The Design And Implementation Of Four-rotor Aircraft Attitude Control System

With the progress of science and technology strength, more and more unknown field is entered by human, sometimes people has to enter the dangerous area of the unknown and do some discovery. The four- rotor aircraft with high mobility and flexibility, can substitute for man to come into the dangerous area for high risk work. However, the four- rotor aircraft of a high performance becomes the biggest problem which is urgently needed to solve. Of course, it is much depends on the development of the MEMS technology. The hardware floating-point library Integrated in the DSP chip is utilized sufficiently in the development of control system which is based on DSP (Digital Signal Processor), and it will greatly improve the operation ability of the system and load capacity of system which is running.This thesis has designed a four- rotor aircraft system including a design of aircraft control panel which is based on DSP, and has developed the software including the study of inertial navigation algorithm and the realization of the control algorithm, which is based on the aircraft control panel.The whole system adopts software and hardware design method. Hardware:Compared with the popular four rotor aircraft design, it summarized a set of hardware solutions suitable for the requirements of the subject, and it designed an aircraft control panel by the Altium designer tool. Algorithm:Compared with the attitude algorithm including the quaternion, the Euler angle and the Rotation matrix, this topic chose the DCM (Direction Cosine Matrix) algorithm which is based on the Rotation matrix. This algorithm is a complementary filter, and it can calculate the accurate attitude angle data by the correction of the gyroscope drift error with the acceleration and the magnetometer. And then compared with the decoding algorithm based on gradient descent in terms of filtering effect. In the part of control algorithm, this topic did not build the aircraft dynamics model because of the nonlinear characteristics of aircraft model. This topic designed a parallel PID controller by the method of experimental debugging, and it has received good effect. In addition, in order to obtain the information of the aircraft in flight, this topic has realized the real-time display of spacecraft attitude by the design of the aircraft data display interface in the Lab VIEW tool.In the end, this thesis has verified the feasibility of design scheme and related algorithm of the four-rotor aircraft through the actual flight of aircraft, and has put forward the improvement direction and methods.