Urgent advice needed: 4 pole or 2 pole motors?

[faico_26]

The guy at the store finally could program the chair according to Burgerman’s indications. Well most of them, the programmer didn’t have some settings like
reverse acceleration and the mínimums like minimum acceleration.


Only dynamic systems dont have that. So he wasnt paying attention and tat will make tit steer crap...

The guy at the store spent a long time trying to find the minimums in the programmer but apparently there was no such option in the machine. So only he could set the maximums.

[faico_26]

The chair works better, more responsive but still it’s super jerky when I move it super slow like for example when I have to park it for the toilet, or to transfer to the van six way seat, these super slow movements are very jerky.


Because you did not follow my instructions!!! Slow movements require MINIMUMS to be set, correct motor load compensation, correct torque values. etc.

I tried to follow your instructions with detail, I had everything you taught me printed on paper and we went point by point setting your parameters.

[faico_26]

I guess it is due to the 4 pole motors. This is what Sunrise indicates in their webpage: “Two-pole motors pull more smoothly in very slow operation than four-pole motors do, making two-pole motors a good choice for cramped, indoor environments.”. “While a two-pole motor will operate well at very low speeds, the same cannot be said of a four-pole motor. A four-pole motor will have a rougher operation than a two-pole motor at very low speeds”.

No. That refers to "cogging" in that at low speeds of maybe 0.005mph (you cant see it moving) its more "lumpy"... It has nothing to do with it being jerky.Its a thing you occaionally feel. I doubt you can feel it. It still goes exactly where told. If programmed correctly.

I didn't know cogging was different that jerky, sorry for my English. What I meant is that it is NOT smooth, but from not moving it goes some abruptly. These small corrections when you are parking the chair in a very tiny space are complicated because it is not smooth.

[faico_26]

What was torque set to? Did you test a bunch of different settings? LAST. Did you even know what it did? Or what you were feeling for?
What was motor compensation set to, and did you change it?
What was the MINIMUM turn and reverse and forward speeds set to?

Torque was set to 90. We raised it to 100, but it still cannot handle small 4 cms curbs. We test the same 4 cms curbs with other Quickie chairs in the shop: Q100R (6 km/h 2 pole), Q200R (10 km/h 2 pole). None of them were able to handle the small 4 cms curb. So it looks like Sunrise does not want users to handle 4 cms curbs. My 180W Invacare Mirage does it with no effort.
Motor compensation: The guy told me it was only necessary to balance motors when for example you install a new motor but the other one is old. So he didn't touch it despite I asked him for.
MINIMUM turn and reverse and forward speeds Reverse speed he put it as you said, and forward speed at 100. Mininum turn speed I don't remember if he could set it. I will check my notes. I wrote everything on paper.

[faico_26]

You cannot expect a man in a shop to fine tune everything to how you want it in less than a couple of 8 hour days with you testing every setting individually so you can get a feel for what each setting does set way too high and low.

I agree, I need the hardware and software to do that and check it by myself.

[faico_26]

have your joystick POSITIONED correctly? As in high enough and with a gap, and slighty inboard of the arm centreline? Post a pic. With hand position.

Yes, hand and joystick good position. 25 years on wheelchair actually!

[faico_26]

What control system is this?

VR2 joystick with 2 actuators (tilt + seat lift) + VR2 90amp control unit
It's like this (picture from internet):

[faico_26]

To make it super smooth at very slow speeds you need to set MINIMUM SPEED when on speed 1 to a speed that the chair barely moves.
To make it super smooth at very slow speeds you need to set MINIMUM REVERSE SPEED when on speed 1 to a speed that the chair barely moves.
To make it super smooth at very slow speeds you need to set MINIMUM TURN SPEED when on speed 1 to a speed that the chair barely moves.
INDIVIDUALLY, then test and fine tune.
DONT lower accelerations!
Then set TORQUE so that it isnt jerky at super slow speeds.

TORQUE: We moved it from 90 to the maximum 100 to try to handle curbs. It didn't make any difference.
MINIMUM SPEED when on speed 1 the guy didn't find an option for it.
MINIMUM REVERSE SPEED when on speed 1 the guy didn't find an option for it.
MINIMUM TURN SPEED when on speed 1 I don't remember if the guy found the option. I will check my notes.

[LROBBINS]

ALL of the parameters can be set, but your dealer probably doesn't have the OEM-level programmer needed to do that. A dealer level programmer sees only a subset and leaves out some of the most important ones. He is WRONG in any case about the purpose of motor compensation: it is not to "balance" unequal motors, but to increase power when the motor is under load so that speed stays closer to constant. If set too low, you will not be able to climb a curb, and you'll have trouble starting a turn if not moving or when moving slowly. It must be adjusted with care however because if set too high the chair can become very difficult to control, or even get into a runaway state where it moves on its own.

Motor compensation is a technique that's been used for decades and decades. A more complete name is IR Motor Compensation because what it does is uses motor current (I) and multiplies that by motor resistance (R) to get a measure of the back EMF (reverse voltage generated by the motor) and increases the commanded voltage by a bit less than that amount. The value you program for compensation is that R. If set too high, as voltage increases the current draw will increase which will further increase voltage which will further increase current. Rinse and repeat and you're in trouble. One also has to err on the safe side because motor resistance isn't really constant: it varies, for example, with temperature of the motor.

[faico_26]

ALL of the parameters can be set, but your dealer probably doesn't have the OEM-level programmer needed to do that. A dealer level programmer sees only a subset and leaves out some of the most important ones. He is WRONG in any case about the purpose of motor compensation: it is not to "balance" unequal motors, but to increase power when the motor is under load so that speed stays closer to constant. If set too low, you will not be able to climb a curb, and you'll have trouble starting a turn if not moving or when moving slowly. It must be adjusted with care however because if set too high the chair can become very difficult to control, or even get into a runaway state where it moves on its own.

Motor compensation is a technique that's been used for decades and decades. A more complete name is IR Motor Compensation because what it does is uses motor current (I) and multiplies that by motor resistance (R) to get a measure of the back EMF (reverse voltage generated by the motor) and increases the commanded voltage by a bit less than that amount. The value you program for compensation is that R. If set too high, as voltage increases the current draw will increase which will further increase voltage which will further increase current. Rinse and repeat and you're in trouble. One also has to err on the safe side because motor resistance isn't really constant: it varies, for example, with temperature of the motor.

OK, thanks for the info, I will ask again the guy in the store to do so following Burgerman's indication: add 5mOhm to the motor load compensation

[Burgerman]

Thats NOT what I said. I said add no more than 5. Until you test. I the chair is really "jerky" it may be too high already.

It as lenny explains an algorythm that increases motor current (by increasing volts) to give more torque when a motor sees more load. It affects EVERY speed, every control, every setting, including deceleration.

As with every setting, you MUST test by redicing to a really low figure and sitting in the chair and feeling what it does.Then setting it to a very high figure and testing it again. DO NOT DO THAT WITH COMPENSATION!!! but do it with EVERY OTHER CONTROL.


>>TORQUE: We moved it from 90 to the maximum 100 to try to handle curbs. It didn't make any difference.
Because you didnt read what I wrote. It affects the initial 1 inch of movement, the very first part of the joystick move,ent. It wont help on curbs at all. But it will help make the chair jumpy... At SMALL stick movements like 1/4 inch.

>>MINIMUM SPEED when on speed 1 the guy didn't find an option for it.
Hes an idiot.
>>MINIMUM REVERSE SPEED when on speed 1 the guy didn't find an option for it.
Again, he isnt looking. This is why YOU must program it in your wn time.

MINIMUM TURN SPEED when on speed 1 I don't remember if the guy found the option. I will check my notes.
It exists in the menu on speed 1 and any other speeds. (It does on all the profiles as well. Which you wont need.)

VR2 is simple. But I didnt look at it in years so will now!

[Burgerman]

Wow. Even more basic than I remember!

Arrows show the MINIMUMS. And reverse speeds etc. That your expert claims dont exist.

Do not try to use a shop or "tech" to program a chair as they nrmally dont have a clue.

Go back and CAREFULLY read my posts and links in this thread. If there is anything you are unsure about, a setting you dont understand, ask!

[faico_26]

“ Thats NOT what I said. I said add no more than 5. Until you test. I the chair is really "jerky" it may be too high already.”

Sorry! I misunderstood. What are the values? I mean, is 0,1,2,3,4,5?

[faico_26]

“ Go back and CAREFULLY read my posts and links in this thread. If there is anything you are unsure about, a setting you dont understand, ask!”
Thanks I really appreciate your help.

[faico_26]

“ It as lenny explains an algorythm that increases motor current (by increasing volts) to give more torque when a motor sees more load. It affects EVERY speed, every control, every setting, including deceleration.

As with every setting, you MUST test by redicing to a really low figure and sitting in the chair and feeling what it does.Then setting it to a very high figure and testing it again. DO NOT DO THAT WITH COMPENSATION!!! but do it with EVERY OTHER CONTROL.”
Ok, I’ll do it so.

[faico_26]

“ Again, he isnt looking. This is why YOU must program it in your wn time.”
Yes, I’m really excited to get hardware and software to be able to modify, check and test by myself. Every time I have to go to the shop is 3h or 4h time (travelling to the shop, time at the shop and travelling back home). It’s like if for my Rc plane I had to do that at the shop and then check it at flying field.
And it’s quite stressing because I can’t be at the shop for a long time, because they have other customers. So I had everything you taught me on a notebook (paper) to follow your instructions step by step.

[faico_26]

Another disappointment is that I wanted the seat lift to be faster. It was on 3 and the guy at the store moved it to 5 but it didn’t make a difference. Then he put it on 1 but there was an error message (like too less voltage or something).

[Burgerman]

Its not a set of instruction. You cant do that step by step and then use it. You need to FEEL what many of these things do to choose the setting correct value.

And I have no idea what your expert was doing.

First of all the actuators are always on max speed and they are not going any faster. Yes way way too slow. We are disabled, slow is cheaper.
What are these numbers refering to?
Sounds like he was messing about with inhibits! You know when I said he was an idiot?

[Burgerman]

Sorry! I misunderstood. What are the values? I mean, is 0,1,2,3,4,5?

Not sure what you are refering too?
Where are those? Profiles?
You only want ONE profile. Disable the rest. Once you get that correct, and it will then do everything you can add another one with a few different setting for a special case such as when not sat in the chair. Like less torque etc. SLOW speeds and slow turn speeds. NOT YET!

First you need to understand what EVERYTHING is doing. You only lear that by trying very high and very low values. Each setting does only 1 specific thing. If you have an idea what it does its easy to test it. And then configure it. At least theres just a few on that controller!

[faico_26]

“ Not sure what you are refering too?
Where are those? Profiles?”
I meant regarding motor load compensation. You said no more than 5. So will I find other values like 4, 3 etc?

[LROBBINS]

The motor compensation parameter is an estimate of motor resistance. A fairly typical value for a 4-pole motor is 60 milliohms. For a 2 pole, 100 or so milliohms. When adjusting this you want to make small changes. So, if the chair seems sluggish, you might increase it by 5 from 60 to 65 milliohms, If it seems skittish, you might decrease it by 5, from 60 to 55.

For other parameters you can set the value very low or very high to get a feel for what that parameter does, then chose some intermediate value and adjust it up or down to where it's comfortable for you.

BUT FOR MOTOR COMPENSATION YOU SHOULD MAKE ONLY SMALL CHANGES, ESPECIALLY WHEN INCREASING IT! The 5 Burgerman talks about is the size of the change you might make.

[faico_26]

The motor compensation parameter is an estimate of motor resistance. A fairly typical value for a 4-pole motor is 60 milliohms. For a 2 pole, 100 or so milliohms. When adjusting this you want to make small changes. So, if the chair seems sluggish, you might increase it by 5 from 60 to 65 milliohms, If it seems skittish, you might decrease it by 5, from 60 to 55.

For other parameters you can set the value very low or very high to get a feel for what that parameter does, then chose some intermediate value and adjust it up or down to where it's comfortable for you.

BUT FOR MOTOR COMPENSATION YOU SHOULD MAKE ONLY SMALL CHANGES, ESPECIALLY WHEN INCREASING IT! The 5 Burgerman talks about is the size of the change you might make.

I understand now, thanks, nice explanation.

[faico_26]

https://youtu.be/UQyEDFp-vVY?feature=shared

Interesting old video. Go to minute 02:52 and there is a visual explanation about FWD, MWD, RWD when handling 15cms curbs. Of course, RWD wins!

Then, in minute 3:41 the guy explains about increasing torque to handle obstacles and he says something that Youtube translator says "healing obstacle compensation". You guys are English speakers, so you will understand much better than I do. Is he referring to "motor load compensation"?

[Burgerman]

In PG chairs, pilott plus, r-net etc the parameter he is talking about is called torque.

What motor compensation does it amplify (increase) the power sent to the motors when it senses a current. So if you move the joystick just a 1/4 of an inch the chair moves very slowly. The motor might be recieving 1V at this point.

Add some extra "resistance" to say the left wheel, say a rock or a bit of grass. A small sope. And now what happens is the this left wheel tries to pull slightly more AMPS because the more you load up (restrict) a motor the greater the current it draws. So in a sense it tries to apply apply its own "compensation". But it isnt adequate. So that wheel doesent move. Or goes slower. So even though you push the stick forwards (straight) the chair turns left.

When the power module sees additional current on this slower or stalled left motor, it adds more! Its a positive feedback loop. So now the left motor gets more power than the right one. So now it can climb the rock/slope/grass. So that the chair now drives straight as you expected and wanted. As if there was no restriction or rock, or whatever in its way.

But... Motor compensation at very low speeds doesent work as well. I mean really low speeds!
So we also have a setting called torque. It does one of two things. I cant decide which.
In both cases it only works at super slow speeds. At small stick movements. Once faster than say 0.1mph it does nothing.
It either INCREASES motor compensation only at very small stick movements. Or it adds a "step" so that the joysick starts at 5% instead of 1% as you move it. The result is the same either way.

This is likely what he is talking about.

[faico_26]

In PG chairs, pilott plus, r-net etc the parameter he is talking about is called torque.

What motor compensation does it amplify (increase) the power sent to the motors when it senses a current. So if you move the joystick just a 1/4 of an inch the chair moves very slowly. The motor might be recieving 1V at this point.

Add some extra "resistance" to say the left wheel, say a rock or a bit of grass. A small sope. And now what happens is the this left wheel tries to pull slightly more AMPS because the more you load up (restrict) a motor the greater the current it draws. So in a sense it tries to apply apply its own "compensation". But it isnt adequate. So that wheel doesent move. Or goes slower. So even though you push the stick forwards (straight) the chair turns left.

When the power module sees additional current on this slower or stalled left motor, it adds more! Its a positive feedback loop. So now the left motor gets more power than the right one. So now it can climb the rock/slope/grass. So that the chair now drives straight as you expected and wanted. As if there was no restriction or rock, or whatever in its way.

But... Motor compensation at very low speeds doesent work as well. I mean really low speeds!
So we also have a setting called torque. It does one of two things. I cant decide which.
In both cases it only works at super slow speeds. At small stick movements. Once faster than say 0.1mph it does nothing.
It either INCREASES motor compensation only at very small stick movements. Or it adds a "step" so that the joysick starts at 5% instead of 1% as you move it. The result is the same either way.

This is likely what he is talking about.

Thanks, clear explanation. My chair has VR2, that is PG right?

[Burgerman]

Yep.