washer motor forward reverse motion with pic

picbits said:

I think the biggest problem with designing the motor controller is controlling the speed when there is a large "lump" of washing in there. The drum needs a hefty push with a load of water and wet washing in the bottom to get going then you need to reduce the speed otherwise the washing won't tumble and will just stick to the sides.

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The "universal motor + speed control feedback" excels in this case, regardless of how many washing there is. No difference in performance observed between drum empty and fully loaded.

picbits said:

Likewise with the spin cycle, if you spin the washing up too fast, the washing clumps and the machine shakes itself to bits. You need an algorithm which will try and spread the washing evenly around the drum before spinning - if there is too much vibration, try again and again and again .......

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Exactly. That was called the "distribution" phase where clothing is distributed evenly around the drum before the drum speed actually rams up. It's about several rpm per second and holds there for a about 15 seconds to also let some of the water to spin/drain off. My washing machine did not have vibration sensor and it will not retry if vibration is excessive. The phase angle control using the universal motor+speed feedback is normally very smooth.

However, it is a big problem if the washing load is small and in this case vibration is excessive during spin dry.

I´m reading a lot about motor speed control and about vibration yet most washer out here come with electromechanical timer, that don´t implement any type of speed control just on or off yet they don´t have big problems with vibration,even some high end washer with electronic controllers don´t do it either. they don´t need it because these washer have about 60lbs of weight on top to stabalize the drumm.............

I would think front-loader would have less of the vibration issue than the top-loader type. I can see where a small load would be more of and issue with vibration as well, that makes total sense. I think that is what is confusing people, one is speaking of a top-loader the other a front version.

However, I am not sure how you could solve a vibration issue with any algorithm. It could be simply an unbalanced load that is the issue, or a small clump that bunches up, as stated. Not trying to be mean or anything, just trying to think it out, and I am not getting anywhere. Or you talking like trying to balance the load going one way then switching or something to that effect?

-BaC

BaCaRdi said:

However, I am not sure how you could solve a vibration issue with any algorithm. It could be simply an unbalanced load that is the issue, or a small clump that bunches up, as stated. Not trying to be mean or anything, just trying to think it out, and I am not getting anywhere. Or you talking like trying to balance the load going one way then switching or something to that effect?

-BaC

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Basically, turning the drum, measuring the RPM variance on the imbalance, slowing/reversing the drum to allow the washing to redistribute, repeat until RPM variance is smoothed to an acceptable level.

What I thought you meant, sure that could work well. I wonder if any of the companies out there do such, as I does sound like a good idea.

-BaC

picbits said:

Basically, turning the drum, measuring the RPM variance on the imbalance, slowing/reversing the drum to allow the washing to redistribute, repeat until RPM variance is smoothed to an acceptable level.

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