We face some problems with modeling forces on humans.
We have modeled several simple human actions and now want our mannequin to be subject to some forces applied to the hand. Moreover, we would want the human to adapt its pose to the force. But we don't get it working the way we would expect.
Lower-back analysis suggests that forces are in effect, but there is no change of the pose (Force-based posturing is switched on, no restrictions for the feet). The documentation is quite short on this part...
Anyone suggestions about our thinking error?
Solved! Go to Solution.
Thank you for the question!
What verison of Jack are you using?
In v7.1, the "Force Based Posturing" functionality can be accessed from the Human Posturing Tool.... available from the Modules Menu.
In v8.0 this is part of the Human Control Panel.
Note: in both versions, only forces applied to the palmcenter sites will be considered during forced based posturing....
Sorry - I just noticed your question was specific to PS Human. Note - here the palmcenter site information is applicable. In PS there is also an option to "Enable Force Based Posturing" in the Posturing Dialog. This needs to be checked.
I got it working in Jack 7.1, but not in Jack 8.0 (x64), nor in PS Human 10.1. Settings applied as you mentioned, did the following to be precise:
-Created new human
-Posture to "stand_hands_ahead"
-Applied forces to both palm centers, 150 N front to back (say, pushing against something)
-No foot restrictions, position lock on both hands
-In Jack 7.1: Solve
-In PS Human: enable force-based posturing
Result in Jack 7.1, as expected, but nothing in PS Human.
In PS the posture should be automatically adjusted whenever you assign a different force to any of the palmcenter locations.
Note: the posture will only be updated when there is "something to solve".
In the human posturing panel, try setting the hands fixed and then adjust the force.
You can also drag the hand around with the manipulator.
With this you should hopefully see the force based posturing kick in.
If not - just let me know and I can e.g. post a video showing the steps.
Just tried it out. I do not get it working the way I like to. Maybe Jack needs to grasp something first?
The use case here is to get the mannequin pull some device to pick up and move a part. There is some force needed to pass the friction level. The pose should reflect this application of force.
It is not (yet) clear to me when proper triggers to solve the posture happen. And why there is a difference between my Jack 7.1 outcome and the lack of success in PS Human.
cards PLM Solutions BV
Finally I obtained a result that comes a bit close to the desired result. The trick seems to be 1) to have the foot restriction zone active and 2) to play around a bit with the hand placement.
My guess is that an approximate starting posture helps to guide the force solver towards a credible result. We will add some good postures to the database (pulling/pushing/lifting a manipulator).
I consider the issue solved. Thanks!