%0 Journal Article
%T Research on Visual Servo Grasping of Household Objects for Nonholonomic Mobile Manipulator
%A Huangsheng Xie
%A Guodong Li
%A Yuexin Wang
%A Zhihe Fu
%A Fengyu Zhou
%J Journal of Control Science and Engineering
%D 2014
%I Hindawi Publishing Corporation
%R 10.1155/2014/315396
%X This paper focuses on the problem of visual servo grasping of household objects for nonholonomic mobile manipulator. Firstly, a new kind of artificial object mark based on QR (Quick Response) Code is designed, which can be affixed to the surface of household objects. Secondly, after summarizing the vision-based autonomous mobile manipulation system as a generalized manipulator, the generalized manipulator¡¯s kinematic model is established, the analytical inverse kinematic solutions of the generalized manipulator are acquired, and a novel active vision based camera calibration method is proposed to determine the hand-eye relationship. Finally, a visual servo switching control law is designed to control the service robot to finish object grasping operation. Experimental results show that QR Code-based artificial object mark can overcome the difficulties brought by household objects¡¯ variety and operation complexity, and the proposed visual servo scheme makes it possible for service robot to grasp and deliver objects efficiently. 1. Introduction A classical mobile manipulator system (MMS) consists of a manipulator which is mounted on a nonholonomic mobile platform. This type of arrangement extends manipulator¡¯s workspace apparently and is widely used in service robot applications [1, 2]. The development of MMS mainly involves two classical items, namely, motion planning [3¨C8] and coordinating control [9¨C13], which are used to overcome the mobile platform¡¯s nonholonomic constraint and make the MMS move quickly and efficiently. When robots operate in unstructured environments, it is essential to include exteroceptive sensory information in the control loop. In particular, visual information provided by vision sensor such as charge-coupled device (CCD) cameras guarantees accurate positioning, robustness of calibration uncertainties, and reactivity of environmental changes. Much of the work related to CCD cameras and manipulators has focused on the applications about the manipulator¡¯s visual servo control, which specifies robotic tasks (such as object grasping, assembling) in terms of desired image features extracted from a target object. The overview of visual servo can be seen in literature [14¨C16]. In general, visual servo approaches can be divided into three different kinds, namely, position-based visual servoing (PBVS) [17, 18], image-based visual sevoing (IBVS) [19, 20], and hybrid visual servoing (HYBVS) [21¨C23]. In PBVS, the feedback signals in vision loop are the intuitive relative 3D pose between current and desired cameras estimated by current and
%U http://www.hindawi.com/journals/jcse/2014/315396/