The Honeywell/DND helicopter integrated navigation system (HINS)

The development of prototype of a high-performance, fault-tolerant navigation system for Canada´s anti-submarine-warfare helicopter is discussed. HINS consists of three primary navigation subsystems (an F/sup 3/INS, a five channel P-code GPS (global positioning system), and a Doppler velocity sensor) and three secondary sensors (a strapdown magnetometer, a vertical gyro, and an air data system). The system is designed to blend the complementary strengths of component sensors, and to provide graceful degradation of performance in the event of failure or slow deterioration of these sensors. During normal operation, the Doppler and secondary sensors are calibrated to enhance performance during degraded mode operation. A multilevel failure-detection and -isolation scheme monitors sensor health and identifies faulty system components. HINS automatically reconfigures itself to optimally integrate remaining components. The system will operate in the event of an INS failure and also provides a worst-case limp-home capability using only the air data system and the magnetometer. The analyses in the original feasibility study and the architecture that is being implemented in the advanced development model are described.<>