Research On Design Of MUAV’s AHRS Based On MPU6050

Attitude heading reference system provides real-time attitude heading information to UAV, which is an important component of flight control system of UAV. Due to the limitations of MUAV in its own load, power consumption, size and cost, MUAV’s AHRS is usually composed of the low cost MEMS inertial sensors and the strap-down inertial navigation technology, but its measurement accuracy is lower. Therefore, studying on the key issues in design of AHRS based on low cost MEMS inertial sensors, and the means to improve its accuracy have important value to the engineering application.It presents a thorough study of the key issues in design of MUAV’s AHRS based on inertial measurement unit MPU6050, which include the calibration method of inertial sensors, the temperature compensation method, the random error compensation algorithm, the attitude algorithm of UAV, etc. Main work includes:(1) It provides an overview of domestic and foreign status of AHRS of MUAV, and the application and development status of commercial MEMS inertial sensors. According to research content of it, experimental research and test platform is built for MUAV, which is based on the low cost inertial measurement unit MPU6050 and the microcontroller STM32F103TBU6.(2) It completed the software design of experimental research and test platform, which includes the data acquisition, the calibration test, the attitude test, the encapsulation and transmission of data frame, etc.(3) The random error compensation algorithm of MEMS sensor is analyzed in depth. Combined with the discrete Kalman filter algorithm, AR model can well compensate the random error. Simultaneously, the temperature compensation methods of the MEMS accelerometer output bias, scale factor and the MEMS gyroscope bias output are analyzed thoroughly in it.(4) Calibration algorithm for MEMS sensors is analyzed in depth. And according to characteristics of the inertial measurement unit MPU6050, the calibration mathematical models of the three axis accelerometers based on the 12 positions tumbling method and the three axis gyroscopes based on the 3 positions method are presented. And the relevant experimental tests were carried out, and the experimental results were good.(5) The basic principle of strap-down inertial navigation system is discussed in detail. It presents the analysis and comparison of the common attitude calculation algorithms. The four element method based complementary filter is designed to experiments, which include the static test and the dynamic test on experimental research and test platform, and the outdoor flight test experiment on UAV. Test results show that AHRS based on MPU6050 can meet measurement requirement of MUAV for pitch angle and roll angle.