Will the INFO below lead to failure in DICE run?

[DonglinWu]

I got the file filled according to requirements, and I run co2mpas several times, it always shows below INFO in log messages, I cannot fix it. But all the INFO are in blue, no yellow(warning) or red(failure) words shown. And I can get the calculated NEDC CO2. May I run DICE just with this condition? Will this lead to failure in DICE run?

2018-06-20 15:35:27,710:co2mpas.model.selector:INFO: Engine speed model selector warning: Models {'tyre_dynamic_rolling_coefficient', 'idle_engine_speed_median', 'gear_box_ratios', 'final_drive_ratios', 'idle_engine_speed_std'} to predict [none, 'wltp_h', 'nedc_h'] failed the calibration. 2018-06-20 15:35:27,710:co2mpas.model.selector:INFO: Engine speed model selector warning: Models {'tyre_dynamic_rolling_coefficient', 'idle_engine_speed_median', 'gear_box_ratios', 'final_drive_ratios', 'idle_engine_speed_std'} to predict ['wltp_l', 'nedc_l'] failed the calibration.

Thanks in advance

[dimitriskomnos]

Dear @DonglinWu,

The failure should not be taken as proof of real failure, but rather a warning that something is not going well with a specific model. We have introduced these qualitative benchmarks in CO2MPAS in order to guide the users in cases where the simulation does not evolve as we would expect it to, but this doesn't necessarily mean that the result is wrong. You may check the produced WLTP graphs in the Output file, if there is a specific input signal is not captured well in the prediction.

In any case, if you are confident with your input data, and since the simulation finishes successfully, then, you may proceed with the DICE.

[DonglinWu]

Thank you very much for your quick response, I will check and try.

[dimitriskomnos]

Dear @DonglinWu ,

In addition, you may check if gear_box_ratios, final_drive_ratios and tyre_code you have provided is correct.

Kind regards.

[DonglinWu]

Dear @dimitriskomnos,

Yes, I am sure I filled in the right gearbox ratios and final drive ratio, also the tyre code. I tried a lot, but still the same log message.

[dimitriskomnos]

A last thing you may check is the proper synchronization of the signals. For this, we suggest that you use the datasync tool included in CO2MPAS, for synchronizing the raw data. Please visit the instructions for synchronizing time series.

In addition, for better understanding the cause of this warning in the specific file, you can send us your data in our FMB.

[DonglinWu]

@dimitriskomnos I think I found a bug, my car is a 4-wheel drive vehicle, and I conduct test on 2 rotating axles dyno with 4 wheels output. But in my input file if I choose 4.0 in "n_wheel_drive WLTP-H" and 2.0 in "n_dyno_axes WLTP-H", it always shows a warning in yellow as "794:co2mpas.model.physical.final_drive:WARNING:WARNING: n_dyno_axes(1) < n_wheel_drive(4) / 2!".

I am sure I chose 2.0 in "n_dyno_axes WLTP-H" in input file, but it seems co2mpas 1.7.3. always take this input"2.0" as "1.0" Could you please help to check???

(I think my previous condition maybe caused by this bug, because after I input 2.0 in "n_wheel_drive WLTP-H" and 2.0 in "n_dyno_axes WLTP-H", it shows no warning in yellow but with my previous warning in blue.)

[dimitriskomnos]

Dear @DonglinWu,

The message:

794:co2mpas.model.physical.final_drive:WARNING:WARNING: n_dyno_axes(1) < n_wheel_drive(4) / 2!"

maybe comes from n_wheel_drive NEDC-H=4 and not from the n_wheel_drive WLTP-H=4 and n_dyno_axes WLTP-H=2 Is this correct?

The NEDC can be performed on 1) one dyno axis or 2) on two axes but synchronous (i.e., only one is applying the loads).

1. to perform the test the transmission is disconnected, so n_wheel_drive for NEDC are 2 (i.e., a 4x4 becomes 4x2).
2. If the transmission is not disconnected your input is correct, so you can ignore the warning.