Design of a perfect balance system for active upper-extremity exoskeletons
Design of a perfect balance system for active upper-extremity exoskeletons
复制标题
主动上肢外骨骼完美平衡系统的设计
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
A. Stienen
中科院分区：
文献类型：
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作者：
Richard L. Smith;J. Lobo;H. Kooij;A. Stienen
外骨骼中的被动重力补偿显着减少了执行器所需的扭矩和能量。到目前为止，还没有一种设计能够在不损害外骨骼特性的情况下实现完美的平衡。在这里，我们提出了一种新颖的设计，将现有的具有两个弹簧和四个自由度的静平衡机构集成到通用外骨骼设计中，可以支持外骨骼和手臂组合重量的任何百分比。由于它允许在肩部有三个旋转自由度，在肘部有一个旋转自由度，因此它不会影响外骨骼的特性，并且可以选择任何被动或主动驱动方法。例如，通过这种设计，一个完美平衡的外骨骼设计具有固有的安全性，每个关节轴上的被动致动器成为可能。该设计的主要优势在于降低了执行机构所需的扭矩、功率和重量，简化了控制，改善了动态性能，增加了安全裕度，同时保持了完美的平衡，但集成系统确实增加了大量的复杂性。未来在实际外骨骼中的集成将证明这种权衡是否有益。
Passive gravity compensation in exoskeletons significantly reduces the amount of torque and energy needed from the actuators. So far, no design has been able to achieve perfect balance without compromising the exoskeleton characteristics. Here we propose a novel design that integrates an existing statically-balanced mechanism with two springs and four degrees of freedom into a general-purpose exoskeleton design, that can support any percentage of the combined weight of exoskeleton and arm. As it allows for three rotational degrees of freedom at the shoulder and one at the elbow, it does not compromise exoskeleton characteristics and can be powered with any choice of passive or active actuation method. For instance, with this design a perfectly balanced exoskeleton design with inherently safe, passive actuators on each joint axis becomes possible. The potential reduction in required actuator torque, power and weight, simplification of control, improved dynamic performance, and increased safety margin, all while maintaining perfect balance, are the major advantages of the design, but the integrated systems does add a significant amount of complexity. Future integration in an actual exoskeleton should prove if this tradeoff is beneficial.