What can Webots be used for?

• Mobile robot prototyping for academic research and industry.
• Robot locomotion research, including legged robots.
• Multi-agent and swarm robotics.
• Adaptive behavior experiments such as genetic algorithms.
• Teaching robotics and running robot contests.

What you should know first

You can use Webots with C, C++, Java, Python, or MATLAB. If you want to create custom robot models or environments, it also helps to know some 3D graphics concepts and the VRML97 descriptive language.

A Webots simulation typically includes:

1. A world file (.wbt) that defines robots and the environment.
2. Controller programs that run the robot logic.
3. Optional physics plugins for custom physics behavior.

Create the first project

Open Webots and go to Wizards > New Project Directory. Name the project bug, name the world file bug.wbt, and select the options to add a rectangular arena.

Before adding a robot, change the arena size from 1 x 1 m to 2 x 2 m by editing RectangleArena > floorSize.

Add an e-puck robot

Click Add in the scene tree, then choose PROTO nodes > robots > gctronic > e-puck > E-puck. The robot should appear in the arena. Save the world before running the simulation.

The e-puck has a default obstacle avoidance controller, so you can run the simulation immediately to see the robot move.

Create a simple controller

Go to Wizards > New Robot Controller, choose Python, and name the controller move_forward.

"""move_forward controller."""
from controller import Robot

robot = Robot()
time_step = 32
max_speed = 6.24

left_motor = robot.getMotor("left wheel motor")
right_motor = robot.getMotor("right wheel motor")

left_motor.setPosition(float("inf"))
right_motor.setPosition(float("inf"))
left_motor.setVelocity(0.0)
right_motor.setVelocity(0.0)

while robot.step(time_step) != -1:
    left_speed = max_speed * 0.5
    right_speed = max_speed * 0.25

    left_motor.setVelocity(left_speed)
    right_motor.setVelocity(right_speed)

Set the e-puck controller to move_forward and run the simulation. Try changing the wheel speeds to make the robot move in a circular path.

Line following with IR sensors

Add infrared ground sensors to the e-puck by using the groundSensorsSlot. Name two sensors ir0 and ir1, then enable them in the controller.

from controller import Robot

robot = Robot()
time_step = 32
max_speed = 6.24

left_motor = robot.getMotor("left wheel motor")
right_motor = robot.getMotor("right wheel motor")
left_motor.setPosition(float("inf"))
right_motor.setPosition(float("inf"))
left_motor.setVelocity(0.0)
right_motor.setVelocity(0.0)

left_ir = robot.getDistanceSensor("ir1")
right_ir = robot.getDistanceSensor("ir0")
left_ir.enable(time_step)
right_ir.enable(time_step)

while robot.step(time_step) != -1:
    left_ir_value = left_ir.getValue()
    right_ir_value = right_ir.getValue()

    left_speed = max_speed * 0.25
    right_speed = max_speed * 0.25

    if left_ir_value > right_ir_value and 6 < left_ir_value < 15:
        left_speed = -max_speed * 0.25
    elif right_ir_value > left_ir_value and 6 < right_ir_value < 15:
        right_speed = -max_speed * 0.25

    left_motor.setVelocity(left_speed)
    right_motor.setVelocity(right_speed)

Original standalone tutorial: https://pratik-ingle.github.io/webots_tutorial/