Reverse pneumatic artificial muscles (rPAMs): Modeling, integration, and control
Reverse pneumatic artificial muscles (rPAMs): Modeling, integration, and control
复制标题
反向气动人工肌肉 (rPAM)：建模、集成和控制
作者：
E. Skorina;Ming Luo;Wut Yee Oo;Weijia Tao;Fuchen Chen;S. Youssefian;N. Rahbar;C. Onal
尽管与传统的刚性执行器相比，软气动执行器具有许多优点，但缺乏全面、计算效率高的模型和精确的嵌入式控制方案，没有庞大的流量控制阀和大量的计算机硬件。在本文中，我们考虑了一种廉价而可靠的软线性执行器，称为反向气动人工肌肉（rPAM），它由对称双螺旋螺纹径向约束的硅橡胶组成。描述了该驱动器的静态分析模型和数值模型，并将其性能与实验结果进行了比较。为了研究rpam在操作底层运动连杆骨架中的应用，我们考虑一个由两个执行器拮抗驱动的单自由度旋转关节。然后推导了一个解析模型，并给出了该模型预测静力接头角随输入压力变化的准确性。利用该分析模型，对该系统进行了动态表征。最后，我们提出了一种滑模控制器，以及一种由前馈项增强的滑模控制器，用于调制控制每个执行器的空气流量的微型电磁阀。实验表明，两种控制器都能很好地工作，而前馈项提高了控制器跟踪动态轨迹的性能。
Despite offering many advantages over traditional rigid actuators, soft pneumatic actuators suffer from a lack of comprehensive, computationally efficient models and precise embedded control schemes without bulky flow-control valves and extensive computer hardware. In this article, we consider an inexpensive and reliable soft linear actuator, called the reverse pneumatic artificial muscle (rPAM), which consists of silicone rubber that is radially constrained by symmetrical double-helix threading. We describe analytical and numerical static models of this actuator, and compare their performance against experimental results. To study the application of rPAMs to operate underlying kinematic linkage skeletons, we consider a single degree-of-freedom revolute joint that is driven antagonistically by two of these actuators. An analytical model is then derived, and its accuracy in predicting the static joint angle as a function of input pressures is presented. Using this analytical model, we perform dynamic characterization of this system. Finally, we propose a sliding-mode controller, and a sliding mode controller augmented by a feed-forward term to modulate miniature solenoid valves that control air flow to each actuator. Experiments show that both controllers function well, while the feed-forward term improves the performance of the controller following dynamic trajectories.