Manipulation of an object based on dynamic tactile information processing

本研究的目的是开发一种触觉传感方法，从接触引起的振动中识别机器人指尖与物体之间的接触状态，并进一步开发一种利用传感器信息的控制方法。主要研究成果如下：(1)基于振动检测的触觉传感器的研制指尖与物体之间的接触或滑动在机器人手指弹性皮肤上产生机械振动。我们已经开发出一种触觉传感器，通过嵌入指尖的压电膜(PVDF)来检测这种振动。暂态响应和频谱取决于接触状态的转变。滑移引起的振动是一种宽带类白噪声信号。滑移速度和接触力对输出影响较小。检测滑移的开始是在操作中。我们开发了一种新的方法来计算波形中的峰值，而不是普通的频域滤波。O…的微小振动该方法可检测到更多的滑移。滑移传感的这种快速响应对稳定的灵巧操作至关重要。(2)机械手的灵巧操作我们已经处理了用两个手指的机械手在桌子上操纵物体的问题。这项任务涉及灵巧操作中的许多基本动作。关键是要区分可控力和被动决定的不可控力。由于现实世界中固有的不确定性，传统的任务规划方法仅仅依赖于计算可控力是不稳定的。我们开发了一种新的方法，通过在移动手指的同时监控传感器输出来适应接触条件的变化。举起握住同一物体的两根手指中的一根，需要调整指尖力量的方向。所提出的传感方法使我们能够实现这一任务。灵巧操作中的其他基本动作都是在相同的概念上实现的。整个控制系统能够控制运动，如连续地在桌子上翻滚物体。较少

The purpose of this research is to develop a tactile sensing method to recognize the contact state between the robot finger tip and the object from the vibration induced by the contact, and further develop a control method utilizing the sensor information. There are two major results.(1) Development of Tactile Sensor based on Detecting VibrationContact or slippage between a fingertip and an object generate mechanical vibration in the elastic skin of the robot finger. We have developed a tactile sensor that detects this vibration by piezoelectric film (PVDF) embedded in the fingertip. The transient response and spectrum depend on the contact state transition. The vibration induced by slippage is a broadband white-noise-like signal. Slip velocity and contact force have small effect on the output. Detecting the onset of slippage is in manipulation. Instead of ordinary frequency domain filtering, we have developed a new method that counts peaks in the waveform. The small vibration at the o … More nset of slippage was detected by this method. This quick response of slip sensing was crucial in stable dexterous manipulation.(2) Dexterous Manipulation by Robotic HandWe have dealt with manipulation of an object on a table with two-fingered robotic hand. This task involves many fundamental motions in dexterous manipulation. The key point is to differentiate controllable forces from uncontrollable forces that are passively determined. Conventional task planning method that relies on calculating the controllable forces only is unstable because of the uncertainty inherent in the real world. We have developed a new method to adapt to the changes in contact conditions by monitoring the sensor outputs while moving the fingers. Lifting one of the two fingers that have been holding the same object requires adjustment of direction of the fingertip force. The proposed sensing method enabled us to realize this task. Other basic motions in dexterous manipulation have been realized on the same concept. The overall control system was capable of controlling motions such as tumbling an object on a table continuously. Less