Showing papers on "Air-to-air missile published in 1984"

Target acceleration modeling for tactical missile guidance

Abstract: For future short-range air-to-air missile concepts, it has been demonstrated that linear optimal guidance laws provide significant performance improvements over proportional navigation guidance laws. This paper addresses the critical problem of estimating the missile-to-target position, velocity, and acceleration (required by the linear optimal guidance law) when only passive (angle only) seeker information is available onboard a highly maneuverable bank-to-turn missile concept. More specifically, the problem is how to model the target acceleration to achieve improved missile performance. Four target acceleration models coupled with an extended Kalman filter are presented and evaluated on a six-degree-of-freedom missile simulation to determine their estimation effectiveness and their influence on missile guidance.

Adaptive noise estimation for homing missiles

Abstract: The presence of a microprocessor makes it possible to utilize a digital filter to process the measurement data and obtain a state estimate to be used in a digital guidance system for tactical homing missiles. Of particular interest is the case of the short-range, air-to-air missile against a highly maneuverable target when angle-only measurements are available. A standard filter for processing the measurements is the extended Kalman filter, the performance of which depends on the value selected for the measurement covariance. It is shown that the performance of this filter can be improved by estimating the,measurement covariance. Two methods for doing so are investigated: the limited-memory and the weighted limited-memory.

Air-to-air missile guidance for strapdown seekers

Abstract: This paper presents results of a study on advanced guidance for short range air-to-air BTT missiles using an active strapdown seeker. The guidance laws, based on modern control theory, utilize an Extended Kalman Filter (EKF) and a Pursuit plus Proportional Navigation type law for autopilot command generation. The nine state EKF estimates relative position, relative velocity and seeker scale factor errors. Low frequency glint is studied in detail and both software and hard-ware solutions to reducing the effect of glint noise are proposed. Other topics considered are: (i) the effect of different coordinate systems on EKF performance, and (ii) robustness of the guidance law with and without the target acceleration term. Detailed sensitivity and performance analyses are performed with respect to all the sources of errors (gyro, accelerometer, seeker, initial conditions, filter parameters) against constant g and 'smart targets. The results show that a modern control theory approach using EKF for on line estimation of scale factor errors is essential for satisfactory guidance loop performance using strapdown seekers.

Missile system for naval use

Abstract: In combination: a system operative to cause an airborne missile to track and impact a point in the wake of a marine vessel in motion; and apparatus for modifying the course of the missile in accordance with the length, velocity and wake formation time constant of the vessel.

Missile for weapon system

Abstract: In a weapon system, a missile 12 having the shape of a cylindrical can is fired on a target. The missile 12 carries a projectile 24 which, when a target is detected, is fired downwards from the bottom of the overflying missile. A movement of rotation is imparted to the missile in order to stabilise its flight and a movement of lateral precession is imparted to the missile along the trajectory. The projectile forms a lower concave end of the missile and is fired by an explosive charge 18.