The design and control of a new series-viscous-elastic joint are presented. The proposed joint consists of 3D printed parts compressing nonlinear elastic silicone springs. The use of silicone springs is the main novelty of the system; they exhibit internal damping, which enhances system performance allowing a simpler and more stable control. Their stiffness allows the system to bear a torque of about 4.5 Nm at a deformation angle of about 20 degrees. In this article, the system is modeled using the Neo-Hookean material model and then characterized through experiments to build the joint torque estimator. A proportional torque controller is implemented to evaluate bandwidth, transparency, impedance rendering, and stability, obtaining satisfactory results. The bandwidth ranges from 6.9 to 9.9 Hz depending on chirp input torque amplitude, as the system is nonlinear. The proposed solution is compact and cheap; both the design and the torque controller are suitable for future integration in an exoskeleton, or a cooperative robot, or a haptic device. SVEJ works as a torque sensor and introduces compliance between the motor and the environment, enhancing safety for robotic devices interacting with humans.

中文翻译：

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用于平滑扭矩控制的紧凑系列粘弹性接头 (SVEJ)

介绍了一种新型串联粘弹性接头的设计和控制。拟议的关节由压缩非线性弹性硅胶弹簧的 3D 打印部件组成。硅胶弹簧的使用是该系统的主要新颖之处；它们具有内部阻尼，可增强系统性能，从而实现更简单、更稳定的控制。它们的刚度允许系统在大约 20 度的变形角下承受大约 4.5 Nm 的扭矩。在本文中，系统使用 Neo-Hookean 材料模型进行建模，然后通过实验表征以构建关节扭矩估计器。实施比例扭矩控制器来评估带宽、透明度、阻抗渲染和稳定性，获得满意的结果。带宽范围为 6.9 至 9.9 Hz，具体取决于线性调频输入扭矩幅度，因为系统是非线性的。所提出的解决方案紧凑且便宜；设计和扭矩控制器都适合未来集成到外骨骼、协作机器人或触觉设备中。SVEJ 用作扭矩传感器，并在电机和环境之间引入顺应性，提高机器人设备与人类交互的安全性。