关键词： Ultrasonic transducers  

摘要： Ultrasonic transducers have often been used in the development of sensory systems for robotics applications. In most cases, these sensory systems are based on the determination of times of flight for signals from every transducer. In this work we have used piezoresistive and piezoelectric materials to measure the instant and position collision in metallic structures by using the difference of the times of propagation of an acoustic wave when it is produced over a ferromagnetic (iron, steel or another material) based structure. An immediate application of the proposed method is the detection and location of impacts over the metallic links of an industrial robot or the collision position in a metallic structure for an automated inspection Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

关键词： 动力学   拉格朗日方程   牛顿-欧拉公式   Gough-Stewart并联机器人   广义坐标  

摘要： 综合采用拉格朗日方程和牛顿-欧拉公式推导了Gough-Stewart并联机器人机构逆动力学模型的封闭解形式.通过选择合适的分支广义坐标,简化了拉格朗日函数对广义坐标的偏导求解,得到了求导矩阵的解析表达式.分析了分支角速度、角加速度轴向分量对机构动力学的影响,仿真结果表明:当机构运动加速度及分支轴向惯量较小时,可以忽略该分量的影响;但当机构运动加速度或者分支轴向惯量较大时,应对传统模型进行修正以满足机构运动高速性和定位精确性的要求.

关键词： 草方格   割断机构   动力学分析   ADAMS  

摘要： 横向割断机构是草方格铺设机器人横向铺设系统中一个重要的组成部分,直接影响机器人的正常运行。针对草方格铺设机器人所要完成的任务,设计出一套既适合工作环境、又能完成割断任务的新型机构。应用计算机仿真技术,利用Pro/ENGINEER软件绘制出割断机构的三维模型,观察模型设计是否存在干涉等现象;利用ADAMS软件对割断机构进行动力学仿真,通过仿真观察机构的运行,绘制出关键部位的速度、位移等参数曲线,在理论上确保割断机构动作方面的可行性、合理性;最后通过实验验证横向割断机构能够按设计完成割断草帘绳的任务。

关键词： 并联机器人   弹性动力学   有限元  

摘要： 采用有限元理论建立Delta并联机器人柔性构件的运动微分方程,结合机构的运动特点,规定了结点位移的方向,得到机构系统的动力学模型。将机构的真实运动看作名义运动与弹性振动的叠加,同时将动平台的位置和方向误差看作名义运动的摄动,得出动平台位形误差与结点位移的关系方程。在实例中,综合考虑重力、惯性力及阻尼共同作用下的动力响应,得到机构模态频率在工作空间的特性,对动平台的6维误差进行了全面评估。

关键词： 点焊机器人   动力学分析   ADAMS软件  

摘要： 如何确立电机和减速器的型号及各轴的运动参数,是机器人设计过程中非常重要的一个技术环节。以点焊机器人为例,主要通过ADAMS软件对机器人进行前处理、动力学分析及后处理,从而获得机器人各轴的运动技术参数,为电机和减速器的选择提供了理论依据。

关键词： 冗余度机器人   动力学   容错  

摘要： 提出了最小关节力矩突变指标,对冗余度机器人动力学容错性能进行了研究,通过构造关节力矩突变的表达式,在不同锁定时刻规划出各个关节力矩,并将规划结果与运动学关节速度突变规划出的关节力矩相比较,证明了在低速运动下可以用最小关节速度突变算法控制机器人的末端误差,而在高速运动下需要使用最小关节力矩突变算法控制机器人的末端误差.最后通过一个平面3R机器人的仿真实例,验证了算法的有效性.

关键词： Die-casting industry -- Equipment & supplies  

摘要： The article offers information on the array of removal and spray robots for the automation of diecasting from Reis Robotics USA Inc., exhibited during the International Foundry Trade Fair GIFA 2011.

关键词： Students  

摘要： This article describes an outreach program to broaden participation in computing to include more students with visual impairments. The precollege workshops target students in grades 7-12 and engage students with robotics programming. The use of robotics at the precollege level has become popular in part due to the availability of Lego Mindstorm NXT kits. The robotics programming tools and materials used in the workshops are designed with an accessibility focus for participants with different degrees of vision. Through the use of available assistive technology and open source software, robotics is accessible to the visually impaired. The quantitative and qualitative results from three robotics workshops conducted during the past three years will be discussed, including some initial long-term results. Strategies, based on our experiences, will also be shared to promote accessible outreach. While many of the participants are in middle and early high school, findings indicate that participant interest in computing is high regardless of whether their schools offer computer science courses or not. Increased interest and confidence with robotics persists throughout follow-up activities. © 2011 ACM.

关键词： Behavior coordination   Discrete event systems   discrete event systems (DESs)   fuzzy logic   mobile robotics   Mobile robots   Robot kinematics   Robot sensing systems   Supervisory control  

摘要： In order to incorporate the uncertainty and impreciseness present in real-world event-driven asynchronous systems, fuzzy discrete event systems (DESs) (FDESs) have been proposed as an extension to crisp DESs. In this paper, first, we propose an extension to the supervisory control theory of FDES by redefining fuzzy controllable and uncontrollable events. The proposed supervisor is capable of enabling feasible uncontrollable and controllable events with different possibilities. Then, the extended supervisory control framework of FDES is employed to model and control several navigational tasks of a mobile robot using the behavior-based approach. The robot has limited sensory capabilities, and the navigations have been performed in several unmodeled environments. The reactive and deliberative behaviors of the mobile robotic system are weighted through fuzzy uncontrollable and controllable events, respectively. By employing the proposed supervisory controller, a command-fusion-type behavior coordination is achieved. The observability of fuzzy events is incorporated to represent the sensory imprecision. As a systematic analysis of the system, a fuzzy-state-based controllability measure is introduced. The approach is implemented in both simulation and real time. A performance evaluation is performed to quantitatively estimate the validity of the proposed approach over its counterparts. [ABSTRACT FROM AUTHOR]