Dynamics, control, and sensing are still challenges for pneumatically actuated soft actuators. We consider feasible solutions based on a radially contracting actuator to overcome these challenges. The radially contracting actuator was inspired by the movement of the stomach wall. It was capable of achieving radial contraction by inflating its circular air chamber. A quasi-static model that relates the pressure with the deformed wall of the air chamber was proposed and validated. In this article, we conduct a thorough experimental investigation into the contracting dynamics of the actuator with embedded sensing capability. We analyze the kinematics of the actuator at its rest and pressurization states focusing on the midpoint of the deformed wall. The actuator dynamics is characterized under the square wave pressure input by two variables that are the pressure in the air chamber and the trajectories of the midpoint. To achieve the desired contraction, we construct a feed-forward control based on the quasi-static model. It proves that the actuator is capable of tracking a prescribed triangular wave displacement of the midpoint with small deviations. A custom-made soft sensor is integrated into the actuator, which brings in the embedded sensing capability without affecting the actuator compliance. The resistance changes of the sensor versus the controlled contraction are examined, which are used to indicate the amount of radial contraction. The experimental investigation provides a foundation for the closed-loop control and practical applications of the radially contracting actuator developed.

中文翻译：

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具有嵌入式传感能力的径向收缩致动器动力学的实验研究。

动力学、控制和传感仍然是气动软执行器的挑战。我们考虑基于径向收缩致动器的可行解决方案来克服这些挑战。径向收缩致动器的灵感来自于胃壁的运动。它能够通过给圆形气室充气来实现径向收缩。提出并验证了将压力与气室变形壁联系起来的准静态模型。在本文中，我们对具有嵌入式传感能力的执行器的收缩动力学进行了彻底的实验研究。我们分析了致动器在静止和加压状态下的运动学，重点是变形壁的中点。执行器动力学在方波压力输入下由两个变量表征，即气室中的压力和中点的轨迹。为了实现所需的收缩，我们构建了基于准静态模型的前馈控制。证明执行器能够以小偏差跟踪中点的规定三角波位移。一个定制的软传感器集成到执行器中，它带来了嵌入式传感能力，而不会影响执行器的合规性。检查传感器的电阻变化与受控收缩的关系，用于指示径向收缩的量。