16 ms·

Robotics Development Environment with ROS in C++ and Python

150 points by protontypes 7y ago

carapace 7y ago
I was reading up on ROS the other day when the thought occurred that Erlang is, in many ways, similar to some of the core functionality of ROS, and might be a good substitute for [parts of] it.
- jefft255 7y ago
  It’s true, the reason for choosing C++ and Python as first class languages is because of their strength in numerical computing and AI capabilities (for python anyway), which erlang mostly lacks. It would definitely be cool to be able to use erlang though.
  - ssivark 7y ago
    No offense (I use Python all the time), but Python seems almost like the worst of all worlds, except for ease of use in the first month of using it -- with its only advantage being library inertia (which is a massive advantage in practice though). As eg: here's an excellent talk on the cruft in Python internals by Armin Ronacher: https://www.youtube.com/watch?v=qCGofLIzX6g https://www.youtube.com/watch?v=qCGofLIzX6g For more discussion on why Python is slow: https://news.ycombinator.com/item?id=12025309 https://news.ycombinator.com/item?id=12025309 There is, after all, a graveyard littered with big-money attempts to speed up (mutually incompatible) subsets of Python. But lack of inertia not something that should deter someone seriously invested (after all, Google/FB created Tensorflow/Pytorch respectively, and now Google might be getting behind Swift). It's a judgement call on whether one feels that most of the work/innovation still needs to be done, or is already done. If it is yet to be done, building on top of a better platform is almost a no-brainer.
    - jefft255 7y ago
      When I say Python is good for numerical computing and AI, what I really mean is that the libraries are there. I share the same reservation as you about the language itself. I wasn't so clear in my comment above
    - isatty 7y ago
      I disagree. I think that the use of Python in ROS is the best of both worlds. ROS makes it easy to do sane-ish IPC even for folks new to programming and enables them to offload heavy numerical processing or real time tasks out to C++ or even other boards on your robot. Python sits by handling state machines (decision making) and similar logic. It’s also great in experimental code that folks want to change often (opencv prototyping). I don’t like the lack of a type system and have run into easily preventable bugs with python but in my case the trade off with developer productivity was worth it.
    - j88439h84 7y ago
      Armin's points are true, but PyPy makes the best of the situation, and hopefully the C-API will be deprecated at some point.
  - isatty 7y ago
    Honestly, the language that I'd love get first class support for on ROS2 would be Rust. Robotics really needs type and memory safety while maintaining performance and I personally feel like Rust is the perfect fit. I'd also love to see a mature linear algebra library in Rust (benchmarked to and as easy to use as Eigen).
    - rmattes 7y ago
      There is an implementation of rust bindings for ROS 2: https://discourse.ros.org/t/announcing-rust-bindings-for-ros2/3870 https://discourse.ros.org/t/announcing-rust-bindings-for-ros... https://github.com/ros2-rust/ros2_rust https://github.com/ros2-rust/ros2_rust It looks like they could use more help pushing things along.
- ssivark 7y ago
  I was wondering about the same, and have been trying to seek prior work along those lines. Here's what I've come across so far, regarding use of Beam VM (Erlang/Elixir) for robotics: 1. Nerves seems like a promising platform: https://nerves-project.org/ https://nerves-project.org/ 2. There's also Grisp ("Erlang on bare metal") 3. Jean Francois Cloutier's DDD talks on using Elixir for behavioral robots (3 annual updates; I really liked these) 4. A handful of talks on YouTube when searching for "erlang robotics" or "elixir robotics", but I haven't had a chance to check out all of them yet. The superficial catch is that most ML progress in the recent past has focused on exploiting data parallellism (SIMD; rather than concurrency / task parallellism), and I don't know whether Erlang is as great at that. But supposedly it has a very good FFI, because it was designed to interface nicely with C programs running on network equipment. ROS "feels" like clunky/heavy scaffolding for what should be simple and transparent plumbing. Instinctively, the Erlang VM seems like the perfect platform for building an agent doing fault tolerant concurrent computations -- but I don't have any Erlang/Elixir experience. I'd love to hear about any other pointers, or discussion along these lines.
  - dnautics 7y ago
    Sadly I know very little about about ROS considering I'm personal friends with one of the maintainers. One of the more exciting things about nerves is that they are making it "easy to do the right thing" in terms of using end to end encryption for all of the parts of your nerves network when you deploy. I would say that ffi on elixir is... Hard. Not impossible. (I'm currently writing a zig ffi library that aims to make it as painless as inlining the ffi code) If you're an abject beginner at both elixir and robotics I don't recommend going beyond what nerves has to offer off the shelf. If you're an expert in one of either the underlying robotics c interfaces or elixir, I think writing your own ffi might be neat and worth giving a go. The documentation on how to do things isn't terrible.
- Iv 7y ago
  To be honest, ROS came in to offer a good balance between modularity, freedom of design and standardization. What it tries to do is not rocket science: make different package communicate using a pre-agreed packet format, and can be done in many languages.
  - Animats 7y ago
    Right. It started as a DARPA-funded effort to get more of the DARPA-funded robotics research projects to talk to each other in some useful way. It's clunky, like CORBA or OLE, but useful.
WhatNewSoftware 7y ago
Can this be easily setup on Windows? Was my biggest obstacle to using ROS in the past.
- imraj96 7y ago
  ROS1 is primarily used with linux unless you use a VM. ROS2 can be used on linux, mac or windows. You can also check out AWS robomaker to use ROS in the cloud. https://wiki.ros.org https://wiki.ros.org https://index.ros.org/doc/ros2/ https://index.ros.org/doc/ros2/ https://index.ros.org/doc/ros2/Installation/Crystal/Windows-Development-Setup/ https://index.ros.org/doc/ros2/Installation/Crystal/Windows-... https://aws.amazon.com/robomaker/ https://aws.amazon.com/robomaker/
- jefft255 7y ago
  While ROS2 promises windows compatibility I’m not so sure how it will turn out. Most guides, drivers and general support will focus on Linux. We’ll see how wrong I am when ROS2 finally takes off!
- rmattes 7y ago
  I've never tried it, so I don't know how easy it is, but there has been a lot of work recently to improve ROS on Windows: https://microsoft.github.io/Win-RoS-Landing-Page/ https://microsoft.github.io/Win-RoS-Landing-Page/
  - danbmil99 7y ago
    Why?
    - rmattes 7y ago
      Why haven't I tried ROS on Windows? I never really had the need to, I primarily use Linux at home and work. I did briefly evaluate ROS 2 (ardent) on Windows at my previous job. It seemed to work fairly well, I built it natively, ran the demos and did some latency/throughput comparisons between DDS implementations.
- 7y ago
heyflyguy 7y ago
If you want to really enjoy the ingenuity of people that otherwise might be considered "simple", check out the ROS for Agriculture group and slack channels. People converting 70s and 80s era farm equipment to be automated, and it's pure gold.
- TaylorAlexander 7y ago
  Oooh I’m working on a farming robot right now. I’m gonna have to join that group!
- BayezLyfe 7y ago
  any specific links to these groups??
  - heyflyguy 7y ago
    Website: http://rosagriculture.org/ http://rosagriculture.org/ Slack: http://rosagriculture.slack.com/ http://rosagriculture.slack.com/ GitHub: https://github.com/ros-agriculture https://github.com/ros-agriculture Twitter: @ROSAgriculture YouTube: https://www.youtube.com/channel/UCnr6AObsHnHSGPge0HVlBpA https://www.youtube.com/channel/UCnr6AObsHnHSGPge0HVlBpA
- archontes 7y ago
  People who would regard farmers as 'simple' don't know any real farmers.
deleted 7y ago
[deleted]
abalaji 7y ago
I brought ROS to FIRST robotics back when I was in high school and I still think it continues to change the game for how people work with robots [1, 2] The modularity / plug-n-play nature of the system makes swapping sensors (which often have ROS driver) or algorithms that much easier. [1] https://www.firstinspires.org/robotics/frc https://www.firstinspires.org/robotics/frc [2] https://www.chiefdelphi.com/t/paper-team-900-presents-zebravision-5-0-ros-for-frc/160468 https://www.chiefdelphi.com/t/paper-team-900-presents-zebrav...
a_t48 7y ago
ROS is really great for getting started with robotics, but from my experience (and from others who I've talked to) tends to buckle under its own weight in larger projects. This isn't to say you shouldn't use it, just be careful with it. It has some really questionable design decisions and implementation details that can bite you later.
- Abishek_Muthian 7y ago
  Isn't this the case with any Python development in general? Once you start building at scale you'll be forced to use Cython extensions and other non-native python code.
  - TeMPOraL 7y ago
    Isn't this the case with most of Python? It did a great job of pretending to be an efficient language by having libraries pawn off the heavy lifting to companion C implementations. I wonder what's so special about Python that it does this much more often than any of the other languages I know.
    - fnord123 7y ago
      >I wonder what's so special about Python that it does this much more often than any of the other languages I know. You answered it: > It did a great job of pretending to be an efficient language by having libraries pawn off the heavy lifting to companion C implementations. That's a feature.
  - a_t48 7y ago
    The C++ side of ROS is better but still not amazing.
  - stinos 7y ago
    Isn't this the case with any Python development in general? No this isn't generally true for Python, and I'm not sure why you'd be forced to use Cython for things at scale. Unless you have some particular type of software in mind perhaps?
Animats 7y ago
Well, yes, that's what ROS does. This "Awesome robotic tooling" GitHub repository adds what? A package index?
- protontypes 7y ago
  ROS has already a package index: https://index.ros.org/packages/ https://index.ros.org/packages/ The list is more intendet to find the gems of modules, resources and tools for an professional robotic development.
tlarkworthy 7y ago
I kind of feel ROS rebuilt a ton of Google tech before it was open sourced. rosbuild is bazel, Ros messages are protobuffers/flatbuffers, orchistration is k8s. I feel we could do a better job these days with the newer tools rather than ROS's less maintained, less interesting to researchers, reimplementation of infra tech.
- isatty 7y ago
  ROS does not do orchestration. The only valid point you have is that ROS IPC can do with better serde and yes, protocol buffers are indeed more elegant. The rest of it's not relevant to the actual project at all.
  - tlarkworthy 7y ago
    "roslaunch is a tool for easily launching multiple ROS nodes locally and remotely via SSH, as well as setting parameters on the Parameter Server. " sounds like a form of orchestration to me
- ragebol 7y ago
  I've seen IPC tools be built from scratch or on top of more popular stuff in several companies I worked in, unfortunately. ROS2 is building on DDS, which is a standardized protocol and has implementations from multiple vendors as well as open source implementations, with QoS built in etc.
  - tlarkworthy 7y ago
    yeah that looks cool but DDS is a technology designed for air gapped factories. AFAIK most ROS teams are still using ROS1 due to the lack of cross language tooling in ROS2. Again, bazel + gRPC* could solve this. * or perhaps better is flatbuffers see tensorflow-lite
    - ragebol 7y ago
      gRPC, ZeroMQ, RabbitMQ, ActiveMQ, there's a whole bunch of them. The decision to use DDS is explained here in https://design.ros2.org/articles/ros_on_dds.html https://design.ros2.org/articles/ros_on_dds.html
ragebol 7y ago
I've been using ROS for some 8+ years now, for university projects, competitions like RoboCup@Home and for work on robots operating in the wild, on water, land and among people in malls etc. I've seen many RoboCup teams convert from their custom stuff to ROS because it allows to profit for so much other great work. In my own team, we replaced most custom stuff implemented in the early days of ROS and with ROS with the now de-facto standard ROS stuff for the same task so we can focus more on the stuff that made us win the competition this year :-)

150 points by protontypes 7y ago

I was reading up on ROS the other day when the thought occurred that Erlang is, in many ways, similar to some of the core functionality of ROS, and might be a good substitute for [parts of] it.

jefft255 7y ago
It’s true, the reason for choosing C++ and Python as first class languages is because of their strength in numerical computing and AI capabilities (for python anyway), which erlang mostly lacks. It would definitely be cool to be able to use erlang though.
- ssivark 7y ago
  No offense (I use Python all the time), but Python seems almost like the worst of all worlds, except for ease of use in the first month of using it -- with its only advantage being library inertia (which is a massive advantage in practice though). As eg: here's an excellent talk on the cruft in Python internals by Armin Ronacher: https://www.youtube.com/watch?v=qCGofLIzX6g https://www.youtube.com/watch?v=qCGofLIzX6g For more discussion on why Python is slow: https://news.ycombinator.com/item?id=12025309 https://news.ycombinator.com/item?id=12025309 There is, after all, a graveyard littered with big-money attempts to speed up (mutually incompatible) subsets of Python. But lack of inertia not something that should deter someone seriously invested (after all, Google/FB created Tensorflow/Pytorch respectively, and now Google might be getting behind Swift). It's a judgement call on whether one feels that most of the work/innovation still needs to be done, or is already done. If it is yet to be done, building on top of a better platform is almost a no-brainer.
  - jefft255 7y ago
    When I say Python is good for numerical computing and AI, what I really mean is that the libraries are there. I share the same reservation as you about the language itself. I wasn't so clear in my comment above
  - isatty 7y ago
    I disagree. I think that the use of Python in ROS is the best of both worlds. ROS makes it easy to do sane-ish IPC even for folks new to programming and enables them to offload heavy numerical processing or real time tasks out to C++ or even other boards on your robot. Python sits by handling state machines (decision making) and similar logic. It’s also great in experimental code that folks want to change often (opencv prototyping). I don’t like the lack of a type system and have run into easily preventable bugs with python but in my case the trade off with developer productivity was worth it.
  - j88439h84 7y ago
    Armin's points are true, but PyPy makes the best of the situation, and hopefully the C-API will be deprecated at some point.
- isatty 7y ago
  Honestly, the language that I'd love get first class support for on ROS2 would be Rust. Robotics really needs type and memory safety while maintaining performance and I personally feel like Rust is the perfect fit. I'd also love to see a mature linear algebra library in Rust (benchmarked to and as easy to use as Eigen).
  - rmattes 7y ago
    There is an implementation of rust bindings for ROS 2: https://discourse.ros.org/t/announcing-rust-bindings-for-ros2/3870 https://discourse.ros.org/t/announcing-rust-bindings-for-ros... https://github.com/ros2-rust/ros2_rust https://github.com/ros2-rust/ros2_rust It looks like they could use more help pushing things along.
ssivark 7y ago
I was wondering about the same, and have been trying to seek prior work along those lines. Here's what I've come across so far, regarding use of Beam VM (Erlang/Elixir) for robotics: 1. Nerves seems like a promising platform: https://nerves-project.org/ https://nerves-project.org/ 2. There's also Grisp ("Erlang on bare metal") 3. Jean Francois Cloutier's DDD talks on using Elixir for behavioral robots (3 annual updates; I really liked these) 4. A handful of talks on YouTube when searching for "erlang robotics" or "elixir robotics", but I haven't had a chance to check out all of them yet. The superficial catch is that most ML progress in the recent past has focused on exploiting data parallellism (SIMD; rather than concurrency / task parallellism), and I don't know whether Erlang is as great at that. But supposedly it has a very good FFI, because it was designed to interface nicely with C programs running on network equipment. ROS "feels" like clunky/heavy scaffolding for what should be simple and transparent plumbing. Instinctively, the Erlang VM seems like the perfect platform for building an agent doing fault tolerant concurrent computations -- but I don't have any Erlang/Elixir experience. I'd love to hear about any other pointers, or discussion along these lines.
- dnautics 7y ago
  Sadly I know very little about about ROS considering I'm personal friends with one of the maintainers. One of the more exciting things about nerves is that they are making it "easy to do the right thing" in terms of using end to end encryption for all of the parts of your nerves network when you deploy. I would say that ffi on elixir is... Hard. Not impossible. (I'm currently writing a zig ffi library that aims to make it as painless as inlining the ffi code) If you're an abject beginner at both elixir and robotics I don't recommend going beyond what nerves has to offer off the shelf. If you're an expert in one of either the underlying robotics c interfaces or elixir, I think writing your own ffi might be neat and worth giving a go. The documentation on how to do things isn't terrible.
Iv 7y ago
To be honest, ROS came in to offer a good balance between modularity, freedom of design and standardization. What it tries to do is not rocket science: make different package communicate using a pre-agreed packet format, and can be done in many languages.
- Animats 7y ago
  Right. It started as a DARPA-funded effort to get more of the DARPA-funded robotics research projects to talk to each other in some useful way. It's clunky, like CORBA or OLE, but useful.

WhatNewSoftware 7y ago

Can this be easily setup on Windows? Was my biggest obstacle to using ROS in the past.

imraj96 7y ago
ROS1 is primarily used with linux unless you use a VM. ROS2 can be used on linux, mac or windows. You can also check out AWS robomaker to use ROS in the cloud. https://wiki.ros.org https://wiki.ros.org https://index.ros.org/doc/ros2/ https://index.ros.org/doc/ros2/ https://index.ros.org/doc/ros2/Installation/Crystal/Windows-Development-Setup/ https://index.ros.org/doc/ros2/Installation/Crystal/Windows-... https://aws.amazon.com/robomaker/ https://aws.amazon.com/robomaker/
jefft255 7y ago
While ROS2 promises windows compatibility I’m not so sure how it will turn out. Most guides, drivers and general support will focus on Linux. We’ll see how wrong I am when ROS2 finally takes off!
rmattes 7y ago
I've never tried it, so I don't know how easy it is, but there has been a lot of work recently to improve ROS on Windows: https://microsoft.github.io/Win-RoS-Landing-Page/ https://microsoft.github.io/Win-RoS-Landing-Page/
- danbmil99 7y ago
  Why?
  - rmattes 7y ago
    Why haven't I tried ROS on Windows? I never really had the need to, I primarily use Linux at home and work. I did briefly evaluate ROS 2 (ardent) on Windows at my previous job. It seemed to work fairly well, I built it natively, ran the demos and did some latency/throughput comparisons between DDS implementations.
7y ago

heyflyguy 7y ago

If you want to really enjoy the ingenuity of people that otherwise might be considered "simple", check out the ROS for Agriculture group and slack channels. People converting 70s and 80s era farm equipment to be automated, and it's pure gold.

TaylorAlexander 7y ago
Oooh I’m working on a farming robot right now. I’m gonna have to join that group!
BayezLyfe 7y ago
any specific links to these groups??
- heyflyguy 7y ago
  Website: http://rosagriculture.org/ http://rosagriculture.org/ Slack: http://rosagriculture.slack.com/ http://rosagriculture.slack.com/ GitHub: https://github.com/ros-agriculture https://github.com/ros-agriculture Twitter: @ROSAgriculture YouTube: https://www.youtube.com/channel/UCnr6AObsHnHSGPge0HVlBpA https://www.youtube.com/channel/UCnr6AObsHnHSGPge0HVlBpA
archontes 7y ago
People who would regard farmers as 'simple' don't know any real farmers.

deleted 7y ago

[deleted]

abalaji 7y ago

I brought ROS to FIRST robotics back when I was in high school and I still think it continues to change the game for how people work with robots [1, 2] The modularity / plug-n-play nature of the system makes swapping sensors (which often have ROS driver) or algorithms that much easier. [1] https://www.firstinspires.org/robotics/frc https://www.firstinspires.org/robotics/frc [2] https://www.chiefdelphi.com/t/paper-team-900-presents-zebravision-5-0-ros-for-frc/160468 https://www.chiefdelphi.com/t/paper-team-900-presents-zebrav...

a_t48 7y ago

ROS is really great for getting started with robotics, but from my experience (and from others who I've talked to) tends to buckle under its own weight in larger projects. This isn't to say you shouldn't use it, just be careful with it. It has some really questionable design decisions and implementation details that can bite you later.

Abishek_Muthian 7y ago
Isn't this the case with any Python development in general? Once you start building at scale you'll be forced to use Cython extensions and other non-native python code.
- TeMPOraL 7y ago
  Isn't this the case with most of Python? It did a great job of pretending to be an efficient language by having libraries pawn off the heavy lifting to companion C implementations. I wonder what's so special about Python that it does this much more often than any of the other languages I know.
  - fnord123 7y ago
    >I wonder what's so special about Python that it does this much more often than any of the other languages I know. You answered it: > It did a great job of pretending to be an efficient language by having libraries pawn off the heavy lifting to companion C implementations. That's a feature.
- a_t48 7y ago
  The C++ side of ROS is better but still not amazing.
- stinos 7y ago
  Isn't this the case with any Python development in general? No this isn't generally true for Python, and I'm not sure why you'd be forced to use Cython for things at scale. Unless you have some particular type of software in mind perhaps?

Animats 7y ago

Well, yes, that's what ROS does. This "Awesome robotic tooling" GitHub repository adds what? A package index?

protontypes 7y ago
ROS has already a package index: https://index.ros.org/packages/ https://index.ros.org/packages/ The list is more intendet to find the gems of modules, resources and tools for an professional robotic development.

tlarkworthy 7y ago

I kind of feel ROS rebuilt a ton of Google tech before it was open sourced. rosbuild is bazel, Ros messages are protobuffers/flatbuffers, orchistration is k8s. I feel we could do a better job these days with the newer tools rather than ROS's less maintained, less interesting to researchers, reimplementation of infra tech.

isatty 7y ago
ROS does not do orchestration. The only valid point you have is that ROS IPC can do with better serde and yes, protocol buffers are indeed more elegant. The rest of it's not relevant to the actual project at all.
- tlarkworthy 7y ago
  "roslaunch is a tool for easily launching multiple ROS nodes locally and remotely via SSH, as well as setting parameters on the Parameter Server. " sounds like a form of orchestration to me
ragebol 7y ago
I've seen IPC tools be built from scratch or on top of more popular stuff in several companies I worked in, unfortunately. ROS2 is building on DDS, which is a standardized protocol and has implementations from multiple vendors as well as open source implementations, with QoS built in etc.
- tlarkworthy 7y ago
  yeah that looks cool but DDS is a technology designed for air gapped factories. AFAIK most ROS teams are still using ROS1 due to the lack of cross language tooling in ROS2. Again, bazel + gRPC* could solve this. * or perhaps better is flatbuffers see tensorflow-lite
  - ragebol 7y ago
    gRPC, ZeroMQ, RabbitMQ, ActiveMQ, there's a whole bunch of them. The decision to use DDS is explained here in https://design.ros2.org/articles/ros_on_dds.html https://design.ros2.org/articles/ros_on_dds.html

ragebol 7y ago

I've been using ROS for some 8+ years now, for university projects, competitions like RoboCup@Home and for work on robots operating in the wild, on water, land and among people in malls etc. I've seen many RoboCup teams convert from their custom stuff to ROS because it allows to profit for so much other great work. In my own team, we replaced most custom stuff implemented in the early days of ROS and with ROS with the now de-facto standard ROS stuff for the same task so we can focus more on the stuff that made us win the competition this year :-)