仿人手掌的机器人变掌机构设计与分析

针对大小不同、形状各异的物体，机器人多指手的抓取规划和控制问题目前尚未得到完善的解决。为此，提出利用仿人手掌来提高机器人多指手的灵巧度以及扩大其工作空间，以降低抓取规划和控制的难度。首先，分析了人体手掌的运动特点，根据人体手掌的骨骼结构，研发了一种仿人手掌的机器人变掌机构，该变掌机构具有6个自由度，通过构型变换，可使安装于变掌机构的手指改变工作空间以及抓取点位置。其次，通过建立变掌机构的数学模型，分析已知抓取点个数和抓取点位置时变掌机构的6个自由度。然后，利用三维软件对变掌机构进行建模，并对其抓取动作进行仿真。最后，通过实验平台以及实物样机进行抓取实验，分别利用刚性手指、柔性手指对13种不同的物体进行抓取，验证了变掌机构的抓取能力以及适应性。该仿人手掌的机器人变掌机构能够简单快速地实现自适应构型，可以对尺寸、质量、形状差异较大的物体进行抓取，适用于二指、三指、四指的抓取，并且可连接刚性或柔性手指，既提高了机器人多指手的抓取质量以及适应性，又降低了其抓取规划和控制的难度。研究结果可对机器人多指手的普遍应用提供借鉴意义。     

片弹簧骨架气动柔性手爪抓持苹果分析

目的 提出片弹簧骨架气动柔性手爪, 以苹果为对象对抓持全过程进行研究。方法 片弹簧大变形状态分析等效于悬臂梁, 利用微分方法和Matlab编程, 求解该大变形的非线性微分方程。结果 建立了驱动负载、 抓持负载下的力学模型, 求解出了手爪片弹簧大变形和稳定抓持时所需的气缸压强,为该柔性手爪的应用提供了依据。结论 该柔性手爪可以实现对目标抓持物的稳定抓持。     

机器人手爪的功能分析与设计研究

本文对机器人手爪的抓取运动范围、工件的定位要求、夹紧力的计算方法、工件的检测、清洁和安全等相关功能要求进行了系统的介绍,对设计手爪时工件结构形式的分析、工件定位点及夹紧方式的确定、工件检测传感器位置及数量的确定、工件表面的清洁、手爪的安全性等相关设计事项进行了研究,在分析了机器人手爪的有关设计要素后,提出了机器人手爪的设计的步骤和设计思路,为机器人手爪在现代工业制造领域的推广和应用提供技术支持。     

精密1号装配机器人控制系统的体系结构

介绍了精密1号装配机器人控制系统体系结构的设计与实现。精密1号机器人是国家863计划智能机器人主题立项研制的一台SCARA结构的4轴装配机器人型号样机。它采用直接驱动技术，具有较高的运动速度和定位精度，配有高性能的视觉和力觉传感器，控制系统以Intel公司的iSBC386／12系列计算机和iRMXⅢ实时多任务操作系统为基础，采用上、下两级分布式计算机结构。控制系统除具有一般的机器人控制器的功能外，还具有用户多任务编程、可基于视觉和力觉传感器信息控制、离线编程和图形动画仿真等特性。     

用于判别连接状态的机器人手爪多传感器数据融合

舱外移动机器人在空间站工作时 ,其手爪与工件及空间站的安全连接至关重要。分别用BP神经网络和径向基函数神经网络 ,对机器人手爪上的力传感器、接近觉传感器和位移传感器的信息进行了融合 ,得到一个关于机器人手爪连接状态的正确判别     

基于DSP的多轴伺服控制器设计及其在灵巧手中的应用

讨论了一种采用电机控制专用DSP及FPGA设计的9轴电机伺服运动控制器。与采用通用DSP设计的多轴电机伺服运动控制器相比，该控制器具有较高的集成度和优良的性能价格比，便于降低机电系统的成本，减小机电系统体积，试验表明，该控制器性能稳定可靠，可满足多轴电机伺服运动控制的需要，已成功应用于16自由度多指灵巧手控制系统设计，该运动控制器在各类型机器人系统，以及数控机床等的控制系统设计上有广泛的应用前景。     

浅析机器人设计与电气自动化

对于机器人而言，它的控制系统是机器人的大脑，是决定机器人主要性能的因素。特别是对于工业机器人来讲，它的主要任务就是控制工业机器人在工作空间中的运动位置、姿态和轨迹、操作顺序及动作的时间等，一般具有编程简单、软件菜单操作、友好的人机交互界面、在线操作提示和使用方便等特点。     

基于机器视觉的机器人辨识及分拣盒装香烟的系统

运用机器视觉技术和机器人技术设计并实现了一种识别、分拣盒装香烟的系统,以提高识别准确率和分拣效率。该系统通过USB摄像头采集烟盒图像信息,从烟盒的特征检测入手,利用Matlab工具对香烟条形码、烟盒颜色和字迹字符三个方面进行处理分析,识别出真伪香烟,并随即通过控制机器人手爪对识别出的香烟进行分拣。     

空间三指形手爪的研制

随着空间机器人技术的进步,空间机器人将用于对空间漂浮目标的包络和抓捕.为了协助空间机器人完成对漂浮目标的捕获任务,研制了一种空间三指形手爪.利用单双手指、V形槽和捕获接口等机械元件,使得机器人可以对大范围位姿不确定的目标实现高精度的对接捕获.研制的蜗轮蜗杆、轴承、密封等机构具备空间环境适应性.在试验中,手爪在较大位姿偏移情况下捕获目标并锁紧在唯一位姿下.因此手爪具有较高的精度并且适应高低温度变化,具备了在空间环境中工作并抓捕对接目标的能力.     

小型地面移动机器人运动学分析及控制研究

研制了一种带前摆臂结构的小型地面移动机器人,建立了该机器人的运动学模型,确定了该机器人驱动轮转角与机器人位姿间的关系,为小型地面移动机器人的控制系统的设计提供了理论依据.该机器人的控制系统采用上下位机控制方式实现了对机器人的遥控控制,即上位机为 PC 机,下位机采用单片机.采用流向控制标志位查询判断驱动信号的流向,使机器人移动载体、摆臂和摄像装置的驱动电机可以协调运动.对该机器人各机构的运动进行了仿真,并得到了机构匀速运动过程中的主驱动轴转角、摆臂转角及摄像头转角等 3 个主要机构的运动参数曲线,验证了机器人各机构的运动性能.     

Intelligent robot control using ultrasonic measurements

We present an intelligent robot control system which employs low-quality ultrasonic measurements to perform high-precision recognition and grasping tasks. The system adaptively restores the ultrasonic image using approximators based on neural networks. Neural networks are also applied to perform object classification and a grasp planning task. Since the grasp planning is not unique, we developed a novel learning scheme that uses the expectation maximization approach. The resulting system works precisely and reliably. The underlying methodology can be extended to other low-quality data problems     

虚拟遥操作系统中灵巧手动作控制研究

介绍了在机械灵巧手虚拟遥操作系统中，关于采用立体视觉方法检测计算操作人员手势姿态及手指各关节参数方面的研究。多指灵巧机械手“复制”操作人员手的动作姿态，目的是进行不规则形状物体的抓取方法及可选择性抓取动作的直接控制研究。     

漂浮基闭链空间机械臂抓持载荷基于神经网络的反演自适应控制

讨论漂浮基闭链空间机械臂抓持系统目标载荷的位置、力混合协调控制问题。结合系统动量、动量矩守恒关系及闭合运动链几何约束关系,利用多刚体动力学建模方法建立了漂浮基闭链双臂空间机器人抓持系统的合成动力学方程。针对参数不确定和外部干扰的情况,提出一种基于反演神经网络的位置、力自适应协调控制方案,从而达到对抓持负载位置与所受内力的双重控制效果。此控制方案无需要求系统动力学方程关于惯性参数呈线性函数关系;同时,它可保证系统渐近稳定性。数值仿真结果证实了该控制方案可有效地消除参数不确定对系统的影响。     

内嵌式SMA驱动器研制与应用

提出了内嵌功能材料记忆合金丝的弹性棒结构,建立了描述变形的方程式。研制的复合棒直径8mm、长40mm、重8g,最大弯曲曲率可达14．8m^-1。以该复合棒为基本单元,设计并制作了组合式多指机械手,并对手爪抓取球体的实验进行了研究。实验证明内嵌式记忆合金驱动器,机构简洁、运行寿命长、可靠性高,使机器人系统变得更加紧凑、柔顺性更好。     

Microgravity experiments of nano-satellite docking mechanism for final rendezvous approach and docking phase

Laboratory for Space Systems (LSS), Tokyo Institute of Technology (Tokyo Tech) conducted three-dimensional microgravity environment experiments about a docking mechanism for mothership-daughtership (MS-DS) nano-satellite using the facility of Japan Micro Gravity Center (JAMIC) with Hokkaido Institute of Technology (HIT). LSS has studied and developed a docking mechanism for MS-DS nano-satellite system in final rendezvous approach and docking phase since 2000. Consideration of the docking mechanism is to mate a nano-satellite stably while remaining control error of relative velocity and attitude because it is difficult for nano-satellite to have complicated attitude control and mating systems. Objective of the experiments is to verify fundamental grasping function based on our proposed docking methodology. The proposed docking sequence is divided between approach/grasping phase and guiding phase. In the approach/grasping phase, the docking mechanism grasps the nano-satellite even though the nano-satellite has relative position and attitude control errors as well as relative velocity in a docking space. In the guiding function, the docking mechanism guides the nano-satellite to a docking port while adjusting its attitude in order to transfer electrical power and fuel to the nano-satellite. In the paper, we describe the experimental system including the docking mechanism, control system, the daughtership system and the release mechanism, and describe results of microgravity experiments in JAMIC.     

Pose estimation for autonomous grasping with a robotic arm system

A robust and accurate method for estimating the 3-D pose of a planar rigid object is presented. This article demonstrates that 3-D pose estimation becomes feasible by using the 2-D tracking points on an object of scale-invariant feature transform (SIFT) and 3-D point cloud detected by stereo vision on an object, assuming that a 3-D geometric model of an object is known a priori. The roll and pitch angles of an object are estimated by the normal vector of approximate plane of 3-D point cloud on an object and the yaw angle is estimated by 2-D tracking point on an object of SIFT. Accurate object detection and localization in the camera coordinate system is crucial for grasping. In the motion planning, the bidirectional rapidly exploring random tree algorithm is used to search for a valid path for efficient grasping. Our robot arm can robustly and autonomously grasp a randomly rotative rigid object detected by SIFT in 3-D space. We have realized a grasping scenario with a dexterous arm (ADAM) such that an object in front of ADAM can be grasped. This demonstration shows how the proposed components build a dexterous and robust system integrating object detection, pose estimation, and motion planning.     

Ultrasonic distance measurement for linear and angular positioncontrol

A robot-arm positioning control is described. It makes use of a microprocessor-based ultrasonic system and of a novel time-of-flight measurement technique. The experimental system consists of a three aligned ultrasonic transducers mounted on a rod. Two transducers work as receivers, while the third works both as a transmitter and a receiver. The system achieves a positioning accuracy of ±0.1° in the field of ±10° of misalignment for a distance ranging from a few centimeters up to 200 mm. For a higher distance range up to 300 mm, the position accuracy is ±0.4°. The system also performs distance measurement, using the same group of transducers. The system can be used in robotic applications in industrial environments, such as for orientation control or object grasping     

Design of a Lightweight Force-Feedback Glove with a Large Workspace

A wearable force-feedback glove is a promising way to enhance the immersive sensation when a user interacts with virtual objects in virtual reality scenarios. Design challenges for such a glove include allowing a large fingertip workspace, providing a desired force sensation when simulating both free- and constrained-space interactions, and ensuring a lightweight structure. In this paper, we present a force-feedback glove using a pneumatically actuated mechanism mounted on the dorsal side of the user’s hand. By means of a triple kinematic paired link with a curved sliding slot, a hybrid cam-linkage mechanism is proposed to transmit the resistance from the pneumatic piston rod to the fingertip. In order to obtain a large normal component of the feedback force on the user’s fingertip, the profile of the sliding slot was synthesized through an analysis of the force equilibrium on the triple kinematic paired link. A prototype five-fingered glove with a mass of 245 g was developed, and a wearable force-measurement system was constructed to permit the quantitative evaluation of the interaction performance in both free and constrained space. The experimental results confirm that the glove can achieve an average resistance of less than 0.1 N in free-space simulation and a maximum fingertip force of 4 N in constrained-space simulation. The experiment further confirms that this glove permits the finger to move freely to simulate typical grasping gestures.     

A behavior based nonlinear multi‐agent framework using a hybrid approach

Abstract

In this paper, a novel design and implementation of a multi‐agent system via a hybrid approach is proposed. First of all, an autonomous agent is insured to be stable by employing the proposed local feedback control besides appropriate switching among well‐posed behaviors including obstacle avoidance, target approaching, wandering, manipulator grasping, etc. Next, a hybrid framework of the multi‐agent system (HMAS) is established for dealing with multi‐agent cooperative problems. The architecture of the inherent hierarchical control is designed consisting of two levels, where the first (lower) level mainly handles the continuous state describing the data acquired from various sensors, whereas the second (higher) level is responsible for providing a well performed supervisory control that can manipulate all available resources to successfully accomplish the underlying mission. In the Advanced Control Laboratory of the Department of Electrical Engineering at National Taiwan University, an actual wheeled mobile robot (WMR) has been developed, named The Treasure Hunter (TTH), which is able to hunt treasures in an unknown environment whereby the effectiveness of the proposed approach can be satisfactorily demonstrated.