Controlling Quadrotors Based On Linear Quadratic Regulator

This articleFour-rotor aircraft is a vertical take-off and landing(VTOL) aircraft can be designed multidisciplinary areas. Four-rotor aircraft does not require complex mechanical transmission device. It has simple structure. The speed of the four-rotor aircraft is depends on the difference speed between two sets of propellers.Now a days, the number of algorithms is growing up fast. With the stability of the vehicle is basic resolved, sensitivity and quickness becomes more and more important. The linear quadratic regulator can cover the four performance index system, thay are Speed, accuracy and stability and sensitivity.Based on a summary of the research status four-rotor aircraft article, the future application of the four-rotor aircraft article. This paper introduces the typical four-rotor aircraft article at home and abroad. Then we designed algorithms of the hovering four-rotor aircraft. Finally, the control system is developed in Mablab/Simulink and analtsis the results of the simulation, be verified by computer simulation. The main work is as follows:First, we analysis the structure and working principle of the four-rotor aircraft. The stress of each action had been give out. Then describes how did the linear quadratic regulator work.Second, we stand on a model of the four-rotor aircraft article. Here we choose two coordinate frames, one of them is fixed at the ground, the other is fixed at the body of the four-rotor aircraft article. Then derived the transformation matrix of the two coordinate frames. According to Newton's law to derive the transformation formula of the various physical quantities.Then we give out a model of the motors. Here we list the formula for the relationship between the input voltage and the output force of the motors. Analysis the body movement trends of the four-rotor aircraft article, and then list the formula.Third, according to the madels, we designed of the linear quadratic controller of this system. Then described the basic principles of linear quadratic controller, list the formula. We select the appropriate weighting matrix as the system feedback. the control system is developed in Mablab/Simulink and analtsis the results of the simulation.Finally, we used real-time window in MATLAB/Simulink to control the four-rotor aircraft. Describe the settings of the software and hardware. Shown the block diagram of the system.We found that simulations and experiments on a prototype of quadrotors are given to demonstrate the effectiveness and feasibility of the proposed scheme.And after we used an 8th order Butterworth lowpass to filterd signals, we can see that the signals becomes distinguishable and the pattern of motion can be seen.