Gravity issue in a 3-RPS parallel robot

I've got a 3-RPS parallel robot consisting of one base and one moving platform and three limbs, my problem is when we apply gravity the moving platform falls down (eventhough we have forces in each limb). I would be so thankful if any body could give any sort of help.

Answer 1

[Steve Miller]

Here are some suggestions:

1. Apply motion actuation at each joint to keep them locked in place and measure the amount of torque required to hold them there.
2. Try turning gravity off (setting the vector to [0 0 0]) and see if the results change. Perhaps your torques are too small.

If you post the model we might be able to offer more suggestions.

--Steve