Research On The Algorithm For Flight Control System Of Quadrotor

MAV(Micro Aerial Vehicle)has small volume and it can realize autonomous flight in the air.These characteristics make it able to complete the specified tasks under certain conditions,making it in military,medical,investigation of surveying and mapping,geological exploration and other fields has been widely used.Compared with other ordinary plane,mechanical structure of the MAV is relatively simple,and the characteristics of low power consumption,easy operation and easy maintenance make it more advantages,so it caused a keen attention in various industries and become a hot research topic.However,the quadrotor is a under-actuated nonlinear systems with four inputs and six outputs,and it has strong coupling between the control volume,its complexity indicate that the necessity of research control system to achieve the goal of a stable flight.This article revolves around flight control system of quadrotor,including hardware and software system configuration,mathematical modeling,the design of flight control system under different control algorithms and the comparison and analysis for experimental results.First of all,mathematical modeling,namely flying system dynamics equation,has been built through the analysis of structures of quadrotor and its physical property.In the process of modeling,Newton-Euler equation and basic content of aerodynamics have been used,in order to analyze the relationship of body structure and its movement better from physics.Then it is about the configuration of hardware and software system.The hardware experiment system designed in this article consisted by micro controller,ultrasonic ranging module,remote control,wireless receiver,electronic governor,motor parts and etc.Software configuration and programming is under the environment of Keil by using C language to implement the function of each module.Due to microcontroller used in this research is a chip that has a kernel based on ARM Cortex-M3 series,development of software environment mainly use the application function as a starting point,this paper is to expound the flight systems software configuration of each part from the angle of the embedded system.The main content of this research is to study the performance of the flight systems of quadrotor for stability problem in the process of flying under different control algorithms.Aiming at the problems of the aircraft during the process of flight,in this paper,the flight control system under the control of the traditional PID,sliding mode variable structure control algorithm and the fuzzy PID hybrid algorithm were studied respectively.Because the quadrotor is an under-actuated system that has six degrees of freedom on the space,but it has only four degrees of freedom of control inputs.We can realize the position control of flight system through the direct control of aircraft space coordinate system linear displacement on the x,y,z and yaw angle ?,thereby to control the roll angle ? and pitching angle ? indirectly.The results indicated that by comparing with the traditional PID control,using fuzzy adaptive PID hybrid control and sliding mode variable structure control system receive better robustness,and improve the performance of stability of the body in the process of flight.