关键词： Robotics  

摘要： The Journal of Mechanisms and Robotics was established five years ago with the first volume being published in February 2009. We owe a profound debt of gratitude to Professor McCarthy, the founding editor, for his bold vision for the journal and for creating a venue for archival publications dedicated to mechanisms and robotics. During his tenure, the journal grew rapidly to critical mass with approximately 200 submissions annually, averaging an acceptance rate of around 25%, and publishing four issues per year. The journal continues to publish research contributions to the fundamental theory, algorithms, design, manufacture, and experimental validation for mechanisms and robots. The current scope of the journal includes topics in theoretical and applied kinematics, mechanism synthesis and design, analysis and design of robot manipulators, hands, and legs, soft robotics, compliant mechanisms, origami and folded robots, printed robots, and haptics devices. The journal is also...

关键词： kinematics   Medical   robotics   Physical Education   Safes   United States  

摘要： Objective: Endovascular robotics systems, now approved for clinical use in the United States and Europe, are seeing rapid growth in interest. Determining who has sufficient expertise for safe and effective clinical use remains elusive. Our aim was to analyze performance on a robotic platform to determine what defines an expert user. Methods: During three sessions, 21 subjects with a range of endovascular expertise and endovascular robotic experience (novices < 2 hours to moderate-extensive experience with > 20 hours) performed four tasks on a training model. All participants completed a 2-hour training session on the robot by a certified instructor. Completion times, global rating scores, and motion metrics were collected to assess performance. Electromagnetic tracking was used to capture and to analyze catheter tip motion. Motion analysis was based on derivations of speed and position including spectral arc length and total number of submovements (inversely proportional to proficiency of motion) and duration of submovements (directly proportional to proficiency). Results: Ninety-eight percent of competent subjects successfully completed the tasks within the given time, whereas 91% of noncompetent subjects were successful. There was no significant difference in completion times between competent and noncompetent users except for the posterior branch (151 s: 105 s;P = .01). The competent users had more efficient motion as evidenced by statistically significant differences in the metrics of motion analysis. Users with > 20 hours of experience performed significantly better than those newer to the system, independent of prior endovascular experience. Conclusions: This study demonstrates that motion-based metrics can differentiate novice from trained users of flexible robotics systems for basic endovascular tasks. Efficiency of catheter movement, consistency of performance, and learning curves may help identify users who are sufficiently trained for safe clinical use of

关键词： hydrogels   tough   LCST   actuator   robotics  

摘要： Tough Al-alginate/poly(N-isopropylacrylamide) (PNIPAM) hydrogel has been synthesized by introducing an interpenetrating network with hybrid physically cross-linked alginate and chemically cross-linked PNIPAM. Varying the concentration of AlCl3 regulates the mechanical properties of the tough hydrogel and tunes its lower critical solution temperature (LCST) as well. The tough Al-alginate/PNIPAM exhibits 6.3 +/- 0.3 MPa of compressive stress and 9.95 of uniaxial stretch. Tunability of LCST is also achieved in a wide range within 22.5-32 degrees C. A bending beam actuator and a four-arm gripper made of bilayer (Na-alginate/PNIPAM)/(Al-alginate/PNIPAM) hydrogel as prototype of all-hydrogel soft robotics are demonstrated. A finite element (FE) simulation model is developed to simulate the deformation of the soft robotics. The FE simulation not only reproduces the deformation process of performed experiments but also predicts more complicated devices that can be explored in the future. This work broadens the application of temperature-responsive PNIPAM-based hydrogels.

摘要： 3166-Pos

关键词： Motion planning  

摘要： For solving serial manipulators path-planning when grabbing target in obstacle workspace, a solution of fuzzy control ant colony algorithm is presented. We transform serial manipulators pathplanning into the multidimensional function maximum problem, at the same time, the independent variables of multidimensional function are gridded. Fuzzy control ant colony algorithm makes a 'path-planning' on the gridded multidimensional domain of the function. And we also improve the conventional Ant Colony Algorithm with fuzzy control intelligent pheromone updating method, it successfully increases convergence, accuracy and heuristic of the algorithm. The experiment of PUMA560 grabbing target in obstacle workspace is solved satisfactorily by the fuzzy control ant colony algorithm, and in laboratory, 6 freedom manipulator is also made an obstacle avoidance grabbing target experiment, it has a good precision and optimal path-planning when grabbing target, and it will be more accurate with increased iterations. Therefore, Practice has proved that the feasible method of solving robotics multi-freedom manipulators grabbing target problem in obstacle workspace is presented by this paper. Copyright © 2015 American Scientific Publishers All rights reserved.

关键词： *ROBOTICS   *MACHINE theory   *AUTOMATION   *HAPTIC devices   *ROBOT dynamics  

关键词： 漂浮基空间机器人   柔性关节   柔性臂   奇异摄动法   鲁棒   模糊   滑模  

摘要： 讨论受到外部干扰影响的参数不确定的漂浮基柔性关节、柔性臂空间机器人系统的动力学建模过程、运动控制律设计和关节、臂双重柔性振动的主动抑制问题。利用动量、动量矩守恒关系和拉格朗日-假设模态法建立系统动力学方程。基于奇异摄动法,将系统分解为相互独立的三个子系统:慢变子系统、快变子系统1和快变子系统2。针对慢变子系统提出一种饱和鲁棒模糊滑模控制律来补偿不确定参数、柔性关节引起的转角误差以及外部干扰的影响,从而实现系统期望运动轨迹的渐近跟踪。饱和函数的运用可减弱滑模控制自身的抖振;针对快变子系统1设计一种速度差值反馈控制器来抑制柔性关节引起的系统柔性振动;针对快变子系统2采用线性二次型最优控制器来抑制柔性臂引起的系统柔性振动。仿真试验证明所提出的混合控制律的有效性。

关键词： 机器人   缠绕系统   动力学分析   纤维复合材料  

摘要： 纤维复合材料非对称形体容器因其结构的特殊性往往采用人工缠绕，但人工缠绕生产出的容器缺点极其明显，不仅外观粗糙、强度低、成本高，而且性能难以保证，这一现状一直制约着整个复合材料行业的发展，实现非对称形体容器自动缠绕是复合材料行业的发展趋势。从上世纪七十年代至今国内外对于自动缠绕，无论是理论基础还是实际应用，发展都非常迟缓。现有的复合材料容器缠绕设备具有活动范围小，灵活度低、未考虑张力影响等缺点，众所周知机器人以其灵活性高的特点广泛应用于各个行业，所以将机器人应用于容器的自动缠绕势在必行。本文主要围绕以下几个方面进行研究。\n 首先，以缠绕容器的形状结构为基础，结合缠绕过程中的速度、加速度等参数，对复合材料容器在缠绕过程中纤维所受到的变张力进行分析，并由机器人各关节驱动力矩与移动耗能的关系，推导出机器人优化位姿判据。其次，根据缠绕机器人六自由度的机械结构，搭建出机器人的虚拟模型，对机器人的三个位姿进行规划，根据位姿的差异分别推导出运动学正逆方程，对机器人坐标系进行建立和分析，并针对在缠绕过程中预设的缠绕轨迹进行编程。最后，将纤维的变张力加载到机器人模型中，使机器人在受变张力和不受张力的情况下沿设计轨迹运动，用 ADAMS测量出机器人三个位姿的各关节的参数变化，分析机器人的最优位姿。\n 本文对六自由度机器人在受变张力和不受张力的情况下进行实验，使机器人模型沿预设轨迹进行运动，通过测量两种情况下的各个位姿六个关节的力矩曲线，并将实验数据与力矩耗能关系相结合，分析出在缠绕过程中机器人的优化位姿。

关键词： 青蛙   机器人   动力学分析   MATLAB   ADAMS  

摘要： 仿青蛙游动机器人的动力学分析,是研制仿青蛙水下机器人的基础。通过对所研制的仿青蛙游动机器人机构进行简化,建立机器人系统运动学模型。在此基础上,利用拉格朗日法建立机器人系统的动力学方程,通过逆动力学分析将前期生物青蛙观测实验获取的各关节运动轨迹转化为各关节驱动力矩,最后通过对比分析分别利用MATLAB和ADAMS得到的各关节驱动力矩在一个运动周期内的变化曲线,不仅验证了动力学方程的正确性,也为后期机器人控制系统的设计提供了理论依据。