关键词： 燃烧室绝热层   打磨机器人   ADAMS软件   独立悬挂   仿真分析  

摘要： 燃烧室是固体火箭发动机中的一个重要结构。燃烧室内表面有一层绝热层,用于确保燃烧室工作时壳体不会因高温而被破坏。初始作业时绝热层表面较为光滑,需要被打磨毛糙,以便进行下一工序。设计了一种体型较小、运行灵活的轮式打磨机器人,可在燃烧室内部运行并自动打磨。绝热层表面有一定高度、宽度的凸起,因此打磨机器人设计有独立悬挂,用来减小跨越凸起时发生的振动或冲击。建立了打磨机器人动力学模型,并利用ADAMS软件对相关设计参数进行分析,以为后续设计提供理论依据。

关键词： U-K理论   约束违约   Baumgarte约束违约稳定法(BSM)   Baumgarte参数   下肢康复机器人  

摘要： U-K理论为获得约束多体系统的解析动力学方程提供了新的理念,但由于数值近似和截断误差等因素的影响,动力学方程在位置和速度层面上存在约束违约。Baumgarte约束违约稳定法(BSM)通过约束修正得到稳定的动力学方程。然而,Baumgarte参数的选择通常涉及一个试错过程,可能会出现失效的仿真结果。为此,利用经典的四阶Runge-Kutta法研究了Baumgarte参数选取问题,创建了基于BSM修正后的U-K理论的机器人系统解析动力学方程。以下肢康复机器人为研究对象仿真分析,结果表明:利用所提方法可以有效抑制约束违约,关节角度误差控制在-5×10^(-3)(°)~5×10^(-3)(°)范围内;关节角速度误差控制在-2×10^(-4)~2×10^(-4) rad/s范围内;机器人末端执行器运行轨迹能够很好地贴近系统预定的目标。

关键词： 空间组装   超大型结构   万有引力梯度   姿-轨-柔耦合   空间机械臂  

摘要： 机器人空间组装是建造超大型航天器的重要方式。当前针对空间组装的研究大多集中于小型结构,没有考虑万有引力梯度和姿-轨-柔耦合效应的影响。本文针对主结构-空间机器人-待组装结构组成的系统,建立姿-轨-柔耦合动力学模型,研究万有引力梯度和姿-轨-柔耦合效应对组装过程的影响。首先,将空间机器人看作刚体,将主结构和待组装结构看作柔性体,分别采用自然坐标法和绝对节点坐标法进行运动学描述;然后,考虑刚体和柔性体的动能、万有引力势能和弹性势能推导系统的Hamilton方程,计入万有引力和万有引力梯度的影响;最后,通过轨迹规划和轨迹跟踪控制实现空间机器人空间组装超大型结构的姿-轨-柔耦合动力学仿真,给出组装过程中系统的轨道运动、姿态运动、空间机器人关节空间和笛卡尔空间、结构振动等动力学响应。研究发现:万有引力梯度和姿-轨-柔耦合效应对空间机器人的控制力矩和组装精度产生显著影响,在组装方案设计和控制系统设计中必须予以考虑。

关键词： 机器人   动力学模型   改进摩擦模型   参数辨识   迭代加权最小二乘算法  

摘要： 为提高机器人动力学参数辨识的准确性,提出了一种基于迭代加权最小二乘(Iterative Reweighted Least Squares,IRLS)算法的辨识方法。首先推导了机器人的线性动力学模型,随后提出了一种改进摩擦模型,并设计了改进傅里叶级数作为激励轨迹采集数据。为提升动力学参数辨识的准确性,在加权最小二乘法基础上进行改进,提出了IRLS算法对动力学参数进行辨识。最后以六自由度机器人为试验对象,进行了参数辨识试验。结果表明,基于IRLS算法的辨识方法与加权最小二乘法相比,前3个关节力矩误差的均方根(Root Mean Square,RMS)值降低了13.28%,后3个关节力矩误差的RMS值降低了28.57%,6个关节力矩误差的RMS值平均降低了17.15%,证明了基于IRLS算法的辨识方法的有效性。

关键词： 机器人   机器人学   伦理治理   伦理问题   伦理原则  

摘要： 本文在简短介绍伦理治理的含义后,着重讨论有关机器人学科技伦理治理的问题,包括设计、制造和使用机器人中的伦理问题,解决这些伦理问题的伦理原则,以及对机器人学科技伦理治理的建议。

关键词： 新工科   电子信息工程   实践教学   机器人竞赛  

摘要： 随着信息时代的到来,尤其是网络技术的发展,加速了电子信息技术的发展和普及。电子信息工程专业旨在为电子信息行业培养高素质技术型人才,我国众多高校均开设了电子信息工程专业。然而,国内电子信息类专业人才依然有很大缺口,高校培养的学生却不能很好地满足工程实践需求。随着2017年教育部明确提出"新工科"的概念,文章以电子信息工程专业为例,分析学生思维模式和工程师思维模式的差异,从新工科的发展方向出发,结合机器人竞赛,探究竞赛对新工科实践教学发展的促进作用和电子信息类专业人才培养模式,提出一种竞赛促进实践教学的解决方案,并在多年的运行中成效显著。

关键词： smart agriculture   robot vehicle   autonomous driving   wireless network quality prediction   overlay network   image processing   IOWN  

摘要： To sustain and expand the agricultural economy even as its workforce shrinks, the efficiency of farm operations must be improved. One key to efficiency improvement is completely unmanned driving of farm machines, which requires stable monitoring and control of machines from remote sites, a safety system to ensure safe autonomous driving even without manual operations, and precise positioning in not only small farm fields but also wider areas. As possible solutions for those issues, we have developed technologies of wireless network quality prediction, an end-to-end overlay network, machine vision for safety and positioning, network cooperated vehicle control and autonomous tractor control and conducted experiments in actual field environments. Experimental results show that: 1) remote monitoring and control can be seamlessly continued even when connection between the tractor and the remote site needs to be switched across different wireless networks during autonomous driving;2) the safety of the autonomous driving can automatically be ensured by detecting both the existence of people in front of the unmanned tractor and disturbance of network quality affecting remote monitoring operation;and 3) the unmanned tractor can continue precise autonomous driving even when precise positioning by satellite systems cannot be performed.

关键词： robot therapy   neurorehabilitation robotics   kinesthetic illusion   muscle spindle   natural frequency   proprioception   optimal condition   modal test   psychophysical experiment  

摘要： Due to increasing demand for rehabilitation and therapy for cerebrovascular diseases, patients require advanced development of medical rehabilitation robots. In our laboratory, we focus on the formation capability of the substitute neural path caused by brain plasticity using the kinesthetic illusion (KI), which is effective for therapies using robots. In KI, people perceive an illusionary limb movement without an actual movement when a vibration stimulus is applied to a limb's tendons. In previous research, the optimal frequency that induces the maximum KI has a correlation factor of about 0.5 with the tendon's natural frequency when a human subject is in a state of laxity. However, we do not know whether the above finding can be applied to actual rehabilitation because muscles and tendons are sometimes in tonus during rehabilitation, a state that varies the natural frequency. In this study, we investigate the correlation between the optimal and natural frequencies of tendon by systematically changing their tension to clarify the effects on the illusion induced by the muscle and the tendon when they are in tonus. We identified a negative correlation between the optimal and natural frequencies when they are in tonus, although a positive correlation appeared when they are in laxity. This result suggests that KI's optimal frequency should be changed based on the degree of the tendon and muscle tonus. Therefore, our present findings provide a suitable vibration frequency that induces KI due to the degree of the tendon and muscle tonus during robot therapies.

关键词： Robotics  

摘要： Automation, robotics, artificial intelligence (AI), and ransomware were among topics at the A3 Business Forum, Jan. 31 to Feb. 2. (For advice from other Association for Advancing Automation (A3) conference speakers, see "Robotics, motion control, machine vision, AI.")

关键词： Robots   Strain   Propulsion   Propellers   Unmanned underwater vehicles   Shape   Prototypes   Soft robot applications   modeling control and learning for soft robots   biologically-inspired robots   marine robotics  

摘要： Prokaryotic flagellum is considered as the only known example of a biological "wheel," a system capable of converting the action of rotatory actuator into a continuous propulsive force. For this reason, flagella are an interesting case study in soft robotics and they represent an appealing source of inspiration for the design of underwater robots. A great number of flagellum-inspired devices exists, but these are all characterized by a size ranging in the micrometer scale and mostly realized with rigid materials. Here, we present the design and development of a novel generation of macroscale underwater propellers that draw their inspiration from flagellated organisms. Through a simple rotatory actuation and exploiting the capability of the soft material to store energy when interacting with the surrounding fluid, the propellers attain different helical shapes that generate a propulsive thrust. A theoretical model is presented, accurately describing and predicting the kinematic and the propulsive capabilities of the proposed solution. Different experimental trials are presented to validate the accuracy of the model and to investigate the performance of the proposed design. Finally, an underwater robot prototype propelled by four flagellar modules is presented.