How to predict GRF with different terrians

[yixing]

Hi all,
I am thinking about whether it is possible to predict GRF when people walk on different terrains, such as the GRF of stairs/ramps ascent and descent. In my opinion, it would be possible if we can edit the ‘the ground system’ to make it change with kinematic data in AnyMoCap framework.
Can anyone tell me any ideas about this? Thanks a lot.

[toerholm (Søren Tørholm)]

Hi Yixing,

You are right this is possible you can simply change the reference frame for the node the plate are inserted into by changing which frame “PLATE_BASE_FRAME” points to, see the script below taken from the file “ForcePlates_GRFRediction.any”

 FootPlateConditionalContact GRF_Prediction_Right(
  NORMAL_DIRECTION = "Y",
  NUMBER_OF_NODES = 25,
  NODES_FOLDER = FootNodes,
  SHOW_TRIGGER_VOLUME = ON,
  PLATE_BASE_FRAME = Main.EnvironmentModel.GlobalRef) =
  {
    CreateFootContactNodes25 FootNodes(foot_ref = 
    Main.HumanModel.BodyModel.Right.Leg.Seg.Foot) = {};
    
    // Additional force plate settings
    Settings = 
    {
      LimitDistHigh = 0.015; // Vertical height
    };
  };

So try to make additional frames inside the GlobalRef and make the plate point at this subframe which can be different than GlobalRef.

Best regards
Søren