Guided missile subsystem
First Claim
1. A missile guidance subsystem disposed onboard a missile and operative during the flight of said missile to cooperate in guiding said missile to the location of a target, said missile guidance subsystem comprising:
- a radar including an antenna system, a front end, and a signal processor, said antenna system governed by beam steering commands to maintain the beam pattern of said radar antenna on said target location, said front end for receiving radar echo signals within said beam pattern and conditioning said radar echo signals for processing by said signal processor, said signal processor for deriving true radar measurements of said missile kinematics in relation to said target kinematics from said conditioned radar echo signals;
control means governed by a set of maneuver commands to control said missile kinematics;
an inertial measuring unit for generating signals corresponding to the acceleration of said guided missile in accordance with predetermined spatial coordinates;
means for integrating said acceleration signals of said inertial measuring unit to generate estimates of the relative kinematics of said missile and target in accordance with said spatial coordinates;
means for converting said estimates of the relative kinematics into a priori estimates of radar measurements of said missile and target relative kinematics, and into beam steering commands for said radar antenna system, said signal processor operative to compute signals representative of the differences between corresponding estimated and true radar measurements;
filtering means for deriving error signals based on an estimating function of said computed radar measurement difference signals, said integrating means operative to generate intermediate relative kinematics estimates according to said spatial coordinates in the integration process thereof, said error signals derived in accordance with said spatial coordinates for correcting corresponding intermediate relative kinematics estimates of said integrating means to render said relative kinemaic estimates; and
means for generating said set of maneuver commands based on a control law function of said relative kinematics estimates.
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Accused Products
Abstract
A guided missile subsystem including a Kalmanized radar track loop driven by acceleration signals of the missile generated by an inertial measuring unit (IMU), and a missile control loop driven by estimates of the relative kinematics of the missile and target computed by the radar track loop is disclosed. The IMU driven Kalmanized radar track loop accommodates the use of a high performance radar, like a synthetic aperture radar, for example, which operates to measure radar data at a low rate on the order of 1 Hz, to generate estimates of relative target and missile kinematics to drive the control loop at rates compatible with high performance missile kinematics. The Kalmanized track loop effects an exchange of IMU errors for "dynamic lag" errors of conventional track loops which cannot be modeled very well, and can change very rapidly. In contrast, the IMU errors can be modeled well, and in addition change very slowly which is what permits the Kalmanization function to work well in the track loop at reduced rates. Because of the dynamic exactness of the track loop, very good estimates of the relative kinematics of the missile may be supplied to the control loop to effect more accurate computations of maneuver commands which drive the controls of the missile. Moreover, the Kalmanized track loop does not let large amounts of angle glint noise into the control loop prior to missile impact. An effective bandwidth decrease as glint noise increases is provided without incurring a dynamic lag error penalty.
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Citations
16 Claims
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1. A missile guidance subsystem disposed onboard a missile and operative during the flight of said missile to cooperate in guiding said missile to the location of a target, said missile guidance subsystem comprising:
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a radar including an antenna system, a front end, and a signal processor, said antenna system governed by beam steering commands to maintain the beam pattern of said radar antenna on said target location, said front end for receiving radar echo signals within said beam pattern and conditioning said radar echo signals for processing by said signal processor, said signal processor for deriving true radar measurements of said missile kinematics in relation to said target kinematics from said conditioned radar echo signals; control means governed by a set of maneuver commands to control said missile kinematics; an inertial measuring unit for generating signals corresponding to the acceleration of said guided missile in accordance with predetermined spatial coordinates; means for integrating said acceleration signals of said inertial measuring unit to generate estimates of the relative kinematics of said missile and target in accordance with said spatial coordinates; means for converting said estimates of the relative kinematics into a priori estimates of radar measurements of said missile and target relative kinematics, and into beam steering commands for said radar antenna system, said signal processor operative to compute signals representative of the differences between corresponding estimated and true radar measurements; filtering means for deriving error signals based on an estimating function of said computed radar measurement difference signals, said integrating means operative to generate intermediate relative kinematics estimates according to said spatial coordinates in the integration process thereof, said error signals derived in accordance with said spatial coordinates for correcting corresponding intermediate relative kinematics estimates of said integrating means to render said relative kinemaic estimates; and means for generating said set of maneuver commands based on a control law function of said relative kinematics estimates. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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Specification