Webots is a free and open-source 3D robot simulator used in industry, education and research. The Webots project started in 1996, initially developed by Dr. Olivier Michel at the Swiss Federal Institute of Technology in Lausanne, Switzerland and then from 1998 by Cyberbotics Ltd. as a proprietary licensed software. Since December 2018, it is released under the free and open-source Apache 2 license. Webots includes a large collection of freely modifiable models of robots, sensors, actuators and objects. In addition, it is also possible to build new models from scratch or import them from 3D CAD software. When designing a robot model, the user specifies both the graphical and the physical properties of the objects. The graphical properties include the shape, dimensions, position and orientation, colors, and texture of the object. The physical properties include the mass, friction factor, as well as the spring and damping constants. Simple fluid dynamics is present in the software. Webots uses a fork of the ODE for detecting of collisions and simulating rigid body dynamics. The ODE library allows one to accurately simulate physical properties of objects such as velocity, inertia and friction. Webots includes a set of sensors and actuators frequently used in robotic experiments, e.g. lidars, radars, proximity sensors, light sensors, touch sensors, GPS, accelerometers, cameras, emitters and receivers, servo motors, position and force sensor, LEDs, grippers, gyros, compass, IMU, etc. The robot controller programs can be written outside of Webots in C, C++, Python, ROS, Java and MATLAB using a simple API. Webots offers the possibility to take screenshots and record simulations movies. Webots worlds are stored in cross-platform.wbt files which format is based on the VRML language. It is also possible to import and export Webots worlds or objects in the VRML format. Users can interact with a running simulation at any time, i.e., it is possible to move the robots and other object with the mouse while the simulation is running. Webots can stream a simulation on web browsers using WebGL.
Web interface
Since August 18, 2017, the robotbenchmark.net website has offered free access to a series of robotics benchmarks based on Webots simulations through the Webots web interface. Webots instances are running in the cloud and the 3D views are displayed in the user browser. From this web interface, users can program robots in Python and learn robot control in a step-by-step procedure.
Controller programming example
This is a simple example of C/C++ controller programming with Webots: a trivial collision avoidance behavior. Initially, the robot runs forwards, then when an obstacle is detected it rotates around itself for a while and then resumes the forward motion.
