I am trying to simulate a small 4WD differential drive robot in Gazebo. I am using the erratic_gazebo_plugin diffdrive_plugin controller which I modified to work with a 4WD system.
My simulation works fine when I use the erratic's wheel diameter of .15 m. But when I change the diameter to .1 m for my wheels the odometry published claims the robot is moving at .7 m/s despite me commanding 1 m/s in the Twist msg.
I am using a moment of inertia of
ixx = 0.01 ;ixy = 0 ; ixz = 0 ; iyy= .01 ; iyz = 0 ; izz = .01.
My wheel mass is
I think my issue has to do with the
mu1, mu2, kp, and kd parameters currently I have them set at
mu1 = 200 ; mu2 = 100 ; kp = 1000000 ; and kd = 1.
I guess my issue is I am unclear how these parameters are used in the simulator as well as what is the effect decreasing the wheel diameter. I can trick the simulator by decreasing my wheel diameter in the controller's parameters but I would like to understand why this phenomenon occurs.
Any help would be much appreciated.
Post score: 2
Comment by Arkapravo on 2012-11-06:
@Malvarado Gazebo has a known issue with very low moments of inertia
Comment by malvarado on 2012-11-07:
I am using the moment of inertia values that are used in the erratic URDF. What do you recommend I increase them to?
Comment by SL Remy on 2013-02-01:
was this concern ever resolved?
Comment by malvarado on 2013-03-07:
No this was never resolved
Comment by dmngu9 on 2015-02-03:
hey, im trying to add differential drive to my custom robot but dont know how. Can you give me any instructions please? I have my robot urdf file from solidworks already