The Altitude Hold Algorithm of UAV Based on Millimeter Wave Radar Sensors

In order to make the unmanned air vehicle(UAV) in the flight process to better complete the altitude control, and can perform more accurate tasks. This paper presents the altitude control based on Millimeter Wave Radar sensors, and combined with the Pixhawk (The flight controller of UAVs) design altitude hold algorithm. The main idea is to transmit the sensor's measurement data to the Pixhawk via the serial port and to fuse with the predictor of the accelerometer. At the same time, the telecontroller switch into Altitude Hold Mode (It is a mode that can make the UAV keep a fixed altitude flight). The UAV will be keeping the target altitude which is set in the program. Finally, compared with the data collected by the Vicon (Motion capture system), to verify the effect of the algorithm. The experimental results show that the Millimeter Wave Radar sensors accuracy meet the demand of subject, and the UAV flight is very stable.