扭曲的弦乐执行器(TSAS)通过产生低输入扭矩的高移动力来在机器人应用中表现出巨大的希望。为了进一步促进其机器人应用,强烈的理想是,但要在保持遵守范围的同时增强其稳定的应变产生。现有的研究主要考虑在常规扭曲阶段之后的明显和盘绕是不希望的不均匀和不可预测的结,纠缠和卷曲,并形成了旨在创建不稳定且容易失败的结构的线圈。当可以始终形成均匀的线圈时,明显的效果将很好地工作。在这项研究中,我们在公开的TSA中意识到统一且一致的线圈形成,这大大增加了它们的应变。此外,我们研究了在关闭TSA中的字符串时启用均匀线圈形成的方法,并提出了系统地“训练”字符串的程序。据作者的最佳知识而言,这是第一项实验研究具有不同刚度的TSA并实现一致均匀线圈形成的研究。超高的分子量聚乙烯(UHMWPE)串形成刚性TSA,而兼容的TSA则用可拉伸和导电的超串制聚合物(SCP)串实现。研究了每个明确的TSA的应变,力,速度和扭矩。固定和盘绕的螺旋和盘绕导致刚性TSA的菌株约70%,兼容TSA的菌株约为60%。这是通过常规扭曲所达到的应变的两倍以上。最后,在机器人二头肌中成功证明了这位公开的TSA。
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意识到高性能软机器人抓手是具有挑战性的,因为软执行器和人造肌肉的固有局限性。尽管现有的软机器人抓手表现出可接受的性能,但他们的设计和制造仍然是一个空旷的问题。本文探索了扭曲的弦乐执行器(TSA),以驱动软机器人抓手。 TSA已被广泛用于众多机器人应用中,但它们包含在软机器人中是有限的。提议的抓手设计灵感来自人类手,四个手指和拇指。通过使用拮抗剂TSA,在手指中实现了可调刚度。手指的弯曲角度,驱动速度,阻塞力输出和刚度调整是实验表征的。抓手能够在Kapandji测试中获得6分,并且还可以达到33个Feix Grasp Grasp分类法中的31个。一项比较研究表明,与其他类似抓手相比,提出的抓手表现出等效或卓越的性能。
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虽然在各种应用中广泛使用刚性机器人,但它们在他们可以执行的任务中受到限制,并且在密切的人机交互中可以保持不安全。另一方面,软机器鞋面超越了刚性机器人的能力,例如与工作环境,自由度,自由度,制造成本和与环境安全互动的兼容性。本文研究了纤维增强弹性机壳(释放)作为一种特定类型的软气动致动器的行为,可用于软装饰器。创建动态集参数模型以在各种操作条件下模拟单一免费的运动,并通知控制器的设计。所提出的PID控制器使用旋转角度来控制多项式函数之后的自由到限定的步进输入或轨迹的响应来控制末端执行器的方向。另外,采用有限元分析方法,包括释放的固有非线性材料特性,精确地评估释放的各种参数和配置。该工具还用于确定模块中多个释放的工作空间,这基本上是软机械臂的构建块。
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拍打翅膀是一种生物启发的方法,可在空中机器人中产生升力和推动,从而导致安静有效的运动。该技术的优点是安全性和可操作性,以及与环境,人类和动物的物理互动。但是,为了实现大量应用,这些机器人必须栖息和土地。尽管最近在栖息场上取得了进展,但直到今天,拍打翼车辆或鸟类动物仍无法停止在分支上的飞行。在本文中,我们提出了一种新颖的方法,该方法定义了一个可以可靠和自主将鸟鸟类降落在分支上的过程。该方法描述了拍打飞行控制器的联合操作,近距离校正系统和被动爪附件。飞行由三重俯仰高空控制器和集成的车身电子设备处理,允许以3 m/s的速度栖息。近距离校正系统,具有快速的光学分支传感可补偿着陆时的位置错位。这是通过被动双向爪设计可以补充的,可以锁定和固定2 nm的扭矩,在25毫秒内掌握,并且由于集成的肌腱致动而可以重新打开。栖息的方法补充了四步实验开发过程,该过程为成功的设计优化。我们用700 g的鸟杆验证了这种方法,并演示了在分支上拍打翼机器人的第一次自主栖息飞行,结果用第二个机器人复制。这项工作为在远程任务,观察,操纵和室外飞行中应用翼机器人的应用铺平了道路。
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This study proposed a novel robotic gripper that can achieve grasping and infinite wrist twisting motions using a single actuator. The gripper is equipped with a differential gear mechanism that allows switching between the grasping and twisting motions according to the magnitude of the tip force applied to the finger. The grasping motion is activated when the tip force is below a set value, and the wrist twisting motion is activated when the tip force exceeds this value. "Twist grasping," a special grasping mode that allows the wrapping of a flexible thin object around the fingers of the gripper, can be achieved by the twisting motion. Twist grasping is effective for handling objects with flexible thin parts, such as laminated packaging pouches, that are difficult to grasp using conventional antipodal grasping. In this study, the gripper design is presented, and twist grasping is analyzed. The gripper performance is experimentally validated.
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软致动器在符合性和形态方面表现出具有很大的优势,用于操纵细腻物体和在密闭空间中的检查。对于可以提供扭转运动的软致动器有一个未满足的需要。放大工作空间并增加自由度。为此目标,我们呈现由硅胶制成的折纸启发的软充气执行器(OSPas)。原型可以输出多于一个旋转的旋转(高达435 {\ DEG}),比以前的同行更大。我们描述了设计和制作方法,构建了运动学模型和仿真模型,并分析和优化参数。最后,我们通过整合到能够同时抓住和提升脆弱或扁平物体的夹具,这是一种能够与扭转致动器的直角拾取和放置物品的多功能机器人,以及柔软的蛇通过扭转致动器的扭转能够改变姿态和方向的机器人。
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为了在医疗和工业环境中广泛采用可穿戴机器人外骨骼,至关重要的是,它们可以适应性地支持大量运动。我们提出了一种新的人机界面,以同时在一系列“看不见的”步行条件和未用于建立控制界面的“看不见”步行条件和过渡期间同时驱动双侧踝部外骨骼。提出的方法使用人特异性的神经力学模型从测量的肌电图(EMG)和关节角度实时估算生物踝关节扭矩。基于干扰观察者的低级控制器将生物扭矩估计转换为外骨骼命令。我们称此“基于神经力学模型的控制”(NMBC)。 NMBC使六个人能够自愿控制六个步行条件下的双边踝部外骨骼,包括所有中间过渡,即两个步行速度,每个步行速度在三个地面高程中进行,不需要预先定义的扭矩轮廓,也不需要先验选择的神经肌肉肌肉反射规则,或国家机器在文献中很常见。在涉及月球漫步的灵活的运动任务上进行了一个单一的主题案例研究。 NMBC始终启用能够减少生物踝扭矩,以及与非辅助条件相比,在步行条件(24%扭矩; 14%EMG)之间以及步行条件(24%扭矩; 14%EMG)之间的八个踝部肌肉EMG。新型步行条件下的扭矩和EMG减少表明,外骨骼在操作员的神经肌肉系统控制的外观上进行了共生。这为系统地采用可穿戴机器人作为现场医疗和职业环境的一部分开辟了新的途径。
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Animals run robustly in diverse terrain. This locomotion robustness is puzzling because axon conduction velocity is limited to a few ten meters per second. If reflex loops deliver sensory information with significant delays, one would expect a destabilizing effect on sensorimotor control. Hence, an alternative explanation describes a hierarchical structure of low-level adaptive mechanics and high-level sensorimotor control to help mitigate the effects of transmission delays. Motivated by the concept of an adaptive mechanism triggering an immediate response, we developed a tunable physical damper system. Our mechanism combines a tendon with adjustable slackness connected to a physical damper. The slack damper allows adjustment of damping force, onset timing, effective stroke, and energy dissipation. We characterize the slack damper mechanism mounted to a legged robot controlled in open-loop mode. The robot hops vertically and planar over varying terrains and perturbations. During forward hopping, slack-based damping improves faster perturbation recovery (up to 170%) at higher energetic cost (27%). The tunable slack mechanism auto-engages the damper during perturbations, leading to a perturbation-trigger damping, improving robustness at minimum energetic cost. With the results from the slack damper mechanism, we propose a new functional interpretation of animals' redundant muscle tendons as tunable dampers.
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软气动执行器已经在许多软机器人系统中看到了应用,其压力驱动的性质提出了控制其运动的独特挑战和机会。在这项工作中,我们提出了一个新概念:通过末端几何形状设计和控制气动执行器。我们演示了一个新颖的执行器类,称为折叠气动人造肌肉(Foldpam),该肌肉具有一个薄纤维的空气袋,两侧对称折叠。改变执行器的折叠部分会改变最终约束,从而改变力 - 应变关系。我们通过测量具有各种长度和折叠量的单个foldpam单元的力 - 应变关系来实验研究这一变化。除静态几何单元外,驱动的FOLDPAM设备还设计为产生末端几何形状的连续,按需调整,从而实现闭环位置控制,同时保持恒定压力。使用设备的实验表明几何控制允许进入力 - 应变平面上的不同区域,并且闭环几何控制可以在驱动范围的0.5%以内实现误差。
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人类无法访问许多空间,机器人可以帮助传感器和设备提供。这些空间中有许多包含三维通道和不均匀的地形,这些通道对机器人设计和控制构成了挑战。通过同时进行的远处和体材料反转移动的环形机器人有望在这些类型的空间中导航。我们提出了一种新型的柔软的环形机器人,该机器人在充满空气的膜内使用电动设备推动自己推动自己。我们的机器人只需要一个控制信号即可移动,可以符合其环境,并且可以垂直爬上电动机扭矩,该电动机与用来支撑机器人对环境的力无关。我们得出并验证了其运动所涉及的力的模型,并演示了机器人导航迷宫和攀登管道的能力。
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我们探索粒状介质(GM)中软机器的运动,由细长杆的弹性变形产生。提出了由细菌的生理结构的低成本,迅速制造的机器人。它由刚性头部,带有电动机和电池的嵌入式和电池,以及多个弹性杆(我们的灯泡模型)来调查通用汽车的运动。弹性鞭毛在电机一端旋转,它们由于从GM的拖动而变形,推动机器人。外部拖动由鞭毛形状决定,而后者由于外部负载和弹力之间的竞争而改变。在该耦合的流体结构相互作用问题中,我们观察到增加鞭毛的数量可以减小或增加机器人的推进速度,这取决于系统的物理参数。这种简单机器人之间的功能关系中的这种非线性激励我们利用理论,数值模拟和实验来从根本上分析其力学。我们提出了一个简单的欧拉伯努利光束理论的分析框架,其能够定性地捕获这两种情况。当鞭毛变形小时,理论预测定量匹配实验。为了考虑经常在软机器人和微生物中遇到的几何非线性变形,我们实施了一种仿真框架,该框架包括弹性杆的离散微分几何形状模拟,这是一种基于电阻理论的拖曳模型,以及用于流体动力学的改进的斯托克斯法机器人头。与实验数据的比较表明模拟可以定量地预测机器人运动。总的来说,本文中提出的理论和数值工具可以在粒状或流体介质中的这类清晰的机器人的设计和控制来阐明。
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The ability to convert reciprocating, i.e., alternating, actuation into rotary motion using linkages is hindered fundamentally by their poor torque transmission capability around kinematic singularity configurations. Here, we harness the elastic potential energy of a linear spring attached to the coupler link of four-bar mechanisms to manipulate force transmission around the kinematic singularities. We developed a theoretical model to explore the parameter space for proper force transmission in slider-crank and rocker-crank four-bar kinematics. Finally, we verified the proposed model and methodology by building and testing a macro-scale prototype of a slider-crank mechanism. We expect this approach to enable the development of small-scale rotary engines and robotic devices with closed kinematic chains dealing with serial kinematic singularities, such as linkages and parallel manipulators.
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Snakes and their bio-inspired robot counterparts have demonstrated locomotion on a wide range of terrains. However, dynamic vertical climbing is one locomotion strategy that has received little attention in the existing snake robotics literature. We demonstrate a new scansorial gait and robot inspired by the locomotion of the Pacific Lamprey. This new gait allows a robot to steer while climbing on flat, near-vertical surfaces. A reduced-order model is developed and used to explore the relationship between body actuation and vertical and lateral motions of the robot. Trident, the new wall climbing lamprey-inspired robot, demonstrates dynamic climbing on flat vertical surfaces with a peak net vertical stride displacement of 4.1 cm per step. Actuating at 1.3 Hz, Trident attains a vertical climbing speed of 4.8 cm/s (0.09 Bl/s) at specific resistance of 8.3. Trident can also traverse laterally at 9 cm/s (0.17 Bl/s). Moreover, Trident is able to make 14\% longer strides than the Pacific Lamprey when climbing vertically. The computational and experimental results demonstrate that a lamprey-inspired climbing gait coupled with appropriate attachment is a useful climbing strategy for snake robots climbing near vertical surfaces with limited push points.
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In unstructured environments, robots run the risk of unexpected collisions. How well they react to these events is determined by how transparent they are to collisions. Transparency is affected by structural properties as well as sensing and control architectures. In this paper, we propose the collision reflex metric as a way to formally quantify transparency. It is defined as the total impulse transferred in collision, which determines the collision mitigation capabilities of a closed-loop robotic system taking into account structure, sensing, and control. We analyze the effect of motor scaling, stiffness, and configuration on the collision reflex of a system using an analytical model. Physical experiments using the move-until-touch behavior are conducted to compare the collision reflex of direct-drive and quasi-direct-drive actuators and robotic hands (Schunk WSG-50 and Dexterous DDHand.) For transparent systems, we see a counter-intuitive trend: the impulse may be lower at higher pre-impact velocities.
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外骨骼和矫形器是可穿戴移动系统,为用户提供机械益处。尽管在过去几十年中有重大改进,但该技术不会完全成熟,以便采用剧烈和非编程任务。为了适应这种功能不全,需要分析和改进该技术的不同方面。许多研究一直在努力解决外骨骼的某些方面,例如,机构设计,意向预测和控制方案。但是,大多数作品都专注于设计或应用的特定元素,而无需提供全面的审查框架。本研究旨在分析和调查为改进和广泛采用这项技术的贡献方面。为了解决此问题,在引入辅助设备和外骨骼后,将从物理人员 - 机器人接口(HRI)的角度来研究主要的设计标准。通过概述不同类别的已知辅助设备的几个例子,将进一步开发该研究。为了建立智能HRI策略并为用户提供直观的控制,将研究认知HRI。将审查这种策略的各种方法,并提出了意图预测的模型。该模型用于从单个电拍摄(EMG)通道输入的栅极相位。建模结果显示出低功耗辅助设备中单通道输入的潜在使用。此外,所提出的模型可以在具有复杂控制策略的设备中提供冗余。
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Springs are efficient in storing and returning elastic potential energy but are unable to hold the energy they store in the absence of an external load. Lockable springs use clutches to hold elastic potential energy in the absence of an external load but have not yet been widely adopted in applications, partly because clutches introduce design complexity, reduce energy efficiency, and typically do not afford high-fidelity control over the energy stored by the spring. Here, we present the design of a novel lockable compression spring that uses a small capstan clutch to passively lock a mechanical spring. The capstan clutch can lock up to 1000 N force at any arbitrary deflection, unlock the spring in less than 10 ms with a control force less than 1 % of the maximal spring force, and provide an 80 % energy storage and return efficiency (comparable to a highly efficient electric motor operated at constant nominal speed). By retaining the form factor of a regular spring while providing high-fidelity locking capability even under large spring forces, the proposed design could facilitate the development of energy-efficient spring-based actuators and robots.
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脑出血(ICH)是最致命的中风子类型,死亡率高达52%。由于颅骨切开术引起的潜在皮质破坏,保守管理(注意等待)历史上一直是一种常见的治疗方法。最小的侵入性疏散最近已成为一种可公认的治疗方法,用于体积30-50 mL的深座性血肿的患者,但适当的可视化和工具敏感性仍然受到常规内窥镜方法的限制,尤其是较大的血肿体积(> 50 mL)。在本文中,我们描述了Aspihre的发展(脑部出血机器人疏散的手术平台),这是有史以来的第一个同心管机器人,该机器人使用现成的塑料管来进行MR引导ICH撤离,改善工具敏感性和程序可视化。机器人运动学模型是基于基于校准的方法和试管力学建模开发的,使模型可以考虑可变曲率和扭转偏转。使用可变增益PID算法控制旋转精度为0.317 +/- 0.3度。硬件和理论模型在一系列系统的基准和MRI实验中进行了验证,导致1.39 +\ -0.54 mm的管尖的位置精度。验证靶向准确性后,在MR引导的幻影凝块疏散实验中测试了机器人的疏散功效。该机器人能够在5分钟内撤离最初38.36 mL的凝块,使残留血肿为8.14 mL,远低于15 mL指南,表明良好的后疏散临床结果。
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空气中的快速且通用的物体操纵是一个开放的挑战。节能和自适应的软抓地力与敏捷航空媒介相结合可以彻底改变仓库等区域的空中机器人操纵。本文提出了一个由生物启发的抓斗者,该抓地力由安装在四轮驱动器上的液压放大的静电执行器提供动力,该执行器可以与其环境安全自然地相互作用。我们抓紧的概念是由鹰的脚激励的。我们的自定义多动物概念的灵感来自蝎子尾部设计(由邻接的小袋组成的基本电极组成)和蜘蛛启发的接头(经典的小袋电动机,带有灵活的铰链层)。与单铰链概念相比,这两种设计的混合体在高达25 {\ deg}的中等偏转下实现了更高的力输出。此外,将铰链层夹紧可改善抓手的稳健性。我们第一次表明,使用静电致动,空气中的软操作可能是可能的。这项研究证明了在空中机器人操作中不受束缚的液压扩增的执行器的潜力。我们的概念证明为在移动航空系统中使用液压静电执行器的使用打开了。
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This paper expounds the design and control of a new Variable Stiffness Series Elastic Actuator (VSSEA). It is established by employing a modular mechanical design approach that allows us to effectively optimise the stiffness modulation characteristics and power density of the actuator. The proposed VSSEA possesses the following features: i) no limitation in the work-range of output link, ii) a wide range of stiffness modulation (~20Nm/rad to ~1KNm/rad), iii) low-energy-cost stiffness modulation at equilibrium and non-equilibrium positions, iv) compact design and high torque density (~36Nm/kg), and v) high-speed stiffness modulation (~3000Nm/rad/s). Such features can help boost the safety and performance of many advanced robotic systems, e.g., a cobot that physically interacts with unstructured environments and an exoskeleton that provides physical assistance to human users. These features can also enable us to utilise variable stiffness property to attain various regulation and trajectory tracking control tasks only by employing conventional controllers, eliminating the need for synthesising complex motion control systems in compliant actuation. To this end, it is experimentally demonstrated that the proposed VSSEA is capable of precisely tracking desired position and force control references through the use of conventional Proportional-Integral-Derivative (PID) controllers.
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In this paper, we present an adjustable-equilibrium parallel elastic actuator (AE-PEA). The actuator consists of a motor, an equilibrium adjusting mechanism, and a spring arranged into a cylindrical geometry, similar to a motor-gearbox assembly. The novel component of the actuator is the equilibrium adjusting mechanism which (i) does not require external energy to maintain the equilibrium position of the actuator even if the spring is deformed and (ii) enables equilibrium position control with low energy cost by rotating the spring while keeping it undeformed. Adjustable equilibrium parallel elastic actuators resolve the main limitation of parallel elastic actuators (PEAs) by enabling energy-efficient operation at different equilibrium positions, instead of being limited to energy-efficient operation at a single equilibrium position. We foresee the use of AE-PEAs in industrial robots, mobile robots, exoskeletons, and prostheses, where efficient oscillatory motion and gravity compensation at different positions are required.
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