The MTi-7 and MTI-G-710 GPS/INS are designed to use acceleration derived from GNSS data to improve orientation and position estimates of a vehicle in motion. This also helps compensate for transient accelerations. However the estimates of position, velocity, and heading may be challenged in automotive applications when GNSS reception is limited and when maneuvering at slow speeds or stopped.
The primary documentation for configuring and getting the most out of the MTi-G-710 is the MTi User Manual, especially the section "MTi System Overview" and the sub-section entitled "Xsens sensor fusion algorithm for MTi-G-710".
Here are some additional general tips for getting the most out of the MTi-7 and MTi-G-710 for automotive applications:
- The "General" filter profile typically gives the best performance. Other filter profiles should only be used in special circumstances.
- We do not recommend the "Automotive" filter profile unless you have have extremely good mounting accuracy (1 degree alignment).
- We generally do not recommend using the "GeneralMag" filter profile due to the high potential to encounter magnetic disturbances in automotive applications. However if the magnetic field environment is suitable (i.e. you do not anticipate passing near magnetic disturbances or fields) and if proper MFM calibration for fixed magnetic fields is done very well, it can be used and it can be effective.
- For initial true north heading when the vehicle has not begun moving yet, use the "GeneralMag" filter if the conditions above are met, otherwise it may be necessary to calculate your own determination of true north heading with raw magnetometer data. However using the raw magnetometer data for initial heading will include errors if the magnetic field is disturbed. The MTi-7 and MTi-G-710 will yield effective true north heading once it has achieved GNSS fix and begun traveling at a sufficient velocity.
- For stabilizing yaw when the vehicle slows down, Active Heading Stabilization (AHS) can be used, but it may not be effective in all cases. Please note that AHS is considered to be in beta for our GNSS/INS products. In addition, the "HighPerformanceEDR" filter was designed for such slow moving platform applications. In this filter during stationary periods the stillness detection mechanism kicks in, giving full observability to the gyroscope biases but it could very well be that if there is a lot of vibrations then the ‘stillness’ might not be detected. Thus the "HighPerformanceEDR" filter should be used only when the motion is slow and there is not too much noise on the data.
- The No Rotation Update command can be used during initialization and periodically to help with gyro bias estimation when GNSS cannot help. This is the most effective extra way to help stabilize yaw if high speeds with GNSS fix cannot be maintained. The "HighPerformanceEDR" filter does this automatically.