Soft gastric simulators are the latest gastric models designed to imitate gastrointestinal (GI) functions in actual physiological conditions. They are used in in vitro tests for examining the drug and food behaviors in the GI tract. As the main motility function of the GI tract, the peristalsis can be altered in some gastric disorders, for example, by being delayed or accelerated. To simulate the stomach motility, a GI simulator must achieve a prescribed healthy or pathological peristalsis. This requires the simulator to be controlled in a closed loop. Unlike conventional controllers that stabilize a controlled plant asymptotically, a finite-time controller regulates state variables to their equilibrium points in a predetermined time interval. This article presents the design and implementation of a finite-time, model-based state feedback controller (based on the differential Riccati equation) on a soft robotic gastric simulator's actuators for the first time. We propose a mass-spring-damper model of a ring-shaped soft pneumatic actuator (RiSPA). RiSPA is a bellows-driven, elastomer-based actuator developed to reproduce motility functions of the lower part of the stomach (pyloric antrum). The proposed model is augmented by a new approach for modeling the soft tissues, where the moments of inertia of the system constituents are considered as time-varying functions. The finite-time controller is successfully applied on the RiSPA in numerical simulation and experimental implementation, and the results were thoroughly analyzed and discussed. Its accuracy and the ability to control in a predetermined time are highlighted in the tracking of peristalsis trajectory and contractive regulations.

中文翻译：

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模拟胃病理运动条件的环形软气动执行器的有限时间收缩控制

软胃模拟器是最新的胃模型，旨在模拟实际生理条件下的胃肠 (GI) 功能。它们在体外使用用于检查胃肠道中药物和食物行为的测试。作为胃肠道的主要运动功能，蠕动在某些胃病中可能会发生改变，例如延迟或加速。为了模拟胃动力，胃肠道模拟器必须达到规定的健康或病态蠕动。这需要在闭环中控制模拟器。与渐近稳定受控对象的传统控制器不同，有限时间控制器在预定时间间隔内将状态变量调节到它们的平衡点。本文首次在软机器人胃模拟器的执行器上介绍了有限时间、基于模型的状态反馈控制器（基于微分 Riccati 方程）的设计和实现。我们提出了一种环形软气动执行器 (RiSPA) 的质量弹簧阻尼器模型。RiSPA 是一种风箱驱动的、基于弹性体的致动器，开发用于重现胃下部（幽门窦）的运动功能。所提出的模型通过一种新的软组织建模方法得到增强，其中系统成分的惯性矩被视为时变函数。有限时间控制器在 RiSPA 上的数值模拟和实验实现中得到成功应用，并对结果进行了深入分析和讨论。它的准确性和在预定时间内的控制能力在蠕动轨迹和收缩调节的跟踪中得到了突出。基于弹性体的致动器开发用于重现胃下部（幽门窦）的运动功能。所提出的模型通过一种新的软组织建模方法得到增强，其中系统成分的惯性矩被视为时变函数。有限时间控制器在 RiSPA 上的数值模拟和实验实现中得到成功应用，并对结果进行了深入分析和讨论。它的准确性和在预定时间内的控制能力在蠕动轨迹和收缩调节的跟踪中得到了突出。基于弹性体的致动器开发用于重现胃下部（幽门窦）的运动功能。所提出的模型通过一种新的软组织建模方法得到增强，其中系统成分的惯性矩被视为时变函数。有限时间控制器在 RiSPA 上的数值模拟和实验实现中得到成功应用，并对结果进行了深入分析和讨论。它的准确性和在预定时间内的控制能力在蠕动轨迹和收缩调节的跟踪中得到了突出。其中系统成分的惯性矩被视为时变函数。有限时间控制器在 RiSPA 上的数值模拟和实验实现中得到成功应用，并对结果进行了深入分析和讨论。它的准确性和在预定时间内的控制能力在蠕动轨迹和收缩调节的跟踪中得到了突出。其中系统成分的惯性矩被视为时变函数。有限时间控制器在 RiSPA 上的数值模拟和实验实现中得到成功应用，并对结果进行了深入分析和讨论。它的准确性和在预定时间内的控制能力在蠕动轨迹和收缩调节的跟踪中得到了突出。