How to edit parameters of auto tire entity?

Hi Sudip,

The auto tire warnings you are seeing are just warnings, as the validity range specified in the tire property file is being exceeded. For example, the following ranges are set in the property file:

$-------------------------------------------------vertical_force_range
[VERTICAL_FORCE_RANGE]
FZMIN                    = 100               $Minimum allowed wheel load         
FZMAX                    = 10000             $Maximum allowed wheel load         
$------------------------------------------------------long_slip_range
[LONG_SLIP_RANGE]
KPUMIN                   = -1.5              $Minimum valid wheel slip         
KPUMAX                   = 1.5               $Maximum valid wheel slip         
$-----------------------------------------------------slip_angle_range
[SLIP_ANGLE_RANGE]
ALPMIN                   = -1.5              $Minimum valid slip angle         
ALPMAX                   = 1.5               $Maximum valid slip angle         
$-----------------------------------------------inclination_slip_range
[INCLINATION_ANGLE_RANGE]
CAMMIN                   = -0.175            $Minimum valid camber angle         
CAMMAX                   = 0.175             $Maximum valid camber angle         

Therefore, if the vertical force on a tire ever goes below 100 N, it will trigger that warning.

The error message you are seeing is independent of the tire warnings.

The Static simulation you are trying to run fails due to an error found in the XML file. 

Please check the LOG file for more information by searching for ERROR.

It will likely show that there is an expression that is not being evaluated properly, or something along those lines.

If you upload the LOG file, we can likely help you find out what went wrong.

Hope this helps!

Adam Reid

Please find the attached log file below. 

Please find the attached log file below. 

 

Hi Sudip,

The LOG file unfortunately does not show what I expected. Does the message window show any information about errors?

You could also try a different simulation type to see if new errors are produced that may help you figure out what is wrong with the static setup.

Hope this helps!

Adam Reid

Hi Sudip,

The LOG file unfortunately does not show what I expected. Does the message window show any information about errors?

You could also try a different simulation type to see if new errors are produced that may help you figure out what is wrong with the static setup.

 

Hope this helps!

Adam Reid

Hi Adam,

As of now message window doesn't show any errors.

I will try in different simulation types for new errors to figure out what is wrong with static setup and will let you know.

Thanks & Regards

Sudip Chavan

Hi,

I have a very similar error and I can not find any solutions. Did you manage to find one Supid ? I also tried different simulation scenarios but the errors stay the same. 

Best regards,

Angus Duff. 

Hi,

I have a very similar error and I can not find any solutions. Did you manage to find one Supid ? I also tried different simulation scenarios but the errors stay the same. 

 

Best regards,

Angus Duff. 

Hi Angus,

Sudip had 2 separate issues earlier in this post:

1. Warnings were reported based on the valid ranges set in his tire file, which are just try alert the User that the tire files are operating outside of the valid range set by the User.
2. The static portion of his simulation was failing due to initialization issues with his vehicle model

If you are encountering failures within your driving events, I recommend that you isolate your vehicle from the driver model and event analyses to find any construction issues. Please try the following:

1. Make a copy of your MDL for this debugging process
2. In the copy, delete the Altair Driver and any events you had previously created.
3. Add a fixed joint from the vehicle chassis to ground
4. Run the Default Analysis as Transient for a few seconds with default global simulation settings.

Ideally, the vehicle will be held in place and the suspension will sag. Since there is no Static portion of the simulation, it should initialize and if there is anything significant happening that is causing the Static failure, you will likely see the issue. Make the correction in your full model, and then try the driving event again.

Please give that a try and let me know how it turns out.

Hope this helps!

Adam Reid

Hi All,

I recently encountered the error FZMIN < 100.
Can I modify the constraint directly so that FZMIN < 0?

From the previous reply,
It seems that it is recommended to perform a static analysis first.
How can I add it directly to an existing analysis?

Best regards,
Ted

Hi @TedTsai,

For full vehicle simulations that use events from the Entity Browser, there already is a STATIC event completed before the event starts. That's how the initial speed and initial attitude of the vehicle is calculated before completing either a double lane change, straight line acceleration, etc.

This warning appears when there is no vertical load measured on the tires, and is commonly from where the road is positioned relative to the tires. The STATIC simulation at the beginning of the simulation will account for a poorly positioned road, but the warning will still appear.

PS. Please begin a new Discussion if the accepted solution to this thread is not suitable for you.

Hope this helps!

Adam Reid