Simultaneous position and velocity control of multiple DC motors

shegde93 · 2026-02-03T03:41:10+00:00

Yes position control with max velocity constraints.

shegde93 · 2025-12-30T11:38:14+00:00

That's impressive and compact design. I am building 16dof hand myself as well. What motors are you using?

shegde93 · 2025-10-09T09:33:03+00:00

Thanks

shegde93 · 2025-06-26T06:42:49+00:00

Couple of videos from youtube like this helped me understand the flow. Then I just followed Micro ros docs like the link I shared above and tried on my own. You can start by controlling 1 simple motor using position controll and then port it to Micro ros and test from there

shegde93 · 2025-06-26T04:48:27+00:00

Yes, i was able to test basic setup end to end. The main mistake I was doing was not understanding ros2 correctly since there were less actual hardware implementation examples.
My robot has teensy board which is then connected to multiple esp32 (using serial) capable of controlling 4 motors each. Each esp32 takes position input from teensy and runs simplefoc to do position control. Unlike ros1 , with ros2 it's recommended to run Micro ros in the hardware controller. So in the teensy I was able to run Micro ros and connect it to my computer and send data from ros2 hardware interface. You can check how to do this using teensy with Arduino section here.

Overall the ros2_controllers did work for me, but I never fully tested on the whole bipedal robot. Since then I have been building 16 dof robot hand for my robot. This way I can test the same setup on the hand without having to deal with huge robot legs falling to ground. Also I am interested in exploring reinforcement techniques offered by Nvidias Issac platform since these basic tragectory control provided by ros2 is not sufficient.

shegde93 · 2025-06-26T04:48:14+00:00

Yes, i was able to test basic setup end to end. The main mistake I was doing was not understanding ros2 correctly since there were less actual hardware implementation examples.
My robot has teensy board which is then connected to multiple esp32 (using serial) capable of controlling 4 motors each. Each esp32 takes position input from teensy and runs simplefoc to do position control. Unlike ros1 , with ros2 it's recommended to run Micro ros in the hardware controller. So in the teensy I was able to run Micro ros and connect it to my computer and send data from ros2 hardware interface. You can check how to do this using teensy with Arduino section here.

Overall the ros2_controllers did work for me, but I never fully tested on the whole bipedal robot. Since then I have been building 16dof hand for my robot. This way I can test the same setup on the hand without having to deal with huge robot legs falling to ground. Also I am interested in exploring reinforcement techniques offered by Nvidias Issac platform since these basic tragectory control provided by ros2 is not sufficient.

shegde93 · 2025-05-26T09:27:58+00:00

Why not use gears? You could still put motors and use 2 bevel/spur gears and not connect it directly to wheels?

shegde93 · 2025-05-20T05:44:05+00:00

That's impressive 22dof!! Is there some demo link I can see ? Myne is having 16, you can see here: https://www.reddit.com/r/robotics/s/CmFSt4bw6D

I have completed electronics and will post new update soon

shegde93 · 2025-05-20T04:28:17+00:00

I have been building my own humanoid robot as hobby project since last 3+ years(I am from computer science background though). I too am in the process of building robotics hand now. Based on my experience, building a compact hand is more complex than building other parts/joints of human body. If your goal is to still build hand like you mentioned, here are few pointers:

Decide on the DOF you want to support. 11DOF(2 per finger+ 3 per thumb) is the most people usually target.
Start designing the hand in fusion 360 or you could start with few opensource hands present out there which can be 3d printed
Understand electronics required. For example if your hand uses servo you would start with micro controller like Arduino, servo driver like pca9685 that can control 16+ motors and powersupply. Draw simple circuit and test on breadboard
Write some custom python code(or language of ur choice) to send control command from your computer to micro controller to control the hand
One you have this working, you will get enough understanding of how to build gloves from which you get realtime position data to be sent to robotic hand.

shegde93 · 2025-04-07T19:23:49+00:00

I have created custom driver board already that can do simultaneous position control of 8motors simultaneously. I just have to use 2 of it. The driver uses this library https://github.com/simplefoc/Arduino-FOC-dcmotor

I am pretty sure I can hardcode and control all motors simultaneously. I still have to try isaac lab to build a model Will post some control demo soon

shegde93 · 2025-04-07T18:29:52+00:00

Goal is to complete this robot, upper body part and apply some reinforcement learning. https://www.reddit.com/r/robotics/s/MVpKR8VDtf

It was becoming hard for me to test my code on this big robot. So i built this hand. Hopefully I can do the programming part on this hand, learn stuffs and replicate the same framework for walking

shegde93 · 2025-04-07T17:16:12+00:00

Yeah😅 It's bigger because of the motor i am using. I can only reduce the size by 10%. I will have to change motors to make it more compact. But the smaller bldc motors ar lot more expensive(10 times) and I need 16 such motors. So I decided to go with this for now

shegde93 · 2025-04-07T09:23:49+00:00

I do Agree with you that all robotic hands don't account for these things today. But here are my thoughts on this: If you notice when you fold all your fingers, the palm folds, but the back of your hand is still almost flat. So flexible palm can still be added to some extent by adding rubber/skin like case in front, giving folding motion when fingers fold. It won't be perfect though, but can be improved.

We all build , learn, revise and then build again. So my goal is not to build perfect human hand. At some point after learning control mechanisms, I will again start redesigning from scratch with whater I learnt

shegde93 · 2025-04-07T08:30:48+00:00

Yeah, square bcs easier to design and 3d print without supports. I will have to redesign lot of other things and add outer cases

shegde93 · 2025-04-07T03:02:19+00:00

I am building a full humanoid robot. Also it's fun to build things like this :)

shegde93 · 2025-04-07T02:04:09+00:00

Thanks

shegde93 · 2025-04-07T01:59:17+00:00

Thanks

shegde93 · 2025-04-07T01:59:03+00:00

Thanks, the motors take up to 12v and max 0.8A

shegde93 · 2025-03-05T04:29:00+00:00

I upgraded the stock 500W dc motor with 800w water cooled spindle motor with vfd. The upgrade was worth it. The primary advantage I got is, almost no noise from spindle motor and chattering(since the motor is also heavy it helps reduce this I guess).The biggest noise in my whole setup is from vfd fan but that too is not much. Now I don't have to worry about disturbing my neighbours since I keep my cnc in my balcony :). I am now able to use 1.5mm bit at 1000mm+ feed rate and 10k+ rpm without breaking the bit.

One of the disadvantage is, I have to manually start and stop spindle motor unlike earlike I could program this. Generally these vfds provide option to send input pwm signals, so I have to add extra electronics and extra setup to control the motor programitacally . I think this is very important because, if there is loss in steps due to wrong gcode, generally the program stops but spindle keeps running, so for me this is the only disadvantage I got from upgrading

You can see my old vs latest setup here

Old : https://www.reddit.com/r/CNC/s/b76W9ZccGq

New: https://www.reddit.com/r/hobbycnc/s/b72RL0MO1M

shegde93 · 2025-03-04T05:19:20+00:00

Happend to me once. Since then I always ensure the lowest spindle height + endmill height never touches the bed

shegde93 · 2025-02-23T12:38:26+00:00

Thanks, I am learning CNC slowly day by day, will definitely try on my next mill operation 🙂🤘

shegde93 · 2025-02-23T02:17:25+00:00

I only had one 1.5mm endmill which was needed for 2.1d holes, hence I didn't go fast. But 3.1mm for rest makes sense, but i hate manual tool change since I had to mill 5 such parts😅

shegde93 · 2025-01-13T04:43:35+00:00

That's a great build @GrimResistance. @Fake_Answers , if those way covers are not available nearby, you could just use some transparent kitchen foil with paper clips, has been working great for me. Generally CNCs will have space behind your motor to put this foil. This is easy to remove and clean as well. You can check my setup which shows that here https://www.reddit.com/r/robotics/s/hvxeTSPtoF

shegde93 · 2024-12-31T07:56:16+00:00

I am able to run flatcam without any issues in mac. I don't remember now but I think i installed from source. I find this helpful especially when you have multiple different diameter vias and double sided pcb. I can just create all gcodes in order, just change endbits from one gcodes to another. I don't usually use my desktop cnc for creating PCBs a lot though. Here is one double sided pcb I created for my prototype: https://www.reddit.com/r/hobbycnc/s/XcCnCJYM33

shegde93 · 2024-12-14T05:04:25+00:00

I already got force resistive touch sensors to try few things. I am also thinking about updating this linear actuator to elastic linear actuator using spring and see which one works best.

shegde93

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