Development of the gripper operated by forced vibration

The theory of grasping method of object with the most suitable force, by which an object could be grasped in no slip condition nor over grasped condition, had been reported already. The purpose of this paper is to describe the details of the vibration gripper applied this theory. The most distinctive point of this gripper, is in the compact vibration roller constructed by Harmonic Gear, by which forced vibration and correction for slipping could be able easily. The second special point is in the control circuit of grasping force, in which the circuit is divided in two sections : one is the grasping motor circuit operated at low response, and another is piezoelectric actuator circuit operated at high response. By the result of experiment, it has been cleared that this gripper had ability to grasp the object with the most suitable force as mentioned above constantly, and, in addition, safety factor for this grasping force could be controlled to adequate value, by regulating the frequency of forced vibration. Also, band width for the control circuit of grasping force has been improved up to 116.5 Hz by the piezoelectric actuator circuit inserted for this purpose.