Research Of Four-Rotor Helicopter Control

Four-rotor helicopter had generated considerable interest in the control and commercial community for several decades due to its advantages of high maneuverability and the increased payload capacity. In this work we focus on designing controller for a four-rotor helicopter, setting up a testing plant and doing some experiment based on this tester.First, the project of four-rotor helicopter has been decided. The four-rotor helicopter is a full six degrees of feedom. So it ideally suited for stationary and quasi-stationary flight conditions. Moreover, it has the advantage of superior maneuverability. Unfortunately, on the other hand, it is an under-actuated dynamic rotorcraft with four input forces and six output coordinates, and this advantage makes it very hard to comtrol, requiring sophisticated sensors and on-board computation. And it using the variant rotor speeds to change the lift forces is dynamically unstable therefore a control law is permanently required to ensure its stability. We design an effective controller with the method of H∞loop shaping. The nonlinear four-rotor helicopter model and its corresponding Simulink model have been presented. The simulation results prove the robustness, good reference tracking and disturbance rejection of H∞loop shaping flight controller.Second, the tester has been established. In the process of setting up it, sensors have been selected and we forces on designing and analyzing the drive circuit of brushless DC motor (BLDCM).At last, RTW (Real-Time Windows Taget) has been builded. The paraments of BLDCM and the inertia of tester have been mensurated by using RTW. The last model is completed by the results. Moreover, the simulations using of Matlab and RTW of tha last system have been completed.