Compact Inertial Measurement System

Applied Technology Associates (ATA) proposes to develop a compact inertial measurement system (CIMS) by combining two inertial rate sensing devices. One rate sensor uses magnetohydrodynamics (MHD) for high frequency motion measurement and is denoted the Angular Rate Sensor (ARS). The second sensor is a new micro-electro-mechancial system (MEMS) gyro denoted the Disk Resonant Gyro (DRG) and is used for low frequency motion measurement. In addition to combined ARS/DRG motion sensing, the CIMS also exploits FPGA-based electronics for multi-sensor signal conditioning and fusion. A complete, autonomous attitude determination system is achieved by optionally including a stellar camera unit / star tracker to provide calibration and inertial sensor drift compensation. Depending on performance requirements, other aiding sensors (magnetometers, horizon sensors, etc) may be substituted for the stellar camera. CIMS achieves motion measurement sensitivity at 5 arcsecs (25 microrads) or less over the bandwidth DC-100 Hz. Measurement noise of CIMS above 1 Hz is estimated to be less than 1 microrad. The mass of CIMS is less than 1.5 kg and power required under 2 W.