Modeling and Inverse Compensation of Hysteresis in Supercoiled Polymer Artificial Muscles
Modeling and Inverse Compensation of Hysteresis in Supercoiled Polymer Artificial Muscles
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DOI：
10.1109/lra.2017.2651401
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发表时间：
2017-04-01
影响因子：
5.2
通讯作者：
Yip, Michael C.
中科院分区：
文献类型：
--
作者：
Zhang, Jun;Iyer, Kaushik;Yip, Michael C.
超螺旋聚合物（SCP）致动器是最近发现的人工肌肉，其在类似肌肉的形状因子中表现出显著的机械功率、大的收缩和良好的动态范围。近年来，对SCP致动器的研究工作迅速增加。对于机器人来说，SCP致动器克服了人造肌肉的特定挑战，例如形状记忆合金线，其中有限的应变和缓慢的动力学以及功耗限制了它们的使用。据了解，滞后非线性的结果，从盘绕的线程，并可能会导致高达30%的应变差在相同的电压下，然而，没有工作已经报道，以表征在SCP致动器的滞后。在本文中，三个新的模型制定来表征三个耦合变量（输入电压，应变和负载）的SCP致动器，即增广广义Prandtl-Ishlinskii模型，增广Preisach模型，增广线性模型之间的滞后关系。通过结合滞回曲线与加载力之间的关系，所提出的模型可以有效地表征滞回特性。通过逆补偿进一步实现开环位置控制。实验结果表明，所提出的方案可以有效地估计和补偿滞后。首次成功地证明了SCP执行器的迟滞特性和补偿，从而可以实现精确的机器人控制。
The supercoiled polymer (SCP) actuator is a recently discovered artificial muscle that demonstrates significant mechanical power, large contraction, and good dynamic range in a muscle-like form factor. There has been a rapid increase of research efforts devoted to the study of SCP actuators. For robotics, SCP actuators overcome specific challenges of artificial muscles such as shape memory alloy wires, where limited strain and slow dynamics, and power consumption had limited their use. It is known that hysteresis nonlinearity results from coiling the threads, and can cause up to 30% strain difference under the same voltage; however, no work has been reported to characterize the hysteresis in SCP actuators. In this paper, three new models are formulated to characterize the hysteretic relationship between three coupled variables (voltage input, strain, and load) of an SCP actuator, namely, the augmented generalized Prandtl-Ishlinskii model, the augmented Preisach model, and the augmented linear model. By incorporating the relationship between hysteresis curves and loading forces, the proposed models can efficiently characterize the hysteresis. Open-loop position control is further realized through inverse compensation. Experimental results show that the proposed schemes can effectively estimate and compensate the hysteresis. For the first time, the hysteresis characterization and compensation of SCP actuators are successfully demonstrated, such that accurate robot control can be realized.