Posts made by ysong

Hi @Elie-NTUMBA, as I know there is no magnetic sensor in MTLT305D. I am a bit curious how you apply magnetic alignment?

Hi @Abdelrahman,

1. Please use AHRS application in low distortion magnetic environment, as mag sensor is very sensitive to magnetic interference.
2. Please apply magnetic alignment (as below screenshot) in no magnetic distortion environment at first and check if initial heading is correct.
   
3. If it takes long time to convergent correct heading in static condition, as AHRS is an open-source app, customers could try to adjust “gKalmanFilter.R[STATE_YAW]” (as below screenshot) to lower values, like 1.0e-3, 1.0e-4, 1.0e-5 … in their customized applications.
   
4. Could you help to collect some field test data? This might require using a custom FW to collect all the information required for the algorithm to do post analysis. Test data should include accel, raw gyro, raw mag, corrected mag data, roll, pitch and heading data at 100Hz message rate from power on, as well as hard and soft iron parameters shown in above screenshot.

Hi Amin,

Roll and pitch are zero before algrithm initlization is done. Normally, algrithm initlization can be done within 1 second. Initial roll and pitch are calculated by averaged 3D acceleration. If you want to modify duration of algrithm initlization for your application, you can adjust 'INITIALIZE_ATTITUDE_DURATION' in source code. Thank you.

Hi, it is claims that the angular rate range is +- 400 dps in datasheet. I think the range was 400 dps in default IMU App before you updated to VG_AHRS App, right?

Assuming you check data in 'a1' or 'a2' packet via RS232, could you please switch 'z1' or 's1' packet to see the rate range?

Hi, from your screenshot, we can see "0X55 0X55 0X61 0X31 ... " at the beginning of data, where 0X5555 is the Preamble of packet, 0X6131 is the packet type 'a1'.

Besides, here is a description of 'a1' packet, hope it is helpful for you.
https://openimu.readthedocs.io/en/latest/apps/ahrs.html?highlight=a1#the-definitions-of-the-output-packets-of-the-vg-ahrs-app

Hi, I used 200Hz before and OpenIMU300ZI worked properly at that time.
Please note that if the length of packet is a bit long, you also need to adjust baud rate to 230400 or higher.

Pin 7 of IMU300ZI is SPI/UART Interface selector, could you please check you have selected UART by pin 7 already on your customer board?

Reference: https://openimu.readthedocs.io/en/latest/300ZI/pinout.html

Hi @mbirley,

Please don't care the info in table 'PROBLEMS', just try to build the project.
I just built the project successfully as below picture.

Yes, you need to provide an external power (4.9 V – 32 V) , please refer to Table 3 in page 7, thank you!

Hi @SeppW ,

I find 300RI can't do mag align via serial port in current version, but can do mag align via CAN, so I have 2 suggestions(ways) for you:

1. Implement 'mag align via serial port' function for 300RI. You can find how 300ZI to implement 'mag align via serial port' by searching key word 'ProcessMagAlignCmds' in 300ZI VG_AHRS project source code, and follow the steps of the implementation in 300ZI VG_AHRS. This is a 'DIY' way that play with 300RI. Welcome your coming contribution!
2. Run mag align via CAN, please refer to: https://openimu.readthedocs.io/en/latest/software/CAN/CAN_J1939_SetCommandMessages.html?highlight=align#can-j1939-set-request-messages

Hi @SeppW ,
We are in holiday this days, I will back to office this Sunday and find a 300RI to try by then. If this is urgent for you, you also can post a new topic of this question to see if other guys knows how to fix it.

Hi @SeppW,

Function "RunUserNavAlgorithm" is invoked at 200 Hz indeed, just output results data via CAN with 100Hz, so I think this should be okay for you.

I think the "mag alignment" is your requirement of "calibrate the sensor", you could have a look at:
https://openimu.readthedocs.io/en/latest/algorithms/MagneticAlignment.html
https://openimu.readthedocs.io/en/latest/algorithms/MeasurementVector.html#magnetometer-based-heading

BTW, magnetic sensor is sensitive, so for your car application, I think the iron part (such as engine, car frame) of your car maybe interference for magnetic sensor, so it it necessary to evaluate only use magnetic sensor to get heading is stable enough for your car application.

Glad to know you have got the linear acceleration!

Do you mean you need a 200 Hz output data rate via CAN? I just know how to modify source code to get 200Hz data output via serial port but not CAN, maybe you need to read and modify the open source code to find a way to achieve that, or post a new topic of this question, maybe other guys knows.

Please run OpenIMU python driver and run mag alignment here: https://developers.aceinna.com/devices/record-next

Hi @robert-jir ,

You can flash Aceinna apps of OpenIMU300RI via the app center . Brief steps are:

1. run OpenIMU Python Drivers (reference: https://openimu.readthedocs.io/en/latest/driver-python.html#openimu-python-drivers)
2. open App center (https://developers.aceinna.com/code/apps), choose your favorite app then click button 'UPGRADE', and wait for the process done. Please do NOT power off until the process is done.

You also can follow this (https://developers.aceinna.com/docs/install) to develop your own app based on Aceinna open sourced algorithm, then flash your app and run it on your 300RI.

No, because if INS app doesn't receive GPS data, it also will not calculate linear acceleration.
So you can use your approach to calculate linear acceleration in VG_AHRS app, I think it should work.

Hi @SeppW ,
Linear acceleration is calculated in INS but not VG_AHRS framework, as linear acceleration is not necessary for VG/AHRS algorithm. If you need linear acceleration in your application, you can follow and implement below approach in your VG_AHRS framework:

Sorry for being late.
Yes, you can use OpenIMU300ZI firmware and apps on the OpenIMU300ZA.

Hi, basically, OpenIMU is used to propagate position, velocity and attitude within the gap of GPS, but can't work as a NTRIP client.

I think you need OpenRTK330 EVK which already contained GPS receiver and IMU, and can get the correction data from base at RTK2GO. You can find details info here: https://openrtk.readthedocs.io/en/latest/ and https://www.aceinna.com/inertial-systems/OpenRTK330
If you have any question about OpenRTK330, please post your question on OpenRTK block: https://forum.aceinna.com/category/9/openrtk

Thank you.

Hi, 'OpenIMU300ZA' is the same as 'OpenIMU300ZI', we just changed the model for some reason, please feel free to keep working on it, it is really a good IMU.

Also you can find data sheet, Online Manual and other useful information of 'OpenIMU300ZI' here : https://www.aceinna.com/inertial-systems/OpenIMU300ZI

Hi, please find another PC and use HTerm to check whether the EVK can work properly or not at first, I think maybe something wrong with the USB 2 Serial port driver on your PC, you can check and reinstall it.