%0 Journal Article
%T Evaluation of Circle Diameter by Distributed Tactile Information in Active Tracing
%A Hiroyuki Nakamoto
%A Futoshi Kobayashi
%A Fumio Kojima
%J Journal of Sensors
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/658749
%X Active touch with voluntary movement on the surface of an object is important for human to obtain the local and detailed features on it. In addition, the active touch is considered to enhance the human spatial resolution. In order to improve dexterity performance of multifinger robotic hands, it is necessary to study an active touch method for robotic hands. In this paper, first, we define four requirements of a tactile sensor for active touch and design a distributed tactile sensor model, which can measure a distribution of compressive deformation. Second, we suggest a measurement process with the sensor model, a synthesis method of distributed deformations. In the experiments, a five-finger robotic hand with tactile sensors traces on the surface of cylindrical objects and evaluates the diameters. We confirm that the hand can obtain more information of the diameters by tracing the finger. 1. Introduction Human voluntarily touches an object and perceives its characteristic features. The procedure is called as active touch. Gibson has indicated that the active touch is important for shape perception [1]. In addition, it has been reported that two-position recognition threshold on human finger tip is 2 to 3£żmm. The threshold gives us an impression of large value. Then, Loomis and collins have reported that the sensitivity for stimulus in active touch becomes high [2]. In order to perceive shape of objects, the results indicate an importance of moving hands. Therefore, not only a development of tactile sensor but also a measurement method based on exploratory moving is necessary for developing dexterous robotic hand. Various studies of robotic hands with tactile sensor have been discussed [3¨C7]. The tactile sensors are used for recognition. Okamura and Cutkosky have proposed a method which detects small textural features by tracing with robotic fingers [4]. In the case, the hand recognized a local area on an unknown object, and it is called the local exploratory operation. Pribadi et al. have proposed a method to estimate the contour of unknown objects [5]. Allen and Michelman have focused on sensing of global object shapes and fitting shapes to object models [6]. Wang and Li have applied a tactile sensor for surface tracking of a manipulator [7]. Nakamoto et al. have proposed a method of classifying the shape of an object that a five-finger robot is grasping [8]. The purposes of them are recognitions of unknown area by robotic hands with tactile sensor. Using tactile information, Wang and Li have proposed a feedback to control a robotic arm interacting
%U http://www.hindawi.com/journals/js/2013/658749/