Mathematical dynamic modelling of a twin-rotor multiple input-multiple output system

Abstract

This investigation presents the mathematical modelling of an experimental aerodynamic test rig, a twin-rotor multiple input-multiple output (MIMO) system (TRMS). The system is modelled in terms of vertical one-degree-of-freedom (1DOF), horizontal 1DOF, and two-degree-of-freedom (2DOF) dynamics using Newtonian as well as Lagrangian methods. The modelling is carried out in two phases. In the first phase the interface circuit, d.c. motors, and propulsive forces due to these motors, common to both Newtonian and Lagrangian approaches, are modelled. Thereafter, the dynamic equations for the remaining parts are formulated taking all the effective forces into account. The responses of both the Newtonian and the Lagrangian models are compared with that of the real TRMS to validate the accuracy of the models. The performances of the two models are also compared.