关键词： 并联机器人   复合柔性铰链   广义刚度矩阵   动力学仿真  

摘要： 并联机器人具有精度高、刚度大、惯性小、承载能力高、易于控制等特点,应用很广泛。柔性铰链的使用是用于精密操作的并联机器人的一大特色。柔性铰链的存在使得传统的刚性机构的研究方法不再适应此种机器人的研究,新的研究方法不断出现。 本文根据材料力学的相关理论知识,对一种新型的平面和空间复合柔性铰链进行了研究,给出了平面复合柔性铰链转动刚度的计算方法,从而推导出空间复合柔性铰链转动刚度及扭转刚度的计算公式,为复合柔性铰链的研究及应用打下了良好的基础。 通过对各个柔性铰链刚度的计算以及对整个并联机器人机构的分析,应用弹性势能的原理推导出整个并联机器人机构的广义刚度矩阵。 最后,本文运用UG、ANSYS及ADAMS软件建立了含柔性铰链并联机器人的多柔体动力学模型,并运用ADAMS对整个机构进行了运动学及动力学仿真研究,为并联机器人多柔体动力学仿真研究提供了有效的方法。

关键词： wheeled mobile robot   parallel manipulators   dynamics modelling   stability measure  

摘要： Kinematics, dynamics, and stability analysis of a hybrid serial-parallel wheeled mobile robot is detailed in this paper. Privileging the advantages of both serial and parallel robots, the suggested structure will provide higher stability for heavy object manipulation by a mobile robotic system. The proposed system is made of a differentially-driven wheeled platform, a planar parallel manipulator, which is called here as star-triangle (ST) mechanism, and a serial Puma-type manipulator arm. In order to develop a comprehensive kinematics model of the robot;first it is divided into three modules, i.e. a mobile platform, a parallel ST mechanism, and a serial robot. Next, a closed-form dynamics model is derived for the whole hybrid system based on a combined Newton-Euler and Lagrange formulation. Then, a careful validation procedure is presented to verify the obtained dynamics model. Finally, using the new postural stability metric named as moment-height stability (MHS), the important role of the parallel ST mechanism for stabilizing the mobile robotic system is demonstrated. The obtained results show that the proposed hybrid serial-parallel arrangement effectively enhances the tip-over stability of the overall mobile robotic system. Hence, it can be successfully exploited to prevent tip-over instability particularly during heavy object manipulation tasks.

关键词： 并联机器人   冗余驱动   运动学分析   动力学建模   轨迹跟踪  

摘要： 与传统的串联机器人相比,并联机器人具有刚度大、精度高、承载力强等优点。冗余驱动并联机器人能够利用冗余特性完全或部分消除奇异性,优化分配驱动力,提高并联机器人的速度和加速度能力。然而,并联机器人存在多条支链的特点给运动学性能分析带来了困难。同时,它又是一个复杂的多输入多输出的非线性系统,具有时变、强耦合和非线性动力学特性,增加了控制的难度。本文针对平面二自由度冗余驱动并联机器人,从运动学分析、机电耦合动力学模型的建立、控制器设计以及实验方面对并联机器人系统进行了深入地研究。 研究了并联机器人的速度性能和加速度性能与装配构型之间的关系。利用位置分析得到了并联机器人的全部装配构型,引入速度性能和加速度性能评价指标对各种装配构型进行性能分析。推导出基于机构一阶Jacobian影响系数矩阵和二阶Hessian影响系数矩阵的运动学性能指标,并将抽象的性能指标用曲线的形式描绘在平面上形成直观的性能图谱。结合并联机器人的工作空间分析、奇异位形分析,得出了具有最优机构运动学性能的装配构型。避免了并联机器人设计过程中的盲目性,有利于实现并联机器人高精度的轨迹跟踪。 建立了交流伺服电机冗余驱动并联机器人的机电耦合动力学模型。首先利用拉格朗日方程得到三个开链机构的动力学方程,在末端执行器处施加约束得到并联机构的动力学模型。用这种方法简化了建模过程,可以利用已经研究成熟的二杆开链机构的动力学模型,从而实现并联机构的快速建模。其次,利用矢量控制技术,建立了交流永磁同步伺服电机的动力学模型。然后,根据力矩匹配的原则,联立并联机构和交流伺服电机的动力学模型,得到整个并联机器人系统的机电耦合动力学模型。最后,通过对并联机器人系统进行的动力学分析,得到了并联机器人末端执行器的轨迹跟踪效果图、三个主动关节的角位移和交流伺服电机q轴电流的变化规律。 利用非线性PID的大范围稳定和对角递归神经网络的非线性逼近能力,设计了非线性PID控制与对角递归神经网络控制相结合的新型智能复合控制器。通过比较三种不同控制策略,即PID控制、神经网络自整定PID控制和新型智能复合控制对并联机器人轨迹跟踪控制效果的影响,说明所设计的新型智能复合控制器无论是对存在初始位置误差的圆轨迹进行跟踪,还是对梯形速度规划下的直线轨迹进行跟踪,都具有较好的控制效果。研究发现,新型智能复合控制器能够克服单一控制方法的不足,鲁棒性强,从而有利于提高轨迹跟踪的精度。 针对并联机器人运行过程中的外部扰动,提出了两种用于机器人轨迹跟踪的滑模变结构控制策略,即Terminal滑模控制和神经滑模控制。Terminal滑模控制对外界扰动具有较强的抑制能力,而且通过设定不同的Terminal时间可以实现不同的收敛速度。神经滑模控制有效抑制了常规滑模控制的抖振,即使存在系统参数误差和外界扰动等非线性不确定性因素的影响,仍能实现对期望轨迹的理想跟踪。 对平面二自由度冗余驱动并联机器人进行了动力学性能及轨迹跟踪控制实验。进行了并联机器人振动及频率特性测试,验证了考虑交流永磁同步伺服电动机和并联机构的相互作用所建立的机电耦合动力学模型的正确性。通过在PID控制的基础上引入速度前馈和加速度前馈,提高了轨迹跟踪的精度。 本文的工作为冗余驱动并联机器人系统的进一步应用研究奠定了基础,也为其它类型并联机器人的理论和应用研究提供了借鉴,有助于实现并联机器人高质量的运行。

关键词： 并联机器人   平面五杆机构   动力学   控制系统  

摘要： 本文在平面五杆并联机器人运动学分析的基础上,主要完成了平面五杆并联机器人动力学建模与分析,开展动态特性实验,开发全伺服控制系统,并开展了连续轨迹规划实验研究。 第一,介绍了并联机器人的产生、特点以及国内外研究概况,综述了平面五杆并联机器人的研究现状、发展与应用等。第二,研究了平面五杆并联机器人的运动学问题,进行了位姿正、逆解分析,采用支链构造并联机器人雅可比矩阵新的方法推导了平面五杆并联机器人速度雅可比矩阵。第三,采用拉格朗日方程法和凯恩方程法建立了平面五杆并联机器人动力学模型,并对平面五杆并联机器人动力学模型进行了数值仿真。应用Solidworks完成了平面五杆并联机器人三维装配图绘制,确定了平面五杆并联机器人结构特性参数。分析了平面五杆并联机器人的速度响应和力矩响应,得出其动力学性能的影响规律。第四,搭建了平面五杆并联机器人测振系统,开展动态特性实验研究,提出了加速度传感器标定系数的方法,分析了平面五杆并联机器人运动过程中末端执行器的时域特性和频域特性。第五,完成了平面五杆并联机器人控制系统方案设计,实现了全伺服控制系统的硬件调试和基于Windows操作系统的Motion Perfect软件系统开发,并且用Visual Basic6.0开发了平面五杆并联机器人人机交互系统的控制程序及控制界面,不但可以实现平面五杆并联机器人的连续轨迹仿真,还可以实现平面五杆并联机器人运动轨迹规划的控制。 平面五杆并联机器人的动力学特性与控制系统研究是提高机器人设计质量、改善动态性能的基础,开发全伺服控制系统是平面五杆并联机器人实用化的关键。本课题的研究成果对于平面五杆并联机器人深入开展具有重要作用。 本文得到北京市自然科学基金项目(3082005)的资助。

关键词： MECHANISM (Philosophy)   ADAPTABILITY (Psychology)   AFFECTIVE neuroscience   ROBOTICS research   AFFECT (Psychology)   COGNITIVE development  

摘要： The article provides information on computational modeling of affective mechanisms. It points out on emotion and motivation that has been an area of growing interest in adaptive behavior, cognitive systems and robotics research. It also notes that the relational study between affect and cognition is mixed with history in science and philosophy. Moreover, affective neuroscience and affective computing are the research areas of cognitive sciences.

关键词： 彩焰   章鱼   舞蹈机器人   智能服务机器人   机器人舞蹈   机电一体化   相关学科   实验平台   控制理论   借鉴经验   机器人学   工程设计   系统化   趣味性   观赏  

摘要： 舞蹈机器人作为智能服务机器人的雏形,不仅为机器人学、控制理论、机电一体化及其它相关学科提供了良好的实验平台,而且为进一步研究智能服务机器人提供了借鉴经验.机器人舞蹈既具有极强的观赏和趣味性,更是一个系统化臼勺工程设计.

关键词： behaviour-based robotics   emotional modulation   adaptive perception  

摘要： The possible modulatory influence of motivations and emotions is of great interest in designing robotic adaptive systems. In this paper, an attempt is made to connect the concept of periodic behaviour activations to emotional modulation, in order to link the variability of behaviours to the circumstances in which they are activated. The impact of emotion is studied, described as timed controlled structures, on simple but conflicting reactive behaviours. Through this approach it is shown that the introduction of such asynchronies in the robot control system may lead to an adaptation in the emergent behaviour without having an explicit action selection mechanism. The emergent behaviours of a simple robot designed with both a parallel and a hierarchical architecture are evaluated and compared.

关键词： surgery   operative   surgical robot  

摘要： The success rates and morbidity of operations on the ear, nose, and throat ( ENT) have improved markedly in the last 20-25 years. This has been largely due to improved vision, by microscopes and endoscopes, and has led to a greatly reduced hospital stay. During this time there has been minimal improvement in surgical tools. This paper discusses the need for robotic tools, detailing the clinical constraints that proposed solutions need to adhere to, and presenting a recently trialled micro drilling robot for creating a cochleostomy in the cochlear implant procedure.

关键词： robot   in vivo   compact   natural orifice translumenal endoscopic surgery   laparo-endoscopic single-site surgery   laparoscopy  

摘要： Minimally invasive surgery (MIS) reduces trauma and improves patient recovery. Traditional laparoscopic procedures are performed using multiple long, thin tools that are inserted through small incisions in the abdominal wall. The advantages of these procedures are often restricted to less complicated procedures owing to imaging and tissue manipulation limitations. These limitations can be overcome using advanced surgical systems, such as da Vinci (R), that provide the surgeon with enhanced visualization and improved tool dexterity. However, the da Vinci system is expensive and occupies significant space in the operating room. The compact bevel-geared robot for advanced surgery, CoBRASurge, is a compact robotic system that addresses the space and expense limitations of large external robotic systems. This system provides a stable platform for laparoscopic tool manoeuvring, while also allowing the surgical team improved access to the patient. New methods for performing MIS, including single incision and natural orifice access, are also being developed to further minimize invasiveness through reducing or eliminating external incisions. However, the instruments for these procedures are further limited by accessing the peritoneal cavity through a single insertion point. Dexterous miniature robots that are completely inserted into the peritoneal cavity are being developed that mitigate these limitations to provide improved triangulation.

关键词： Inverse dynamics   parallel robot   Newton-Euler model  

摘要： This paper addresses the inverse dynamics of a 4-d.o.f. parallel robot, H4. Simplified inverse dynamics models have been proposed so far in which the inertia of a rod is neglected. Computation of the inertia of the rod was a heavy load for past computers and, hence, the simplified inverse dynamics were useful for online computation. However, owing to the recent great progress in computer hardware, online computation of the full dynamics is no longer a heavy load for modern computers. Therefore, a detailed inverse dynamics model of H4 is proposed in this paper. The Newton-Euler method is adopted for generating inverse dynamics solutions for H4 which have four (S-S)(2) (two spherical-spherical) chains in each rod. In order to evaluate the proposed inverse dynamics model, three controllers are tested: (i) PD controller, (ii) PD controller with velocity feed-forward and (iii) dynamic compensation controller based on the proposed dynamics model. The experimental results are presented and analyzed. It is also shown that the simplified dynamics model can be used without clear deterioration of control quality. (C) Koninklijke Brill NV, Leiden and The Robotics Society of Japan, 2010