Research Of Micro UAV Flight Control System Based On MEMS Sensors

Micro unmanned aerial vehicle(UAV)has lots of advantages: low cost,low power consumption,high mobility,and high concealment and so on.In recent years,they have developed rapidly in many fields and played a more important role in many emerging application fields.They are stepping up their research and development on drones,hoping to capture the market of micro drones as soon as possible.Therefore,in order to realize the low-cost and practical micro-UAV flight system in the paper,the micro-UAV flight control system based on MEMS sensor is designed from four aspects,namely the filter of MEMS sensor,attitude fusion algorithm,hardware system and software system,so as to make the whole system stable.Firstly,the error of MEMS sensor is analyzed for the problem of severe drift of low-cost MEMS sensor.Secondly,the data collected by MEMS sensor is analyzed and filtered.The sensor zero offset and noise interference are reduced,avoiding the accumulation of flight control system errors caused by sensor errors and ensuring the stability and accuracy of the sensors' output data.Aiming at the problems in the practical application of the micro-UAV flight system,such as excessive calculation,inconsistent sensor data fusion time,and co-variation matrix divergence in the operation process,the Extended Kalman Filter(EKF)attitude fusion algorithm based on triple optimization method is proposed in the paper,that is,adding data validation and error judgment at the input of EKF,adding output correction filter to the output of EKF,and optimizing the calculation in EKF prediction update.Then the algorithm simulation experiment is carried out in this paper,and the experimental result shows that the optimization method has good robustness and real-time performance for UAV flight.The triple optimization method reduces the computational complexity,especially for the unmanned aerial vehicle attitude solution based on embedded microprocessor.There is a good suppression effect on the noise and interference of the flight control system,making the low-cost micro UAV more operable in practical applications.In the paper,the hardware system and software system of the micro UAV system are designed.First of all,the redundant design idea is adopted to realize the UAV hardware system as a whole.The information acquisition circuit is designed by using dual accelerometers,dual gyroscopes and dual magnetometers.The sensors are divided into two groups according to their functions,which improves the safety of the hardware system.the anti-interference ability of the hardware circuit is improved by adopting the four-tier Printed Circuit Board(PCB)design.The software of UAV flight system is realized based on the Nutt X embedded system,which is modularized.The EKF attitude fusion algorithm based on the triple optimization method is used to perform attitude estimation and the attitude control is performed by the cascade PID(proportional-integral-derivative)controller,achieving the accurate attitude calculation and attitude control functions successfully.Finally,the micro-UAV aircraft is successfully built and outdoor flight experiment is carried out.The hovering,climbing and other action are completed by manipulating the UAV,which verified the robustness and operability of the entire UAV flight system.