My robot is driving to slow with gazebo_ros_diff_drive

edit

Hi

I figured it out there was a math problem: The wheel velocity was computed incorrect. The wheel speed has to be divided by the radius and not the diameter. changing the lines 309/310 to solved my problem

joints_[LEFT]->SetVelocity(0, wheel_speed_[LEFT] / (wheel_diameter_ / 2.0));
joints_[RIGHT]->SetVelocity(0, wheel_speed_[RIGHT] / (wheel_diameter_ / 2.0));

I will make a pull request for my solution

Greetings Max