机械式娱乐机器人手臂联动机构的设计与研究

针对目前娱乐机器人多自由度手臂机构设计存在成本高、发展速度缓慢等问题提出机械式手臂联动机构,即利用六杆机构实现手臂前、后、左、右同步或交错摇摆,从而完成鼓掌、欢呼的动作。将优化设计思想与Matlab相结合,利用外惩罚函数法对两次简化后的手臂异步联动进行建模优化,求解出参数并用分支定界法确定杆件参数;利用控制变量法对手臂同步联动进行参数优化,以SolidWorks、ADAMS软件为工具,建立其仿真模型,进行运动学仿真,结果显示,优化设计的六杆机构异步联动行程比系数最优、同步联动两臂相位差最小,能很好地满足机器人手臂娱乐需要。最终从六杆机构参数映射到手臂联动机构,为娱乐机器人手臂联动机构的设计和计算提供参考。     

Position analysis of a 3-DOF parallel manipulator

The forward and inverse kinematics of a 3-DOF parallel mechanism for beam aiming applications is derived in closed form. The mechanism has three actuated arms attached to a base via revolute joints. Another three arms are also attached to an upper platform via passive revolute joints. Each of the three base arms is connected to its respective opposing passive arm via a spherical joint. The platform has three degrees of freedom with respect to the base, two rotational and one radial motion.     

Configuration Design of an Under-Actuated Robotic Hand Based on Maximum Grasping Space

Capture is a key component for on?orbit service and space debris clean. The current research of capture on?orbit focuses on using special capture devices or full?actuated space arms to capture cooperative targets. However, the structures of current capture devices are complex, and both space debris and abandoned spacecraft are non?cooperative targets. To capture non?cooperative targets in space, a lightweight, less driven under?actuated robotic hand is proposed in this paper, which composed by tendon?pulley transmission and double?stage mechanisms, and always driven by only one motor in process of closing finger. Because of the expandability, general grasping model is constructed. The equivalent joint driving forces and general grasping force are analyzed based on the model and the principle of virtual work. Which reveal the relationship among tendon driving force, joint driving forces and grasping force. In order to configure the number of knuckles of finger, a new analysis method which takes the maximum grasping space into account, is proposed. Supposing the maximum grasped object is an envelope circle with diameter of 2.5m. In the condition, a finger grasping maximum envelope circle with different knuckles is modeled. And the finger lengths with corresponding knuckles are calculated out. The finger length which consists of three knuckles is the shortest among under?actuated fingers consists of not more than five knuckles. Finally, the principle prototype and prototype robotic hand which consists of two dingers are designed and assembled. Experiments indicate that the under?actuated robotic hand can satisfy the grasp requirements.     

电动栏杆栏杆臂自动返回装置

收费站广泛使用的电动栏杆偶尔会发生栏杆臂砸车事故。本文设计一种栏杆自动返回装置，电动栏杆装上这种装置后，栏杆臂万一砸车时，行程开关动作，控制电动机反转，栏标臂迅速返回到竖直位置，不会损坏车辆。     

基于Pro/E对泵车臂架变幅油缸受力分析

通过对混凝土臂架变幅机构受力的理论分析以及公式推导,得出了臂架油缸的受力表达式和最大受力的计算方法;结合Pro/E的三维建模及油缸受力分析,建立了臂架变幅油缸最大受力的快速计算分析方法。该方法较传统设计方法更快捷、更高效、更准确,且已经在臂架产品设计中得到有效运用。     

混凝土泵车臂架运动学分析与工作空间仿真

基于混凝土泵车臂架系统的结构特点,对臂架结构进行模型简化,得出臂架系统自由度。将臂架模拟成机械臂,运用D-H法对臂架模型进行运动学分析,列出臂架运动数学模型,进而借助Matlab求解臂架工作空间,绘制出臂架末端参考点的工作空间点云图。分析臂架机构参数对工作空间的影响,为泵车臂架的设计研发和现场施工泵车选型提供了参考。     

Dynamic optimization of robot arm based on flexible multi-body model

This paper examines the effect mechanism of torsional stiffness on flexible joints and the dynamic optimization of a six Degree-of-freedom industrial robot arm. The design optimization of the robot arm is investigated based on the rotor-torsional spring model and finite element method. The flexible multi-body dynamic model of the robot arm are established by considering the flexible characteristics of arms and joints, and the natural frequencies of a robot arm are calculated to obtain the torsional stiffness of the flexible joints. Natural frequency results gradually increased with joint stiffness improvement. Using the established dynamic model, the topology optimization on the robot arm is carried out by regarding lightweight as design goal and total displacement as constraints. The tare-load ratio and dynamic performance of the optimized robot arm are significantly enhanced compared with the original design model. This research can provide the theoretical basis for the dynamic optimization and upgrade of lightweight robot arm.     

肠道机器人扩张机构设计与优化

为了满足肠道机器人在肠道中运动和驻留的要求,设计了一种大变径比的新型扩张机构。该机构通过采用双层叠腿式设计,增大了与肠道的接触面积,最大扩张半径达到24.5mm,变径比增加到3.27。为了进一步研究该扩张机构的性能,建立了扩张臂的数学模型,对扩张臂的力学与运动学特性进行了理论分析。然后通过有限元分析,对扩张臂运动过程进行了动力学仿真,研究了不同扩张半径下,扩张臂的应力分布和变化趋势,基于有限元分析结果,对扩张臂进行了优化设计,优化后的等效应力最大值比优化前减小了12.89%。之后通过ADAMS对扩张臂进行运动学仿真,以验证其运动学模型的准确性。最后搭建了力学性能实验台,对其扩张力进行了测试,以验证其力学模型的准确性。实验结果显示:实验值与理论值的变化趋势基本一致,而且实验值小于理论值;机构扩张初始阶段误差较大,扩张半径为7.5 mm时,实验值仅为理论值的14.30%;之后误差急剧减小并趋于稳定,扩张半径为10~23mm时,实验值平均为理论值的73.64%;扩张臂1、2、3的实际扩张半径分别为24.5、24和23mm。结果显示本文设计的肠道扩张机构基本满足肠道安全性和大变径比的设计要求,而且结构优化效果明显。     

A force/position control for two-arm motion coordination and its stability robustness analysis

This paper presents a motion coordination of two robot manipulators coordinating an object. To coordinate the object, a force/position control scheme in a mode of leader/follower is devised. The dynamics of the object is incorporated into the dynamics of the leader arm, which yields a reduced order model of two arm system. In order to regulate interaction forces between two arms, the dynamics of the follower arm is expressed as force dynamic equations such that a novel direct force control scheme is devised. For the devised control scheme, a numerical simulation is shown. Under the coupling forces between two arms and two different type of bounded input disturbances, boundedness and asymptotic stability results based on a proposed Lyapunov function are shown. Also, a sufficient condition for a stability robustness is derived based on the Lyapunov approach.     

混凝土泵车臂架柔性多体动力学建模与仿真

用柔性多体动力学的理论分析四节臂混凝土泵车臂架系统的动态特性。把泵车的臂架模拟成柔性机器臂,采用拉格朗日方程和虚功原理建立混凝土泵车臂架系统的柔性多体动力学方程,通过对泵车臂架运动微分方程的推导和数值求解,对泵车各臂杆的运动情况进行分析。结合动力学仿真分析软件,分别建立四节臂混凝土泵车臂架的刚性模型和柔性模型,给定相同的驱动力矩对两种不同情况下的运动模型进行分析。仿真得出两种模型的变形曲线和第四节臂杆的角速度曲线,对比仿真结果表明,在研究轻质长臂杆混凝土泵车的臂架系统时,考虑各个臂杆柔性变形的影响是非常必要的,同时,研究成果也为混凝土泵车浇注自动化的研究提供了数学模型。     

Multi-displacement continuum model for discrete systems

A first-order multi-displacement microstructure continuum model is introduced to represent a discrete diatomic lattice system. This model is developed based on a two-term Taylor series expansion of the local displacement of the lattice. It is found that the multi-displacement continuum model obtained by keeping two terms in the Taylor series yields, in general, a better representation of the lattice system than the effective modulus model. However, this microstructure continuum model cannot characterize the negative group velocity of an optical mode of harmonic wave motion in the diatomic lattice. To capture the negative group velocity, a higher-order multi-displacement continuum model is necessary.     

Study on a ultra-light dual revolute manipulator with high joint torque

This paper details a study performed on a new proposed twelve degree-of-freedom dual robot arm, which is very light but capable of handling heavy loads. The proposed robot arm has a higher value for the ratio of the load capacity/robot weight than conventional robot arms, which are actuated by motors with speed reducers, such as a harmonic drives, since it adopts a new type of robot actuator based on a closed chain mechanism. Because of the high value of the ratio of the payload capacity/robot weight, it can be used as a robot arm for mobile robots and for walking robots. Analyses of the design scheme and of the mechanism of the joint actuator used for the robot arm are presented. Also, the control system developed for the robot arm is introduced. The superior characteristics of the new proposed robot arm, handling heavy payloads with light weight links compared to industrial robots, are presented through carrying out various payload capacity tests. Since the robot arm is designed with light links, it has some deflections and these deflections of the links are analyzed using the Finite Element Method (FEM). The results of performance tests are presented to check the correctness of the FEM analysis and to demonstrate the actual capability of handling heavy payloads applied to the robot arm.     

双摇杆机构在立方氮化硼研磨技术中的应用

从运动学和几何学原理出发,建立了双摇杆机构的数学模型,得出了双摇杆机构中工件中心点的运动轨迹方程,用Visual Basic语言编制了相应的计算机仿真软件,以图形的形式显示出运动轨迹曲线。对各杆的长度及相关角度等设计参数进行了优化,成功地将双摇杆机构应用于立方氮化硼等超硬材料的研磨。     

软体机械臂控制方法研究现状及展望

软体机械臂由于具有多自由度、高灵活性、较强的环境适应能力以及安全可交互性高等优势,近年来在生物医疗和海洋 勘探等诸多领域得到广泛应用。 软体机械臂采用高度可变形的柔性材料制作而成,由于其材料的非线性特征,软体机械臂的精 确控制一直是该领域的研究重点和难点,国内外研究人员针对软体机械臂的控制方法开展了大量研究并取得了较大进展。 但 是目前仍然存在若干问题,亟待探讨解决方法。 为此,本文梳理了近十年来国内外研究人员在软体机械臂的运动控制方法上取 得的研究成果,分析总结了目前软体机械臂常用的控制方法和最新技术等,指出了软体机械臂控制面临的难题与挑战,并对软 体机械臂控制方法的未来发展方向进行了探讨和展望。     

Vision guided dual arms robotic system with DSP and FPGA integrated system structure

Usually, a humanoid robot has two arms and stereo vision system to execute human daily actions. It has complicate mechanism and mechatronics control system structure. The hardware control structure should be planned ingeniously to execute the complicate computation of 3D image processing and manipulate a multi degree of freedom dual arms motion control, especially for mobile robot system. Here a 7 DOF dual arms robot with FPGA hardware control structure and a digital signal processor (DSP) based CMOS stereo vision system are designed and built in our lab. The intelligent fuzzy sliding mode control strategy is employed to establish the visual guided robotic motion control software. This low cost humanoid robotic system has compact control structure and mechanism integration for mobile application purpose. Object detecting and tracking schemes in 3D space were developed for locating the target position and then guided the robot arm to pick and place objects or track the specified moving target. Experimental results show that this delicate robotic system has basic humanoid function.     

基于优化理论的机构综合方法研究

提出了将优化设计的思想应用于机构综合中，并据此开发出了相应的软件。现主要以平面四杆机构的9位置轨迹生成问题为例，介绍了机构综合的优化方法的实现：以杆长等9个参数为设计变量，以相应的方程组中9个方程的左式平方和最小为目标函数，以杆长能构成四杆机构等为约束函数，采用惩罚函数法进行编程求解。最后给出了一个应用实例，表明了方法的有效性。     

仿生连续体机器人的研究现状和展望

仿生连续体机器人是一种基于章鱼臂、象鼻等生物器官仿生的新型机器人,近年来正逐步成为一个新的研究热点.文中讨论了连续体机器人的运动机理和应用领域,从仿生设计、运动学、动力学与控制等方面详细介绍了其研究现状,指出了目前连续体机器人研究中存在的问题及有待深入研究的方向.     

双臂机器人轴孔装配的运动学关系分析

研究了双臂进行轴孔装配的运动学约束关系。双臂协调作业的关键,在于根据作业要求确定双臂运动的约束关系。结合轴孔装配的特点,推导了主从臂在位置、方位、关节速度和关节加速度上的完整约束,由主臂的运动变量来规划从臂的运动变量。仿真结果表明所建立的约束关系,能确保轴孔装配的顺利完成。     

A robust and adaptive force/position control for two cooperating robot arms under uncertainty

This paper presents a motion coordination of a two-cooperating robot arm when there are unknown system parameters and bounded input disturbances. The order of the model of the two-arm system is reduced. To control this, a force/position control scheme based on an inverse dynamics control scheme is devised. On the top of the control scheme, an adaptive control scheme to take care of parametric uncertainties, and a robust control scheme to compensate coupling forces between two arms and input disturbances are devised. The adaptive and the robust control scheme are derived based on a devised Lyapunov function. The adaptive control algorithm is practical since it does not require the feedback of the second derivative of joint angles and interacting forces. The robust control scheme guarantees that the tracking error of the leader arm and the interacting forces between two arms are confined in a certain region. Numerical examples using dual 3 degree of freedom robot arm are shown.     

Dynamic modeling and cooperative control of a redundant manipulator based on decomposition

This paper demonstrates the use of a redundant manipulator to execute multiple tasks specified at different points on the manipulator. This is accomplished by decomposing a redundant arm at an intermediate arm location, called “elbow”, into two non-redundant local arms, referred to as the “bascarm” and the forearm. This decomposition transforms a redundant arm into a “serially linked dual-arm system,” where the cooperation between the basearm and the forearm is carried out through the task distribution and the elbow control. To distribute a given task to individual local arms according to their dynamic capabilities, the Cartesian space model of a serially linked dual-arm system is derived using Lagrangian mechanics. The Cartesian space dynamic model enables us to quantify the dynamic capbilities of individual arms based on two hyper ellipsoids: the Cartesian Force Ellipsoid (C. F. E.) representing the range of Cartesian forces due to the unit norm of joint torques, and Cartesian Acceleration Ellipsoid (C. A. E.) representing the range of Cartesian accelerations due to the unit norm of Cartesian forces. In addition to the local dynamic characteristics, the global task requirements such as singularity avoidance, joint torque limit avoidance, motion generation efficiency, and accurate motion control, are improved by elbow control. Elbow control can also be used to execute a subtask at the elbow, for example, obstacle avoidance.