Webots

What is Webots

Webots allows you to launch a simulated NAO moving in a virtual world.

It offers a safe place to test behaviors before playing them on a real robot.

Since Webots 8, a module named nao_qi is available for the owners of a Webots for NAO license. It provides predefined NAO simulations and with their ready-to-use controllers.

Warning

Webots for NAO license owners only have access to a subset of Webots features. They cannot use other robots nor create new robot controllers.

Installing Webots

To install Webots:

Step	Action
	Retrieve the installer Webots 8 for your operating system: Windows: webots-8.x.x_setup.exe, Mac: webots-8.x.x.dmg, Linux 32 bits: webots-8.x.x-i386.tar.bz2, Linux 64 bits: webots-8.x.x-x86-64.tar.bz2. You can download the latest release from Aldebaran Community website. For further details, see: Downloading & Installing Aldebaran Software.
	Uninstall completely any old version of Webots.
	Launch the installer then follow the step-by-step instructions. For further details or in case of trouble, see the Chapter 1: Installing Webots in Webots online user guide here: http://www.cyberbotics.com/guide/

Getting started

Launching a simulated robot

Step	Action
	Launch Webots.
	Choose File > Open Sample World... and select the entry robots/aldebaran/nao.wbt

Connecting Choregraphe to the simulated robot

Step	Action
	Launch Choregraphe.
	Choose Connection > Connect to or click the Connect to button.
	Select your simulated robot (the name should include the name of your computer). Its icon should be: In Choregraphe, you can now: control the virtual robot with the Robot view panel and check what the virtual robot is seeing in the Video monitor panel.

Testing a behavior in Webots

Step	Action
	Make sure you have launched a simulated robot and have connected Choregraphe to it. For further details see: Launching a simulated robot and Connecting Choregraphe to the simulated robot.
	In Choregraphe, create a behavior. For example, test the Tai Chi Chuan box.
	Make sure the Stiffness is on or click the Wake Up button.
	Click the Play button and follow the behavior both in Choregraphe and in Webots.
	Try to modify your point of view. For further details, see: How do I navigate in 3D world? in the Help menu.

Monitoring the simulated NAO

Step	Action
	In Webots, double-click the robot. The panel below appears.
	Choose one of the tabs and select the data you want to monitor.

Customizing NAO’s worlds

Adding an object

Let’s add a table, for example:

Step	Action
	Make sure the simulation is stopped. Otherwise, choose, Simulation > Stop then File > Revert World.
	In the Scene Tree, select the last node.
	Click the Add a new object button and select this object: PROTO > objects > indoor > tables > Desk (Solid)
	Click the Add button.

Moving objects

Let’s play with objects in order to learn how to move them.

Step	Action
	Make sure the simulation is stopped. Otherwise, choose, Simulation > Stop.
	In the Scene Tree, select the last node.
	Click the Add a new object button and select this object: PROTO > objects > indoor > fruits > FruitBowl (Solid)
	Click the Add button.
	Try to put the fruit bowl on the table. For further details, see: How do I move an object? in the Help menu.

NAO and Webots

Read the Section 8.2 Using the NAO robot of the Webots user guide to learn more about managing one or several NAOs using Webots.

Tips

I can’t see my simulated robot in the Choregraphe Browse robots panel.

Make sure the simulation is not stopped in Webots.

Navigating I lost sight of NAO.

Choose View > Restore Viewpoint or press F6 key. The view is reset to the origin point.

Troubleshooting

If the simulation is slow, you will have a warning displayed in the console of Webots:

A possible approach to improve the simulation is to reduce the number of frames sent to NAOs cameras by changing the “FPS” field of the “WorldInfo” node in the Scene Tree:

Try some low values (e.g. 1, 5 or 10) to speed up the simulation.