Robotized Sewing of Fabrics Based on a Force Neural Network Controller

The robotized sewing of a wide range of fabrics is presented. A conventional industrial sewing machine in cooperation with a scara robot manipulator is used for producing straight line seams in single pieces of rectangular fabrics. A force controller based on neural networks is implemented in order to control the robot end-effector motion so as to ensure that a desired tensional force is applied to the fabric throughout the process of the sewing. The force controller scheme is designed and closes the loop outside the standard robot control law. All the necessary algorithms are implemented and executed inside the robot's controller board. The 12-specimens of fabrics, which have been used for the robotized sewing experiment, represent a broad range of fabric types and compositions. The seams produced by the robot are compared with seams that are produced by a human operator under the same sewing machine conditions. The results reveal that the seams produced by the robot are comparable with that produced by the human operator and in few cases better.