MIT Mini Cheetah Actuator
ฝัง
- เผยแพร่เมื่อ 1 มิ.ย. 2024
- This time I've tested the MIT Mini Cheetah Actuator!!! This is a great part for robot! I know that many my viewers are interested in this technology (quasi direct drive (QDD)), because it provides affordable and capable actuators. So I bought this actuator to play with it and to show you how it works. It uses CAN bus for control. So I learned how to do this and I share this knowledge with you. Like this you don't need to spend your time searching about CAN bus.
Link to the Actuator: www.aliexpress.com/item/32985...
Special thank you to my special Patron: Wesley Corp! Thank you for your longtime support!
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#robotics #robot #actuator - วิทยาศาสตร์และเทคโนโลยี
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I didn't understand the sentence at the begining of the video. You said that if robot jumps the actuator doesn't get broken because of ?
High gear ration actuators cannot sustain high impact. Thus if the robot has traditional harmonic drive actuator, when it jumps it can easily break actuators during the landing. The quasi direct drive actuators (like the one in this video) can manage this kind of load easily.
Thank you for the answer.
rpi/jetson can bus ?
Не читАх, а чИта. Или чИИтаа
1. Please do a tear down and show the planetary gears and the motor windings.
2. Please test the torque and positional accuracy
3. Please test the position backlash
@@rodstartube From the thesis: "The actuator has roughly 0.005 rad (0.28∘
) of backlash at the output from
its planetary geartrain, as it uses off-the-shelf gears and no mechanisms for compensating backlash."
@@jimtaylor8123 do u know what is the max continuous rpm for this motor?
very nice information in this thread .... i always like confirmation
I really like this actuator. I will order one and test. I can see how these can become very useful in my robots! Thank you for posting.
You somehow always manage to address my very specific interest areas :) I'm seriously considering making my first patreon contribution to you. Keep up the good work!
Thank you for your super kind comment!
Do it Yigit :) I signed up too because I love his content and want to support it. Just start off at $1 and go from there.
That is some bit of tech.. Wow, has my mouth watering. Useful for a small robot arm rotation axis.
Thank you for this amazing review.
Thank you for your comment!
Thank you for explaining CAN Bus!!
Sir, thanks a lot,can't thank you enough for such awesome content
Finally.
I really appreciate your video.
that gonna be helpful for my robot arm
I wish I knew about your channel before, thanks alot :)
Thank you!
Love that is has built in temperature measurement! Very handy :D
Yes! I always wanted to have this feature in actuator!
Seems like preprocess data on the build in chip
как всегда интересно! СПАСИБО!
Interesting video and motor! I didn't knew these motors had so many internal control features
Carl Bugeja Oh hey, it's the flappy PCB guy! Love your work
Dear Skyentific, I love all your videos! I was wondering if you can make a video explaining a little more the control of the motor using can bus?
Smart approach, you cracked it!
Katerina Rostova thank you! :)
love your videos... keep growing
Thank you!
Using hex notation for 1 bit values. That’s what I call belt and suspenders. 😁👍
Great video, thanks for bringing this actuator to my attention! I am currently working on my own motor controller and was planning on making something similar, so I was wondering if you were planning on taking it apart. It would be very instightful to me!
Very good, the firmware and CAN bus explanation. I think everyone is curious about the actuator, I wish more Chinese companies can build and sell them more cheap, so in future we can build the various robots more as OpenSource, like what is Arduino but a personal robot.
I think this time is coming! And soon we will have a lot of robots everywhere :)
Excellent Video!
When I saw the MIT cheetah a few months ago, I immediately thought I wanted to duplicate that shoulder actuator. I did a search on ali express, but what I found looked like a scam. BUT YOU FOUND IT. Excellent. But $329 with the original driver, 269 without. For my project I would need 6 of them, which is way too expensive for a hobby project.
Now, I wonder if a DIY version could be built with less expensive components, I think I'd start with a 3d printed plastic housing, that custom machined aluminum housing must be a good amount of the expense. I bet the reduction gears are also custom machined, or cast, steel.
Thanks again for the review.
The gears are most likely sintered, you don't cast gears. Some gears are machined out of a round piece of stock. A DIY version might not be too crazy of an idea, MIT manufactured them in house IIRC. If you don't care about shaving off every little bit of weight a lot of the features on the housing could be eliminated. If you didn't care about keeping the exact same form factor you could try changing the design to be able to use existing mass produced sintered gears for the planetary reduction. Maybe even just replace the planet carrier with a custom machined one so that you still get that same output face and the spot for the center support bearing for the motor shaft to keep the length down.
Thank you very much for the video.
Regards.
Great video! Thank you! Does this motor support torque control?
Good work! Good video.
Thank you! :)
Another great video! I also would like to ask You, will You do some tests with the hold torque, to see how does it work and how the temperature is changing then? What about the resolution, on Your video, You were changing the position from 1 to 254, so it means that there is only 8 bit resolution? Or maybe I missed something.
That can interface that you found defective has a 8mhz crystal while most libraries seem to assume that its 16mhz this will result at transmitting at half speed. i got it to work with the CAN library by Sandeep Mistry. You need to add CAN.setClockFrequency(8e6);
You can also edit the MCP2515.h file at line 13 to change the default . there you change
#define MCP2515_DEFAULT_CLOCK_FREQUENCY 16e6
to
#define MCP2515_DEFAULT_CLOCK_FREQUENCY 8e6
Wow! Great! Thank you a lot! I will try it!!!
@@Skyentific Good luck. Ps have you tried socketCAN? It gives you tools like a cansniffer and cansend. I'm using the canable with candlelight firmware.
@Skyentific did you try in the end with the cheaper arduino module (with 8 MHz crystal)?
Very interesting! Does not seem too terribly costly given all the integrated hardware.
Good day, and thank you for great videos. Did you ever experiment with hoverboard 350w brushless wheel motors (they are cheap) with additional magnetic encoder and if you did what would be the best driver to drive them by STEP and DIRECTION signal? Thank you very much.
Great video! I have the simpler MCP2515 (broken one that you have). Can you comment on how to connect that to the ARDUINO??
Have you seen the Dynamixel line of servos from robotis? They are not brushless but provide bus connectivity and feedback for temperature and current.
Hey, Skyentific ! You might not remember me but we spoke together some time ago and I even briefly supported your project via Patreon. Anyways, just saw that you will have a booth (n°106) at MakerFaire Paris 2019. Guess what : we'll have a booth just next to yours. I am delighted.
Now that's a really cool building block for a cobot. I wonder, what kind of precision can you get with 300mm-400mm arms in 5 DOF configuration. Also interesting about its internal construction - if backlash will increase by much after some use..
Great questions! I need to check this.
it might be light weight but the mit mini cheetahs actuators are probably lighter because they're open on the sides rather than hiding the stator
funy0n Completely agree. But for some reason they don’t make open one.
@@Skyentific yes
I love your channel! This seems to be the most adequate bldc motor for DIY robotics, that‘s certain. Please, which controller did you put inside? In case it‘s the one that Ben Katz designed, let us know if where and how you had it manufactured. In case you used one of Ben‘s china copies let us know which.
China copy company name: steadywin. copycat website: www.steadywin.cn/. their product website: www.aliexpress.com/item/32985671853.html. The copycat even not mention the originator Ben Katz, shame on them.
Nice video, as usual.
If you do a better serial output, you can plot data in the arduino IDE in a graph.
Thank you. I did exactly this in today video with T-motor actuator. :)
Have you seen the Robotis Dynamixel servos? You can talk multidrop serial port to them with some simple wiring to the Arduino.
The "best bang for buck" models have half the torque of the cheetah, at a quarter of the weight, and 75% of the cost.
Great. Spasibo
Thank you for your comment!
Hello. One Question: When the power is on, it is not possible to rotate the actuator by hand. BUT, when the power is off, (no 24 V connected), is it still possible to rotate the actuator by hand and get position values through CAN? Thank you for your cooperation.
What part number/type of connector do the CAN/Battery connectors use on this integrated driver one? Did it come with some little test connector pig-tails to get started quickly?
Hello Skyentific,
Thank you for this video, really helpful. I would like to know from where can I get example arduino code used in video for reference?
Great review, please add missing details for example how to turn motor continuously. Can you contact producer to let you know that details.
@Skyentific When opening the link to the actuator, there are two different actuators shown in the pictures (one in black and one in white). Would you tell me the difference? and how one is able to specify the item he wants when ordering one?
Can you please share the code?
hello sir. I'm very interested in your video and the motor. I wonder if the motor knows its output angle position without uncertainty. The motor has an absolute encoder but it is at the motor shaft. The motor spins several times while the output spins one time. Suppose gear ratio is six, does it mean it has six possible position candidates? If so, how does robots such as MIT cheetah robot deal with it? Do they use another external rotary encoder at the output side ? Or perhaps a homing procedure as we do with stepper motors?
Спасибо! Хорошо объяснил.
Sergej Kolmogorov спасибо за комент!
I'm impressed, may I know which power supply you used. I don't have any yet & i want to buy the best one.
Here I used 24V power supply. I buy them from Stepperonline, usually I buy 400W, as it is relatively cheap and powerful.
will you do some speed and torque tests on it ?
I plan, but may be in a couple of weeks. I am very busy now with the design and build of the 7DoF robot arm.
Очень круто, спасибо!
May I know the accurate definition of Quasi Direct Drive (QDD)? I assume Direct drive is that the joint is directly mount onto the motor, then does QDD mean "small reduction ratio" or the fact that reducer is embedded into the motor?
Usually QDD means reduction ratio less than 10.
@@Skyentific understood! Thank you for your reply as well as the terrific videos!
What would you make with these actuators? I would know a couple of awesome projects to start with.
Very good, but how much it's torque?
spasibo. otlichno! eto luchshiy kanal po robotam
Spasibo za kommentariy!
Excuse me, could you please explain on how to control this motor more with UART communication base on V3 of this actuator.
Hello sir, Your video is very helpful. Thanks for uploading this type of videos.
I have also purchased the AK 80-9 motor from CubeMars. Actually I am unable to rotate the motor by arduino code through CAN. I used the same code which have been used by you. So, could you please help me or could you give link for the same code and library.
I read a research article I found that mit cheetah has used proprioceptive actuator it does not look like that... As like another rotator to create complaint mechanism... Please correct me... Dose it have that kind of functionality?
Fodu Tech this one is similar to MIT Mini Cheetah. Not to MIT Cheetah.
Hi, did you try the speed mode? I tried sending the packet to switch to speed mode but after that the motor doeesn't respond to any command...also, when powered on, even if it has the green led lighted, i cannot hear the sound of the motor powered and it has no torque (actually, its not holding the position, so it seems like its not in position control anymore, but doesnt execute speed commands)
Hi skln69 , looks like you have worked on these motors. I would be glad if you can answer few of my queries. Kindly ping me on psantoshsan@gmail.com. i have few doubts about interfacing the motors.
Great stuff! Are you thinking of using these in your robot arm?
I don't think so. It is too expensive...
How many actuators like this will your arm use?
More specifically, what is the budget for the arm you're building?
@@basementadmin (th-cam.com/video/8AziOykde30/w-d-xo.html) check out this video, I believe his is aiming for a 6 DOF robot.
Wes Corp I don’t want to use this actuator for the arm. It is too expensive :)
im sure that motor can be used for prostetics for disabled people
great looking product. too pricey for me though !
Interesting topic.
ACTUATOR
$300 is more than a lot of nice servo motors.For example, why not use a Clearpath servo instead? How many of these will your robot arm use?
Top speed?
What happens when you exceed max torque?
CAN BUS
Before Makers choose the CAN bus, we need to understand:
does it use a clock for timing? speed? sensitivity to drift.
signaling method, voltages?
topology? mater-slave?
initialization sequence?
broadcasts supported?
are messages acknowledged?
any error correction? retries?
max # of devices
any bus statistics?
how are device ids assigned? how to prevent collisions?
how susceptible to noise?
troubleshooting tools? line monitors?
how does it compare to 10/100/1000 Ethernet?
are there chips to convert to CAN from other protocols? serial, SPI, etc
etc
A Clearpath with the same toque weigh around 11kg and costs around 1k USD.
CAN bus: Given that it’s been how my foot talked to my ABS system when I’ve pressed the brake pedal for the last 25 years, I would say that Makers can safely choose CAN bus for their toys.
300 dollars, so two shoulder joints, and two femur joints and you're broke.
It costs an arm and a leg
Thats for a fully integrated motor, encoder, controller, and gearbox. Tbh a good deal
I want to build a dog robot with 5kg weight including motors and Payload. Could you please advice me a best motor to use?
thanks for a video about mini cheetah actuator, do you can make a video about atlas motor? I would like to know more about that
Thank you for comment. I would love to make a video about atlas motor, but I don't have one, and I don't know where to get one.
@@Skyentific would you recommend Mini Cheetah actuator for build a humanoid robot? (for legs, arms) Iam thinking servomotor 100kg vs minicheetah actuator, which is better for humanoid robot, (1.3m of height)
What kind of motor is it? .. what's the resolution .. is it stepper?
nice!
Thank you!
Hi, im working with these motors GIM8008 V3 and i was wondering if you could send me the manual. Unfortunately i cant controll the motors and my manual is in chinese. Thank you for your patience
Test it with multiple actuators please
What's the angular speed during unload and load, kindly?
Where did you get the CAN protocol? I bought a motor, but it looks a little different. They have not been responding to my emails. It would be great if you could send me the protocol.
I get it from my seller. I can send you my documentation, although I am not sure that the protocol would be the same if you motor is different.
@@Skyentific Yes, it is different. I have since found the right protocol. For others looking for links, look here. drive.google.com/drive/folders/18MTH-pIlA5Aj_5wRNHYVa4wPpjKYbfco?usp=sharing
can you open it and show what it is have inside and how can it is work
Богатый и великий русский акцент. Ардуино, резисторс...) Интересно реализован код и достойно объяснен принцип работы кан шины. Отличный видос!
Дмитрий пресс Спасибо!
do u try find good hydraulic actuator ?
How to control more than one drive on the same bus? They have identical addresse by default. I gues you need to programm a custom address for the device and only then connect several of them to one bus?
You can easily change the ID of each actuator. For this you need to connect them to CAN one by one and change the address. It should be easy.
Хорошее объяснение по работе с CAN шиной. Только я так и не понял,почему он квази директ то? В общем,ждем разборки)
Hi, really love your review and channel. I just purchased a few of these motors but am struggling to get it to work. Any chance I can get a copy of the arduino code. The documentation is also not the best
Write me on instagram or facebook your email, I will send you my Arduino code.
зат зе кан бас кан би рили юзефул фор зе роботикс
sorry, i couldn't help myself))
Hello, How can i control this motor in torque mode ?
how to watch the serial data on Mac like yours
Is this a closed loop motor?
Does the black part on the motor is a zero position???
No, I don’t think so. I think the black part just cover the wires inside.
are you going to take it apart to see how the gearing works ?
May be one day. Don't want to brake it immediately, it is quite expensive :)
@@Skyentific pleaseeeeeeee hahahahaha
I’m pretty sure it has nothing special. There are billions of planetary gears videos. No need to risk damaging this pricey unit.
“pretty sure” is not .... certainty
99guspuppet Fair enough but I wonder what makes you expect anything out of the ordinary in this motor. Especially from the output gear set.
Could you teach me about the motor brake mechanism when no supply or power off ?
There is none. It is said in the video.
@@ArnaudMEURET thanks
Take it a part I feel like there is a build in limiter switch to home the motor or built in encoder put
Lots of preprocessed data on ic and build in sensors
There's an absolute encoder in it i think.
Wow motor, where can someone buy it from? where did you get it?
How about opening the video description?
Спасибо интересное видео, ваш акцент вас выдает ))
Spasibo za komentarij
Hi, Can you please share your code?
THanks!
Where is a link to the code?
is there a cheaper equivalent with less torque?
I wanna know the answer too
how much is it?
If the motor has a harmonic drive instead of the planetary gear , it would be perfect for robot arm I think.
Mustafa YETİŞ yes, but it will cost two or three times more.
how many watts
how to buy this motor please....where..
Link in the description to this video.
akjuator?
What did you say at 1:02? C**t Pass? Con Pass? Oh Compass! Why would an actuator have a compass?
CAN-BUS
make it
Nice motor but quite expensive I think.
Compared to the performance, this motor is quite inexpensive.
The main problem with hobby robotics is sticker shock; equipment to interact reliably with the real world costs a lot more than software or consumer products sold in the millions.
(Also, cost of motors scale by the cube of the size!)
Alternative motors of similar capabilities are $2000 USD, and usually have ~$1000 drives to run them, and maybe another $1000 controller to be the brains for a bunch of drives.
@Skyentific Hello friend, I like your program, I am Colombian, I am building a Robot with multiple capacities, I want to introduce this type of motors to control the legs. I would like to know if this type of motors can be controlled by means of a FrSky X8R Receiver that accepts Telemetry, with a RadioMaster TX16S Transmitter. Thank you, I hope any comment would be useful.
you need 11 more motors :)
Mr Swan ...... 123 more
Do you share your code?
Yes, I wrote you email :) . And you can see the code in the video. It is quite simple.
Is it Simpson?
Evgeny Duk spider pig, spider pig! :)
where can I get one?
you could contact with me .thanks .
Or you could click on the video description