thankyou for a very good scaling webcast the other day. It seemed to focus on the new 7.1 repository, but I am currently using the TLEM model. I am currently using the UniformScaling parameter in my models, but I am looking to use the LengthMassFat scaling law to give a better representation of the ‘normal’ human anatomy.
I see in the DataForConfigFile (for the optimisation) there is an option to use LengthMassScaling but I haven’t been able to implement it in my models accurately. I see in the GaitUniMiami model that the scaling laws can be changed with no obvious physical adverse effects (just from viewing the model), but it does change the contact forces.
Can you give me some recommendations for scaling laws within the TLEM model and how to implement them with the optimisation method?
The length mass fat scaling law is implemented in GaitApplication2. As you have already seen, it has to be changed in the DataForConfigFile.any. It is called LENGTHMASS. Besides changing it there, you also have to change the scaling law in your MarkerPlacementModel and the HumanModel used in the OptStudy.
Please notice that when you have changed the scaling law, you have to re-run GaitApplication2 because the changed geometrical scaling law will also affect the determined motion of the model and of course also the calculated segment scaling and local marker coordinates.
Finally, it is also important that you make sure that you have specified the correct segment masses in your AnyMan.any file before you save a new ModelGait.txt file because these are part of the scaling law.
Last but not least, the length mass scaling law for the TLEM model has not been used yet, so please be aware if you encounter any problems.
If you have further questions, please ask again.
Michael Skipper Andersen
AnyBody Technology A/S
thanks for the advice, its all up and running now with pleasing results. Did have some problems with the knee inverting, but that seems to have been resolved now.
I’m sticking to PosVelAcc optimisation for the moment, I have the script for the variance study ready for you as soon as possible.