ROS Interfaces

There is a ROS interface and a ROS2 interface available for CoppeliaSim, both duplicate the C++ ROS/ROS2 API with good fidelity. They are implemented via the simROS plugin and simROS2 plugin. Use the catkin tools to build those packages, otherwise you might run into difficulties.

As an example, a vision sensor ROS2 publisher could look like:

#python

def sysCall_init():
    sim = require('sim')
    simROS = require('simROS')

    self.visionSensor = sim.getObject('/Vision_sensor')

    # Enable an image publisher:
    self.pub = simROS2.createPublisher('/image', 'sensor_msgs/msg/Image')
    simROS2.publisherTreatUInt8ArrayAsString(self.pub)

def sysCall_sensing():
    # Publish the image of the vision sensor:
    img, resolution = sim.getVisionSensorImg(self.visionSensor)
    data = {}
    data['header'] = {'stamp': simROS2.getTime(), 'frame_id': 'a'}
    data['height'] = resolution[1]
    data['width'] = resolution[0]
    data['encoding'] = 'rgb8'
    data['is_bigendian'] = 1
    data['step'] = resolution[0] * 3
    data['data'] = img
    simROS2.publish(self.pub, data)

def sysCall_cleanup():
    simROS2.shutdownPublisher(self.pub)

--lua

function sysCall_init()
    sim = require('sim')
    simROS = require('simROS')
    visionSensor = sim.getObject('/Vision_sensor')

    -- Enable an image publisher:
    pub = simROS2.createPublisher('/image', 'sensor_msgs/msg/Image')
    simROS2.publisherTreatUInt8ArrayAsString(pub)
end

function sysCall_sensing()
    -- Publish the image of the vision sensor:
    local img, resolution = sim.getVisionSensorImg(visionSensor)
    data = {}
    data.header = {stamp = simROS2.getTime(), frame_id = 'a'}
    data.height = resolution[2]
    data.width = resolution[1]
    data.encoding = 'rgb8'
    data.is_bigendian = 1
    data.step = resolution[1] * 3
    data.data = img
    simROS2.publish(pub, data)
end

function sysCall_cleanup()
    simROS2.shutdownPublisher(pub)
end

The subscriber on the other hand could look like:

#python

def sysCall_init():
    sim = require('sim')
    simROS = require('simROS')
    
    # Enable an image subscriber:
    self.sub = simROS2.createSubscription('/image', 'sensor_msgs/msg/Image', image_callback)
    simROS2.subscriptionTreatUInt8ArrayAsString(self.sub)

def image_callback(msg):
    # Here we have received an image
    pass

def sysCall_cleanup():
    simROS2.shutdownSubscription(self.sub)

--lua

function sysCall_init()
    sim = require('sim')
    simROS = require('simROS')
    
    -- Enable an image subscriber:
    sub = simROS2.createSubscription('/image', 'sensor_msgs/msg/Image', 'image_callback')
    simROS2.subscriptionTreatUInt8ArrayAsString(sub)
end

function image_callback(msg)
    -- Here we have received an image
end

function sysCall_cleanup()
    simROS2.shutdownSubscription(sub)
end

Also have a look at the ROS tutorial and the external controller tutorial.