System model of a UAV and sensor package for the measurement of sea ice freeboard, roughness, and topography.

摘要

The problem of measuring freeboard sea ice roughness and topography using a UAV and sensor package was modeled. The sensor package consists of a laser altimeter, IMU (Inertial Measurement Unit), and GPS sensor. The geometry and relevant equations for the system were developed to characterize the relationship between the sensor platform (aircraft) and the reference coordinate frame on Earth's surface.; A full 6DOF model for the Aerosonde UAV platform was developed using x-plane software by laminar research. This software utilizes the blade element theory to model the dynamic behavior of the aircraft, and required a full 3D model to be constructed with the proper geometries, weights and balances, and power of the Aerosonde UAV aircraft. An additional 6DOF model for the Aerosonde created in Simulink using flight control derivatives was obtained from the Aerosonde Company.; The two IMUs (Inertial Motion Units) from Microstrain(TM) are considered for determining the attitude of the UAV. The 3DM and 3DM-G Microstrain(TM) IMU sensors were tested statically and dynamically to determine their accuracy, variance, bandwidth, and bias. The dynamic IMU sensor testing was completed through the use of a driven rocker platform that was developed and construction specifically for testing the IMUs. The characteristics of each IMU obtained through testing were used to develop sensor simulations in Simulink. Additional sensor simulations for the GPS receiver, and the laser altimeter were also created.; A total system model of the UAV and sensor package was developed by combining the output from the aircraft simulators with the sensor package simulator and a simple flat surface model. Simulated flights over the flat surface were conducted and the error in the final solution attributed to the IMU sensor was determined. The error attributable to the tested 3DM-G IMU sensor at a flying height of 100 m is 1.2631e-2 cm with a standard deviation of 0.29 cm.