A Hyper-redundant Elephant’s Trunk Robot with an Open Structure:Design,Kinematics,Control and Prototype

As for the complex operational tasks in the unstructured environment with narrow workspace and numerous obstacles,the traditional robots cannot accomplish these mentioned complex operational tasks and meet the dexterity demands.The hyper-redundant bionic robots can complete complex tasks in the unstructured environments by simulating the motion characteristics of the elephant’s trunk and octopus tentacles.Compared with traditional robots,the hyper-redundant bionic robots can accomplish complex tasks because of their flexible structure.A hyper-redundant elephant’s trunk robot(HRETR)with an open structure is developed in this paper.The content includes mechanical structure design,kinematic analysis,virtual prototype simulation,control system design,and prototype building.This design is inspired by the flexible motion of an elephant’s trunk,which is expansible and is composed of six unit modules,namely,3UPS-PS parallel in series.First,the mechanical design of the HRETR is completed according to the motion characteristics of an elephant’s trunk and based on the principle of mechanical bionic design.After that,the backbone mode method is used to establish the kinematic model of the robot.The simulation software SolidWorks and ADAMS are combined to analyze the kinematic characteristics when the trajectory of the end moving platform of the robot is assigned.With the help of ANSYS,the static stiffness of each component and the whole robot is analyzed.On this basis,the materials of the weak parts of the mechanical structure and the hardware are selected reasonably.Next,the extensible structures of software and hardware control system are constructed according to the modular and hierarchical design criteria.Finally,the prototype is built and its performance is tested.The proposed research provides a method for the design and development for the hyper-redundant bionic robot.

Design and Kinematics Study on Space Hyper-Redundant Robot

The design of space hyper-redundant robot with high dexterity is problem with great complexity. Taking the aim at robot product seriation and combination design, the combination design method of space hyper-redundant robot based on the omnidirectional unit arm of 3 degrees of freedom (d.o.f) is proposed in this paper. The kinematics model of this kind of robot is established through the equivalent mechanism model. On the basis of successful research on 3-d.o.f unit arm, the 7-d.o.f bionics arm redundant robot with double unit arm has been developed further.The content discussed in this paper is very important to the robot technology in future space station, nuclear industry andunderwater work on the sea floor.

基于MATLAB和RobotStudio的6-DOF机器人运动学分析与仿真

针对船体密封舱、箱柜等狭窄空间普遍存在的机器人难以工作问题,提出了一种新型6-DOF(degrees of freedom)机器人。首先分析了该机器人的机械结构,基于D-H坐标理论建立了机器人D-H坐标表格以及机器人正、逆运动学方程,其次应用MATLAB对机器人的运动学进行了仿真,结果表明所得的机器人正、逆运动学方程完全正确;最后设计了虚拟样机,利用RobotStudio仿真分析了机器人箱体焊接的优点;为进一步验证设计的机器人运动性能,与通用6-DOF机器人做了对比分析。研究结果表明新型机器人运动的可行性,为设计适应箱柜等狭窄空间的工业机器人提供了理论依据。

基于合成数据集的多目标识别与6-DoF位姿估计

多目标识别及六自由度(6-DoF)位姿估计是实现物料无序堆放状态下机器人自动分拣的关键。近年来,基于深度神经网络的方法在目标识别及位姿估计领域受到广泛关注,但此类方法依赖大量训练样本,而样本的采集及标注费时费力,限制了其实用性。其次,当成像条件差、目标相互遮挡时,现有位姿估计方法无法保证结果的可靠性,进而导致抓取失败。为此,文中提出了一种基于合成数据样本的目标识别、分割及位姿估计方法。首先,以目标对象的3维(3D)几何模型为基础,利用3D图形编程工具生成虚拟场景的多视角RGB-D合成图像,并对生成的RGB图像及深度图像分别进行风格迁移和噪声增强,从而提高合成数据的真实感,以适应真实场景的检测需要;接着,利用合成数据集训练YOLOv7-mask实例分割模型,运用真实数据进行测试,结果验证了该方法的有效性;然后,以分割结果为基础,基于ES6D目标位姿估计模型,提出了一种在线姿态评估方法,以自动滤除严重失真的估计结果;最后,采用基于主动视觉的位姿估计校正策略,引导机械臂运动到新的视角重新检测,以解决因遮挡而导致位姿估计偏差的问题。在自行搭建的6自由度工业机器人视觉分拣系统上进行了实验,结果表明,文中提出的方法能较好地适应复杂环境下工件的识别与6-DoF姿态估计要求。

Design and Experiments of Ultrasound Image-Guided Multi-DOF Robot System for Brachytherapy

To implant radioactive seeds through a needle precisely and safely, a novel multi-DOF surgical robotic system is presented in this paper for percutaneous prostate intervention through the patient’s perineum under real-time ultrasound image guidance. The proposed robot, which is designed with 9-DOF, consists of a 3-DOF automatic location platform for position adjustment, 2-DOF for automatic ultrasonic probe adjustment mounted with electromagnetic trackers, and 4-DOF for manually adjusting the guided template. Meanwhile, a new registration method based on the quaternion algorithm and least square method is developed, and the needle insertion is performed under the real-time guidance of a navigation system. Furthermore, the robot system has undergone some preliminary experiments with a laser tracker to evaluate the repeatability and accuracy of the robot system. The location error of the puncture needle tip can be controlled under 0.7 mm in air for the whole robotic system. The acquired results endorse the precision of the robot system for prostate seed implantation brachytherapy. © 2017, Tianjin University and Springer-Verlag GmbH Germany.

Research of 6-DOF Serial-Parallel Mechanism Platform for Stability Training of Legged-Walking Robot

The concept of legged-robot stability training with a training platform is proposed and a serial-parallel mechanism platform with 6 degrees of freedom is designed for this target. The designed platform is composed of 4-DOF parallel mechanism with spherical joints and prismatic pairs,and 2-DOF serial mechanism with prismatic pairs. With this design,the platform has advantages of low platform countertop,big workspace,high carrying capacity and high stiffness. On the basis of DOF analysis and computation of space mechanism,weight supporting auxiliary mechanism and raceways-balls supporting mechanism are designed,so as to improve the stiffness of designed large platform and payload capacity of servo motors. And then the whole structure design work of the platform is done. Meanwhile,this paper derives the analytical solutions of forward kinematics, inverse kinematics and inverse dynamics. The error analysis model of position and orientation is established. And then the simulation is done in ADAMS to ensure the correctness and feasibility of this design.

RESEARCH ON THE DOF DISPOSITION AND MECHANISMS DESIGN OF HUMANOID ROBOT

The DOF of human being was analyzed in this paper. Three reasonable kinds of DOF disposition programs came up to design a humanoid robot and an optimal DOF disposition program was chosen according to configuration appearance, realizing the balance and torsion movement and analysis of torque of the humanoid. Three special mechanisms were designed so that the humanoid robot has some special function.

Arduino Based Planar Two DoF Robot Manipulator

In this research, two DoF five bar robot manipulator is controlled by using a human-machine interface program working in a computer. The human machine interface program is developed in Visual C#. Net environment after completing inverse kinematic analysis of the robot manipulator. Human machine interface in computer screen calculates two rotational joint variables for given positions of the robot end point. Then the computer program sends a data package containing these joint variables to Arduino microcontxoller. Arduino microcontxoller set the position of two servo motors according to calculated joint angles. Any position in workspace can be obtained by using the algorithm. The robot can follow traj ectories such as a line, a circle and a rectangle. Furthermore, a lot of patterns can be generated using function with variable radius and angle of rotation.

Micro-Scale Motion Precision Simulation Method for a New-Type 6-DOF Micro-Manipulation Robot

A new 6-DOF micro-manipulation robot based on 3-PPTTRS parallel mechanisms in combination with flexure hinges is proposed. The design principle of the mechanism is introduced, and the kinematics analysis method based on differentiation is used to get the (inverse) kinematics equations. Then a micro-scale motion precision simulation method is proposed according to finite element analysis (FEA), and the prediction of robot’s motion precision in design phase is realized. The simulation result indicates that the 6-DOF micro-manipulation robot can meet the design specification.

The Inverse Kinematics Analysis of Six-DOF Robots

The kinematics of robots mainly analyses the transformational relation between links and the end-actuator position and orientation of robots,its two kinds of topics mainly include:direct kinematics topic and inverse kinematics topic[1].This paper mainly researched the inverse kinematics of Six-DOF robots,built Six-DOF robots inverse kinematics model with D-H parameter model,and worked out the robot’s homogeneous transformation matrix[2].Now we will build the model and study to the inverse kinematics of RBT-6SO3S which from Jiang Su Hui-Bo Robots Company.

基于改进RRT算法的6-DOF机器人路径规划

针对传统快速扩展随机树(RRT)算法在机器人路径规划中随机性大、冗余节点多、无法生成最优路径这一系列问题,从引入权重系数、路径缩短、拐角平滑处理这三方面对传统RRT算法进行优化,使6-DOF机械臂能有效避开障碍物,并通过距离最短路径到达目标点。同时,在角速度不连续处根据机械臂曲率约束进行路径平滑过渡处理,消除初始路径中锯齿状部分,保证路径平稳性。仿真实验表明,改进RRT算法提高了路径搜寻成功率并将原始路径距离缩短25%,平均规划时间缩短75%。

一种9-DOF模块化机器人的运动学反解

本文针对德国 AMTEC公司生产的一种 9- DOF模块化机器人提出了一种新颖的运动学反解方法 .这种方法运用螺旋理论并通过分析机器人的结构特征将机器人分解成几个相对解耦的子结构 ,通过给系统增加三个约束 ,可以得出在给定末端位姿下的全部关节角 .由于模块化机器人理论上可以组合成任何形式上的机器人系统 ,所以这种解法对其它机器人系统有一定的借鉴意义 .

Stewart平台6-DOF并联机器人完整动力学模型的建立

采用RPY角描述方法,基于拉格朗日方程建立了Stewart平台6-DOF并联机器人完整动力学模型。此 模型具有与一般机器人相同的结构,同时给出了模型所具有的基本性质。

医疗转运机器人3-DOF手臂轨迹规划

提出一种新型医疗转运机器人,可完成无自主行动能力的患者在病床、轮椅、手术台等不同设备之间的转运工作;对机器人手臂进行结构设计,基于D-H法对3-DOF机械臂进行运动学分析,采用五次多项式插值方法进行轨迹规划,保证转运患者过程中手臂能够平稳作业。

基于6-DOF并联机器人医疗器械道路运输模拟平台的关键技术及实现

针对目前医疗器械道路运输模拟平台短缺的问题,提出了一种使用6-DOF并联机器人进行道路运输模拟的实现方法。通过改进谐波叠加法建立三维道路谱模型,与标准功率谱对比验证仿真模型的准确性。将三维道路谱作为激励源转化为机器人运动数据,通过绝对位置S形直线插补方法控制并联机器人,使其能够高效准确地模拟车辆在不同车速、各种等级路面上的运动状况。

基于Robotic Toolbox和ADAMS的机器人运动学及动力学仿真

对国产机器人BRIR801-5进行运动学分析,采用MATLAB工具箱Robotic Toolbox对机器人进行了建模仿真,通过轨迹规划得到关节位移、角速度、角加速度曲线,利用ADAMS软件对机器人进行了动力学仿真,得到关节力矩曲线,验证理论分析正确性和机器人机构设计的合理性,为机器人结构设计和仿真提供参考。

5-DOF并串联机器人运动学分析及仿真

并联机器人强度刚度较高,但是工作空间较小;串联机器人工作空间较大,但强度刚度较小。混联机构因兼顾了并联和串联机构的优点而具有更加广泛的应用前景。文中介绍了一种新型五自由度并串联机器人来实现复杂曲面的加工。应用螺旋理论对其运动性质进行分析并计算了自由度。通过数值法推导了机器人的正解,运用解析法推导了机器人的反解。用SolidWorks构建了机器人的三维模型并导入到ADAMS中对其进行运动学仿真。仿真结果显示,该机器人能够实现复杂曲面的加工,可以为工业生产提供帮助。

基于MATLAB/Robotics Toolbox的六自由度机械臂仿真

设计了一种六自由度的机械臂,用D-H法建立数学模型,并运用MATLAB中的simulink模块对机械臂的运动学和路径规划问题进行了仿真。给出关节变量值,求解机械臂末端姿态;已知空间姿态,求解关节变量;采用改进点到点的路径规划,得到了仿真时间为2s,间隔为0.025s的机械臂末端运行轨迹图,进而得到机械臂末端在坐标空间的姿态和速度、加速度的关联图形。仿真结果作为机械臂控制系统设计的依据。

Novel Door-opening Method for Six-legged Robots Based on Only Force Sensing

Current door-opening methods are mainly developed on tracked, wheeled and biped robots by applying multi-DOF manipulators and vision systems. However, door-opening methods for six-legged robots are seldom studied, especially using 0-DOF tools to operate and only force sensing to detect. A novel door-opening method for six-legged robots is developed and imple- mented to the six-parallel-legged robot. The kinematic model of the six-parallel-legged robot is established and the model of measuring the positional relationship between the robot and the door is proposed. The measurement model is completely based on only force sensing. The real- time trajectory planning method and the control strategy are designed. The trajectory planning method allows the maximum angle between the sagittal axis of the robot body and the normal line of the door plane to be 45°. A 0-DOF tool mounted to the robot body is applied to operate. By integrating with the body, the tool has 6 DOFs and enough workspace to operate. The loose grasp achieved by the tool helps release the inner force in the tool. Experiments are carried out to validate the method. The results show that the method is effective and robust in opening doors wider than 1 m. This paper proposes a novel door-opening method for six-legged robots, which notably uses a O-DOF tool and only force sensing to detect and open the door.

STATE TRANSFORMATION PROCESSES FOR FREE-FLOATING THREE-LINK PLANAR ROBOTS

The transformation process of an m-DOF free-floating robot from one staticstate to a different static state has m degrees of freedom. The proposed approach of thesetransformations utilizes a series of single-DOF transformation processes as an alternative to them-DOF transformation process. Two static state transformation processes are studied in detail.First, a single-DOF transformation process is established using a newly defined concept, referred toas transformation planning, and the definite integral of conservation of angular momentum. Second,the governing equation of the single-DOF transformation process is established using the dynamicequations of motion of the robot. This allows the joint torques to be computed to effect the statetransformation. Finally, an extension of the single-DOF transformation process is proposed to extendthe application of this proposed transformation methodology to create a transformation net whichallows the reconfiguration of a robot from one state to many other possible states.