Research On Control Of The Four-Rotor VTOL Helicopter

Compared with single-rotor helicopter, the four-rotor VTOL(vertical take-off and landing)helicopter has smaller propellers, which can reduce the risk of crashing into the surrounding objects. o it can make the flight safer. In addition, the thrust produced by four propellers can realize flight vehicle's circling in static state better comparing with that of single propeller, and can change its posture in the hovering condition instantly.It also has good mobility and the effective supporting capacity. Gradually it was highly valued by the people in controlling and commercial domain. The article establishes the dynamic model of the four- rotor VTOL helicopter. Specific to the built model, we design H_∞loop shaping controller, simultaneously set up the physical platform, and carry on semi-physical simulation on the RTW environment.Firstly we determine the design proposal of the four-rotor VTOL helicopter in the article. The four-rotor VTOL helicopter has four inputs and six outputs, therefore it is a underactuated control system. Moreover the four-rotor VTOL helicopter makes the lifting force changed by changing the propeller speed, which causes the instability of its power.Therefore we need to have the stable inverse amplification factor to guarantee its stabilized flight.The H_∞loop shaping can combine the robustness merits of the classical frequency domain and the state space methods of the modern control theory, so we select H_∞loop shaping method to design flight controller. In order to design the controller,firstly we establish its non-linear model and carry on the linearization to the model, then through the Matlab simulation, confirm the control effect of the H_∞loop shaping controller we designed.Next, to determine the actual model parameter, we design the drive circuit for-four propellers, and then set up the entire physics platform.Finally, we construct the real-time emulation environment, and determine the electrical motor parameter and the system moment of inertia, obtain the model of the actual object and carry on the real-time simulation to system roll channel, confirm the controller's effect.