Estimation of helicopter and target motion for teh advanced attack helicopter fire control system

Abstract

The problem of estimating helicopter and target motion for the Advanced Attack Helicopter tire control system is formulated using the Kalman-Bucy one-step predictor. Dynamic models for the helicopter and target were developed based on point mass and correlated random accelerations. Observations include own-ship velocity and acceleration, range, line-of-sight (LOS) angles and rates. The estimation problem is formulated in moving LOS coordinates, where the dynamic models depend on the LOS rate vector, which is assumed noise-free and constant in the sampling interval. The 9-stage helicopter estimator is ommited and helicopter velocity and acceleration measurements are used directly in the evaluation of the target state estimator performance. A scenario-based simulation program and test data on ground vehicle motion are used in this evaluation. The effect of various error sources, including LOS rate gyro noise, is investigated and the miss distance is computed based on the predicted projectile impact point. It is shown that target state estimates perpendicular to the LOS, which affect the predicted future target position, are quite good ad opposed to the target estimates along the LOS.