Sensor implementation

edit

The packages on the page you list almost exclusively support real hardware, so sensors you would install physically on a real robot system.

These so called drivers (just as you would call them under Windows or OSX) are typically not used with simulated robots, as the simulators either don't support simulation at that level of detail and/or the models don't use / support any of those sensors.

Perhaps already clear, but just to emphasise: ROS is not primarily targetting simulations. It's a software framework which can be used with both real and simulated hardware/robots. It's relatively easy to setup ROS applications which are agnostic to whether a real robot or a simulated one is what they are controlling, but you will need to be aware of the difference and not attempt to use drivers for real hardware with a simulated robot.

As to the issue with apt-get there are many potential causes. You'll have to provide more information about things such as which OS you are using, which version, which version of ROS you've installed and how you installed it.

Edit:

Actually I am working on theconstructsim.com on Ubuntu 16.04 + ROS Kinetic + Gazebo 7 with different simulation environments and robots. As far as I could understand from the sources I read, sensor implementation can be done from the shell.

If you're using The Construct's environment I would not be able to help you. I've not used that, so I would not know whether or how you'd install additional packages.

You'd have to ask them.

For a regular installation of ROS, such as on your own PC, laptop or even in a VM, the command line you showed would/should work. But to reiterate: it would not help you with your simulation, as the package you mention (usb_cam) is for working with real hardware, not with a simulator.

As you seem to be working with Gazebo, you may want to take a look at gazebosim.org/tutorials, especially the categories Build a Robot and Connect to ROS. They should show you that with Gazebo, you use virtual sensors, but those don't use regular driver nodes, but directly publish their sensor data from the simulation.