Nonlinear guidance gain factor for guided missiles

Abstract

A system (10') for generating a missile guidance gain factor adapted for use with guided missiles. The inventive system includes a guidance control system (52) for obtaining current guidance parameters(55, 57) including ideal navigation gain, closing rate, line of sight rate, missile maneuverability, and missile velocity parameters. Software (56) running on a guidance control processor (54) computes a current guidance gain factor reflective of the current maneuverability of the missile from the guidance parameters (55, 57). In the illustrative embodiment, the system 10' further includes a nonlinear notch circuit (56) that generates an acceleration command (59) from the guidance parameters (55, 57) that varies in response to varying missile maneuverability parameters (57). The guidance control system (10') includes a conventional guidance law computation circuit (54, 55) and electromagnetic sensing equipment (52). An autopilot circuit (58) included in the system (10') provides the missile maneuverability parameters (57). In a specific embodiment, the nonlinear notch circuit (56) is implemented via software running on a guidance processor (54) which performs the following computation for generating the acceleration command (59): A.sub.new =G.sub.nl .times.A, where A.sub.new is the acceleration command (59), A is a pre-existing acceleration command (53), and G.sub.nl is the missile guidance gain factor of the present invention. The guidance gain factor is a function of the ratio of the measured line of sight rate with respect to the ideal line of sight rate maximum, and is tailored to existing missile characteristics and performance requirements.