Erin Onder, Pol Nishant, Valle Luis
Annu Int Conf IEEE Eng Med Biol Soc. 2016 Aug;2016:2115-2119. doi: 10.1109/EMBC.2016.7591146.
Pneumatic artificial muscles (PAMs) are one of the most famous linear actuators in bio-inspired robotics. They can generate relatively high linear force considering their form factors and weights. Furthermore, PAMs are inexpensive compared with traditional electromagnetic actuators (e.g. DC motors) and also inherently light and compliant. In robotics applications, however, they typically require external sensing mechanisms due to their nonlinear behaviors, which may make the entire mechanical system bulky and complicated, limiting their use in simple systems. This study presents the design and fabrication of a low-cost McKibben-type PAM with a self-contained displacement and force sensing capability that does not require any external sensing elements. The proposed PAM can detect axial contraction force and displacement at the same time. In this study, the design of a traditional McKibben muscle was modified to include an inductive coil surrounding the muscle fibers. Then, a thin, soft silicone layer was coated outside of the muscle to protect and hold the sensing coil on the actuator. This novel design measures coil inductance change to determine the contraction force and the displacement. The process can be applied to a variety of existing McKibben actuator designs without significantly changing the rigidity of the actuator while minimizing the device's footprint.
气动人工肌肉（PAMs）是仿生机器人领域最著名的线性致动器之一。考虑到其外形尺寸和重量，它们能够产生相对较高的线性力。此外，与传统电磁致动器（如直流电机）相比，气动人工肌肉价格低廉，而且本身重量轻且具有柔顺性。然而，在机器人应用中，由于其非线性行为，它们通常需要外部传感机制，这可能会使整个机械系统变得庞大而复杂，限制了它们在简单系统中的应用。本研究介绍了一种低成本麦基本型气动人工肌肉的设计与制造，该肌肉具有独立的位移和力传感能力，无需任何外部传感元件。所提出的气动人工肌肉能够同时检测轴向收缩力和位移。在本研究中，对传统麦基本肌肉的设计进行了改进，使其在肌肉纤维周围包含一个感应线圈。然后，在肌肉外部涂覆一层薄的柔软硅胶层，以保护并将传感线圈固定在致动器上。这种新颖的设计通过测量线圈电感变化来确定收缩力和位移。该工艺可应用于各种现有的麦基本致动器设计，在不显著改变致动器刚度的同时，最小化设备的占地面积。
