Initial state estimation for a gun launched projectile in a spatially varying magnetic field /
Smart weapons promise to provide leap ahead capability with regard to accuracy and engagement range for medium and large caliber projectiles. One of the most critical components of a smart weapon system is its sensor suite that provides position, orientation, and velocity information as the projectile flies down range so that effective control action can be taken in flight. Great strides have been made in creating very small and rugged Inertial Measurement Units (IMU) using MEMS accelerometers and vibrating gyroscopes. However, all IMU systems operate by integrating accelerometer and gyroscope measurements. Thus, they must be initialized at launch to produce sufficiently accurate position and orientation data. Due to inherent uncertainty in shot-to-shot launch conditions, for gun launched projectiles, initial conditions cannot be adequately specified by the firing platform like it can with aircraft and missiles. Currently, there is no adequate method to initialize IMU sensor suites on gun launched munitions. This thesis investigates a novel concept for determining the full state of a projectile near the muzzle of the gun. The methodology relies on the gun system inducing a known spatially varying magnetic field in the vicinity of the muzzle of the gun. Using readings from a cluster of magnetometers embedded within the projectile, the full state of the projectile is determined by solving a nonlinear set of equations.
School:Oregon State University
School Location:USA - Oregon
Source Type:Master's Thesis
Keywords:projectiles precision guided munitions magnetometer
Date of Publication: