What is the measurement unit for cmd_vel in android_teleop?

edit

Yes, the twist topics generally use SI units. And also yes, for android_teleop, the linear and angular velocities are normalized.

The piece of code you are looking for that does the math is in the JoystickView class of android_app_manager

  motionX = (motionEvent.getX() - (arg0.getWidth() / 2)) / (arg0.getWidth());
  motionY = (motionEvent.getY() - (arg0.getHeight() / 2)) / (arg0.getHeight());

The motion event is what you perform on your touchscreen and the arg0 here is the display view. The reason the values are normalized are probably so you can have the same display view for all robots instead of having to set min and max limits each time.

In your case, the easiest thing is to multiply the output you are getting by scale factors - one for linear velocity and one for angular velocity based on the corresponding max values for your robot.

Hope this helps.