Sliding Surface Designs for Visual Servo Control of Quadrotors

Autonomy is the main task of a quadrotor, and visual servoing assists with this task while providing fault tolerance under GPS failure. The main approach to visual servoing is image-based visual servoing, which uses image features directly without the need for pose estimation. The classical sliding surface design of sliding mode control is used by the linear controller law of image-based visual servoing, and focuses only on minimizing the error in the image features as convergence. In addition to providing convergence, performance characteristics such as visual-feature-convergence time, error, and motion characteristics should be taken into consideration while controlling a quadrotor under velocity limitations and disturbance. In this study, an image-based visual servoing system for quadrotors with five different sliding surface designs is proposed using analytical techniques and fuzzy logic. The proposed visual servo system was simulated, utilizing the moment characteristics of a preset shape to demonstrate the effectiveness of these designs. The stated parameters, convergence time, errors, motion characteristics, and length of the path, followed by the quadrotor, were compared for each of these design approaches, and a convergence time that was 46.77% shorter and path length that was 6.15% shorter were obtained by these designs. In addition to demonstrating the superiority of the designs, this study can be considered as a reflection of the realization, as well as the velocity constraints and disturbance resilience in the simulations.