Design of an Airship On-Board Crane

Abstract

This paper presents the design and mathematical model of an innovative smart crane, CHAYA-SC, based on the principle of a cable-driven parallel manipulator, as well as its stabilization. This crane is mounted on the airship hold and intended for handling at altitude. Our objective is to design a precise light crane that can be used for container loading or unloading, particularly in deep-sea ports. Thus, the model developed includes the oscillations as well as the transverse and longitudinal vibrations of the heavy cable supporting the load to be handled. The highly nonlinear partial differential equations (PDE) and ordinary derivative equations (ODE) that govern the motion of the system are obtained via the Lagrange equations coupled with a modal synthesis. So that the mathematical model of the system is compatible with control and real time, we developed a simplified dynamic model which proved to be equivalent to the complete model. As a first validation of the modelling, a simple control vector is applied to stabilize the airship and its load under the effect of a squall. Numerical simulations are presented at the end of the paper to show the relevance of the design.