Optimal Division of the Roll Angle Gyroscope Encoder for the Antitank Missile

Miodrag Ćurčin

 

A formula for the estimate of the standard deviation of the missile roll rate in the buster phase is derived for an antitank line of sight-guided missiles where the free gyroscope is used to measure the roll angle and roll rate is determined by “two-point differencing”. Taking into account process noise (model uncertainty) an expression for the optimal division of the free gyro encoder (optimal number of information on roll angle per revolution) is obtained. By numerical simulation of a complete system of equations of missile motion and guidance and control system, the estimate of the standard deviations of the coordinates from the line of sight is determined by using the Monte-Carlo simulation technique. The estimation of the roll rate and the roll angular acceleration by the Kalman filter is included optionally in the model. The influence of the division of free gyro encoder on maximal values of the estimate of the standard deviation of coordinates is determined by numerical simulation and its optimal value is found in order to obtain minimum of the standard deviation estimate.

Key words: anti-tank missile, guided missile, roll rate, angular rate, encoder, Kalman filter, free gyro, pulse width modulation, finite difference method, numerical simulation.