This article introduces the analysis and control of a meso-scale two degree-of-freedom robotic endoscopic tool body for minimally invasive surgeries. The design of the robotic tool uses two types of a tendon-driven joint known as a bending flexure joint that allows us to control each degree-of-freedom by minimizing interjoint coupling by design. Pure kinematic modeling and control for these robots may not provide precise control performance due to kinematic uncertainties arising from tendon elongation, tendon slacking, gear backlash, etc. We propose a static model for each of the joints of the robotic tool that avoids several of these problems. Depending on the direction of tendon tension application, the proximal joint displays considerable hysteresis due to the superelastic material characteristics and this is included in our static model. The statics of a highly compliant distal joint is also modeled and validated using finite element analysis and experimental data. Using these models, we develop a control system that comprises of a disturbance observer and the proposed static model to provide precise force control and compensate for joint hysteresis.

中文翻译：

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用于小儿神经外科的 2-DoF 中尺度连续机器人工具的建模和控制

本文介绍了一种用于微创手术的中尺度二自由度机器人内窥镜工具体的分析和控制。机器人工具的设计使用两种类型的腱驱动关节，称为弯曲挠性关节，允许我们通过设计最大限度地减少关节间耦合来控制每个自由度。由于肌腱伸长、肌腱松弛、齿轮间隙等引起的运动学不确定性，这些机器人的纯运动学建模和控制可能无法提供精确的控制性能。我们为机器人工具的每个关节提出了一个静态模型，以避免其中的几个问题。根据肌腱张力施加的方向，由于超弹性材料特性，近端关节显示出相当大的滞后，这包括在我们的静态模型中。还使用有限元分析和实验数据对高度顺应的远端关节的静力学进行建模和验证。使用这些模型，我们开发了一个控制系统，该系统由干扰观测器和建议的静态模型组成，以提供精确的力控制并补偿关节滞后。