Player/Stage is a robot simulation tool, it comprises of one program, Player, which is a Hardware Abstraction Layer. That means that it talks to the bits of hardware on the robot (like a claw or a camera) and lets you control them with your code, meaning you don't need to worry about how the various parts of the robot work. Stage is a plugin to Player which listens to what Player is telling it to do and turns these instructions into a simulation of your robot. It also simulates sensor data and sends this to Player which in turn makes the sensor data available to your code.
A simulation then, is composed of three parts:
- Your code. This talks to Player.
- Player. This takes your code and sends instructions to a robot. From the robot it gets sensor data and sends it to your code.
- Stage. Stage interfaces with Player in the same way as a robot's hardware would. It receives instructions from Player and moves a simulated robot in a simulated world, it gets sensor data from the robot in the simulation and sends this to Player.
Together Player and Stage are called Player/Stage, and they make a simulation of your robots.
These instructions will be focussing on how to use Player/Stage to make a simulation, but hopefully this will still be a useful resource for anyone just using Player (which is the same thing but on a real robot, without any simulation software).
1.1 - A Note on Installing Player/Stage¶
Instructions on how to install Player/Stage onto your computer aren't really the focus of this document. It is very difficult though. If you're lucky the install will work first time but there are a lot of dependencies which may need installing.
For computers running Ubuntu there is a very good set of instructions here (including a script for downloading the many prerequisites): http://www.control.aau.dk/~tb/wiki/index.php/Installing_Player_and_Stage_in_Ubuntu
For OSX users you might find the following install instructions useful: http://alanwinfield.blogspot.com/2009/07/installing-playerstage-on-os-x-with.html
Alternatively, you could try the suggestions on the Player ``getting help'' page: http://playerstage.sourceforge.net/wiki/Getting_help
Even after it's installed, you may need to do some per-user setup on your
system. For example, on our system, the following two lines (adapted as
needed to your particular system) need to be
added to each user's
$HOME/.bashrc file (or to the system-wide one):
export LD_LIBRARY_PATH=/usr/local/lib64:$LD_LIBRARY_PATH} export PKG_CONFIG_PATH=/usr/local/lib64/pkgconfig:$PKG_CONFIG_PATH}
1.2 - A Note about TRY IT OUT sections¶
There will be sections scattered throughout this tutorial labeled TRY IT OUT
that explain how to run examples. You'll need to download the example
which will contain the files. In these sections, you'll be given commands to
type in a terminal
window (or bash shell). They'll be shown prefixed with a carrot
typeset in monospace font. For example,
means to go to a terminal window and type the command given (
> character, then hit return.
In many cases, you'll need to run the first command (
player configfile.cfg) in the background, since it doesn't quit till player is
done. To do this, you add an ampersand (
&) after the command. So if you
player configfile.cfg in a terminal, it will appear to freeze. If
you however type
player configfile.cfg & into the terminal, it will start
up player and return. Player will however print information and debugging
messages to your terminal, which can be a bit confusing at times.
When you use files, you should examine the files to see how they are working, just running the examples will not teach you (as) much!
1.3 - TRY IT OUT (Preparation)¶
- If you haven't already, download the sample code from http://github.com/NickelsLab/Player-Stage-Manual/archive/latest.zip
- Next, you'll need to extract the sample code. To do this, open a
terminal and cd to the directory where you put the file
master.zip, then extract using zip. Yes, there are GUI-based ways to do this too. I won't cover them here.
- I'll assume that you want to put this directory in your home directory. If not, just replace the commands given with the appropriate directory.
- I'll likewise assume that you downloaded the code into $HOME/Downloads. (Again, your specific path may differ.)
- (From here on out, I'll just say that your extracted source code is in
<source_code>for brevity and generality.)
> cd $HOME > unzip $HOME/Downloads/Player-Stage-Manual-master.zip > cd $HOME/Player-Stage-Manual-master/code > ls
At this point, you should see one directory for each setion of this manual,
which contain the code examples for the respective chapters, and one,
bitmaps, that has pictures used in several different examples.
1.4 - TRY IT OUT¶
First we will run a world and configuration file that comes bundled with
Stage. In a terminal window, you will navigate to the Stage/worlds folder, by
default (in Linux at least) this is
the following commands to run the ``simple world'' that comes with
> cd /usr/local/share/stage/worlds > player simple.cfg
Assuming Player/Stage is installed properly you should now have a window open which looks like the figure below. Congratulations,you can now build Player/Stage simulations!