Contact-based Bridge Inspection Multirotors: Design, Modelling and Control Considering the Ceiling Effect

This paper presents the design, modelling and control of a multirotor for inspection of bridges with full contact. The paper analyzes the aerodynamic ceiling effect when the aerial robot approaches the bridge surface from below, including its aerodynamic characterization using Computational Fluid Dynamics (CFD). The proposed multirotor design takes the modelled aerodynamic effects into account, improving the performance of the aerial platform in terms of the stability and position accuracy during the inspection. Nonlinear attitude and position controllers to manage the aerodynamic effects are derived and tested. Last, outdoor experiments in a real bridge inspection task have been used to validate the system, as well as the controller and the aerodynamic characterization. The experiments carried out also include a complete autonomous mission of the aerial platform during a structural assessment application.