Patent classifications
F41G7/36
SYSTEMS AND METHODS FOR MODEL BASED INERTIAL NAVIGATION FOR A SPINNING PROJECTILE
Model based inertial navigation for a spinning projectile is provided. In one embodiment, a navigation system comprises: a strapdown navigation processor; a propagator-estimator filter, the processor inputs inertial sensor data and navigation corrections from the filter to generate a navigation solution comprising projectile velocity and attitude estimates; an upfinding navigation aid that generates an angular attitude measurement indicative of a roll angle; and a physics model performing calculations utilizing dynamics equations for a rigid body, the model inputs 1) projectile state estimates from the navigation solution and 2) platform inputs indicative of forces acting on a projectile platform, and outputs a set of three orthogonal predicted translational acceleration measurements based on the inputs; the filter comprises a measurement equation associated with the physics model and the upfinding navigation aid and calculates the navigation corrections as a function of the navigation solution, the predicted translational acceleration measurements, and attitude measurement.
ROTARY-WING, HOVER-CAPABLE AIRCRAFT AND METHODS
A projectile-launched aircraft system includes a projectile launcher including a triggering mechanism, a rotary-wing, hover-capable aircraft including a rotor assembly that includes at least one rotor blade, wherein the rotor blade includes a stowed configuration and a deployed configuration that is circumferentially spaced from the stowed configuration about a pivot axis, wherein, upon actuation of the triggering mechanism, the projectile launcher is configured to launch the aircraft along a flightpath.
TIGHTLY COUPLED TRAJECTORY PREDICTOR WITH CONSTANT UP-FINDING
Systems and methods for a tightly coupled trajectory predictor with constant up-finding are provided. In certain embodiments, a system includes an inertial measurement unit that provides inertial measurements of a vehicle. The system also includes an up-finding sensor that provides up-finding measurements based on when a portion of the vehicle is pointing up. Further, the system includes one or more processors that bound errors from the inertial measurements in a navigation solution during navigation of the vehicle using the up-finding measurements.
TIGHTLY COUPLED TRAJECTORY PREDICTOR WITH CONSTANT UP-FINDING
Systems and methods for a tightly coupled trajectory predictor with constant up-finding are provided. In certain embodiments, a system includes an inertial measurement unit that provides inertial measurements of a vehicle. The system also includes an up-finding sensor that provides up-finding measurements based on when a portion of the vehicle is pointing up. Further, the system includes one or more processors that bound errors from the inertial measurements in a navigation solution during navigation of the vehicle using the up-finding measurements.
COURSE CORRECTION SYSTEMS FOR PROJECTILES
A course correction system for a projectile can include a pre-steering trajectory determination module. The pre-steering trajectory determination module can be configured to receive a series of possible trajectories from an estimation module including a physical model defining trajectory as a function of gravitational pull and one or more launch variables, and receive a sensor data from one or more on-board sensors of the projectile. The pre-steering trajectory determination module can also be configured to reduce the possible trajectories from the estimation module to one or more refined trajectories using the sensor data, and output the one or more refined trajectories.
COURSE CORRECTION SYSTEMS FOR PROJECTILES
A course correction system for a projectile can include a pre-steering trajectory determination module. The pre-steering trajectory determination module can be configured to receive a series of possible trajectories from an estimation module including a physical model defining trajectory as a function of gravitational pull and one or more launch variables, and receive a sensor data from one or more on-board sensors of the projectile. The pre-steering trajectory determination module can also be configured to reduce the possible trajectories from the estimation module to one or more refined trajectories using the sensor data, and output the one or more refined trajectories.
Inertial navigation system
An inertial measurement system for a spinning projectile includes: a first, roll gyro to be oriented substantially parallel to the spin axis of the projectile; a second gyro and a third gyro with axes arranged with respect to the roll gyro; a controller, arranged to: compute a current projectile attitude from the outputs of the first, second and third gyros, the computed attitude comprising a roll angle, a pitch angle and a yaw angle; calculate a roll angle error; provide the roll angle error as an input to a Kalman filter that outputs a roll angle correction and a roll rate scale factor correction; and apply the calculated roll angle correction and roll rate scale factor correction to the output of the roll gyro.
Inertial navigation system
An inertial measurement system for a spinning projectile includes: a first, roll gyro to be oriented substantially parallel to the spin axis of the projectile; a second gyro and a third gyro with axes arranged with respect to the roll gyro; a controller, arranged to: compute a current projectile attitude from the outputs of the first, second and third gyros, the computed attitude comprising a roll angle, a pitch angle and a yaw angle; calculate a roll angle error; provide the roll angle error as an input to a Kalman filter that outputs a roll angle correction and a roll rate scale factor correction; and apply the calculated roll angle correction and roll rate scale factor correction to the output of the roll gyro.
REDUCED NOISE ESTIMATOR
A system and method to aid in guidance, navigation and control of a guided projectile including a precision guidance munition assembly is provided. The system and method obtain raw position data during flight of the guided projectile, the raw position data including a plurality of position data points from the guiding sensor for determining positions of the guided projectile, establish a window including a portion of the plurality of position data points, smooth the portion of the plurality of position data points in the window, and determine a reduced noise position estimate of the guided projectile, based, at least in part, on the smoothed portion of the plurality of position data points in the window. The system and method may determine a velocity estimate of the guided projectile and predict an impact point of the guided projectile relative to a target.
DYNAMIC AUTOPILOT
[A system and method for dynamic autopilot control comprising providing input to a guidance and control autopilot comprising Mach and dynamic pressure; tailoring parameters of the autopilot, the parameters comprising: roll gain; a pitch/yaw gain; a pitch/yaw loop compensator frequency; a guidance filter bandwidth; a guidance filter lead compensator frequency; and a navigation gain.