, as the research is fast growing, we can expect to see many developments be incorporated into maxillofacial surgery practice, after adequate evaluation by the scientific community
Aerial Robotics for Inspection and Maintenance
Aerial robots with perception, navigation, and manipulation capabilities are extending the range of applications of drones, allowing the integration of different sensor devices and robotic manipulators to perform inspection and maintenance operations on infrastructures such as power lines, bridges, viaducts, or walls, involving typically physical interactions on flight. New research and technological challenges arise from applications demanding the benefits of aerial robots, particularly in outdoor environments. This book collects eleven papers from different research groups from Spain, Croatia, Italy, Japan, the USA, the Netherlands, and Denmark, focused on the design, development, and experimental validation of methods and technologies for inspection and maintenance using aerial robots
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