Raw IMU Specifications
As an IMU is the main component of an inertial navigation system, the new Ellipse IMU has been carefully designed to take full advantage and performance of MEMS technology.
While the IMU is the core of the Ellipse, the performances of the sensor when used in its standard mode of operations (AHRS or INS) will not reflect directly the performances of the IMU described below.
Indeed SBG have built extensive filtering technology that will use the raw IMU data and estimate, in real time, the different sensor imperfections and apply the correction before computing a position, an attitude or a velocity.
Therefore make sure you do not use these values directly to estimate the performances of the products when used as AHRS or INS.
Accelerometers
The Ellipse IMU embeds 3 high performance, industrial grade MEMS accelerometers. Coupled with a cutting edge calibration and advanced filtering techniques, these accelerometers will provide excellent performance, even in highly vibrating environment.
Value | Remarks | |
|---|---|---|
| Full scale (g) |
| The Ellipse series are available in three versions depending on the application. |
| Scale factor stability (ppm) | 1000 | After one year accelerated aging |
| Non-Linearity (ppm of FS) | 1500 | Best Fit Straight Line |
| One year bias stability (mg) | 1.5 | After one year accelerated aging |
| Velocity Random Walk (μg/√hz) | 57 | |
| In run bias instability (μg) | 14 | Allan variance – @ 25°C |
| Vibration Rectification Error (μg/g²) | 50 | Tested up to 3g RMS for A2 and 10g RMS for A3/A4 |
| Bandwidth (Hz) | 390 | Internal low pass filters attenuation < 3 dB |
| Sampling rate (kHz) | 4 | Advanced anti-aliasing FIR filter |
| Orthogonality (°) | 0.05 |
Gyroscopes
The set of 3 high end industrial grade MEMS gyroscopes is sampled at 10 KHz. An efficient FIR filter ensures best performance in vibrating environments.
Value | Remarks | |
|---|---|---|
| Full scale (°/s) |
| The Ellipse series are available in three versions depending on the application. |
| Scale factor stability (ppm) | 500 | After one year accelerated aging |
| Non-Linearity (ppm of FS) | 50 | |
| One year bias stability (°/s) | 0.4 | After one year accelerated aging |
| Angular Random Walk (°/√hr) | 0.18 | Allan variance – @ 25°C |
| In run bias instability (°/hr) | 7 | Allan variance – @ 25°C |
| Vibration Rectification Error (°/h/g²) | <1 | Tested up to 10g RMS |
| Bandwidth (Hz) | 133 | Internal Gyro bandwidth |
| Sampling rate (kHz) | 10 | Advanced anti-aliasing FIR filter |
| Orthogonality (°) | 0.05 |