Research On Hovering Technology Based On ARM Eight-rotor

In recent years,with the development of micro-mechanics and micro-electronics technology,more and more scholars and companies have begun to engage in research in the field of multi-rotor UAVs.Compared with traditional fixed-wing UAVs,multi-rotor UAVs have the advantages of vertical lifting,hovering flying,lightweight body,small size,and low cost,and are used in military and civil and other related fields.Multi-rotor UAV operation is often an outdoor environment with variable conditions and complex terrain.Whether long-term suspension of stable flight is a very important parameter index for multi-rotor UAVs.This paper takes the eight-rotor as the research object,and conducts the following research on the problem of the eight-rotor hovering flight.Firstly,based on the analysis of the multi-rotor structure and principle,the dynamic modeling analysis and formula derivation for the characteristics of eight-rotor nonlinearity,strong coupling,under actuation,and multiple input and multiple output are established to establish a theoretical mathematical model and decouple the eight Rotary multi-input and multi-output mathematical expressions.The correlative analysis of the filter algorithm and the attitude calculation algorithm involved in the eight-rotor flight control system was done.The sensor data acquisition and data in the process of remote data reception involve related digital filtering.This paper analyzes the advantages of Kalman filtering algorithm in the attitude data filtering and makes detailed derivation and simulation tests.By analyzing the transformation matrix of the quaternion method between the geographic coordinate system and the body coordinate system,the matrix relational expression of the quaternion expression attitude angle is obtained.Then the eight-rotor flight control system hardware scheme is designed,including the central control unit,navigation system unit,power management unit,motor drive unit,command receiving unit and data interaction unit,and the hardware circuit design of each unit module is analyzed in detail.Through the PCB design,proofing,welding and debugging four stages to complete the flight control system hardware design.The control algorithm is the key to the flight control and hovering research.The traditional PID control algorithm,double closed-loop cascade PID control algorithm and RBF neural network algorithm are used to analyze and study.Combined with the eight-rotor mathematical model,the MATLAB tool is used to simulate the RBF neural network PID.The simulation and analysis of the control algorithm has a very good control effect.However,due to hardware limitations,the double closed-loop cascade PID control algorithm is eventually selected as the core control algorithm of the flight control system.Then design the overall program structure of the upper computer,according to the modular programming idea,the upper computer software is divided into several functional modules,the data communication protocol is analyzed in detail and the content of the protocol frame data is analyzed.Use C# programming language to complete the coding and debugging of each function module.Finally,the eight-rotor software and hardware system was commissioned for platform debugging and outdoor flight test.Combine with the upper computer software and debugging platform to complete the eight-rotor ground debugging work;outdoor experimental testing mainly tests its outdoor low altitude hovering,high altitude hovering,one-click takeoff and landing hovering performance.Experimental tests show that the design meets the expected requirements and the eight-rotor hovering technology is completed.