VIC3DA Dead reckoning not working

yclin · ‎2025-02-24

I have some problem with DR mode.

I can't recieve any $PSTMDR2 or $PSTMDRCAL messages, so the status of DR remains unknown.

But I checked the CDB 228-230 with $PSTMGETPAR, the following are the response.

========

$$PSTMSETPAR,1228,0x00000000*5A
$$PSTMSETPAR,1229,0x6cc22000*5D
$$PSTMSETPAR,1230,0x00000000*53

==========

In CDB 229, bit 60-63 is 6, meaning that the $PSTMDR and $PSTMDRCONFID are enabled, but I can only see $PSTMDRCONFID. There are no $PSTMDR message there. Are there any problem with my configurations?

Also, I had enabled these messages in CDB 229, meaning that these message should be update in 10 Hz. But it still be updated in 1 Hz, as following.

==========

$$PSTMDRCONFID,0.00,0.00,0.0000,0.0000,0.00,0.0000,0.000000,0.000000,0.0000,0.0,0.0,-0.0,0.0*1A
$$PSTMDRPVA,162640.000,2945690305,37.5517719,14.2984835,730.1,0.00,0.00,0.00,0.00,0.00,0.00*57
$$PSTMDRCONFID,0.00,0.00,0.0000,0.0000,0.00,0.0000,0.000000,0.000000,0.0000,0.0,0.0,-0.0,0.0*1A
$$PSTMDRPVA,162641.000,2946713305,37.5517719,14.2984835,730.1,0.00,0.00,0.00,0.00,0.00,0.00*5F
$$PSTMDRCONFID,0.00,0.00,0.0000,0.0000,0.00,0.0000,0.000000,0.000000,0.0000,0.0,0.0,-0.0,0.0*1A
$$PSTMDRPVA,162642.000,2947736306,37.5517719,14.2984835,730.1,0.00,0.00,0.00,0.00,0.00,0.00*59
$$PSTMDRCONFID,0.00,0.00,0.0000,0.0000,0.00,0.0000,0.000000,0.000000,0.0000,0.0,0.0,-0.0,0.0*1A
$$PSTMDRPVA,162643.000,2948758283,37.5517719,14.2984835,730.1,0.00,0.00,0.00,0.00,0.00,0.00*53

=========

Are there some configurations needs to be changed? Thank you.

yclin · ‎2025-06-05

Hi @GalaxyQuest

Sorry I had provide the wrong file.

The new file is the data collected on the train passing through a long tunnel.

GalaxyQuest · ‎2025-06-11

Hi,

I have been looking at the log and see the drop in speed that you mentioned.

However I noticed that in the log you provided where the speed drops, the message output is also different.

Did you change the NMEA and ST proprietary messages that are being output for the test run that worked well compared to the test run that is giving this bad result?

I am uploading the spreadsheet of 26_06 log, please have a look.

You will see that in 26_05 log, GPRMC and PSTMDRPVA is being output at the same rate. However in the previous log I shared where it worked well, it looks like PSTMDRPVA and PSTMDRGPS are output at 1 Hz while GPRMC is output at 10 Hz. Could you please revert to this configuration?

Can you please send command,

$PSTMGETPAR,1000 and send me the output? You can filter the output by the key word "SET" in the "Filter" box and you will only the see response and not see NMEA output.

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yclin · ‎2025-06-13

Hi @GalaxyQuest

Which log file did you find the data rate problem? I am looking at 26.05.25_13.12.24_NMEA_Device_D0 file. It seems fine.

Also, the following file is the response of $PSTMGETPAR,1000

Thank you.

GalaxyQuest · ‎2025-06-13

Hi,

Regarding log, it was my mistake, when filtering the data I accidentally pasted the wrong column in my comparison.

So I had a chance to look at your data, the speed output and also the accelerometer output.

As indicated during the time when DR showed a speed of 0, the accelerometer also was showing ~0 values indicating the vehicle was not in motion.

I discussed this our R&D team and they indicated couple of considerations,

1. You mentioned you calibrate this in a car and then put the calibrated unit on a train. In this specific case for your testing, the calibration values were almost similar when placed in a car and train, therefore VIC3DA worked. However we cannot guarantee this will be the case for all units that is calibrated in such a way. This can result in some units in the field not being calibrated.

2. VIC3DA is primarily intended for automobile applications and not really for train. The vibrations of a train will be different than a car and this could be the reason why VIC3DA misinterpreted the speed value.

I have forwarded your case to your marketing team. Meanwhile, can you also please get in touch with your local ST sales/distributor team and initiate discussion. They can guide with the right solution.

Attached is result of my analysis for your reference. You can refer to timestamp of ~52900.

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