Methods involve using a guided munition (e.g., a mortar round or a grenade) that utilizes deployable flow effectors, activatable flow effectors and/or active flow control devices to extend the range and enhance the precision of traditional unguided munitions without increasing the charge needed for launch. Sensors such as accelerometers, magnetometers, IR sensors, rate gyros, and motor controller sensors feed signals into a controller which then actuates or deploys the flow effectors/flow control devices to achieve the enhanced characteristics.

A system and method for state estimation in spinning projectiles is provided. The state estimation is based, at least in part, on magnetic sensor data, angular velocity data, and correction terms applied to the magnetic sensor data and the angular velocity data. The system and method for state estimation in spinning projectiles estimates roll angles and roll rates of the spinning projectiles. The roll angle and roll rate estimates allow steering commands to be applied to steer the spinning projectiles in the proper direction.

Apparatus and associated methods relate to determining a course-correction signal for a spin-stabilized projectile based on a time sequence of images of a scene aligned with and obtained by a forward-looking imager coupled to the projectile. As the projectile rotates, the aligned scenes captured in the images obtained by the forward-looking imager are rotated. The rotation angle of each of the captured scenes corresponds to the spin angle of the projectile at the time of image exposure. Objects in the captured scenes will circle about a rotation center of the time-sequence images. The distances from a rotation center to the objects in the captured scenes, as well as the rotation angles of the captured scenes can be used to generate a course-correction signal so that the projectile can be guided to a target selected from the objects in the captured scene.

A system and method for state estimation in spinning projectiles is provided. The state estimation is based, at least in part, on magnetic sensor data, angular velocity data, and correction terms applied to the magnetic sensor data and the angular velocity data. The system and method for state estimation in spinning projectiles estimates roll angles and roll rates of the spinning projectiles. The roll angle and roll rate estimates allow steering commands to be applied to steer the spinning projectiles in the proper direction.

A method is provided of generating a course-correction signal for a spin-stabilized projectile. The method includes capturing a time-sequence of images of a scene at a frame rate, comparing respective current images of the time-sequence of images to a corresponding previous image of the time-sequence of images, determining a rotation angle between the current and previous images, rotating the images using the rotation angle, identifying a target in the rotated images, generating target bearing angles to cause the projectile to correct its course toward the target using the target bearing angles, and adjusting the target bearing angles to compensate for the rotation of the images.

A system for finding up in a projectile flight relative to earth. The system having a transmitter which transmits polarized reference signals to a guidance sub-system on the projectile. The guidance sub-system includes a magnetometer and polarized and non-polarized receivers. Measurements from the magnetometer are used to determine a general up direction. The polarized and non-polarized receivers are arranged such that, during rotation of the projectile, reference signals received by the polarized receiver modulate whereas reference signals received by the non-polarized receivers are unaffected. A ratio of the strengths of the signals received by the polarized and non-polarized receivers determines alignment of a vertical axis. From the general up direction and alignment of the vertical axis, a precise up direction of the projectile in flight relative to the earth can be determined.

The system and method for accurately determining range-to-go for a time-delayed command detonation of a projectile. Using dual laser and/or radio frequency detectors on the tail and on the nose of a spinning projectile to determine the range-to-go, time-to-go, and/or lateral offset from the projectile to the target. A time to detonation clock is used to determine when a projectile transitions from an exterior to an interior of a structure such that the projectile can more accurately detonate within a fixed structure.

Techniques are provided for determination of a guided-munition orientation during flight based on lateral acceleration, velocity, and turn rate of the guided-munition. A methodology implementing the techniques, according to an embodiment, includes obtaining a lateral acceleration vector measurement and a velocity of the guided-munition, and calculating a ratio of the two, to generate an estimated lateral turn vector of the guided-munition. The method also includes integrating the estimated lateral turn vector, over a period of time associated with flight of the guided-munition, to generate a first type of predicted attitude change. The method further includes obtaining and integrating a lateral turn rate vector measurement of the guided-munition, over the period of time associated with flight of the guided-munition, to generate a second type of predicted attitude change. The method further includes calculating a gravity direction vector based on a difference between the first and second types of predicted attitude change.

The system and method for accurately determining range-to-go for a time-delayed command detonation of a projectile. Using dual laser and/or radio frequency detectors on the tail and on the nose of a spinning projectile to determine the range-to-go, time-to-go, and/or lateral offset from the projectile to the target. A time to detonation clock is used to determine when a projectile transitions from an exterior to an interior of a structure such that the projectile can more accurately detonate within a fixed structure.

The system and method for accurately determining range-to-go for the command detonation of a projectile. Using dual laser and/or radio frequency detectors on the tail and on the nose of a spinning projectile to determine the range-to-go, time-to-go, or lateral offset from the projectile to the target.