Bipedal walking robot flying to infinity

Hi,

My bipedal robot will fly upward to infinity once I start the simulation. What's the reason?

Here is my framework and updated diagram.

[Divya Yerraguntla]

Could you attach your Simulink file?

Answer 1

[Michael McGeehan]

Could be that you have gravity turned off. Or the contact model parameters are mismatched with the mass of the model.