The research of hardware-in-the-loop simulation on the Double-module Altimeter of Unmanned Aerial Vehicle(UAV)

It is a new experience to apply constant slip frequency scheme and constant period scheme to one frequency modulation radio altimeter for height measurement. A brief introduction of the height measurement of UAVpsila double-module altimeter is given first, and then mathematic model of the whole system is developed then. Finally, hardware-in-the-loop simulation system based on RS422 is builded, and the height measuring simulation data can be changed with delayed time. RF dealy line method and the RF reflection method are applied through the whole height measurement simulation experiments, By the experiments, the critical switching height of double-module altimeter of UAV is finded, and his switching height can supply precise height data for the UAVpsila automatical land system.From the height measuring principle and test result, the measuring data is accuracy and stable.