A robotic system based on fuzzy visual servoing for handling flexible sheets lying on a table

Abstract

PurposeThe purpose of this paper is to present a flexible automation system for the manipulation of fabrics lying on a work table and focuses on the design of a robot control system based on visual servoing and fuzzy logic for handling flexible sheets lying on a table. The main contribution of this paper is that the developed system tolerates deformations that may appear during robot handling of fabrics due to buckling without the need for fabric rigidization.Design/methodology/approachThe vision system, consisting of two cameras, extracts the features that are necessary for handling the fabric despite possible deformations or occlusion from the robotic arm. An intelligent controller based on visual servoing is implemented enabling the robot to handle a variety of fabrics without the need for a mathematical model or complex mathematical/geometrical computations. To enhance its performance, the conventional fuzzy logic controller is tuned through genetic algorithms and an adaptation mechanism and the respective performance is evaluated. The experiments show that the proposed robotic system is flexible enough to handle various fabrics and robust in handling deformations that may change fabric's shape due to buckling.FindingsThe experiments show that the proposed robotic system is flexible enough to handle various fabrics and robust in handling deformations that may change fabric's shape due to buckling.Research limitations/implicationsIt is not possible to cover all the aspects of robot handling of flexible materials in this paper, since there are still several related issues requiring solutions. Considering the future research work, the proposed approach can be extended to sew fabrics with curved edges and correcting the distortions presented during robot handling of fabrics.Practical implicationsThe paper includes implications for robot handling a variety of fabrics with low and medium bending rigidity on a working table. The intent of this paper deals with buckling in context of achieving a successful seam tracking and not the correction strategy against folding or wrinkling problems.Originality/valueThis paper fulfils an identified need to study the fabrics' behavior towards robot handling on a working table.

Multi-Modal Sensing and Robotic Manipulation of Non-Rigid Objects: A Survey

“…Some research work attempted to solve more general problems related to the handling of non-rigid sheets rather than focusing on a specific task. Zacharia et al [74] proposed a model-free approach to handling flexible sheets laying on a table by augmenting fuzzy logic with genetic algorithms for visual servoing. Shibata et al [75] used simultaneous control of the displacement and deformation of a piece of cloth to perform the "wiping motion", one of the motion primitives used by humans when handling fabrics.…”

Robot Intelligence for Real World Applications

“…The difficulties in using a FEM model include identification of the physical parameters and high computational cost. Zacharia et al [52] investigated visionbased cloth-handling problems in which dynamic interactions between cloth and a robot can be neglected for small mass of cloth. Foresti and Pellegrino [53] studied visionbased grasping of deformable objects, which is different from manipulation.…”

Robot Handling Fabrics Towards Sewing Using Computational Intelligence Methods

“…Since modeling the mechanical behavior of fabrics for real-time applications is rather difficult due to their low bending rigidity, an approach based on a fuzzy logic controller (FLC) is developed (Zacharia et al, 2009) considering the robustness and the fast response requirements. The block diagram for the control system is shown in Fig.…”