Wha's the purpose of ResultantReactions.any?

Hi,

I am still studying the stairs assist exo model. In the Exo.any, the author first introduced the Exo model, then the external force. Then the reference nodes were built for the body model and Exo model. Followed by an interface model. For the KJ interface model, KinJoint.any was used to define the driver. But I don't know why the ResultantReactions.any is still needed. Till now, there are the Exo model and the human model. The nodes and responding drivers are defined. Why do we need to compute the resultant forces of thigh, shank, and food? If I don't need this output, can I omit this ResultantReactions.any? Thanks!

Best,

TJ

Hi TJ,

Resultant reactions are used to express the interface outputs in specific reference frames. The idea was to compare the outputs from the different interface models and this was done using the resultant reactions file to generate equivalent outputs from the interfaces.

You are right, resultant reactions is not needed to make the model work. That is, the kinematics and kinetics are taken care of elsewhere. But if you omit only this file, then maybe the code will complain because probably there is another file that exports the outputs to a csv file and it would look for the outputs defined in the resultant reactions file.

Best
Dave

P.S. For other users, the example referred to in this question is available here.