HG1700 inertial sensing unit

The HG1700 is a tactical-grade inertial measurement unit from Honeywell Aerospace that senses angular rate and acceleration on three axes. It is a ring laser gyroscope (RLG) based inertial sensing unit, designed for guidance and control applications on unmanned aircraft, stabilized platforms and other vehicles that need high-quality inertial data.

The unit contains three ring laser gyroscopes and three quartz resonating beam accelerometers, together with their electronics, sealed in a rugged aluminum housing. Honeywell lists weaponry, ground survey, UAVs, mobile mapping and stabilized platforms among its uses, and the flight control side of an unmanned system can use its output for navigation, attitude estimation and autopilot loops.

Two variants are offered: the HG1700 AG and the shorter and lighter HG1700 SG. The AG is 2.865 in (7.25 cm) in its quoted dimension and weighs under 2 lb (0.9 kg); the SG is 2.262 in (5.75 cm) and weighs under 1.5 lb (0.7 kg). Five performance grades and thirty off-the-shelf configurations are available. Accelerometer range varies by configuration from +/-12 g to +/-70 g, and the gyro range from +/-358 deg/s to +/-1620 deg/s, so the configuration has to be matched to the dynamics of the platform. The sensors are specified for bias as a combination of stability and repeatability, and an external environmental ring isolator filters unwanted inputs from vibration.

Electrical integration is through an RS-422 serial interface, with factory-configurable protocols including SDLC, asynchronous serial and gated clock. Typical power consumption is +15 V at 0.25 A plus +5 V at 0.15 A. Data output rates of 100 Hz for guidance and 600 Hz for control are standard, and other rates can be set, along with flight control filtering. Honeywell states that external heat sinks and cooling are not needed, which simplifies mounting. The operating temperature range is -54 to +85 degrees C.

The HG1700 is designed and built in the USA. It typically falls under ECCN 7A003.d.1, though this can vary with the model, and it generally requires an export license. Buyers should confirm export classification for the specific configuration. Radiation-hardened variants are also offered.

Typical applications are flight control and navigation on UAVs, mobile mapping, ground survey, stabilized sensor platforms and guidance systems.