An Affordable Rugged Inertial-Based Navigation System for Highly Accurate Position and Attitude Estimation Without the Use of GPS

Impact Technologies, in collaboration with the Rochester Institute of Technology, Virginia Tech and the Boeing Company, proposes to develop and demonstrate a rugged, GPS-independent, miniature, low-power and light-weight device that provides highly accurate position and attitude measurements for USV operations in harsh marine environments encompassing highly dynamic maneuvers and vibrational effects. In contrast to the conventional GPS-dependent devices, our device implements an Unscented Kalman Filter-based three-dimensional position and attitude estimator that makes use of low-cost sensors such as accelerometers and rate gyros. The key innovation is to identify the local gravitational position in real-time and use it to bound sensor drift errors to achieve highly accurate state estimation. The objective is achieved by a unique hardware design that combines a dual-arc accelerometer array with three-axis rate gyros and optional heading sensors. High vibration effects are estimated and eliminated by subtracting the imposed loading from the accelerometer measurements to provide a highly robust system. Preliminary simulation studies have demonstrated a position estimation accuracy that exceeds Navy"s requirements (<0.5 nmi/hr drift rate). While Phase I will focus on proof-of-concept software-in-the-loop demonstration, a hardware prototype will be fabricated, tested on Virginia Tech"s USV platform and delivered to Navy in Phase II.