Abstract The greatest limitation for an amputee subject who uses a prosthesis having no sensory feedback is the difficulty to manage unexpected events in an autonomous way. In grasp and manipulation tasks, the possibility of object slippage is high. For this reason, it is necessary to detect the beginning of the slippage and provide the control with a fast contrast action. In this work, a touch-and-slippage detection algorithm for effective grasp control of a prosthetic hand embedding monoaxial, low-cost sensors is proposed. The algorithm has a low computational burden, and is capable of detecting slippage events using only the normal force component. Three experimental sessions were performed to validate the touch-and-slippage algorithm. In the first one, the variation of the normal force component provided by a Force Sensing Resistor (FSR) sensor was compared with the tangential force component measured by a triaxial force sensor. In the second one, the threshold for detecting slippage events was obtained and applied to study the dependence of the number of slippage events on sliding velocity and force applied on the sensor. Finally, the algorithm was tested on a real system made of the IH2 Azzurra robotic hand provided with FSR on the fingertips. The obtained results are illustrated in terms of false positives and negatives and true positives and negatives. The low computation time of the algorithm, i.e. 4.9 ms, and the high success rate in terms of detected slippage events (99.4%) suggest that the algorithm applicability in real systems is feasible.

中文翻译：

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假手触摸和滑动检测算法

摘要 对于使用没有感觉反馈的假肢的截肢受试者来说，最大的限制是难以以自主方式处理突发事件。在抓取和操纵任务中，物体滑动的可能性很高。出于这个原因，有必要检测滑动的开始并为控件提供快速的对比动作。在这项工作中，提出了一种触摸和滑动检测算法，用于对嵌入单轴、低成本传感器的假手进行有效的抓握控制。该算法具有较低的计算负担，并且能够仅使用法向力分量来检测滑动事件。进行了三个实验会话来验证触摸和滑动算法。在第一个中，将力敏电阻 (FSR) 传感器提供的法向力分量的变化与三轴力传感器测量的切向力分量进行了比较。在第二个中，获得检测滑动事件的阈值并将其应用于研究滑动事件数量对滑动速度和施加在传感器上的力的依赖性。最后，该算法在由 IH2 Azzurra 机械手制成的真实系统上进行了测试，该系统在指尖上配备了 FSR。获得的结果以假阳性和阴性以及真阳性和阴性来说明。该算法的低计算时间（4.9 ms）和检测到的滑点事件的高成功率（99.4%）表明该算法在实际系统中的适用性是可行的。