HG4930 inertial sensing unit

The HGuide HG4930 is a MEMS inertial measurement unit made by Honeywell Aerospace, sold in the S-class (HG4930-S) version as a tactical-grade IMU for stabilization and control. It measures angular rate and acceleration on three axes and is meant for installations where space is limited, such as gimbals, antenna pointing systems, camera stabilization and the navigation and flight control chain of unmanned aircraft.

The maker positions the HG4930-S as a rugged unit that approaches the performance of some fiber-optic-gyro IMUs in a smaller, lighter, lower-power package. Its high bandwidth suits closed-loop control, where the sensor feeds a stabilization loop directly. A standard HG4930 is offered for lower dynamics, and a different model, the HG1930, covers higher dynamic ranges under an export license.

The sensor figures are as follows. Gyro bias in-run stability is 0.25 deg/hr (1 sigma), gyro bias repeatability is 7 deg/hr (1 sigma) and angle random walk is 0.04 deg/sqrt(hr). The gyro operating range is 400 deg/s. The accelerometers have an in-run bias stability of 0.025 mg (1 sigma), a bias repeatability of 1.7 mg (1 sigma), a velocity random walk of 0.03 m/s/sqrt(hr) and an operating range of 20 g. In practice, in-run stability and random walk govern how fast an unaided navigation solution drifts, while the operating ranges set the maneuvers and vibration levels the unit can measure without saturating.

Physically, the unit has a mass of 140 g and measures 65 mm x 51 mm x 35.5 mm. It operates from -54 degrees C to +85 degrees C, which covers cold-soaked high-altitude and hot-ramp conditions. Power consumption is below 3 W from a supply of +5 VDC.

For integration, the communication ports are 5 V CMOS UART and RS-485, with ASYNC and SDLC protocols and an asynchronous baud rate of 4 Mbit/s. The data rate is listed as 600/100. Honeywell provides DataReader software for Windows to read the HG4930-S output. The HG4930-S is designed and built at a Honeywell facility in the USA, carries an ECCN of 7A994 and is generally available without an export license.

Typical applications named by the maker are camera, antenna and gimbal stabilization, and closed-loop control applications generally. Integrators also use MEMS IMUs of this class as the inertial reference in INS and attitude systems for drones and eVTOL aircraft.