Bae Systems Information and Electronic Systems Integration Inc.

Quang M Lam

Michael J Choiniere

Ira B Ekhaus

David Anthony Richards

Jason T Stockwell

George M Horihan

Egor V Degtiarev

Ned B Thammakhoune

Ryan P Carney

The system and method of projectile flight management using a combination of radio frequency orthogonal interferometry for the long range navigation and guidance of one or more projectiles that does not need to be accurate all the way to the ground based on the use of larger artillery. The system provides for more accurate targeting, especially in GPS-denied and GPS-limited environments.

Grid munition pattern utilizing orthogonal interferometry reference frame and range radio frequency code determination

The system and method of projectile flight management using a combination of radio frequency orthogonal interferometry for the long range navigation and guidance of one or more projectiles and a short range navigation and guidance system to provide for more accurate targeting, especially in GPS-denied and GPS-limited environments.

Radio frequency/orthogonal interferometry projectile flight management to terminal guidance with electro-optical handoff

The system and method of projectile flight management using a combination of radio frequency orthogonal interferometry for the long range navigation and guidance of one or more projectiles and a short range navigation and guidance system to provide for more accurate targeting.

Orthogonal interferometry artillery guidance and navigation

The dual mode INS high performance system using an IMM mixing method presented in this disclosure utilizes a MEMS-based IMU as the inertial sensor due, in part, to low cost and low power consumption. A dual filtering system, one with fifteen state EKF and the other with twenty one state EKF is mixed in real-time to address dynamic overlapping and continuous transition from a low dynamic mode to a high dynamic mode. The IMM estimation scheme is employed to compute the real-time mixing coefficients via the IMM probability mixing formulation. The present disclosure is applicable to earth to orbit platforms, spinning projectiles, and the like to successfully reconstruct the object's state estimate vector even under a high angular rate and high g operating environment.

High performance dual mode mixing inertial navigation system

An integrated architecture and its associated sensors and processing software subsystems are defined and developed allowing a conventional unguided bullet to be transformed into a guided bullet without the use of an on-board inertial measurement unit (IMU). Some important SW components of the present disclosure include a target state estimator (TSE); a bullet state estimator (BSE); Multi-Object Tracking and Data Association; NTS GL; and a Data Link. Pre-conversion of two angles and range information of an OI sensor from spherical coordinates into Cartesian coordinates eliminates the Jacobian dependency in the H matrix for the BSE, thus increasing the miss distance performance accuracy of the bullet target engagement system.

IMUless flight control system

The system and method for EO/IR and RF sensor fusion and tracking using a dual extended Kalman filter (EKF) system provides a dynamic mixing scheme leveraging the strength of each individual sensor to adaptively combine both sensors' measurements and dynamically mix them based on the actual relative geometries between the sensors and objects of interest. In some cases the objects are adversarial targets and other times they are assets.

EOIR and RF sensors fusion and tracking using a dual EKFs system

Radio frequency / orthogonal interferometry projectile flight navigation

An angle only (AO) target state estimation (TSE) system and method using a mixed coordinate system (Modified Spherical Coordinate (MSC) and Reference Cartesian Coordinate (RCC)) as an integrated system. This integrated system is achieved due to the state vector information of two frames (RCC and MSC) is effectively preserved between processing cycles and state vector transformation steps. The AO TSE architecture and processing schemes are applicable to a wide class of passive sensors. The mixed coordinate system provides robust real-time slant range estimation in a bootstrap fashion, thus turning passive AO measurements into equivalent active sensor measurements with built-in recursive range information but with greatly improved the TSE accuracy meeting the miss distance required by many engagement missions.

Angle only target tracking solution using a built-in range estimation

A method and system for nonlinear trajectory shaping guidance law capable of providing a robust guidance solution suitable for multi-mission, multi-mode operations. The nonlinear trajectory shaping guidance law offers (1) a dual layered GL gains calculation: (i) NTS time varying adjustment accounting for engine on/off and L/D variation and (ii) general explicit guidance algorithm based sub-optimal fixed-gain selection while still maintaining its trajectory shaping capability for short range to go missions; (2) flight path angle (FPA) command tracking and following to ensure a high probability of target destruction while minimizing collateral damages; (3) high precision impact point calculation factoring in target location errors or motion and maneuvering uncertainties; and (4) heading error angle minimization.

Multi-mode adaptive nonlinear trajectory shaping (NTS) guidance law

The system and method of dynamic weapon to target assignment (DWTA) using a control based methodology to dynamically assign each projectile to a target in a multiple target engagement situation. In some cases, closest proximity is used in a real-time, to accomplish the DWTA functional requirement and performance criteria. In some cases, g pulling acceleration and projectile fin deflection motion are also used to assess the best matched pair for each projectile and each target with an end goal of intercepting the target or guiding the projectile to an acceptable error basket for target destruction via detonation. For the closest distance criterion for projectile/target pairing, a cutoff time is used to ensure the pairing is conducted within an acceptable duration while still being able to intercept the target or meet a required miss distance basket (e.g., &#x3c;3 m).

Dynamic weapon to target assignment using a control based methodology

Poor BSE estimation accuracy resulting from conventional Extended Kalman Filtering (EKF) approaches using RF OI sensors mounted on the ground as a remote bullet tracking sensor motivated the design and development of the present disclosure. The observer based BSE removes EKF process noise (state noise) and measurement noise (OI sensor noise) covariance matrices selection and tuning which have been long recognized by the estimation community as a time consuming process during the design stage; requires no consideration of interactions when having the control input signal as part of the state propagation equation; and provides a significant improvement in velocity estimation accuracy, in some cases to less than 1 m/s errors in all axes, thereby meeting the miss distance requirement with amble margin.

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Fairfax Station, VA, United States of America

Quang M Lam