Does the THIV function use the same sign convention as EN 1317/SAE J211?

[DavidCorless]

I am trying to work out the THIV from a test involving a car hitting a pole. For this particular test the THIV function in Diadem works out the time of flight/collision to occur well after the x-displacement of 0.6m, and instead says that the time of collision is at the time the y-displacement is 0.3m. I didn't think this correct, as the vehicle showed very little y-direction movement. When I inverted the x-direction acceleration data the THIV function works out that the time of collision occurs much earlier, when the x-displacement is at 0.6m.

• I know it isn't a big problem to invert the channel each time for the THIV function, but does that mean the rest of the function doesn't match the vehicle sign convention as stated in EN 1317 and SAE J211(positive directions are x=forward, y=right, z=down)?

• What sign convention does this function use?

• Is this the reason why Diadem's THIV function doesn't match my calculations in Excel?

I'm using Diadem 9.1 service pack 2c, and the THIV function states that it is version '100'.

Thanks,

David

[Walter_Rick]

Hi David,

I'm very sorry, but you found a bug in this mathematically calculation. It is fixed in DIAdem 11.1.

Greetings

Walter

[DavidCorless]

So there's no way to get it to work without purchasing a $5k upgrade?

[Otmar]

Hello David,

We are very sorry that you have run into trouble with a bug in DIAdem. 

The DIAdem version you are using was released in January 2006 (that's DIAdem 9.1 SP2c - DIAdem 9.1 was first released in September 2004), that's about three and a half years ago. We have no way of maintaining code for multiple versions of DIAdem (we have since released version 10, 10.1, 10.2, 11 and just this week version 11.1).  Bugs are fixed at the time when we are made aware of them, that's why we release service packs on a regular basis.

We offer maintenance contracts for our software to allow customers to get regular upgrades and bug fixes for our products. We make the service packs available for free, but can only fix bugs in the most current version of DIAdem. It is impossible to maintain older versions of code (such as for instance version 9.1) and at the same time develop new versions. 

The upgrade to your software should not be $5,000 - is this the amount quoted to you by someone here at National Instruments? Feel free to contact me directly via email (NI email addresses are firstname.lastname@ni.com) or call our customer service desk at (800) 531-5066 and ask to be connected to me. Please have your DIAdem serial number ready and I will see what we can do for you to upgrade you to the latest version of DIAdem.

Best regards,