Quadrotor Aircraft Flight Control Board Design And Robust Control Of The Attitude Control Application

Four rotor aircraft is a kind of symmetrical distributed by four rotor consisting of an aircraft, since it has vertical take-off and landing, hover, the characteristics of simple structure, which makes the four rotor aircraft began nearly a decade since 2005,one of the most rapid development. Four rotor has four control input, six control output(state), four rotor is underactuated system, therefore, the system also has the characteristics of highly coupled, is more complex, so the system modeling and is difficult to model processing and controller design.This paper studied the domestic and foreign research present situation,discovered four rotor is the core of the controller, a four rotor without controller is unable to control, so the four rotor controller design is the focus of this article. Based on a small four rotor flying object, the controller design of rotor on the to do the research. This article will first flight control need to complete the task of division,according to the division of tasks selected the ARM kernel STM32F103 MCU(micro control processor). Choose MPU6050 sensor acquisition of XYZ triaxial acceleration and Angle acceleration, barometer 5883 l acquisition vehicle height information.According to each IC device Datasheet, it is not difficult to draw the flight control principle diagram, due to the flight control system to realize the function is not very complex, PCB line is relatively simple, consider the cost reason, flight control PCB board is made of two layers of plate structure.To the design of the controller, most of them are designed based on the accurate mathematical model, this paper first work is to establish the mathematical model of the rotor four, according to the Newton- euler’s theorem in the inertial coordinate system(geodetic coordinate system), set up the differential equations of differential equations of force and moment, and transform it into the body coordinate system,because the euler Angle sensor is expressed in the body coordinate system, now under the body coordinate system of differential equations are obtained. As the coordinate system transformation using the matrix representation method, because for any two different coordinate system, three rotary Angle respectively, can transform a coordinate system to another coordinate system, the matrix of the geodetic coordinate system to the body coordinate system conversion in accordance with the yaw, pitch and roll in order to find the transformation matrix of transformation, so that you canavoid when expressing roll Angle to singular point. In trigonometric functions contained in the equation and the second item, such as nonlinear expression, and by using the differential equation of small perturbation theory approximation, give high order under infinite amount, to get a first order linear differential equation. In the balance of movement and can be divided into horizontal and vertical movement, so the differential equation is divided into lateral movement differential equation and differential equation of longitudinal motion.Because of uncertainty factors in the practical environment, the other in the process of modeling also will produce the error, in this case the design of the controller in the ideal model simulation shows very good performance, but in the actual may be related to the simulation of flight control and debugging appear large deviation. For the design of the controller in this paper, the robust controller design method, main is not solve the problem of craft of anti-interference, robust controller design thought is in the worst case is to ensure the stability of the system, so this kind of controller is not optimal controller, but its practicability is strong. In the state space of linearized suboptimal method to design controller, the design of the controller into nonlinear model verification, using this method to the stand or fall of simulation can well demonstrate the controller.