Study Of Assistant Location System For Small Unmanned Aerial Vehicle

The Small Unmanned Aerial Vehicle(SUAV)has the advantage of small size,light weight,low cost and high cost performance and so on.These advantages make it has been widely used in military and civil field.Take the civil field as an example,bridge detection,aerial photography,geological and geomorphological mapping,forest fire prevention,seismic survey and other fields has its figure.At present,the main navigation mode of SUAV is Global Positioning System(GPS),but in practical application,unmanned aerial vehicle may enter bridges,urban areas,dense forests,tunnels and other areas easy to lose GPS signals in flight.When the effective satellite information received by the GPS receiver is blocked,in other words,there are less than 4 satellites,the GPS will lose its lock,which will affect the normal operation of the SUAV.Therefore,the research on autonomous navigation of SUAV under the environment without GPS signal,and improve the reliability of autonomous navigation and positioning of SUAV,it has a good application prospect.Inertial navigation positioning system is a kind of independent positioning method that does not rely on external materials,but completely rely on the sensors carried by itself to collect information.It mainly use inherent inertia to calculate the position of the carrier.Position,speed and attitude information can be provided continuously,and the momentary accuracy is high.Traditional inertial navigation devices are huge,expensive and impractical.With the development of micro-electromechanical systems(MEMS),MEMS sensors become a new choice for inertial devices because of their small size,light weight,low price and high reliability.In this paper,micro inertial navigation and positioning system is adopted to solve the problem of autonomous navigation and positioning of SUAV under condition that the GPS signals was lost,the specific research content are shown below:First,this paper introduces the fundamental principle of inertial navigation,the initial alignment and attitude algorithm;Aiming at the characteristics of micro inertial navigation system and the requirements of experimental environment,the device selection of micro inertial navigation system is analyzed,and made plan for micro inertial navigation and positioning system.Second,according to the mathematical models of gyroscope and accelerometer,the two main components in inertial navigation module,and in the MATLAB software environment,the inertial sensor module used in this paper is modified by kalman filter.and adding the white gaussian noise to the simulation to form the object's three dimensional motion trajectory,using the Zero Velocity Update(ZUPT)to correct the collected data,using the Quaternion method to calculate the attitude,and the trajectory show that the trajectory after kalman filter and zero velocity correction basically coincides with the set trajectory.The feasibility of the system design in this paper is demonstrated by the simulation results of the system,which lays a theoretical foundation for the design of the micro inertial navigation positioning system.Again,using STM32F103 chip as the core control component,MPU9255 micro inertial sensor module as the measurement module,radio frequency module as the wireless transmission,design and realize the micro inertial navigation and positioning system based on STM32F103 in the development environment of Altium Designer.This system can output the longitude,latitude and height information of the carrier in the 3d space in real time.Finally,the experimental results of the micro-inertial navigation and positioning system show that in the 100s,the attitude angle error of the system is within10~°,and the position error is within 30m.The system has a high short-term accuracy,which can meet the requirement of high instantaneous accuracy of the navigation system with medium and low precision.And the system has strong autonomy,which meet the requirements of the detection system for real-time position information,thus proving the effectiveness of the micro inertial navigation and positioning system.