Study on Multi-jointed Robotic Finger Equipped with Soft Skin and Hard Nail

本研究的目的是开发一种由柔软皮肤和硬指甲组成的新型指尖灵巧机器人手指系统。并对其性能进行了研究。为此，利用柔软皮肤的弹性和拟人手指的形状，结合安装在指尖连接底部的六轴力/扭矩传感器、连接在人造指甲底部的应变计和安装在每个关节上的关节编码器的综合感官信息，开发了灵巧的操作方法。研究结果如下：将铝质内壳与硅橡胶软皮相结合，设计制造出新型指尖。结果表明，使用力/扭矩传感器测量接触点位置的精度不会降低。纸张翻页任务已成功执行。人造指甲已被研制出来并附着在指尖上，可以对表面亚毫米级的小步骤进行触觉检测。提出了一种利用指尖软接触判别边缘与平面的新方法。提出了一种利用软指尖进行边缘方向触觉感知的新方法。建立了一个由多指机械手的精细操作功能和手臂和移动体基座的全局操作功能组成的操作运动仿真系统。

The purpose of this study is to develop a dexterous robotic finger system composed of a novel fingertip with soft skin and hard nail. Its performance was also investigated. For this purpose, dexterous manipulation method has been developed utilizing elasticity of the soft skin and the human mimetic shape of the finger together with the integrated sensory information from a six-axis force/torque sensor mounted at the base of the fingertip link, a strain gauge attached at the base of the artificial nail, and joint encoders mounted at each joint. Results of the study are as followings.1.Novel fingertip was designed and manufactured by combining a inner shell made of aluminum and soft skin made of silicon rubber. It was cleared that accuracy of the position measurement of contact point using the force/torque sensor is not deteriorated. Page turning task of paper sheet has been successfully executed.2.Artificial nail has been developed and attached to the fingertip enabling tactile detection of small step of sub-millimeter on the surface.3.A new method of discriminating edge and planar surface has been developed using the soft fingertip contact.4.A new method of tactile sensing of edge direction has been developed using the soft fingertip.5.A simulation system has been developed to evaluate manipulation motion composed of the fine manipulation function by the multi-fingered robotic hand and the global manipulation function by the arm and mobile body base.