Inertial MEMS System Applications

The performance of MEMS inertial technology has evolved from automotive quality to that approaching tactical-grade quality (1 deg/h, 1 mg). This evolution is a direct result of advances made in the key technology areas driven by gun-launched projectile requirements. The application of silicon MEMS inertial technology to competent munitions efforts began in the early 1990s. Initially, gun hardness was demonstrated at the sensor level, although the bias-and-scale factor of these gyros and accelerometers was mostly suitable for automotive or commercial use. Subsequently, development programs were initiated to develop gun-hard inertial systems with greatly improved sensor performance, and with a goal of low production cost. This paper discusses the evolution of low-cost MEMS inertial system technology development for guided projectile INS/GPS systems and high performance IMUs. The evolution in sensors and packaging to realize performance improvement and system size reduction are presented. Recent data from the culmination of a three-year effort to develop an 8 cu in IMU are summarized, and represent the highest performance to date for an all-silicon IMU. Further investments in Silicon MEMS systems will ultimately realize IMUs that are smaller (less than 2 in (33 cc), higher performing (1 deg/h and less than 1 mg), and lower in cost (less than $1200 per IMU and $1500 per INS/GPS) than is achievable in any competing technology. 1