# Basic kinematics of Mobile Robots - Proposed solution incorrect publisher

Hello,

Found in my environment, in the above course, excercise 2.2 in solution “convert_vels.py” for invoking the publisher, the solution provides:
self.left_wheel_pub = rospy.Publisher(’/joint2_position_controller/command’, Float64)
potentially my solution shows:
self.left_wheel_pub = rospy.Publisher(’/left_wheel_controller/command’, Float64, queue_size=1)
Regards
Christoph

Hello @mailenistdoof,

Yes, that’s right. It’s an error in the notebook. I will update it right now. Thanks for the feedback!