Research On Embedded Flight Control System For Tilt-rotor Unmanned Aerial Vehicle

Vertical Take-Off and Landing(VTOL)technology is gradually becoming an important focus in the development of unmanned aerial vehicles(UAV).One representative type is tilt-rotor aircraft,which combines the advantages of rotor drones and fixed wing drones.It not only solves the problems of slow forward flight speed,short range,and short duration of traditional rotor drones,but also makes up for the shortcomings of traditional fixed wing drones that cannot take off,land,and hover at fixed points.This article takes the tilt-rotor unmanned aerial vehicle as the research object,conducts research on its embedded control system,in order to stably and reliably control it to work according to the predetermined plan.The research content of this article mainly consists of the following parts:(1)The composition and working principle of tilt-rotor UAV are studied.Based on this,the force analysis is carried out,and the six degrees of freedom mathematical model of tilt-rotor UAV is constructed by combining the common coordinate system of UAV and its transformation relationship,which provides preparation conditions for simulation and test verification;(2)Design a control scheme for tilt-rotor unmanned aerial vehicles based on the classic PID controller,combining the control principles of multi rotor and fixed wing.Develop hardware for the tilt rotor unmanned aerial vehicle control system,and use Qt design to develop ground station software for tilt rotor unmanned aerial vehicles.Build a simulation environment under Matlab,connect Pixhawk4 flight control and computer for Hardware-in-the-loop simulation simulation,and verify the rationality of the control scheme;(3)The hardware functions,especially communication functions,of the flight control system were tested using CCS(Code Composer Studio),and the test results met expectations and communication was stable.Using ground station software for ground testing,achieving interactive communication between the ground station and the flight control board,achieving direct control of equipment by the ground station,and recording test data;(4)Finally,the control scheme was further validated through actual flight tests.The control system developed in this paper can realize the stable control of attitude and altitude of tilt rotor UAV in quad-rotor mode,transition mode and fixed wing mode.The deviation between the attitude angle and flight altitude of the flight control system in the quad-rotor mode and the input control quantity is small,the switching between the quad-rotor and fixed wing modes is smooth and stable in the transition mode,and the smooth turning and cruise flight of the tilt rotor UAV are realized in the fixed wing mode.The control system is stable and reliable,with certain feasibility and application value.