Research And Design Of Automatically Returned Quad-rotor Aircraft Using Inertial Navigation Parameters

Quad-rotor aircraft is a kind of intelligent vehicles.It is composed of four distribution crossed propeller,and rely on the circuit board and mathematical algorithm to realize intelligent air flight.Four rotor aircraft has advantages of small volume,light weight,low cost,easy to control,can be used for hovering,vertical take-off and landing and low altitude flight.Therefore it is widely used in military,agriculture,fire patrol and etc.In recent years,It gets more and more people's favour.More and more colleges and technical workers devoted to the study of the four rotor aircraft and a large number of aircraft company appears at home and abroad.At present,with the control system improving and optimizing,other new requirements are put forward on the quad-rotor aircrafts.Aircrafts' automatic return is becoming one of the highlights in the aircraft for it can protect data,avoid damaga and loss.The current market and laboratory use satellite signal to record aircrafts' flight route.when it returning,according to the previous memory route to return.Considering in the complex environment,the satellite signal becomes weak or missing.So,in this design,explored a kind of automatic return method using inertial navigation parameters.Therefore,this article begin with the structure and the flying principle of the quad-rotor aircraft,then develop a set of aircraft flying control system and debugging successfully on the existing four rotor aircraft structure framework,Finally,design the method using navigation parameters to realize aircraft's automatic return and conduct experiments to prove the validity of the method.In the hardware system of the aircraft system,using microcomputer STM32F103 as main control chip,using a motion sensor MPU6050 obtain accelerated velocity and angular velocity and using the wireless module NRF24L01 to transfer data between the remote control and the aircraft.In the software system,using IIR filter and sliding window filter to smooth accelerated velocity and angular velocity,using the quaternion attitude algorithm to do the attitude algorithm and get the euler angle,using double loop PID to control the aircraft's flight,finally,realized the basic flight of aircraft.In the aircraft's automatic return system,using the method of strapdown inertial navigation and the inertial parameters which are get in the aircraft control system and then designed straight route return back method,right-angled line return back method and the square shape route return back method respectively using the design thought from simple to complex.And then conduct experiments to obtain the data in the process of fiying,using the data to veritify the automatic return method,finally,analysing the factors that affect this method's accuracy.In the end,explore the automatic return method for any route and select the appropriate parameters to do the confirmatory experiment.The results show that the method can preliminary achieve the aircraft' automatic return using inertial navigation parameters.To sum up,this article includes the development of quad-rotor aircraft flight control system and the realization of quad-rotor aircraft returns automatically using the method of attitude algorithm of quaternion and inertial navigation parameters.And this article provides a new method for quad-rotor aircraft returns automatically under the condition of the lack of satellite signal,which is also the innovation point of this article.