ODrive: 2 axis motor controller for robotics

General topics and discussions about the VESC and its development.
madcowswe
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Joined: 08 Jan 2016, 15:37
Location: San Jose
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ODrive: 2 axis motor controller for robotics

Postby madcowswe » 25 May 2016, 15:08

I have been collaborating a bit with Ben for a while now on some of the FOC stuff, and I think it is about time I also shared with the rest of this community what I've been working on.
My project, ODrive, is a high power 2-axis motor controller, with some robotics specific features like motion profiles, and simultaneous connection to a li-po battery and a power supply. Most of the specs and details are listed at the project page.
ODrive is completely open source, and I invite anyone who is interested to contribute and create derivative works.

The state of the project is currently: I am checking that the v3 board is working properly. Then I will try to do a small production batch to send out to anyone who is interested in development or alpha testing.

Check out that speed (:


Cheers,
Oskar

rew
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Joined: 25 Mar 2016, 12:29
Location: Delft, Netherlands.

Re: ODrive: 2 axis motor controller for robotics

Postby rew » 25 May 2016, 18:22

It's not fair to make people think it's real-time but in reality posting a timelapse! :D

Whow!!!!

jaroslavnovotny
Posts: 49
Joined: 16 Feb 2016, 13:10

Re: ODrive: 2 axis motor controller for robotics

Postby jaroslavnovotny » 25 May 2016, 19:19

I would be very interested in this, but I would like to drive smaller motors (200-300W) at 15A max. Application would be locomotion of a robot chassis. I very like the $50 price you aim at, what would be the price of the v3 prototype?

rew
Posts: 904
Joined: 25 Mar 2016, 12:29
Location: Delft, Netherlands.

Re: ODrive: 2 axis motor controller for robotics

Postby rew » 26 May 2016, 06:59

The expensive components are the CPU $10, The DRV chips $7 and the FETs. For fets you can go from about $0.7 (PSMN5R8-40) to about $3 (IRFS7530). For $3 you get the ones that VESC uses: 50A continuous, 60V theoretical, 50V in practise. You need 6 fets per motor.

You're not winning much by using smaller fets.

The software, I expect will be able to handle smaller motors, just like now. It may take a bit of tuning if you're using a smaller motor than what the system is currently tuned for.

jaroslavnovotny
Posts: 49
Joined: 16 Feb 2016, 13:10

Re: ODrive: 2 axis motor controller for robotics

Postby jaroslavnovotny » 26 May 2016, 08:20

Now I use 2x vecs 4.7 with 5mOhm shunts connected through CAN. So to be able to drive 2 motors with 1 MCU would be awesome and the cost would be also less.

madcowswe
Posts: 14
Joined: 08 Jan 2016, 15:37
Location: San Jose
Contact:

Re: ODrive: 2 axis motor controller for robotics

Postby madcowswe » 26 May 2016, 08:45

jaroslavnovotny wrote:I would be very interested in this, but I would like to drive smaller motors (200-300W) at 15A max. Application would be locomotion of a robot chassis. I very like the $50 price you aim at, what would be the price of the v3 prototype?


Driving smaller motors should be no problem. I'm not sure yet how much the earliest batch of prototypes would be, but I feel fairly confident that they should be less than $100.

Prevas_erra
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Joined: 11 Apr 2016, 16:03
Location: Stockholm

Re: ODrive: 2 axis motor controller for robotics

Postby Prevas_erra » 26 May 2016, 10:21

Hi

Is the firmware based on VESC or can be made to run like a custom application in VESC?
I see that you have an FPGA based design also, is it working too or abandoned?

madcowswe
Posts: 14
Joined: 08 Jan 2016, 15:37
Location: San Jose
Contact:

Re: ODrive: 2 axis motor controller for robotics

Postby madcowswe » 26 May 2016, 10:26

Prevas_erra wrote:Hi

Is the firmware based on VESC or can be made to run like a custom application in VESC?
I see that you have an FPGA based design also, is it working too or abandoned?

The firmware will share many features of the VESC, but at the moment there is no code shared except for some of the FOC core.
The plan is to (along with CAN and USB Serial with Gcode) expose a motor control / motion control API, and allow people to easily add applications directly on the board. I'm not sure if that answers your question about custom applications?
Yes v2 is FPGA based, and is a more expensive but more versatile option. I think for this reason I will continue to support it, but my main focus is to get v3 up an running at the moment.
Cheers!

jaroslavnovotny
Posts: 49
Joined: 16 Feb 2016, 13:10

Re: ODrive: 2 axis motor controller for robotics

Postby jaroslavnovotny » 29 May 2016, 19:30

@madcowswe

Do you have a rough estimate when would be the prototypes ready to ship? Also can you give the board dimensions (didn't find them on hackwana or github)? I can start making a motorized chassis for the board soon:)

madcowswe
Posts: 14
Joined: 08 Jan 2016, 15:37
Location: San Jose
Contact:

Re: ODrive: 2 axis motor controller for robotics

Postby madcowswe » 29 May 2016, 19:36

jaroslavnovotny wrote:@madcowswe

Do you have a rough estimate when would be the prototypes ready to ship? Also can you give the board dimensions (didn't find them on hackwana or github)? I can start making a motorized chassis for the board soon:)

I'm not really sure, I can only really work on this project on the weekends and sometimes in the evenings. But I'm trying my best to get the major components tested. I have already found 2 (minor) problems with the circuit.

We should be talking weeks, not tens of weeks.

This is me today: https://drive.google.com/file/d/0B5Zwiu1SQzGMdEFqWWRNR3llQ2M/view

Cheers!


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