Soft robotics, with their inherent flexibility and infinite degrees of freedom (DoF), offer promising advancements in human-machine interfaces. Particularly, pneumatic artificial muscles (PAMs) and pneumatic bending actuators have been fundamental in driving this evolution, capitalizing on their mimetic nature to natural muscle movements. However, with the versatility of these actuators comes the intricate challenge of hysteresis - a nonlinear phenomenon that hampers precise positioning, especially pronounced in pneumatic actuators due to gas compressibility. In this study, we introduce a novel 2-DoF adaptive control for precise bending tracking using a pneumatic continuum actuator. Notably, our control method integrates adaptability into both the feedback and the feedforward element, enhancing trajectory tracking in the presence of profound nonlinear effects. Comparative analysis with existing approaches underscores the superior tracking accuracy of our proposed strategy. This work discusses a new way of simple yet effective control designs for soft actuators with hysteresis properties.

翻译：软体机器人凭借其固有的柔顺性和无限自由度（DoF），为人机接口领域带来了令人瞩目的进步。特别是，气动人工肌肉（PAMs）和气动弯曲执行器因其模拟自然肌肉运动的仿生特性，成为推动这一演进的基础技术。然而，这些执行器的多功能性也带来了迟滞这一复杂挑战——一种阻碍精确定位的非线性现象，在气动执行器中因气体可压缩性而尤为显著。本研究提出了一种新颖的二自由度自适应控制方法，用于使用气动连续执行器实现精确弯曲跟踪。值得注意的是，我们的控制方法将自适应性同时集成到反馈和前馈环节中，从而在存在显著非线性效应的条件下增强了轨迹跟踪能力。与现有方法的对比分析突显了我们所提出策略的优越跟踪精度。本文探讨了一种针对具有迟滞特性的软体执行器的简单而有效的控制设计新途径。