New MOVE_TO_COMMAND diagonal move problem

[Łukasz]

Hi,

In new Advanced Motion Control my move XY command looks like: M204 S745 X100 Y200 F1000.  I understand it is acceleration and veliocity for XY motion vector but i need separated S and F for X axis and separated for Y axis. How can i get it?

[ma...@makr.zone]

Hi

You can't :-(

Is this for a custom controller?

_Mark

Am 06.04.2021 um 17:51 schrieb Łukasz:

Hi,

In new Advanced Motion Control my move XY command looks like: M204 S745 X100 Y200 F1000.  I understand it is acceleration and veliocity for XY motion vector but i need separated S and F for X axis and separated for Y axis. How can i get it?

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[Jarosław Karwik]

Blasphemy !!!

Well, but seriously - what you suggest would result in non synchronic arrival to end point for X and Y.

If you have different characteristic for X and Y then it should be handles in the controller itself - it would scale movement to slowest axis ( after casting F to X and Y axis). 

[ma...@makr.zone]

If this is a self made controller, the calculation is simple.

Let's use these names:

s = distance (see calculation below)

V = feedrate (the value given by the F word)

a = acceleration (the value given by the M204 S word)

X = X (the value given by the X word)

V_X  = the feedrate for the X axis

a_X = the acceleration for the X axis

etc. for the other axes.

Calculation:

s = √(X²+Y²+...)

V_X = V*X/D

a_X = a*X/D

and analog for Y, Z, ...

_Mark

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[Łukasz]

Yes, its my own  controller  based on STM32 . I think it would be best if openpnp could just deliver me calculated feedrate and acceleration  for x and y axis separatly so XY could make synchronated move.
What i actually get is preety useless for me beacuse my controller have to calculate it separatly for XY axis what i think is waste of controller time. But if there is no other way i will calculate it in my controller. Thanks for mathematical formulas.

[Jarosław Karwik]

STM32 is powerfull enough to calculate it ( I use Stm32H7 for my controller and it has huge overkill for it)

You will not avoid quite many other calculations - even if you want only trapezoidal  shape of speed for the moves. 

See e.g. https://www.linearmotiontips.com/how-to-calculate-velocity/#:~:text=A%20trapezoidal%20move%20profile%20is,machining%2C%20dispensing%2C%20and%20painting.

[Łukasz]

I like keep it as simple as it can be.

Im using trinamic stepper drivers so i only need to write calculated acceleration,feedrate and target position via SPI. Then magic happens.