Design and Motion Planning for a Reconfigurable Robotic Base

A robotic platform for mobile manipulation needs to satisfy two contradicting requirements for many real-world applications: A compact base is required to navigate through cluttered indoor environments, while the support needs to be large enough to prevent tumbling or tip over, especially during fast manipulation operations with heavy payloads or forceful interaction with the environment. This paper proposes a novel robot design that fulfills both requirements through a versatile footprint. It can reconfigure its footprint to a narrow configuration when navigating through tight spaces and to a wide stance when manipulating heavy objects. Furthermore, its triangular configuration allows for high-precision tasks on uneven ground by preventing support switches. A model predictive control strategy is presented that unifies planning and control for simultaneous navigation, reconfiguration, and manipulation. It converts task-space goals into whole-body motion plans for the new robot. The proposed design has been tested extensively with a hardware prototype. The footprint reconfiguration allows to almost completely remove manipulation-induced vibrations. The control strategy proves effective in both lab experiment and during a real-world construction task.Comment: 8 pages, accepted for RA-L and IROS 202

Consensus standards for acquisition, measurement, and reporting of intravascular optical coherence tomography studies

Objectives: The purpose of this document is to make the output of the International Working Group for Intravascular Optical Coherence Tomography (IWG-IVOCT) Standardization and Validation available to medical and scientific communities, through a peer-reviewed publication, in the interest of improving the diagnosis and treatment of patients with atherosclerosis, including coronary artery disease. Background: Intravascular optical coherence tomography (IVOCT) is a catheter-based modality that acquires images at a resolution of ∼10 μm, enabling visualization of blood vessel wall microstructure in vivo at an unprecedented level of detail. IVOCT devices are now commercially available worldwide, there is an active user base, and the interest in using this technology is growing. Incorporation of IVOCT in research and daily clinical practice can be facilitated by the development of uniform terminology and consensus-based standards on use of the technology, interpretation of the images, and reporting of IVOCT results. Methods: The IWG-IVOCT, comprising more than 260 academic and industry members from Asia, Europe, and the United States, formed in 2008 and convened on the topic of IVOCT standardization through a series of 9 national and international meetings. Results: Knowledge and recommendations from this group on key areas within the IVOCT field were assembled to generate this consensus document, authored by the Writing Committee, composed of academicians who have participated in meetings and/or writing of the text. Conclusions: This document may be broadly used as a standard reference regarding the current state of the IVOCT imaging modality, intended for researchers and clinicians who use IVOCT and analyze IVOCT data

PLASTR: Planning for Autonomous Sampling-based Trowelling

Plaster is commonly used in the construction industry to finish walls and ceilings, but the application is labor-intensive and physically strenuous, which motivates the need for automation. We present PLASTR, a receding horizon optimization-based planning algorithm for robotic plaster trowelling. It samples trowelling sequence rollouts from a new plaster simulator and weights them according to the flatness of the finished wall.\\ The proposed simulator approximates the real-world plaster-trowel interaction adequately while allowing execution orders of magnitude faster than real-time. We evaluate PLASTR in simulation and on a real-world test setup and compare it to two handcrafted heuristic baseline algorithms. PLASTR performs equal to or better than the best heuristic in terms of material coverage for both simulated and real-world experiments while being 50% more efficient in terms of trowelled distance.ISSN:2377-376

Design and Motion Planning for a Reconfigurable Robotic Base

ISSN:2377-376

Continuous Mobile Thin-Layer On-Site Printing

Quasi-static robotic systems and discrete fabrication strategies fall short of the capabilities needed for automating on-site plastering, which involves operating over large spans and maintaining material continuity. This paper presents continuous, mobile Robotic Plaster Spraying (RPS) – a thin-layer, spray-based printing-in-motion technique using cementitious plaster – realized on a prototypical construction site. The experimental setup consists of a fully mobile, custom wheeled base that is synchronized with a robotic arm, and an integrated pumping and spraying system. In this 1:1 scale application, the print layers are executed during the motion of the mobile robot and they are printed vertically on the walls of an existing building structure. The experiments showcase the potentials of producing bespoke – three-dimensional – or standardized – flat – plasterwork with the proposed technique. The results demonstrate the applicability and scalability of RPS and the findings contribute to the research on mobile additive fabrication.ISSN:0926-580

Consensus standards for acquisition, measurement, and reporting of intravascular optical coherence tomography studies: a report from the International Working Group for Intravascular Optical Coherence Tomography Standardization and Validation

The purpose of this document is to make the output of the International Working Group for Intravascular Optical Coherence Tomography (IWG-IVOCT) Standardization and Validation available to medical and scientific communities, through a peer-reviewed publication, in the interest of improving the diagnosis and treatment of patients with atherosclerosis, including coronary artery disease