What to expect from 6.5 Inch hover board wheels

1 year 11 months ago #29533889 by glmnet
Well, Im building an AGV tape follower with this Motor/wheel the 6.5 Inch hover board wheels, 15 pole with hall sensors,
The controller is the FBL2360A with the MagSensor in MultiPwm mode

So far I got it working, my current setup is running them in open loop mode and mixing 1 and then using pretty much the sample script of the AGV application PDF from this web site, with just a tweaks in the speed and P gain (did not add I or D gains)

I see this AGV has no strength, i.e. if it had to climb a very small slope or if I load it with some weight, etc, the output the controller sends to the motors is not enough to move it.
So my question here is what is the best way to configure the roboteq for this setup? and what can I expect from this motors / wheels? I am not using encoder at this moment, I find interesting how the hover board controller can handle this motors with considerable power and at very slow speeds, how they do it?

Is there a resource with more detailed information in handling this that I can be pointed to?

Thanks

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1 year 11 months ago #29533890 by Gabriel_Isko
Replied by Gabriel_Isko on topic What to expect from 6.5 Inch hover board wheels
I can help! However, my concern is that your motors are undersized. These hoverboard motors only look they have 350W of torque. This is pretty undersized - you should be able to drive them properly with an SBL2360. An FBL2360A is just overkill. Let me know what kind of load you are going for and I can provide sizing recommendations.

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1 year 11 months ago #29533891 by glmnet
This particular AGV is more for research so I don't expect to load it with more than 30kg total weight, this wheels can handle a person weight (80kg) so I though they were suitable, for another project were we have heavier loads we could use other hardware. Anyway, if this is not going to work, I'm not trying to make them work.
The FBL2360A is the only controller I have in hand, I'm in Argentina and switching just because is overkill is not a problem I guess.
May be I was not clear enough in my problem. I cannot drive this wheels slowly and precisely and with high torque at the same time. Im pretty sure the AGV will move forward at high speed with no issue on power side, I don't think I'll be able to do a sharp turn on the tape at high speed though.

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1 year 11 months ago - 1 year 11 months ago #29533892 by Gabriel_Isko
Replied by Gabriel_Isko on topic What to expect from 6.5 Inch hover board wheels
Okay. With a similar setup in our test lab I was able to get about 2 m/s, making turns at around a 2ft turn radius on a magnetic tape track. If you are using our magsensor (I was using MGS1600GY), I think the limiting factor should actually be the magsensor width. I hope that gives you an idea of what kind of maximum performance specs you should be looking for.

I am getting a little bit lost here. Looks like you are going for a load of 30kg. Let's also establish:

1) Top speed you are trying to achive
2) Acceleration you are trying to achieve.
3) Turn radius you are trying to achieve.
4) Any slope that you need to handle.

You also mention that you are trying to turn the motor precisely at low speed. Let me How slow you are trying to go also. I can make sure that you aren't running into quantisation errors.

Also, no worries on the over sizing. It just means that it should be fairly simple for the controller to drive the full torque output of the motors, so if they are not outputting enough torque we should try to get to the bottom of what is going on. Perhaps trying Closed Loop Speed Position mode is a good step as well.

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1 year 11 months ago #29533894 by glmnet
Top speed like 50 meters per minute,
Acceleration 15-20 meters per minute / second
Turn radius 50 cm at 15 meters per minute, 1 meter at 30 m/m, no turn at higher speed expected
Slopes none, what I meant on my first post was the AGV trying to go over a small slope, e.g. uneven tiles or the tape on the floor itself, and when it is setup for slow speed it does not have torque to climb this. < 3mm height difference.

Regarding the slowest speed I'd like it to move at 1meter/minute if possible, I really don't know if this is possible, in any case what will be the slowest speed I can achieve while still having considerable torque to move this load.

In a previous AGV using other hardware we had a 15:1 gear box reduction a smaller wheel like 4 inches, rated at 100W. We could achieve like 3m/min with this AGV, I could use this hardware instead, but I'd rather not.

So far I only tried open loop, sinusoidal mode, wheels spins noiseless and very smooth, for feedback I only have available the hall sensors.
Would an optical encoder help?

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1 year 11 months ago #29533895 by Gabriel_Isko
Replied by Gabriel_Isko on topic What to expect from 6.5 Inch hover board wheels
At 1m/min you are trying to achieve a wheel speed of around 2 RPM. You are not going to be able to do this for any significant load with these hub motors. You will almost certainly need some sort of transmission system to achieve these speeds. Hall sensors won't be great either due to their resolution, but I don't think you can get enough power out of these hub motors at that speed.

This is a pretty slow AGV. Your main priority should be looking at drive systems with a lot of gear reduction. 15:1 is okay, but it's pretty common to find systems that will do 50:1 or 100:1, which is probably more in the ballpark of such a slow application.

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1 year 11 months ago #29533896 by glmnet
Ok, I'm switching to the old motors and wheels then.
Anyway, what kind of AGV will run successfully with these wheels and most important how the Roboteq should be configured for them? My first guess is Close loop speed, but I'm still learning.

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1 year 11 months ago #29533910 by Gabriel_Isko
Replied by Gabriel_Isko on topic What to expect from 6.5 Inch hover board wheels
Well, they are hover board wheels, so that gives you a good idea of what they can drive, and the speeds they go at.

Configuration and motor selection really depend a lot on your application. I would recommend reading our User Manual

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