£100 for Quadruped Robot Blueprint [Brushless, Closed Loop Control]

This is the most informative project I’ve found so far which I also like the aesthetic of the robot.

However on the github none of it makes sense to me lol. If anyone could convert the info into easy instructions, I could also pay for that if you like.

Kind regards

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Quite honestly, I’m not surprised.

Looking through the repo, there is of course a structure to it, as well as some instructions. But it’s based on Python, but also using ROS and docker to run stuff.

For someone familiar to this way of working, they can probably get started fairly quickly. For people new to all this, especially coming to robotics outside of an University setting, this will be a really big task to learn all the different abstractions…

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I actually hypothesize that a lot of the stuff that gets done in this world is a result of people that just have a truth be told irrational passion for doing something they perceive to be important, despite all the incentives being to the contrary. There are tales of situations where people who were not technical wizards played valuable roles in getting things done in the open source community. I would pick your favorite project and identify the ways you see it needing improvement and try to lead the charge. It’s a lot more fun working with people.

i have stl files of the legs ive designed, as you know already i have no idea how to make the robot learn to walk, also im not sure how to start a team to try solve to problem of trying to make the quadruped robot. if anyone could contribute towards the idea let me know. also i just remembered my designs were using servos which is inefficient for the robot.

I learned python at uni [I did electrical electronic engineering] so am familiar with that but as for ROS , can’t find any info for how to use that online, and also for Gazebo for teaching the robot to walk.

Anthony and David have my favourite quadruped robot designs so far but it seems like the blueprints are not available online

It’s true that the Bittle isn’t completely open source, but there are alternative open source versions:

The Bittle people are fairly open, and provide a software framework:

David’s robot is still in development, you’d have to ask him about his plans.

Gazebo seems to have decent docs online:

ROS also has documentation:
http://wiki.ros.org/ROS/Tutorials

The project page on gut hub has some brief instructions how to run things.

Of course, each of these topics will need quite a bit of study and tinkering with, a certain amount of determination would be needed, but it looks possible.

In a way, you’re probably quite familiar with the electrical side of things from your studies, and this is a similar kind of level for the software side of things.
The interesting (and difficult) thing about a quadruped robot is that it is interdisciplinary and really needs expertise from mechanical, electrical engineering and computer science.

Perhaps an idea is to visit a local makerspace or similar facility, and see if there’s some software people interested in working on it with you?

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Unitree quadrapeds look cool. If I had $4000 going spare I might want some of that. I’m guessing their actuators (motor + driver) are going to be $200 each and there are 12 of them, and it has a jetson nano as ML brain so you can see where the money goes.

A lot cheaper than the $70K for a spot dog.

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There is also a quadruped robot from Open Dynamic Robot Iniative:

Its open-source and very capable. :smiley:

The project is made by the guys from the French robotics laboratory LAAS-CNRS.

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Hi, I’ve seen this one in the past, it’s one of my favourites. However theres so much info on the github and also I don’t really understand it unfortunately, not sure why though.

Here is a link to what has to be the lowest cost to produce cheetah-like robot. It is 3D printable and it is powerfull enough to jump taller than its own standing height.

All of the design files and software are open source. It is very well documented. See the link below
https://open-dynamic-robot-initiative.github.io

I am working on a redesign that could cut the cost by 1/2.

If you are still wanting to do this, you can start with an open source quadruped controller. It is genral purpose and can control just about any 4-legged robot. It can drive a simulator or a real robot. I would start with the simulation. It is in C++ and uses ROS

Champ can control an MIT Cheetah and a dozen others.

I personally do not like some of their design decisions but, again it is open source and can be changed

@ChrisA the new version you are working on, what is the total build price likely to be? The antigravity motors are about $75 each so I’m guessing old build cost was more than $1k

There are several areas where cost can be reduced.

  1. Some of the parts are machined metal. re-design to eliminate the needs for these.
  2. Use a cheaper motor, although performance might be reduced. I don’t know yet
  3. they used some expensive ball bearings. I can redesign to use less expensive sizes
  4. I think custom driver electronics can be very low cost if made by places like JLCPCB in China.
  5. Buy timing belt in bult and slice to make loops. This can save about $15 per joint (12 joints)

But the main hold-up is software. I started building a simulation using PyBullet. I will get it to work in simulation first

@ChrisA - thanks for the tip of using PyBullet - I’ve been looking for a good simulator, zero experience with simulations. Any tips? I’m working my way through the ‘getting started’ docs.

I just uploaded a “Hello World” example of a quadruped robot running in a pybullet simulation. It is the minimum example to help get people started. I call it “Hello Cheetah” as I used the MIT Mini Cheetah as the example. You should be able to just clone the repository and run the example.

It is VERY minimal. Next I’ll write something like “Hello. IK” to demo how to add inverse Kinematics and then we can move the robot’s feet by specifying (X,y,z) points rather then joint angles. Then comes the very hard task of figurig out what (x,y,z) points to use to make the robot walk and run and jump. I have this working for a smaller robot I build but it uses hobby servoes and is grossly underpowered.

I was planning on packaging my quad controller as an Arduino Library, it’s still on my personal roadmap.

Sooo, I’ve made some progress with my Robot Fox myself haha. Check it out :grinning:

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