Modelling, Simulation and Control of a Twin Rotor MIMO-System

Abstract

The object of the project is to simulate and control the laboratory helicopter model called Twin-Rotor Multiple Input-Multiple Output System (TRMS 33-220), manufactured by Feedback Instruments Limited Company. So the first aim was to get familiar with the physical basics of the model what implicated an intensive literature research at the beginning of the work on this project. Having built up the basic mathematical model there was to deal with adjusting the particular parameters by engaging several experiment on the real model comparing the results of the simulation done in Matlab/Simulink. This was one of the most delicate tasks during the projects since there was to deal with constants that were not directly measurable and because particular parts of the model had been changed in the past so that the constant parameters given in the manual went out of date. The control design as well was done using Matlab/Simulink Having reached satisfactory results of the model further experiments were thenceforward on a simulator, firstly implemented in Labview, then embedded on a real-time platform called PXI-1002 manufactured by National Instruments to avoid physical damages of the real model by possible failures during the controller testing. The two control objects were first to keep the helicopter at a certain point and second to follow a given trajectory. So the first effort to create a control was to design two independent PID-Controllers, one for the vertical axis and one for the horizontal one, considering the cross-coupling forces as disturbance. This form of control worked out quite fine as long as only one input was changed. To compensate the disturbances correctly we had to deal with a different type, called state-space-control. The final task was to run the designed controller on the PXI-1002 controlling the physical system.