7,527 research outputs found
Modeling and Control of Robot-Structure Coupling During In-Space Structure Assembly
This paper considers the problem of robot-structure coupling dynamics during in-space robotic assembly of large flexible structures. A two-legged walking robot is used as a construction agent, whose primary goal is to stably walking on the flexible structure while carrying a substructure component to a designated location. The reaction forces inserted by the structure to the walking robot are treated as bounded disturbance inputs, and a trajectory tracking robotic controller is proposed that combines the standard full state feedback motion controller and an adaptive controller to account for the disturbance inputs. In this study, a reduced-order Euler-Bernoulli beam structure model is adapted, and a finite number of co-located sensors and actuators are distributed along the span of the beam structure. The robot-structure coupling forces are treated as a bounded external forcing function to the structure, and hence an output covariance constraint problem can be formulated, in terms of linear matrix inequality, for optimal structure control by utilizing the direct output feedback controllers. The numerical simulations show the effectiveness of the proposed robot-structure modeling and control methodology
Effect of skin surface stimulation on acupoints for phonotraumatic injuries
From a recent large-scaled randomized controlled trial, it was found that genuine acupuncture was not significantly different from the placebo, or skin surface stimulation, in improving the vocal functions of dysphonic subjects with benign vocal pathologies. This randomized, double-blind, placebo-controlled study investigated the effects of skin surface stimulation on acupoints for treating phonotraumatic injuries. Four female subjects were randomly assigned to either a treatment group or a placebo group. Subjects in the treatment group received skin surface stimulation on voice-related acupoints Hegu (Li4), Lieque (Lu7), Lianquan (CV23), Renying (St9) and Zhaohai (Ki6), whereas subjects in the placebo group received skin surface stimulation on non-voice related acupoints Tianchuang (SI16), Neiguan (PC6), Zhongzhu (SJ3) and Shangqiu (SP5). All subjects completed 12 sessions within a 6-week timeframe. Outcome measures included aerodynamic measures, the voice range profile, and self-perceived voice-related quality of life by subjects. Limited by a small sample size, significant changes over time were not found in both groups from pre-treatment to post-treatment and 14 days post-treatment. There were no conclusive results regarding whether skin surface stimulation on acupoints is an effective treatment for improving the vocal functions and quality of life in patients with phonotraumatic injuries.published_or_final_versionSpeech and Hearing SciencesBachelorBachelor of Science in Speech and Hearing Science
Bipedal Isotropic Lattice Locomoting Explorer: Robotic Platform for Locomotion and Manipulation of Discrete Lattice Structures and Lightweight Space Structures
A robotic platform for traversing and manipulating a modular 3D lattice structure is described. The robot is designed specifically for its tasks within a structured environment, and is simplified in terms of its numbers of degrees of freedom (DOF). This allows for simpler controls and a reduction of mass and cost. Designing the robot relative to the environment in which it operates results in a specific type of robot called a "relative robot". Depending on the task and environment, there can be a number of relative robots. This invention describes a bipedal robot which can locomote across a periodic lattice structure made of building block parts. The robot is able to handle, manipulate, and transport these blocks when there is more than one robot. Based on a general inchworm design, the robot has added functionality while retaining minimal complexity, and can perform numerous maneuvers for increased speed, reach, and placement
Adoption of robotic assisted partial nephrectomies: a population-based analysis of U.S. surgeons from 2004-2013
The advent of minimally invasive and robotic techniques has resulted in the rapid adoption of this novel technology, with the field of urology at the forefront. Since the first Robotic‐Assisted Laparoscopic Radical Prostatectomy (RALP) was performed in 2000 using the da Vinci Surgical System (Intuitive Surgical, Inc., Sunnyvale, CA, USA), surgeons have rapidly incorporated robotic technology for the use of radical prostatectomies for prostatic carcinoma. Prior to 2005, only a minority of surgeons‐‐fewer than 2.5%‐‐performing radical prostatectomies utilized robotic assistance. However, robotic assistance has become the predominant approach for radical prostatectomies, increasing from 22% to 85% between the years 2002 to 2013, representing a nearly five‐fold increase in utilization
A Mobile Robot for Locomotion Through a 3D Periodic Lattice Environment
This paper describes a novel class of robots specifically adapted to climb periodic lattices, which we call 'Relative Robots'. These robots use the regularity of the structure to simplify the path planning, align with minimal feedback, and reduce the number of degrees of freedom (DOF) required to locomote. They can perform vital inspection and repair tasks within the structure that larger truss construction robots could not perform without modifying the structure. We detail a specific type of relative robot designed to traverse a cuboctahedral (CubOct) cellular solids lattice, show how the symmetries of the lattice simplify the design, and test these design methodologies with a CubOct relative robot that traverses a 76.2 mm (3 in.) pitch lattice, MOJO (Multi-Objective JOurneying robot). We perform three locomotion tasks with MOJO: vertical climbing, horizontal climbing, and turning, and find that, due to changes in the orientation of the robot relative to the gravity vector, the success rate of vertical and horizontal climbing is significantly different
SpRoUTS (Space Robot Universal Truss System): Reversible Robotic Assembly of Deployable Truss Structures of Reconfigurable Length
Automatic deployment of structures has been a focus of much academic and industrial work on infrastructure applications and robotics in general. This paper presents a robotic truss assembler designed for space applications - the Space Robot Universal Truss System (SpRoUTS) - that reversibly assembles a truss from a feedstock of hinged andflat-packed components, by folding the sides of each component up and locking onto the assembled structure. We describe the design and implementation of the robot and show that the assembled truss compares favorably with prior truss deployment systems
Stable switch action based on quantum interference effect
Although devices working on quantum principles can revolutionize the
electronic industry, they have not been achieved yet as it is difficult to
control their stability. We show that one can use evanescent modes to build
stable quantum switches. The physical principles that make this possible is
explained in detail. Demonstrations are given using a multichannel Aharonov -
Bohm interferometer. We propose a new matrix for multichannel junctions to
solve the scattering problem.Comment: 12 figure
Meso-Scale Digital Materials: Modular, Reconfigurable, Lattice-Based Structures
We present a modular, reconfigurable system for building large structures. This system uses discrete lattice elements, called digital materials, to reversibly assemble ultralight structures that are 99.7% air and yet maintain sufficient specific stiffness for a variety of structural applications and loading scenarios. Design, manufacturing, and characterization of modular building blocks are described, including struts, nodes, joints, and build strategies. Simple case studies are shown using the same building blocks in three different scenarios: a bridge, a boat, and a shelter. Field implementation and demonstration is supplemented by experimental data and numerical simulation. A simplified approach for analyzing these structures is presented which shows good agreement with experimental results
Geometry Systems for Lattice-Based Reconfigurable Space Structures
We describe analytical methods for the design of the discrete elements of ultralight lattice structures. This modular, building block strategy allows for relatively simple element manufacturing, as well as relatively simple robotic assembly of low mass density structures on orbit, with potential for disassembly and reassembly into highly varying and large structures. This method also results in a structure that is easily navigable by relatively small mobile robots. The geometry of the cell can allow for high packing efficiency to minimize wasted payload volume while maximizing structural performance and constructability. We describe the effect of geometry choices on the final system mechanical properties and automated robotic constructability of a final system. Geometric properties considered include number of attachments per voxel, number of attachments per coefficient of volume, and effects of vertex, edge, and face connectivity of the unit cell. Mechanical properties considered include strength scaling, modulus scaling, and packing efficiency of the lattice. Automated constructibility metrics include volume allowance for an end-effector, strut clearance angle for an end-effector, and packing efficiency. These metrics were applied to six lattice unit cell geometries: cube, cuboctahedron, octahedron, octet, rhombic dodecahedron, and truncated octahedron. A case study is presented to determine the most suitable lattice system for a specific set of strength and modulus scaling requirements while optimizing for ease of robotic assembly
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