Intent of Study on the Use of a Dual Airborne Laser Scanner (ALS) in Conjunction with a Tactical Grade Inertial Measurement Unit (IMU) for Unmanned Aerial Vehicle (UAV) Navigation and Mapping in Unknown, Non-Global Positioning System (GPS), Environments

摘要

The goal of our AFOSR proposal was to study the feasibility, characteristics and limitations of using two Airborne Laser Scanners (ALS) mounted on an Uninhabited Airborne Vehicle (UAV) to aid its Inertial Measurement Unit (IMU) in unknown terrain environments. One area of interest to AFRL is the ability to navigate in GPS-denied environments where prior information about the terrain the UAV is traversing, is unknown. Conventional TRN schemes are inadequate since they all require prior terrain information in the form of a terrain elevation database. Ohio University's proposed concept of using Dual Airborne Laser Scanner (Dual ALS) meets the requirement of not needing prior terrain information. Conceptually similar to an Inertial Navigator, Dual ALS is a dead-reckoning system that keeps track of a vehicle's position state changes over time, since initialization. The Dual ALS error states can then be used to correct or reset the IMU states, thus effectively constraining its drift error. Simulation results provided in this final report demonstrate that the concept works extremely well with residual horizontal drift errors of magnitudes as small as 60 meters per hour.