aero base keeps sliding on Gazebo

[sasabot]

As in the below images (see the position of the robot in relation to the red axis), the robot constantly keeps on moving in gazebo (version 9.0.0).

Note, no commands are sent between Fig.1 and Fig.2 (only the simulator is running for about 5 simtime minutes). Note, for the lifter gain, I'm using the ones from #384. Note, the robot only starts slipping after some pose is sent to the robot. Note, Fig.3, 4 is the same problem on a different pose. In these two images, the robot is very shaky and slips much faster than the poses in Fig.1 and 2 (less than 5 simtime minutes between Fig. 3 and 4).

Regarding this issue, I have several questions.

@y-shiigi How were the inertia parameters calculated for the base? Could you provide the specific equations you used (to me, it looks like some random number was copied and pasted) Reference: #138

@YoheiKakiuchi Do you think this problem is related to mass, inertia, friction parameters? or could it be different reasons? Any suggestions for handling this problem?

Thanks in advance

Fig. 1

Fig. 2

Fig. 3

Fig. 4