To ensure the continuity of the MTi 1-series, its End Of Life components are being replaced and a hardware version 2.0 has been released in June 2018. In addition, the MTi 1- series’ part number naming is changing to a new format. This document provides all practical information that is important for the customer regarding the migration.
Hardware version 2.0 introduces new and improved accelerometers, gyroscopes and magnetometers. Figure 1 and Figure 2 show the Allan variance plots of the two hardware versions (1.x vs 2.0) respectively for the gyroscope and accelerometer sensors. As visible from Figure 1, the 2.0 version shows better characteristics for the gyroscope in terms of noise density (~0.005 °/s/√Hz versus ~0.007 °/s/√Hz) and bias floor (~6-8 °/h versus ~10-12 °/h). Table 1 reports a comparison of all specifications for the two gyroscope versions.
Figure 2 shows that the accelerometer characteristics have also been improved in terms of noise density (~90-100 µg/√Hz versus 120-160 µg/√Hz) and bias floor (~30 µg versus ~70 µg). Table 2 reports a comparison of all specifications for the two accelerometer versions.
The magnetometers used previously for the MTi 1-series v1.x have been declared End of Life and have therefore been replaced in hardware version v2.0. For a comparison between the two versions, refer to Table 3. Although the full-scale range of the magnetometers has decreased with respect to v1.x, noise characteristics and resolution have improved significantly. The decrease in full-scale range is not an issue since the on-board sensor fusion algorithm rejects magnetic fields that are too high to be considered part of the Earth’s magnetic field.
It is evident that the MTi 1-series v2.0 hardware has better specifications with respect to the MTi 1-series v1.x hardware. In addition to the better inertial sensor data specifications, the new hardware improves robustness resulting in a product with stress related issues lower by 10 times with respect the previous version. In particular, the components change will lead to an increased performance due to:
- Increased robustness to mechanical stress. The v2.0 hardware and its sensor components are less susceptible to torsional stress;
- Increased consistency and repeatability among parts with the v2.0 hardware and its sensor components.
The new output data rate for the high-rate calibrated data (XDI_AccelerationHR and XDI_RateOfTurnHR) messages is 800 Hz. This compares to the previous version’s 1000 Hz, but it is sufficient to capture high frequency motions and for performing a coning & sculling compensation.
Additionally, the component placement has changed, as is shown in Figure 3. This design change may require a change to assembly reflow processes previously designed for the 1-series, especially automatic pick and place machine programs.
Figure 1: Allan variance curves of the gyroscopes for the new HW version 2.0 (continuous) and old HW version 1.x (dotted). The new component shows a lower bias floor with less variation across parts.
Figure 2: Allan variance curves of the accelerometers for the new HW version 2.x (continuous) and old HW version 1.x (dotted). The new component shows a lower bias floor with less variation across parts.
Table 1: Gyroscope specifications of MTi 1-series (from components’ datasheets).
Table 2: Accelerometer specifications of MTi 1-series (from components’ datasheets).
Table 3: Magnetometer specifications of MTi 1-series (from components’ datasheets).
Figure 3: Component placement change of the MTi 1-series module.
New Development Kit
Together with the MTi 1-series v2.0, a new Development Kit is released. The new DK features Arduino pin header compatibility as well as a Mikrobus pin header for GNSS daughter cards that are compatible with the MTi-7. For more information on the new DK, refer to the MTi 1-series DK manual.
All MTi 1-series with hardware version v2.0 will be produced and released with firmware version 1.2.7. It is not possible to downgrade to older firmware versions released for the v1.x.
Firmware version 1.2.1 will be the final firmware version for the MTi 1-series with hardware version v1.x.
New versions of the MTi 1-series Datasheet and the MTi 1-series DK User Manual (rev D, March 2018) have been released in order to be fully compatible with the new v2.0 hardware. Documentation for the previous hardware version will remain available. In addition, a Hardware Integration Manual has been released. We recommend customers to carefully follow the guidelines of this document before starting integration of the MTi 1-series module.
Online links to the latest available documentation can always be found at https://www.xsens.com/xsens-mti-documentation or in the installation folder of the MT Software Suite.
The MTi 1-series v2.0 are fully supported by MT Software Suite version 4.9.1 and higher. The latest version can be downloaded at: https://www.xsens.com/software-downloads
In order to identify the hardware version of an MTi 1-series module through software, the ReqHardwareVersion low-level command can be used. For more information, refer to the LLCP Manual. The hardware version is also mentioned in the MT Settings window of MT Manager.
The new hardware version comes with an update in part numbering. Please update purchasing systems with the new part number as described in Table 4. If MTi-x-8A7G6x part is ordered, Xsens will deliver the ordered MTi-x-8A7G6x part until the stock runs out, after which Xsens will deliver the 1-series part with the new part number (MTi-xx).