Abstract
An intelligent gripper has been developed. The gripper can handle an object of unknown weight and unknown surface condition with the most suitable grasping force. Additionally, the gripper can adapt the grasping force to the most suitable value for the object even if the weight or the surface conditions of the object change. The gripper has two parallel fingers. Each finger is composed of a mechanical vibration system having two degrees of freedom. The system consists of a structural finger, a support spring, a grasping finger, an absorber spring and an oscillator. In the grasping finger, a harmonic force is always generated and absorbed by a dynamic vibration absorber consisting of the oscillator and the absorber spring, so that the grasping finger is kept in a stationary condition and the oscillator vibrates with a constant amplitude. The object is grasped between both grasping fingers. When the object is grasped with the most suitable grasping force, not only the object and both grasping fingers become stationary but also both oscillators become stationary because harmonic forces are transmitted to the object from each grasping finger and the two harmonic forces cancel each other out. In this gripper, the grasping force is adjusted to the most suitable value as the amplitudes of both oscillators are reduced to zero. This paper describes a fundamental principle of this intelligent gripper and the principle is confirmed by experiment.
