Bounded UDE-Based Control for a SLAM Equipped Quadrotor with Input Constraints

Simultaneous Localization and Mapping (SLAM) system equipped quadrotors are preferable candidates for autonomous building inspections and surveillance tasks, because of their mobility and capability of working in both indoor and outdoor environments. However, the lack of robustness still remains as one of the challenging problems of SLAM implementations. Sudden camera moving, motion blur, occlusion all might cause a pose lost and map corruption. This problem becomes significant when the SLAM system is mounted on a quadrotor, since the high agility of the quadrotor might lead to a wide camera motion. Therefore, a control strategy that can constrain the quadrotor motion angles is proposed in this paper. A bounded design is embedded into the existing uncertainty and disturbance estimator (UDE) control framework, which can regulate the motion angles, e.g., roll and pitch angles of the quadrotor, always within predefined appropriate ranges. The proposed control strategy eliminates the sudden camera motion and provides a suitable platform for SLAM. Finally, experimental studies are provided for validation.