In this work we present a novel, inductance-based system to measure and control the motion of bellows-driven continuum joints in soft robots. The sensing system relies on coils of wire wrapped around the minor diameters of each bellows on the joint. As the bellows extend, these coils of wire become more distant, decreasing their mutual inductance. Measuring this change in mutual inductance allows us to measure the motion of the joint. By dividing the sensing of the joint into two sections and measuring the motion of each section independently, we are able to measure the overall deformation of the joint with a piece-wise constant-curvature approximation. This technique allows us to measure lateral displacements that would be otherwise unobservable. When measuring bending, the inductance sensors measured the joint orientation with an RMS error of \(1.1^\circ \). The inductance sensors were also successfully used as feedback to control the orientation of the joint. The sensors proposed and tested in this work provided accurate motion feedback that would be difficult to achieve robustly with other sensors. This sensing system enables the creation of robust, self-sensing soft robots based on bellows-driven continuum joints.

中文翻译：

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用于软机器人中波纹管驱动连续关节的基于电感的传感系统。

在这项工作中，我们提出了一种新颖的基于电感的系统，用于测量和控制软机器人中波纹管驱动的连续关节的运动。传感系统依赖于缠绕在接头上每个波纹管小直径上的线圈。随着波纹管延伸，这些线圈变得更远，从而降低了它们的互感。通过测量互感的变化，我们可以测量关节的运动。通过将关节的传感分为两个部分并独立测量每个部分的运动，我们能够通过分段常曲率近似来测量关节的整体变形。这项技术使我们能够测量原本无法观察到的横向位移。测量弯曲时，电感传感器测量关节方向，RMS 误差为\(1.1^\circ \)。电感传感器也成功地用作控制关节方向的反馈。这项工作中提出和测试的传感器提供了精确的运动反馈，而其他传感器很难实现这一点。该传感系统能够创建基于波纹管驱动连续关节的坚固、自感知软机器人。