Development of a Low-Power Digital Inertial Reference Assembly

Current and projected system requirements for inertial reference assemblies emphasize high accuracy, long life, and low power. An inertial reference assembly ( IRA) which embodies the aforementioned characteristics was developed recently. Pulse rebalanced gas-bearing gyroscopes were used to attain high accuracy and long life. Temperature compensation of gyroscope parameters (in lieu of temperature control) and dual voltage spinmotor operation helped achieve low-power operation. The latter two items represent an advancement in the state of the art and form the subject of this paper. These techniques were used in the construction of a three-axis IRA with an operating power less than 50 watts. It has achieved 0.1 percent scale factor accuracy over a 60°F range.