Haro-Olmo María Isabel, Mérida-Calvo Luis, Feliu-Talegón Daniel, Feliu-Batlle Vicente
Instituto de Investigaciones Energéticas y Aplicaciones Industriales, Universidad de Castilla-La Mancha, 13005 Ciudad Real, Spain.
Department of Mechanical and Nuclear Engineering, Khalifa University of Science and Technology, Abu Dhabi P.O. Box 127788, United Arab Emirates.
Biomimetics (Basel). 2024 Jul 7;9(7):414. doi: 10.3390/biomimetics9070414.
Haptic organs are common in nature and help animals to navigate environments where vision is not possible. Insects often use slender, lightweight, and flexible links as sensing antennae. These antennae have a muscle-endowed base that changes their orientation and an organ that senses the applied force and moment, enabling active sensing. Sensing antennae detect obstacles through contact during motion and even recognize objects. They can also push obstacles. In all these tasks, force control of the antenna is crucial. The objective of our research is to develop a haptic robotic system based on a sensing antenna, consisting of a very lightweight and slender flexible rod. In this context, the work presented here focuses on the force control of this device. To achieve this, (a) we develop a dynamic model of the antenna that moves under gravity and maintains point contact with an object, based on lumped-mass discretization of the rod; (b) we prove the robust stability property of the closed-loop system using the Routh stability criterion; and (c) based on this property, we design a robust force control system that performs efficiently regardless of the contact point with the object. We built a mechanical device replicating this sensing organ. It is a flexible link connected at one end to a 3D force-torque sensor, which is attached to a mechanical structure with two DC motors, providing azimuthal and elevation movements to the antenna. Our experiments in contact situations demonstrate the effectiveness of our control method.
触觉器官在自然界中很常见，有助于动物在无法依靠视觉的环境中导航。昆虫常常使用细长、轻便且灵活的肢体作为传感触角。这些触角有一个由肌肉驱动的基部，可改变其方向，还有一个能感知施加的力和力矩的器官，从而实现主动传感。传感触角在运动过程中通过接触检测障碍物，甚至能够识别物体。它们还能推开障碍物。在所有这些任务中，触角的力控制至关重要。我们研究的目标是基于传感触角开发一种触觉机器人系统，该系统由一根非常轻便且细长的柔性杆组成。在此背景下，本文所展示的工作聚焦于该装置的力控制。为实现这一目标，（a）我们基于杆的集中质量离散化，建立了在重力作用下移动并与物体保持点接触的触角动力学模型；（b）我们使用劳斯稳定性判据证明了闭环系统的鲁棒稳定性；（c）基于这一特性，我们设计了一种鲁棒力控制系统，无论与物体的接触点如何，该系统都能高效运行。我们制造了一个复制这种传感器官的机械设备。它是一个柔性连杆，一端连接到一个三维力 - 扭矩传感器，该传感器通过两个直流电机连接到一个机械结构上，为触角提供方位角和仰角运动。我们在接触情况下的实验证明了我们控制方法的有效性。
