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Posts tagged with 'robotics'

Jeremie Deray

Disclosure: read the post until the end, a surprise awaits you!

Moving from ROS 1 to ROS 2 can be a little overwhelming.
It is a lot of (new) concepts, tools and a large codebase to get familiar with. And just like many of you, I am getting started with ROS 2.

One of the central pieces of the ROS ecosystem is its Command Line Interface (CLI). It allows for performing all kind of actions; from retrieving information about the codebase and/or the runtime system, to executing code and of course helping debugging in general. It’s a very valuable set of tools that ROS developers use on a daily basis. Fortunately, pretty much all of those tools were ported from ROS 1 to ROS 2.

To those already familiar with ROS, the ROS 2 CLI wording will sound very familiar. Commands such as roslaunch is ported to ros2 launch, rostopic becomes ros2 topic while rosparam is now ros2 param.
Noticed the pattern already ? Yes that’s right ! The keyword ‘ros2‘ has become the unique entry-point for the CLI.

So what ? ROS CLI keywords where broke in two and that’s it ?


Well, yes pretty much.

Every command starts with the ros2 keyword, followed by a verb, a sub-verb and possibly positional/optional arguments. The pattern is then,

$ ros2 verb sub-verb <positional-argument> <optional-arguments>

Notice that throughout the CLI, the auto-completion (the infamous [tab][tab]) is readily available for verbs, sub-verbs and most positional arguments. Similarly, helpers are available at each stage,

$ ros2 verb --help
$ ros2 verb sub-verb -h

Let us see a few examples,

$ ros2 run demo_node_cpp talker
starts the talker cpp node from the demo_nodes_cpp package.

$ ros2 run demo_node_py listener
starts the listener python node from the demo_nodes_py package.

$ ros2 topic echo /chatter
outputs the messages sent from the talker node.

$ ros2 node info /listener
outputs information about the listener node.

$ ros2 param list
lists all parameters of every node.

Fairly similar to ROS 1 right ?

Missing CLI tools

We mentioned earlier that most of the CLI tools were ported to ROS 2, but not all. We believe such missing tools is one of the barriers to greater adoption of ROS 2, so we’ve started added some that we noticed were missing. Over the past week we contributed 5 sub-verbs, including one that is exclusive to ROS 2. Let us briefly review them,

$ ros2 topic find <message-type>
outputs a list of all topics publishing messages of a given type (#271).

$ ros2 topic type <topic-name>
outputs the message type of a given topic (#272).

$ ros2 service find <service-type>
outputs a list of all services of a given type (#273).

$ ros2 service type <service-name>
outputs the service type of a given service (#274).

This tools are pretty handy by themselves, especially to debug and grasp an overview of a running system. And they become even more interesting when combined, say, in handy little scripts,

$ ros2 topic pub /chatter $(ros2 topic type /chatter) "data: Hello ROS 2 Developers"

Advertisement:
Have you ever looked for the version of a package you are using ?
Ever wondered who is the package author ?
Or which other packages it depends upon ?
All of this information, locked in the package’s xml manifest is now easily available at the tip of your fingers !

The new sub-verb we introduced allows one to retrieve any information contained in a package xml manifest (#280). The command,

$ ros2 pkg xml <package-name>
outputs the entirety of the xml manifest of a given package.
To retrieve solely a piece of it, or a tag in xml wording, use the --tag option,

$ ros2 pkg xml <package-name> --tag <tag-name>

A few examples are (at the time of writing),

$ ros2 pkg xml demo_nodes_cpp --tag version
0.7.6

$ ros2 pkg xml demo_nodes_py -t author
Mikael Arguedas
Esteve Fernandez

$ ros2 pkg xml intra_process_demo -t build_depend libopencv-dev
rclcpp
sensor_msgs
std_msgs

This concludes our brief review of the changes that ROS 2 introduced to the CLI tools.

Before leaving, let me offer you a treat.

— A ROS 2 CLI Cheats Sheet that we put together —

Feel free to share it, print and pin it above your screen but also contribute to it as it is hosted on github !

Cheers.

The post ROS 2 Command Line Interface appeared first on Ubuntu Blog.

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alfonsosanchezbeato

Niryo has built a fantastic 6-axis robotic arm called ‘Niryo One’. It is a 3D-printed, affordable robotic arm focused mainly on educational purposes. Additionally, it is fully open source and based on ROS. On the hardware side, it is powered by a Raspberry Pi 3 and NiryoStepper motors, based on Arduino microcontrollers. When we found out all this, guess what we thought? This is a perfect target for Ubuntu Core and snaps!

When the robotic arm came to my hands, the first thing I did was play with Niryo Studio; a tool from Niryo that lets you move the robotic arm, teach sequences to it and store them, and many more things. You can programme the robotic arm with Python or with a graphical editor based on Google’s Blocky. Niryo Studio is a great tool that makes starting on robotics easy and pleasant.

Nyrio studio for Ubuntu
Nyrio Studio

After this, I started the task of creating a snap with the ROS stack that controls the robotic arm. Snapcraft supports ROS, so this was not a difficult task: the catkin plugin takes care of almost everything. However, as happens with any non-trivial project, the Niryo stack had peculiarities that I had to address:

  • It uses a library called WiringPi which needs an additional part in the snap recipe.
  • GCC crashed when compiling on the RPi3, due to the device running out of memory. This is an issue known by Niryo that can be solved by using only two cores when building (this can be done by using -j2 -l2 make options). Unfortunately we do not have that much control when using Snapcraft’s catkin plugin. However, Snapcraft is incredibly extensible so we can resort to creating a local plugin by copying around the catkin plugin shipped with Snapcraft and doing the needed modifications. That is what I did, and the catkin-niryo plugin I created added the -j2 -l2 options to the build command so I could avoid the GCC crash.
  • There were a bunch of hard coded paths that I had to change in the code. Also, I had to add some missing dependencies, and there are other minor code changes. The resulting patches can be found here.
  • I also had to copy around some configuration files inside the snap.
  • Finally, there is also a Node.js package that needs to be included in the build. The nodejs plugin worked like a charm and that was easily done.

After addressing all these challenges, I was able to build a snap in an RPi3 device. The resulting recipe can be found in the niryo_snap repo in GitHub, which includes the (simple) build instructions. I went forward and published it in the Snap Store with name abeato-niryo-one. Note that the snap is not confined at the moment, so it needs to be installed with the --devmode option.

Then, I downloaded an Ubuntu Core image for the RPi3 and flashed it to an SD card. Before inserting it in the robotic arm’s RPi3, I used it with another RPi3 to which I could attach to the UART serial port, so I could run console-conf. With this tool I configured the network and the Ubuntu One user that would be used in the image. Note that the Nyrio stack tries to configure a WiFi AP for easier initial configuration, but that is not yet supported by the snap, so the networking configuration from console-conf determines how we will be able to connect later to the robotic arm.

At this point, snapd will possibly refresh the kernel and core snaps. That will lead to a couple of system reboots, and once complete  those snaps will have been updated. After this, we need to modify some files from the first stage bootloader because Niryo One needs some changes in the default GPIO configuration so the RPi3 can control all the attached sensors and motors. First, edit /boot/uboot/cmdline.txt, remove console=ttyAMA0,115200, and add plymouth.ignore-serial-consoles, so the content is:

dwc_otg.lpm_enable=0 console=tty0 elevator=deadline rng_core.default_quality=700 plymouth.ignore-serial-consoles

Then, add the following lines at the end of /boot/uboot/config.txt:

...
# For niryo
init_uart_clock=16000000
dtparam=i2c1=on
dtparam=uart0=on

Now, it is time to install the needed snaps and perform connections:

snap install network-manager
snap install --devmode --beta abeato-niryo-one
snap connect abeato-niryo-one:network-manager network-manager

We have just installed and configured a full ROS stack with these simple commands!

Nyrio robotic arm in action
The robotic arm in action

Finally, insert the SD card in the robotic arm, and wait until you see that the LED at the base turns green. After that you can connect to it using Niryo Studio in the usual way. You can now handle the robotic arm in the same way as when using the original image, but now with all the Ubuntu Core goodies: minimal footprint, atomic updates, confined applications, app store…

As an added bonus, the snap can also be installed on your x86 PC to use it in simulation mode. You just need to stop the service and start the simulation with:

snap install --devmode --beta abeato-niryo-one
snap stop --disable abeato-niryo-one
sudo abeato-niryo-one.simulation

Then, run Niryo Studio and connect to 127.0.0.1, as simple as that – no need at all to add the ROS archive and install manually lots of deb packages.

And this is it – as you can see, moving from a ROS debian based project to Ubuntu Core and snaps is not difficult, and has great gains. Easy updates, security first, 10 years updates, and much more, is a few keystrokes away!

The post Your first robotic arm with Ubuntu Core, coming from Niryo appeared first on Ubuntu Blog.

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Canonical

Drones, and their wide-ranging uses, have been a constant topic of conversation for some years now, but we’re only just beginning to move away from the hypothetical and into reality. The FAA estimates that there will be 2 million drones in the United States alone in 2019, as adoption within the likes of distribution, construction, healthcare and other industries accelerates.

Driven by this demand, Ubuntu – the most popular Linux operating system for the Internet of Things (IoT) – is now available on the Manifold 2, a high-performance embedded computer offered by leading drone manufacturer, DJI. The Manifold 2 is designed to fit seamlessly onto DJI’s drone platforms via the onboard SDK and enables developers to transform aerial platforms into truly smarter drones, performing complex computing tasks and advanced image processing, which in-turn creates rapid flexibility for enterprise usage.

As part of the offering, the Manifold 2 is planning to feature snaps. Snaps are containerised software packages, designed to work perfectly across cloud, desktop, and IoT devices – with this the first instance of the technology’s availability on drones. The ability to add multiple snaps means a drone’s functionality can be altered, updated, and expanded over time. Depending on the desired use case, enterprises can ensure the form a drone is shipped in does not represent its final iteration or future worth.

Snaps also feature enhanced security and greater flexibility for developers. Drones can receive automatic updates in the field, which will become vital as enterprises begin to deploy large-scale fleets. Snaps also support roll back functionality in the event of failure, meaning developers can innovate with more confidence across this growing field.

Designed for developers, having the Manifold 2 pre-installed with Ubuntu means support for Linux, CUDA, OpenCV, and ROS. It is ideal for the research and development of professional applications, and can access flight data and perform intelligent control and data analysis. It can be easily mounted to the expansion bay of DJI’s Matrice 100, Matrice 200 Series V2 and Matrice 600, and is also compatible with the A3 and N3 flight controller.

DJI has now counted at least 230 people have been rescued with the help of a drone since 2013. As well as being used by emergency services, drones are helping to protect lives by eradicating the dangerous elements of certain occupations. Apellix is one such example; supplying drones which run on Ubuntu to alleviate the need for humans to be at the forefront of work in elevated, hazardous environments, such as aircraft carriers and oil rigs.

Utilising the freedom brought by snaps, it is exciting to see how developers drive the drone industry forward. Software is allowing the industrial world to move from analog to digital, and mission-critical industries will continue to evolve based on its capabilities.

The post Customisable for the enterprise: the next-generation of drones appeared first on Ubuntu Blog.

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Sarah Dickinson

In Europe, the cost of running a cereal farm – cultivating wheat, rice, and other grains – has risen by 85% in the last 25 years, yet crop yields and revenues have stagnated. And while farms struggle to remain profitable, it won’t be long before those static yields become insufficient to support growing populations.

Reliance on tractors is at the heart of both of these problems. Not only are tractors immensely costly to buy and maintain, they are also inefficient.

The Small Robot Company (SRC), a UK based agri-tech start up, is working to overturn this paradigm by replacing tractors with lightweight robots. Developed using Ubuntu, these robots are greener and cheaper to run than tractors, and generate far higher yields thanks to AI-driven precision.

In this innovative deployment of robotics and AI for commercial farming, you’ll learn:

  • How the agri-tech start up is using robotics to grow crops and reduce waste, including its current partnership with a leading UK supermarket chain.
  • The emergence of Farming as a Service (FaaS) business model, eliminating the need to invest upfront in expensive machinery
  • How the use of Ubuntu in the cloud and on the hardware powers SRC’s three robots – Tom, Dick and Harry – plus Wilma, its AI system, to accelerate development and provide a stable platform.

The post Small Robot Company sows the seeds for autonomous and more profitable farming appeared first on Ubuntu Blog.

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