Fuzzy logic control of a novel robotic hanger for garment inspection: Modeling, simulation and experimental implementation

This paper presents a novel robotic hanger system for the garment inspection of knitting production. This 3-DOF hanger consists of three groups of linkages which can freely move in the 2D plane. In order to thoroughly understand the structure and motion of the robotic hanger so as to facilitate control simulations and experiments, the mathematical dynamic model of the hanger is analyzed and derived by using the Lagrangian energy approach. Since the dynamic model is complex, coupled and nonlinear, the fuzzy tuned PID (FT-PID) algorithm is employed to establish the controller. This FT-PID controller is found to be less susceptible to the sensor noise, the variation of garment material and size. Therefore, it possesses a certain degree of robustness and adaptability. The simulation and experimental results validate the dynamic model and the effectiveness of the FT-PID control method through comparisons with the conventional PID controller.