e-Spring: Circular arch mechanism for large and linear tunable stiffness control based on tuning deformation mode contributions
e-Spring: Circular arch mechanism for large and linear tunable stiffness control based on tuning deformation mode contributions
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e-Spring：基于调谐变形模式贡献的大线性可调刚度控制的圆拱机构
DOI：
10.1016/j.mechmachtheory.2018.06.007
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发表时间：
2018-10
影响因子：
5.2
通讯作者：
Johnson S
中科院分区：
文献类型：
--
作者：
Qaiser Zeeshan;Kang Liping;Ou Haihua;Johnson S
传统的机器人和结构设计具有几乎刚性的构件和执行器，以具有刚性输出以实现更好的控制；然而，这种设计方法通常产生的系统缺乏自然系统的精巧性和敏感性，在低力和高力应用中都具有灵活控制。自然系统通过肌肉来实现这一功能，肌肉作为执行器工作，同时拥有可调谐的力和刚度控制。结构控制刚度(SCS)可调刚度机构(TSM)通常通过改变特定变形模式内的结构参数来改变刚度，即改变弯曲弹簧的转动惯量或梁的长度。提出了一种新型的低轮廓TSM，其目的是通过调节变形模式的贡献来获得较高的刚度范围。E形弹簧由一个非棱柱形的锥形圆拱梁组成，它用一个短支柱连接到一个固定的中心。径向施加的载荷和圆形在固定中心提供了“零力矩”条件，减少了主动驱动系统所需的大扭矩容量，而与传动轴连接的蜗轮提供了旋转的无动力锁定，从而提高了节能效果。刚度的变化是通过绕其中心旋转e弹簧来改变力的施加点，从而改变变形模式(从弯曲到剪切再到轴向)。建立了e-弹簧分析的解析模型和有限元模型。在一组定义的约束条件下，使用设计优化来最大化系统的总刚度范围。在优化结果的基础上，选择了刚性、中位性和柔软性三种设计方案，采用带编码器的直流电机和带反馈控制的蜗轮蜗杆组合的方式进行了加工和测试，以获得期望的转角。分析和有限元计算结果与不同刚度随控制角度变化的实验结果吻合较好。在所定义的系统约束条件下，优化设计的线性刚度响应为0.5 N/mm~1782 N/mm，实验观察到了较大范围的刚度变化。通过实施适当的控制算法，本研究开发的系统可以实现更好的人机交互和具有新的自适应/可调特性的结构。
Traditional robots and structures are designed with nearly rigid members and actuators to have a stiff output for better control; however, this method of design typically produces systems which lack the finesse and sensitivity of natural systems with nimble control in both low force and high force applications. Natural systems achieve this function by muscles which work as actuators and possess both tunable force and stiffness control. Structure controlled stiffness (SCS) tunable stiffness mechanisms (TSMs) typically change stiffness by varying the structural parameters within a particular deformation mode, i.e. varying moment of inertia or length of a beam for a spring in bending. A novel low profile TSM is proposed with the purpose of achieving a high range of stiffness by tuning the deformation mode contributions. The e-Spring consists of a non-prismatic, tapered circular arch beam which is connected with one short strut to a fixed center. The radially applied loading and circular shape provide a "zero moment" condition at the fixed center reducing the need for large torque capacity to actively drive the system, and a worm gear interfacing with the drive shaft provides powerless locking of the rotation for improved power savings. The variation of the stiffness is achieved by rotating the e-Spring about its center to change the point of application of the force, thus changing the mode of deformation (from bending to shear to axial). Analytical and finite element (FE) models are developed for e-Spring analysis. The total stiffness range of the system is maximized using design optimization under a set of defined constraints. Based on the optimization results, three designs (stiff, median and soft) are selected, fabricated and tested by using the assembly of a DC motor with encoder and worm gears with feedback control to obtain the desired angle of rotation. Analytical and FE results closely match the experimental validations for different stiffness vs. angle of control conditions. A wide range of stiffness change is experimentally observed with a linear stiffness response of 0.5 N/mm to 1782 N/mm for the optimal design under the set of defined system constraints. By implementing the proper control algorithms, better human robot interactions and structures with new adaptable/tunable features can be achieved with the system developed in this research.
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影响因子：
2.8
作者：
Jezernik, S;Colombo, G;Morari, M
通讯作者：
Morari, M
DOI：
10.1007/978-1-4613-4277-9_4
发表时间：
1976
期刊：
--
影响因子：
--
作者：
T. Dawson
通讯作者：
T. Dawson
DOI：
10.1109/iros.2011.6095006
发表时间：
2011-12
期刊：
2011 IEEE/RSJ International Conference on Intelligent Robots and Systems
影响因子：
--
作者：
N. Tsagarakis;I. Sardellitti;D. Caldwell
通讯作者：
N. Tsagarakis;I. Sardellitti;D. Caldwell
影响因子：
5.7
作者：
Bicchi, A;Tonietti, G
通讯作者：
Tonietti, G
DOI：
10.1115/1.4007843
发表时间：
2013-02
期刊：
Journal of Mechanisms and Robotics
影响因子：
--
作者：
Kevin C. Galloway;Jonathan E. Clark;D. Koditschek
通讯作者：
Kevin C. Galloway;Jonathan E. Clark;D. Koditschek