Inertial Measurement Unit SBG Ellipse-A Land/Air AHRS - CAN interface

The Ellipse-A is an attitude and heading reference system (AHRS). It integrates inertial sensors (accelerometers, gyroscopes) and magnetometers to provide reliable orientation data (roll, pitch, heading) in dynamic environments. It uses its built-in magnetometer as the sole source for heading calculation.

The Ellipse-A unit in its housing has compact dimensions of 46 x 45 x 24 mm and weighs 45 g.

The Ellipse-A IMU integrates the following MEMS sensors, each individually calibrated across the full operating temperature range (-40°C to +85°C):

• A 3-axis accelerometer
• A 3-axis gyroscope
• A 3-axis magnetometer
• A barometer

The measurement ranges of the Ellipse-A sensors are as follows:

• Accelerometer: +/- 20g
• Gyroscope: +/- 450°/s
• Magnetometer: 50 Gauss

The attitude and heading accuracy of the Ellipse-A is as follows (error 1-sigma over the full temperature range):

• Roll / Pitch:0.1° in static conditions, 0.4° in dynamic conditions
• Heading:0.8° in static conditions, 1° in dynamic conditions (under a homogeneous magnetic field after calibration)

No, the Ellipse-A is an AHRS system that provides attitude (roll, pitch, heading), but it does not provide position or heave measurement. The heave functionality is available only on the marine version.

The Ellipse-A unit is shock-resistant up to 500 g and withstands vibrations of 8 g RMS (20 Hz to 2 kHz per MIL-STD 810G).

The Ellipse-A IMU is designed to operate within a temperature range of -40°C to +85°C. All its sensors are calibrated across this range to ensure accuracy.

The Ellipse-A IMU can output inertial measurement unit (IMU) data and Euler angles at up to 1 kHz.

Yes, the version in the Ellipse-A housing is rated IP68, meaning it is resistant to dust and water.

No, the Ellipse-A (AHRS) cannot accept external GNSS aids for heading calculation. The only heading source it uses is its integrated magnetometer.

The Ellipse-A autopilot has the following communication interfaces:

• 1x RS-232 interface (input/output)
• 1x CAN output (CAN 2.0A/B)
• 2x sync inputs (RS-232)
• 1x sync output (TTL)

The Ellipse-A supports sbgEcom (binary), REST API, NMEA protocols, as well as other third-party protocols.

The Ellipse-A’s CAN interface can reach a data rate up to 1 Mbps.

The Land/Air version of the Ellipse-A can be used for maritime applications that do not require heave measurement or the SHIP_MOTION message. For these features, a Marine version would be required.

The cable CA-ELI-USB-3M (reference 100-0776) is required for the first purchase of an Ellipse in a housing. This 3-metre cable provides an easy connection to a PC, includes a RS RS-232 to USB converter, and powers the sensor, enabling configuration and firmware updates. It is sold separately.

For integration into a system, the following open-ended cables are available:

• CA-ELI-RS232-CAN-3M (100-0777):This cable provides access to the main and auxiliary connectors of the Ellipse and is designed for RS-232 communication, but can also be used with CAN versions.
• CA-ELI-RS422-3M (100-0778):This cable also provides access to the main and auxiliary connectors of the Ellipse and is designed for RS-422 communication, but can also be used with CAN versions.

The Ellipse-A core unit requires an input DC voltage between 5 and 36 V.

To connect the Ellipse-A to a PC, you must use the cable CA-ELI-USB-3M (100-0776). This cable includes a RS RS-232 to USB converter and provides power to the sensor, enabling configuration and firmware updates.

The SBG Ellipse-A inertial measurement unit (IMU) comes with a 2-year warranty.