Production Line Calibration for Sensors on Actively Controlled Bullets

Abstract

A simple testing device is presented that simultaneously calibrates all dominant error sources for accelerometers and gyroscopes found in typical microelectromechanical inertial measurement units on smart projectiles, including bias, scale factor, cross axis sensitivity/misalignment, and misposition. The device consists of a table which rotates about a gimbal joint and is supported on the corners by elastic and damping elements. Using dynamic simulation it is shown that motion created by free vibration of the testing platform suitably excites sensors on projectiles so calibration can be performed. Calibration parameters are estimated using an extended Kalman filter. Platform support stiffness and damping characteristics significantly alter the time required to identify calibration parameters by shaping platform motion. A critical level of initial motion of the testing platform is required for adequate prediction of calibration parameters.