Position Estimation for Projectiles Using Low-Cost Sensors and Flight Dynamics.

Navigation of gun-launched precision munitions using affordable technologies is investigated. Estimation algorithms were developed to blend flight dynamic models with measurements from inertial sensors. The launch and flight characteristics of the unique, gun-launched environment were exploited both in the state estimator and for novel heuristic parameter identification. Using the heuristic parameter, the inertial navigation system was calibrated without a global positioning system (GPS), and its performance was compared with a similar calibration performed with a GPS. The experimental results from guided mortar flights indicate that the algorithm with only inertial sensor measurements yields position errors of less than 40 m over a 30-s flight. Trade studies were conducted in simulation to assess algorithm performance over a wider range of conditions such as variation in the flight dynamic model parameters. These results demonstrate that position errors are less than tens of meters for flight times of interest to munitions. Estimation is tolerant to inertial sensor errors because of the novel manner in which known flight dynamics are used to compensate measurements. Overall, this effort shows that navigation error resulting from a low-throughput algorithm using affordable inertial sensors is sufficient to increase system accuracy for munitions in GPS-denied environments. [ABSTRACT FROM AUTHOR]