Research On Heading Measurement Technology Of Small UAV

In recent years,unmanned aerial vehicle,which can simply be called UAV,are gradually developing towards miniaturization,intelligence,integration,low cost,and low power consumption,and their applications in military,civilian,and has been widely used in various fields.When a small UAV is flying in the air,due to its structural characteristics,it is greatly affected by airflow and wind speed.As the main source of UAV navigation parameter information,heading measurement system is the basic component of UAV to achieve smooth flight.According to the characteristics of small unmanned aerial vehicles and the demand for heading measurement systems,this subject conducts research on small unmanned aerial vehicles' heading measurement system.At this stage,it is difficult for small UAV to use high-precision and bulky highprecision inertial navigation equipment,and MEMS inertial devices that meet the requirements of small UAV cannot autonomously seek north and it is difficult to achieve the desired accuracy.In order to solve the above problems,this subject used the geomagnetic field for magnetic heading measurement.Magnetic field measurement was performed using the magnetoresistive sensor HMC1053,and attitude compensation was performed using the gyroscope and accelerometer assembly MPU6050.In order to reduce the influence of attitude angle error on the accuracy of magnetic heading measurement,this subject proposed a complementary filtering parameter optimization method based on a combination of digital simulation and static test,which improved the accuracy of attitude angle measurement based on complementary filtering of gyroscope and accelerometer.In order to solve the problem that the magnetic sensor was easily interfered by the sensor itself and the external magnetic field environment in the actual working environment,resulting in a reduction in the measurement accuracy of the magnetic heading angle,this subject proposed a joint calibration method for magnetic heading errors based on ellipsoid fitting self-calibration and satellite direction finding information fusion.On the one hand,it used the ellipsoid fitting algorithm to calibrate the output data of the magnetic sensor.On the other hand,it used satellite direction finding information fusion technology to externally compensate and calibrate the heading measurement system.Based on the overall system design and algorithm research,this subject carried out embedded hardware design and software development,and developed a prototype of the heading measurement system to meet the application of small UAV.Using ellipsoid fitting self-calibration and satellite direction finding information fusion technology,the effective compensation of the magnetic heading measurement error was achieved,and the RMSE of the magnetic heading after calibration is 1.06°,which verified the feasibility of the system and the effectiveness of the compensation algorithm.The heading measurement system developed by this subje ct can achieve high-reliability performance requirements for a long time,which greatly improved the heading measurement accuracy and system robustness of small UAV in different working environments.