VN-100 Rugged inertial measurement and attitude sensor

The VN-100 Rugged from VectorNav is a miniature inertial measurement unit (IMU) and attitude heading reference system (AHRS) in an enclosed housing. It combines 3-axis accelerometers, gyros and magnetometers with a barometric pressure sensor and a 32-bit processor, and it outputs calibrated inertial data together with a real-time 3D attitude solution that stays continuous over the full 360 degrees of motion. It is the plug-and-play version of the VN-100 surface-mount sensor, placed in a clamshell anodized aluminum enclosure for added protection of the sensors and electronics.

The key figures describe the quality of the sensor. Gyro in-run bias stability is 5°/hr typical and below 10°/hr by specification, with a gyro range of ±2,000°/s and an accelerometer range of ±16 g. Magnetic heading accuracy is 2.0° RMS, and static pitch and roll accuracy is 0.5° RMS. Bias stability tells an integrator how quickly the attitude estimate drifts when no external correction is available, and heading accuracy applies with correct magnetic declination, a suitable magnetic environment and hard and soft iron calibration. The unit has no integrated GNSS receiver.

Output rates reach 800 Hz for IMU data and 400 Hz for the attitude solution from the onboard extended Kalman filter. The filter is a vector processing engine that provides disturbance rejection, adaptive filtering, real-time gyro bias tracking and compensation, and hard and soft iron compensation. Messages are user configurable, in ASCII or VectorNav binary format, and heave estimation is available. Each sensor is individually calibrated for bias, scale factor, misalignment and temperature over its operating range.

For integration, the Rugged version measures 36 x 33 x 9 mm and weighs 15 g, with a 10-pin Harwin connector. It runs from a 4.5 to 5.5 V supply, draws 40 mA at 5 V and uses 220 mW. Interfaces are RS-232 and UART, and the Rugged and surface-mount versions share a communication protocol with the whole VectorNav product line, so software written for one works with the other. The VectorNav Control Center application is used to configure, view and log data. The operating temperature range is -40° to +85° C and the MTBF of the Rugged version is above 240,000 hours.

The product is described as ITAR-free. Calibration and acceptance testing take place at the maker's AS9100 certified manufacturing facility.

Typical applications are attitude and heading sources for unmanned aircraft flight control, gimbal and payload stabilization, antenna pointing and general platform orientation measurement in robotics.