Abstract: Missile motion information from an inertial measurement set and the angle-to-target information from a seeker/sensor is used to estimate range and/or time to go on a homing missile without a direct measurement of range or range rate. Up to six comparisons of spectrally matched linear and angular measurements, corrected by target state estimates and analytical coupling terms, are used to determine the error in the range estimate. A nonlinear sorting and filtering procedure rejects the unusable error sources among the six potential error sources, and thresholds against too little information. The stability margin in the missile guidance loop is used as a sensor indicator for excessive estimated range.

Abstract: A guidance system for directing a vehicle toward a target which includes a measurement processing section, a target state estimator, and a command processing section. The measurement processing section determines the inertial orientation and length of a line-of-sight vector which conceptually connects the vehicle with the target from measurements taken by a plurality of sensors. The target state estimator provides an estimation of the speed and angular aspect of the target relative to line-of-sight vector, by relating the vehicle and the target to each other through a mechanical conceptualization. This mechanical conceptualization treats the line-of-sight as a collapsible rod which is connected at one end through a mechanical gimbal set, and connected at the other end through a universal joint with four degrees of freedom. The command processing section generates command signals for the autopilot of the vehicle.

Abstract: A control system for thrust vector controlled (TVC) cruciform missiles having only pitch and yaw thrusters is disclosed wherein roll damping feedback signals are generated from bank angle data in a separate feedback loop with appropriate gain and compensation. Additional roll rate compensation is added to the missile pitch and yaw rate control subsystem by multiplying actual roll rate by pitch and yaw control deflections and inserting the resultant roll rate compensation command in the pitch and yaw rate error control loops. The addition of these two control feedback loops to the existing pitch and yaw thrust vector control system reduces roll rates caused by aerodynamic forces without the need for aerodynamic or reaction roll control means.