Grip Force Control of the Elastic Body based on Contact Surface Eccentricity During the Incipient Slip

Abstract

In this research, the slip margin between an elastic object and a rigid plate is estimated based on the analysis of Hertz contact model. A method of the grip force control using the slip margin is proposed. When an elastic object is pressed and slid slightly on a rigid plate, a partial slip, called“incipient slip”occurs on the contact surface. The slip margin can be estimated based on tribology from the deformation of the elastic object, the tangential force and the radius on the contact surface. The deformation and the displacement of the elastic object are measured by the camera. In addition, the load force can be measured by the force sensor. In this research, a measuring device consists of a camera and a force sensor is developed.“Eccentricity”is defined to estimate the displacement of the elastic object from the shift of the contact area. The grip force is controlled based on the estimated slip margin without knowing the friction coefficient. The proof of the contact stability is obtained. The validity of the proposed method is confirmed by the experiment.