基于Virtual.lab的柔性并联机器人仿真平台

为了实现柔性并联机器人的快速可视化建模,提供柔性并联机器人动力学分析的新途径,针对柔性并联机器人系统内刚体、柔体耦合的难点,利用Virtual.lab软件对VBA的支持及其处理机械系统弹性动力学问题的优势,结合数据库技术、参挝数化建模原理和柔性并联机器人动力学仿真的特点,对Virtual.lab软件进行二次开发,建立柔性并联机器人动力学仿真平台,可实现柔性并联机器人动力学特性的分析.该平台操作简单,建模效率高,计算速度快,便于机械工程师在机械设计中使用.为柔性并联机器人结构优化设计及运动学、动力学规划指标的确定提供科学依据.     

全柔性铰链平面并联微动机器人的有限元分析

介绍了并联机器人的特点及其应用,对全柔性铰链平面并联机器人建立了刚性模型,并采用闭环线型原理建立理论运动学线性模型（Jacobian矩阵）,用ANSYS软件对其进行有限元分析,得到有限元运动学模型（Jacobian矩阵值）,讨论两者关系,发现有限元模型比理论模型要精确.     

全柔性机器人机构的结构构型研究

本文对全柔性机器人机构的结构构型问题进行了系统的讨论：首先从应用层面上对 全柔性机器人机构进行了分类，着重讨论了并联机构与全柔性机器人机构之间存在的有机联 系．通过对并联机构的结构及柔性铰链的几何模型进行系统的总结，为全柔性机器人机构“ 型”的选择与构筑提供了丰富的素材．此外，还重点讨论了对全柔性机器人机构的性能产生 较为显著影响的结构布局问题．     

两柔性机器人协调操作的动力学模型及其逆动力学分析

柔性机器人动力学是当前机器人研究的热点,而其协调操作问题目前仍为空白．本 文首次建立了柔性机器人协调操作刚性负载的动力学模型,利用有限元法和Lagrange方程, 在柔性机器人协调操作的运动学和动力学协调约束条件基础上,推导出系统的动力学方程, 提出了其逆动力学问题的解决方案,并成功给出了平面两3R柔性臂协调操作的数值算例．     

基于有限元方法的3-PPSR大长径比柔性并联机器人刚度模型分析

为实现较大工作空间的运动,设计了一种大长径比的3-PPSR结构的微操作柔性并联机器人.该机器人由压电马达驱动,采用大长径比柔性铰链连接,柔性铰链的变形范围在毫米级,适用于要求大变形的场合,同时具有结构简单、无奇异、无间隙、运动精度高等特点.由于系统的刚度直接影响系统的运动精度、承载负荷等性能,针对大长径比柔性铰链特点,运用有限元方法,建立了柔性铰链的数学模型,并采用整体刚度的方法,结合机构协调方程和力平衡方程,得到系统的柔性刚度模型.最后,采用ANSYS比较了所建理论刚度模型结果与有限元模型分析的结果.分析结果表明,理论刚度模型合理,符合机构的运动特征.     

基于柔性铰链的热驱动微夹钳的实验和仿真分析

微执行器在整个微机电系统中直接面对其应用对象,需要满足定位精度高,稳定性好,响应速度快,控制方便的要求.柔性铰链以其特殊的性能广泛应用于操作执行器的设计应用中.以一种基于柔性铰链的电热驱动微夹钳为研究对象,通过实验和ANSYS有限元仿真分析对微夹钳的机械性能进行了分析,发现微夹钳端部的输出位移与输入电压基本呈线形关系.通过仿真分析探讨了柔性铰链结构尺寸变化对微夹钳性能的的影响.     

基于ADAMS的并联机器人运动学和动力学仿真

应用机械系统动力学仿真分析软件ADAMS,建立了Stewart型并联机构的虚拟样机模型,包括对并联机器人各部件的简化方法、在ADAMS中的模型描述及仿真过程控制,并利用该虚拟样机模型对并联机器人进行了运动学和动力学分析。为并联机器人系统的设计、制造和模拟运动作业提供了理论依据和主要参数。实现了在计算机上通过使用CAE仿真软件朱对并联机器人的运动和动力性能进行分析,为并联机器人的设计提供了一套有效的分析方法。     

一种带力传感的微夹持器设计及试验

设计制作一种带力传感的微夹持器,通过压电陶瓷堆驱动和柔性铰链放大来实现夹持动作,由粘贴于悬臂应变梁的半导体应变片构成惠斯通电桥测量微夹持力．优化设计了柔性铰链的结构,对悬臂式应变梁进行了仿真分析．最后,制作并组装成微夹持器,进行了力传感标定试验和微夹持操作试验．制作和试验结果验证了这种带力传感的微夹持器的可行性和实用性．     

六自由度微动机构的运动分析

本文对作者设计的一种六自由度微动机进行位移分析，该机构由３条ＰＰ－Ｒ－Ｓ支链并联而成，为消除间隙，每条链的运动副都设计柔性铰链，本文用坐标变换方法求出了机构的输入输出微位移关系，由于柔性铰链的运动范围受到材料强度的限制。文中还建立了柔性铰链微小角位移与机构输出位移的关系，以上关系式为六自由度微动机构的结构设计提供了计算依据。     

基于变阻抗控制的冗余驱动并联机器人多目标内力优化

由于冗余驱动的存在, 冗余驱动并联机器人系统逆动力学模型存在无限组可跟踪期望轨迹的控制力矩解, 这使得机器人在运行过程中具有完成附加任务的能力. 以实现骨科机器人的安全精准操控为目的, 提出了基于变阻抗控制的冗余驱动并联机器人多目标内力优化方法. 首先, 采用支链分解法对冗余驱动并联机器人的动力学进行建模. 其次, 为实现机器人的安全操作, 设计了冗余驱动并联机器人时变阻抗控制器, 利用李雅普诺夫理论分析了系统的稳定性; 在此基础上, 以消除冗余驱动并联机器人运动过程中的传动间隙为附加任务, 提出了一种以力矩传递性能、驱动功率和控制力为优化目标的多目标融合驱动力优化方法. 最后, 通过仿真实验与对比分析, 验证了所提方法的有效性, 实现了机器人系统传动间隙的消除.     

Design and performance evaluation of a biomimetic microrobot for the father–son underwater intervention robotic system

Underwater intervention is a favorite and difficult task for AUVs. To realize the underwater manipulation for the small size spherical underwater robot SUR-II, a father–son underwater intervention robotic system (FUIRS) is proposed in our group. The FUIRS employs a novel biomimetic microrobot to realize an underwater manipulation task. This paper describes the biomimetic microrobot which is inspired by an octopus. The son robot can realize basic underwater motion, i.e. grasping motion, object detection and swimming motion. To enhance the payload, a novel buoyancy force adjustment method was proposed which can provides 11.8 mN additional buoyancy force to overcome the weight of the object in water. Finally, three underwater manipulation experiments are carried out to verify the performance of the son robot. One is carried by swimming motion and buoyancy adjustment; the other two are only carried by buoyancy adjustment. And the experimental results show that the son robot can realize the underwater manipulation of different shape and size objects successfully. The swimming motion can reduce the time cost of underwater manipulation remarkably.     

新型仿生水下子母机器人系统设计

传统的水下子母机器人在水下作业时母机器人会有噪音大、体积大和隐蔽性差的缺点,而且子机器人作为提高水下机器人位置精度和续航时间的重要手段大多采用尾部摆动、机身两侧划水、小型螺旋桨推进等方式,造成运动过程中稳定性差、噪音大而且尺寸难以微型化的缺点.为了克服这些不足,设计一种新型仿生水下子母机器人系统.该系统球形母机器人采用喷水电机进行喷水推进,减少噪音,增加隐蔽性,并为微型子机器人提供控制信号和能源.微型子机器人以樽海鞘为原型基于仿生原理设计,在水下运动透明度高、隐蔽性强、稳定性高.建立球形母机器人的喷水推进器和微型子机器人的微型驱动器的驱动力计算模型,同时建立微型子机器人的水下转向模型.最后制作子母机器人样机并进行子母机器人的水下运动实验,以验证所设计的子母机器人系统的有效性.     

A constrained assumed modes method for dynamics of a flexible planar serial robot with prismatic joints

In the present study, for the first time, flexible multibody dynamics for a three-link serial robot with two flexible links having active prismatic joints is presented using an approximate analytical method. Transverse vibrations of flexible links/beams with prismatic joints have complicated differential equations. This complexity is mostly due to axial motion of the links. In this study, first, vibration analysis of a flexible link sliding through an active prismatic joint having translational motion is considered. A rigid-body coordinate system is used, which aids in obtaining a new and rather simple form of the kinematic differential equation without the loss of generality. Next, the analysis is extended to include dynamic forces for a three-link planar serial robot called PPP (Prismatic, Prismatic, Prismatic), in which all joints are prismatic and active. The robot has a rigid first link but flexible second and third links. To model the prismatic joint, time-variant constraints are written, and a motion equation in a form of virtual displacement and virtual work of forces/moments is obtained. Finally, an approximate analytical method called the “constrained assumed modes method” is presented for solving the motion equations. For a numerical case study, approximate analytical results are compared with finite element results, which show that the two solutions closely follow each other.     

Development of a novel type of microrobot for biomedical application

This paper proposes a new type of microrobot that can move along a narrow area such as blood vessels which has great potential for application in microsurgery. Also, the development of a wireless microrobot that can be manipulated inside a pipe by adjusting an external magnetic field has been discussed. The model microrobot utilizes an electromagnetic actuator as the servo actuator to realize movement in biomedical applications. The structure, motion mechanism, and evaluation characteristic of motion of the microrobot have been discussed, and the directional control can be realized via the frequency of the input current. The moving experiments have been carried out in branching points in the horizontal direction, and the moving speed of the robot has been measured in vertical direction by changing frequency. Based on the results, the microrobot has a rapid response, and it can clear out dirt which is adhering to the inner wall of pipe. This microrobot will play an important role in both industrial and medical applications such as microsurgery.     

Robust adaptive controller design for flexible joint manipulators

In this paper the control problem for robot manipulators with flexible joints is considered. A reduced-order flexible joint model is constructed based on a singular perturbation formulation of the manipulator equations of motion. The concept of an integral manifold is utilized to construct the dynamics of a slow subsystem. A fast subsystem is constructed to represent the fast dynamics of the elastic forces at the joints. A composite control scheme is developed based on on-line identification of the manipulator parameters which takes into account the effect of certain unmodeled dynamics and parameter variations. Stability analysis of the resulting closed-loop full-order system is presented. Simulation results for a single link flexible joint manipulator are given to illustrate the applicability of the proposed algorithm.     

考虑关节柔性的模块机器人动力学参数辨识

提出了一种基于3维运动测量系统Optotrak3020的柔性关节模块机器人动力学模型参数辨识方法.首先将机器人的动力学模型参数化为不包括刚度力矩的线性形式,避免了参数矩阵的标定问题.激励轨迹基于有限的傅里叶级数函数,采用自适应遗传算法得出了优化的傅里叶级数系数.机器人每一关节单独跟随优化激励轨迹进行运动,同时电机位置、...     

Coupling characteristics of rigid body motion and elastic deformation of a 3-PRR parallel manipulator with flexible links

Modeling of multibody dynamics with flexible links is a challenging task, which not only involves the effect of rigid body motion on elastic deformations, but also includes the influence of elastic deformations on rigid body motion. This paper presents coupling characteristics of rigid body motions and elastic motions of a 3-PRR parallel manipulator with three flexible intermediate links. The intermediate links are modeled as Euler–Bernoulli beams with pinned-pinned boundary conditions based on the assumed mode method (AMM). Using Lagrange multipliers, the fully coupled equations of motions of the flexible parallel manipulator are developed by incorporating the rigid body motions with elastic motions. The mutual dependence of elastic deformations and rigid body motions are investigated from the analysis of the derived equations of motion. Open-loop simulation without joint motion controls and closed-loop simulation with joint motion controls are performed to illustrate the effect of elastic motion on rigid body motions and the coupling effect amongst flexible links. These analyses and results provide valuable insight to the design and control of the parallel manipulator with flexible intermediate links.     

仿人机器人柔性腰部机构研究

仿人机器人腰部的构成对仿人机器人的运动学、动力学性能起着重要的作用．本 文着重分析了目前仿人机器人腰部机构存在的问题，提出了一种具有柔性特征的仿人机器人 腰部设计方案，并分析了此腰部机构对机器人的运动稳定性、操作柔顺性的影响．本设计使 仿人机器人具有良好的柔顺性，提高了机器人与人协作时的安全性、稳定性和抗干扰能力．     

3-RRRT并联机器人位置正向求解研究

研究一种3-RRRT型并联机器人机构的运动学正向求解方法。根据3-RRRT型并联机器人机构特点以及关节运动的取值范围,提出了以并联机器人支链中支杆的方向余弦和动平台绝对位置坐标为系统的广义坐标的方法,并详细地推导了3-RRRT型并联机器人运动学模型,通过进一步消除中间变量的方法最终获得了易于正、逆运动学求解的只包含3个驱动关节坐标与动平台3个绝对位置坐标的约束方程组。最后,运用基于Moore—Penwse广义逆的牛顿迭代格式编制了MATLAB运动学正向求解程序,并进行了运动学正向求解数值仿真,结果表明求解程序快速有效。     

Recursive modelling in dynamics of Agile Wrist spherical parallel robot

Recursive matrix relations for kinematics and dynamics of the 3-RRR Agile Wrist spherical parallel robot are established in this paper. The prototype of the robot is a three-degrees-of-freedom mechanism with three identical legs. Controlled by concurrent torques, which are generated by some electric motors, the active elements of the robot have three independent rotations. Knowing the rotation motion of the moving platform, we develop first the inverse kinematical problem and determine the velocities and accelerations. Further, the principle of virtual work is used in the inverse dynamic problem. Matrix equations offer iterative expressions and graphs for the power requirement comparison of each of three actuators in two computational complexities: complete dynamic model and simplified dynamic model.