Modeling of Generic Slung Load System

Abstract

This paper presents the result of modelling and verification of a generic slung load system using a small-scale helicopter. The model is intended for use in simulation, pilot training, estimation, and control. The model is derived using a redundant coordinate formulation based on Gauss’ Principle of Least Constraint using the Udwadia-Kalaba equation and can be used to model all body to body slung load suspension types. The model gives an intuitive and easy-to-use way of modelling and simulating dierent slung load suspension types and it includes detection and response of wire slacking and tightening, and aerodynamical coupling between the helicopter and the load. Furthermore, it is shown how the model can be easily used for multi-lift systems either with multiple helicopers or multiple loads. A numerical stabilisation algorithm as well as a trim algorithm is presented for the complete helicopter/load system and finally the use of the model is illustrated through simulations.