IEEE Robotics & Automation Magazine - March 2023 - 14

smart switches are placed in such a way that they can connect
directly to the Internet cloud to feed information about
bed states and manipulate bed positions in relation to ongoing
tasks. Also, a mobile service robot based on the TurtleBot2
robot platform is currently developed for applications such as
delivering small objects to users and interacting with them
during different tasks.
WEB-BASED MESSAGE PASSING INTERFACE FOR
ROBOTS USING ROBOT OPERATING SYSTEM
In the CARE project, we are working on cooperative control
of multiple robot groups and sensor groups using a common
interface for communication and exchanging information
between users and robots operating in the Living Lab. We
focus on developing a smart decentralized multirobot architecture
in which the most appropriate robot will come to a
user based on individual needs and requests.
A communication medium is necessary for different
robots to pass messages and share information. In the past,
plenty of research has been carried out about the topic of
communication and coordination among robots, and different
approaches have been proposed [22]. Recently, cloud
robotics has been getting a lot of attention [23]. It invokes
cloud-based technologies, such as cloud computing and storage,
parallel processing, and Internet services, for sharing
information among different robots and agents. All these
approaches are solutions crafted for a specific application,
and it is necessary to adapt and implement them for particular
applications.
In our framework, we have considered Robot Operating
System (ROS) the middleware for the sake of modularity and
also for the smooth integration of different sensor libraries into
our robot framework. Using ROS accelerates the development
process vastly and enables researchers to implement complex
systems quickly. ROS relies on host computer network
capabilities to distribute messages in a system. When multiple
robots are run in the same network to communicate with one
another, all their sensory information travels through the network
so that each robot is able to see the other robots' status
(i.e., the other robots' topics, where sensor readings are published,
messages, and services). This can be very data intensive:
when the number of sensors in the system increases, the
network traffic becomes larger, and this is duplicated when
an additional robot is added. To this end, creating a way for
different robots to transmit only the necessary data at the right
time is desirable.
To achieve this asynchronous communication among different
systems using ROS, we proposed an interface based on
the Node.js JavaScript runtime. Node.js is traditionally used to
create websites and back-end application programming interface
services; in this case, we use it to provide an interface
among systems. We based this architecture on the framework
proposed by Giller et al. [24] to connect ROS with IFTTT,
which is a software platform that connects apps, devices, and
services from different developers to trigger one or more automation
processes in those apps, devices, and services.
Living Room
Entrance
Care
Toilet and Bath
Bedroom
Kitchen
Operation Space
17,800 mm
Outdoor Space
INTERFACE STRUCTURE
The proposed interface's general layout can be seen in Figure
4. The interface was developed as a ROS node that creates
a webserver with custom webhooks that the developer can
specify via the launch file. The webserver interacts with ROS
in a bidirectional way: it can launch ROS services when a
webhook is triggered, or it can trigger a webhook in other
webservers when a specific type of
message is published in topics that the
webserver is subscribed to. The relations
between the webhooks and the
service to be launched (incoming information)
as well as the topic name and
the webhook to be triggered (outgoing
information) are easily configured in
the launch file, requiring no further
programming. The information among
systems is transmitted using the HTTP
protocol, and custom fields can be
added to the request as JavaScript
Object Notation (JSON) payload.
Bedroom
8,000 mm
FIGURE 3. The Aobayama Living Lab.
14 IEEE ROBOTICS & AUTOMATION MAGAZINE MARCH 2023
NETWORK REQUIREMENTS AND
WEBSERVER ADDRESS
With this architecture, we can have
multiple robots running their own
ROS core in their local loopback network,
which is much lighter and faster
than communicating over wireless networks.
If the robots were connected to
the same network, they would be able
10,000 mm
6,000 mm
4,000 mm 3,500 mm
IEEE Robotics & Automation Magazine - March 2023

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