Planning, Sensing and Control of Power Grasp of a Multi-Fingered Robot Hand

多指机械手的力量抓取不仅利用手指芯片，还利用手指甚至手掌的中环，并通过手指的多次接触来约束物体。自1988年K.Salisbury指出其重要性以来，人们已经进行了几项研究工作。动力抓取具有一个重要的特点，即在一类未知的外部干扰力的作用下，能够以恒定的力矩保持抓取。在不改变关节力矩的情况下，功率抓取的鲁棒性优于普通指尖抓取，因为在不改变关节力矩的情况下，功率抓取能够响应突然的外力而不会由于反馈控制而产生任何时延。通过本研究，我们在(1)基于允许外力集的评估来规划功率抓取，(2)感知接触点和力，以及安装在每个手指根部的三个六维力传感器的信号，以及(3)控制功率抓取以努力验证其鲁棒性方面取得了许多成果。

The power grasp of multi-fingered robot hand utilizes not only finger chips but also middle links of the fingers and even the palm, and constraines the object with multiple contacts of the fingers.Since K.Salisbury pointed out its importance in 1988, there have been made several research works. The power grasp possesses an important feature that the grasp can be maintained with constant torques against a class of unknown external disturbing forces. The robustness of power grasp is superior to the common fingertip grasp wihch cannot resist against disturbing forces without changing the joint torques, in a sense that the power grasp can respond to abrupt external forces without any time delay due to feedback control.Through this research, we worked and obtained many results on(1) Planning the power grasp based on the evaluation of the set of allowable external forces,(2) Sensing the contact points and forces knowing the joint torques and the signals of three 6-axis-force sensors mounted at the base of each finger, and(3) Controling the power grasp to exerimentally verify the robustness.