DESIGN AND IMPLEMENTATION OF AN INERTIAL MEASUREMENT UNIT (IMU) FOR SMALL DIAMETER BALLISTIC APPLICATIONS

摘要

The US Army Research Laboratory currently uses a variety of ballistic diagnostic systems for gathering aerodynamic information pertaining to gun launched munitions. Sensors are a vital component of each of these diagnostic systems. Since multiple sensors are commonly used, they are often configured into a sensor suite or inertial measurement unit (IMU). In order to gather information on smaller diameter projectiles, a small diameter IMU was designed using commercial-off-the-shelf (COTS) sensors and components. This IMU was first designed with a 21.6 mm diameter and then later reintegrated into a 17.5 mm diameter unit. The IMU provides up to ten sensor data channels which can be used to make in-flight projectile motion measurements. These measurements are then used in the determination of the projectile's aerodynamics. It has been successfully flight tested on a variety of projectiles. It has been used in conjunction with an on-board recorder (OBR) to take measurements on 40 mm and 25 mm projectiles. It has also been used in a telemetry based system on-board a flare stabilized 25 mm projectile. This paper covers the design of the IMU and gives examples of various sensor data.