查看更多>>摘要：Systems for ambient assisted living (AAL) that integrate service robots with sensor networks and user monitoring can help elderly people with their daily activities, allowing them to stay in their homes and live active lives for as long as possible.In this paper, we outline the AAL system currently developed in the European project Robot-Era, and describe the engineering aspects and the serviceoriented software architecture of the domestic robot, a service robot with advanced manipulation capabilities.Based on the robot operating system (ROS) middleware, our software integrates a large set of advanced algorithms for navigation, perception, and manipulation.In tests with real end users, the performance and acceptability of the platform are evaluated.
查看更多>>摘要：In this paper, we briefly introduce the history of the Defense Advanced Research Projects Agency (DARPA) Grand Challenge programs with particular focus on the 2012 Robotics Challenge.As members of team DRC-HUBO,we propose different approaches for the Rough-Terrain task, such as enlarged foot pedals and a transformation into quadruped walking.We also introduce a new gait for humanoid robot locomotion to improve stability performance, called the Ski-Type gait.We analyze the stability performance of this gait and use the stability margin to choose between two candidate step sequences, Crawl-1 and Crawl-2.Next, we perform a force/torque analysis for the redundant closedchain system in the Ski-Type gait, and determine the joint torques by minimizing the total energy consumption.Based on the stability and force/torque analysis, we design a cane length to support a feasible and stable Crawl-2 gait on the HUBO2 humanoid robot platform.Finally, we compare our experimental results with biped walking to validate the Ski-Type gait.We also present our team performance in the trials of the Robotics Challenge.
查看更多>>摘要：The configuration space is a fundamental concept that is widely used in algorithmic robotics.Many applications in robotics, computer-aided design, and related areas can be reduced to computational problems in terms of configuration spaces.In this paper, we survey some of our recent work on solving two important challenges related to configuration spaces: ① how to efficiently compute an approximate representation of high-dimensional configuration spaces;and ② how to efficiently perform geometric proximity and motion planning queries in high-dimensional configuration spaces.We present new configuration space construction algorithms based on machine learning and geometric approximation techniques.These algorithms perform collision queries on many configuration samples.The collision query results are used to compute an approximate representation for the configuration space, which quickly converges to the exact configuration space.We also present parallel GPU-based algorithms to accelerate the performance of optimization and search computations in configuration spaces.In particular, we design efficient GPU-based parallel k-nearest neighbor and parallel collision detection algorithms and use these algorithms to accelerate motion planning.
查看更多>>摘要：In this paper, we develop a decentralized algorithm to coordinate a group of mobile robots to search for unknown and transient radio sources.In addition to limited mobility and ranges of communication and sensing, the robot team has to deal with challenges from signal source anonymity, short transmission duration, and variable transmission power.We propose a two-step approach: First, we decentralize belief functions that robots use to track source locations using checkpoint-based synchronization, and second, we propose a decentralized planning strategy to coordinate robots to ensure the existence of checkpoints.We analyze memory usage, data amount in communication, and searching time for the proposed algorithm.We have implemented the proposed algorithm and compared it with two heuristics.The experimental results show that our algorithm successfully trades a modest amount of memory for the fastest searching time among the three methods.
查看更多>>摘要：This paper presents the formulation and practical implementation of positioning methodologies that compensate for the nonholonomic constraints of a mobile microrobot that is driven by two vibrating direct current (DC) micromotors.The open-loop and closed-loop approaches described here add the capability for net sidewise displacements of the microrobotic platform.A displacement is achieved by the execution of a number of repeating steps that depend on the desired displacement, the speed of the micromotors, and the elapsed time.Simulation and experimental results verified the performance of the proposed methodologies.
查看更多>>摘要：In this paper, a novel flexible robot system with a constrained tendon-driven serpentine manipulator (CTSM) is presented.The CTSM gives the robot a larger workspace, more dexterous manipulation, and controllable stiffness compared with the da Vinci surgical robot and traditional flexible robots.The robot is tele-operated using the Novint Falcon haptic device.Two control modes are implemented, direct mapping and incremental mode.In each mode, the robot can be manipulated using either the highest stiffness scheme or the minimal movement scheme.The advantages of the CTSM are shown by simulation and experimental results.
查看更多>>摘要：For a domestic personal robot, personalized services are as important as predesigned tasks, because the robot needs to adjust the home state based on the operator's habits.An operator's habits are composed of cues, behaviors, and rewards.This article introduces behavioral footprints to describe the operator's behaviors in a house, and applies the inverse reinforcement learning technique to extract the operator's habits, represented by a reward function.We implemented the proposed approach with a mobile robot on indoor temperature adjustment, and compared this approach with a baseline method that recorded all the cues and behaviors of the operator.The result shows that the proposed approach allows the robot to reveal the operator's habits accurately and adjust the environment state accordingly.
查看更多>>摘要：Additive manufacturing and 3D printing technology have been developing rapidly in the last 30 years,and indicate great potential for future development.The promising future of this technology makes its impact on traditional industry unpredictable.3D printing will propel the revolution of fabrication modes forward, and bring in a new era for customized fabrication by realizing the five "any"s: use of almost any material to fabricate any part, in any quantity and any location, for any industrial field.Innovations in material, design, and fabrication processes will be inspired by the merging of 3D-printing technology and processes with traditional manufacturing processes.Finally, 3D printing will become as valuable for manufacturing industries as equivalent and subtractive manufacturing processes.
查看更多>>摘要：The most promising strategies in tissue engineering involve the integration of a triad of biomaterials,living cells, and biologically active molecules to engineer synthetic environments that closely mimic the healing milieu present in human tissues, and that stimulate tissue repair and regeneration.To be clinically effective, these environments must replicate, as closely as possible, the main characteristics of the native extracellular matrix (ECM) on a cellular and subcellular scale.Photo-fabrication techniques have already been used to generate 3D environments with precise architectures and heterogeneous composition, through a multi-layer procedure involving the selective photocrosslinking reaction of a light-sensitive prepolymer.Cells and therapeutic molecules can be included in the initial hydrogel precursor solution, and processed into 3D constructs.Recently, photofabrication has also been explored to dynamically modulate hydrogel features in real time, providing enhanced control of cell fate and delivery of bioactive compounds.This paper focuses on the use of 3D photo-fabrication techniques to produce advanced constructs for tissue regeneration and drug delivery applications.State-of-the-art photo-fabrication techniques are described, with emphasis on the operating principles and biofabrication strategies to create spatially controlled patterns of cells and bioactive factors.Considering its fast processing, spatiotemporal control, high resolution, and accuracy, photo-fabrication is assuming a critical role in the design of sophisticated 3D constructs.This technology is capable of providing appropriate environments for tissue regeneration, and regulating the spatiotemporal delivery of therapeutics.
查看更多>>摘要：In order to build a ceramic component by inkjet printing, the object must be fabricated through the interaction and solidification of drops, typically in the range of 10-100 pL.In order to achieve this goal, stable ceramic inks must be developed.These inks should satisfy specific rheological conditions that can be illustrated within a parameter space defined by the Reynolds and Weber numbers.Printed drops initially deform on impact with a surface by dynamic dissipative processes, but then spread to an equilibrium shape defined by capillarity.We can identify the processes by which these drops interact to form linear features during printing, but there is a poorer level of understanding as to how 2D and 3D structures form.The stability of 2D sheets of ink appears to be possible over a more limited range of process conditions that is seen with the formation of lines.In most cases, the ink solidifies through evaporation and there is a need to control the drying process to eliminate the "coffee ring" defect.Despite these uncertainties, there have been a large number of reports on the successful use of inkjet printing for the manufacture of small ceramic components from a number of different ceramics.This technique offers good prospects as a future manufacturing technique.This review identifies potential areas for future research to improve our understanding of this manufacturing method.
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