Hello, I'm playing around with some simple gripping actions in Gazebo-7. At the beginning, I always had the problem, that the object to grip always slipped out of my gripper. After some time I just increased the and parameters in the gazebo-referenc tag (to approx 10). I'm now wondering about the meaning of these parameters. The description in the Gazebo Tutorial says: "Friction coefficients μ for the principal contact directions along the contact surface as defined by the Open Dynamics Engine (ODE) (see parameter descriptions in ODE's user guide)". Section 7.3.7. of the ODE guide, tells the same but section 3.11. tells something about "Friction Approximatin" where the parameters seem to be forces rather than friction coefficients. This section also tells, that there are two approximation models to choose. So the question popped up for me, which one is used in Gazebo-7?