关键词： 并联机器人   刚柔耦合系统   逆动力学   绝对节点坐标法   自然坐标法  

摘要： 随着我国社会快速发展，经济结构加速升级，制造业中机器人保有量屡创新高。本文中所研究的平面3-RRR刚柔耦合并联机器人，在快速运动过程中，轻质杆件由于内力作用不可避免地会发生柔性大变形，使其力学特性应和刚性模型有所差别。文章以轻质杆件在运动中会变形为先决条件，以绝对节点坐标法与自然坐标法描述了刚柔耦合系统的逆动力学模型，利用generalized-alpha法与牛顿迭代法结合进行数值求解。另外，本文还将机器人刚柔耦合模型与刚性模型的力学特征做出了比较。本文主要工作如下：\n （1）平面3-RRR刚体逆运动学与逆动力学分析。本文介绍了该机器人的构型，应用矢量环路法对关节角、关节角速度、关节角加速度进行了分析。通过仿真图像可知关节角速度图像关节与角位移图像，关节角加速度图像与关节角速度图像皆成导数关系，证明了逆运动学模型的正确性。根据柯尼希原理分别计算各杆件与动平台的动能，进而得到了机构动能。利用刚体尺寸不变原理，约束方程即利用动平台外接圆半径固定不变的约束条件来建立。逆动力学模型依据拉格朗日原理利用拉格朗日乘子来建立，并应用MATLAB软件对其力学性能进行仿真。\n （2）平面3-RRR刚柔耦合逆动力学模型分析。采用自然坐标法描述刚性构件，可推导出刚性构件的质量矩阵。采用绝对节点坐标法描述柔性构件，需先利用待定系数法求得形函数，从而推导出柔性构件质量矩阵。由此可对各构件质量矩阵进行装配，得到整个机器人的质量矩阵，以推导出惯性力。利用等效力偶，依据虚功原理可推导出广义驱动力。依据刚性构件几何尺寸不变原理，构建约束方程即刚性杆杆长方程与刚性动平台边长方程，从而推导出约束力。加入弹性力与轨迹约束方程即可构建机器人刚柔耦合逆动力学模型。\n （3）平面3-RRR刚柔耦合逆动力学建模数值求解。采用了缩减积分的方法来分割应变能以规避泊松闭锁问题，应用不变矩阵来提高求解运算速度。以S-型加减速圆周轨迹为算例，结合generalized-alpha法、牛顿迭代法与刚体校正法来求解并联机器人的逆动力学模型。实验迭代结果满足设定精度要求。所求柔性梁中点处最大横向变形为4.701mm，其剪切角的变化规律具有对称性，驱动关节角速度与理想刚性模型相比变化明显，驱动关节变量的变化规律比较平滑，由此验证了建模方法、求解算法的正确性和使用S-型加减速的必要性，对将来控制具有重要的理论意义。

关键词： 机器人学   虚拟仿真   教学实践  

摘要： 针对机器人课程教学中理论与实践脱节的问题,采用基于三维建模软件和工程数学软件建立虚拟仿真平台的方法,架起理论知识与机器人实体的桥梁,帮助学生能够快速地进入机器人课程的学习.首先介绍了机器人本门课程的相关特点与国内外关于机器人教学的现状,然后分析了目前在机器人教学中存在的一些问题,最后以典型的工业机器人为例,说明了采用虚拟仿真技术构建机器人本体的方法.希望该方法能够更好地激发学生学习机器人课程的兴趣,调动学生的积极性,提高教师传授机器人知识的效率.

关键词： 机器人竞赛   特长生   科技   中考   生理   理论学习   专业知识   复习资料  

摘要： 很多学生在课外参加过各种类型的机器人竞赛,但大多没有经过系统的理论学习。而中考科技特长生的理论加试中有“考察相关专业知识”的要求,在备考过程中很难找到有针对性的复习资料。我将自己在备考过程中收集的资料进行补充和整理,为报考机器人科技特长生的学生以及对机器人感兴趣的人们提供参考。

关键词： 鳗鱼机器人   牛顿-欧拉建模法   非惯性系   动力学模型  

摘要： 在惯性系下得到的鳗鱼机器人的动力学方程由于耦合度高、非线性强而不利于控制器的设计。本文受自主水下航行器(AUV)基于体坐标系的模型表示法的启发,定义了一个与鳗鱼机器人运动方向一致的非惯性系。在该非惯性系下,利用科里奥利定理获得鳗鱼机器人的二维运动学模型,并利用改进的牛顿第二定律和力矩平衡原理获得水下二维鳗鱼机器人在非惯性系下的动力学模型。该模型是解析的,可直接获得切向速度子动力学,更适合于基于模型的现代控制方案,与精确模型相比,其通过方向角参数解耦实现了模型的简化。最后,对一个9模块的机器人系统进行了数值仿真,并与已有的精确模型进行了对比分析,发现所建立简化模型和精确模型的几乎重合,从而验证了所建立简化模型的准确性。

关键词： 机器人竞赛   中小学生   综合素质  

摘要： 随着科学技术的不断发展,计算机科学和人工智能逐渐走入校园,中小学生也开始参与到机器人的创作和比赛中去。机器人竞赛对提升中小学生综合素质有着十分重要的意义,它可以培养学生的创新能力、自学能力以及实践能力等,所以我们教师要明确中小学生进行机器人竞赛的目的和意义,积极引导学生开拓创新,努力提升中小学生的综合素质。

关键词： 工业机器人   腕关节   锥齿轮动力学分析  

摘要： 六自由度工业机器人手腕锥齿轮由于齿轮碰撞力波动幅度较大,且齿轮处于旋转运动状态,可能导致接触区域应力值很难利用测量手段获得。因此,利用Pro/E参数化建模工具构建六自由度工业机器人手腕锥齿轮传动模型,将锥齿轮模型导入ANSYS中,根据机器人工作状态,对啮合后齿轮施加动态载荷进行瞬态动力学分析,然后再利用Matlab绘制出应力变化曲线,得到机器人手腕大齿应力变化规律,从而验证该工业机器人手腕大齿结构设计合理性,旨在对其他机械传动机构结构设计起到一定指导作用。

关键词： Learning and adaptive systems   Bayesian non-parametrics   online learning   hidden semi-Markov model   subspace clustering   teleoperation  

摘要： Small-variance asymptotics is emerging as a useful technique for inference in large-scale Bayesian non-parametric mixture models. This paper analyzes the online learning of robot manipulation tasks with Bayesian non-parametric mixture models under small-variance asymptotics. The analysis yields a scalable online sequence clustering (SOSC) algorithm that is non-parametric in the number of clusters and the subspace dimension of each cluster. SOSC groups the new datapoint in low-dimensional subspaces by online inference in a non-parametric mixture of probabilistic principal component analyzers (MPPCA) based on a Dirichlet process, and captures the state transition and state duration information online in a hidden semi-Markov model (HSMM) based on a hierarchical Dirichlet process. A task-parameterized formulation of our approach autonomously adapts the model to changing environmental situations during manipulation. We apply the algorithm in a teleoperation setting to recognize the intention of the operator and remotely adjust the movement of the robot using the learned model. The generative model is used to synthesize both time-independent and time-dependent behaviors by relying on the principles of shared and autonomous control. Experiments with the Baxter robot yield parsimonious clusters that adapt online with new demonstrations and assist the operator in performing remote manipulation tasks.

关键词： aerial gripping   flying robots   high-speed landing   MBZIRC   multiagent aerial system  

摘要： This study describes the hardware and software systems of the Micro Aerial Vehicle (MAV) platforms used by the ETH Zurich team in the 2017 Mohamed Bin Zayed International Robotics Challenge (MBZIRC). The aim was to develop robust outdoor platforms with the autonomous capabilities required for the competition, by applying and integrating knowledge from various fields, including computer vision, sensor fusion, optimal control, and probabilistic robotics. This paper presents the major components and structures of the system architectures and reports on experimental findings for the MAV-based challenges in the competition. Main highlights include securing the second place both in the individual search, pick, and place the task of Challenge 3 and the Grand Challenge, with autonomous landing executed in less than 1 min and a visual servoing success rate of over 90% for object pickups.

关键词： Helical swimmer robot   Single helical flagellum   Hydrodynamics maneuver   Flagellum inclination angle  

摘要： Helical swimming robots with a capable propulsion system at low-Reynolds numbers have been proposed for many applications. Although linear propulsion characteristics of swimming robots with a single helical flagellum have been extensively studied, the characteristics of maneuverability have not been completely investigated yet. This study presents a new method for the maneuverability of the helical swimming robot with a single helical flagellum. This mechanism is based on the change in the angle between the helical and body axes. This study shows that a change in the aforementioned angle can enable the swimming robot to have turning maneuvers in clockwise or counterclockwise directions. Moreover, the swimming robot will move in a straight line if the helical and body axes are parallel. To investigate this new method and predict the robot's behavior at various inclination angles, a hydrodynamics model is used. To validate the hydrodynamics model, an experimental prototype of a macro-size swimming robot with specific inclination angles is fabricated. The results indicate that the helical swimming robot swims on circular trajectories through specific inclination angles between the helical flagellum and the body axis. Moreover, the radius of curvature decreases by increasing the inclination angle. Results of the validated hydrodynamics model indicate that the turning velocity has approximately a constant value at different inclination angles depending on the rotational frequency and geometrical parameters of the swimming robot. Finally, the effects of geometrical parameters of the body and the helical flagellum on the radius of curvature and turning velocity are investigated through the proposed hydrodynamics model. The verified results indicate that the hydrodynamics model provides a viable alternative model to predict the behavior of a helical swimming robot at various inclination angles within a range of design variables. This new method can be introduced as a mechan