LinuxCNC S-Curve Accelerations

@grandixximo

After commenting out " || (dx - moveL <= dlen2)", the scope looks like this.

 

test with this, this is dlen2 code

 

this is without

    

we know is not ideal, but at the moment, best we can do

My apologize ...
sorry I can not show same speed test because I am currently weeks out of office but we can just multiply or devide values ... because it is linear dependecy during constant speed movemet ... 

I can just customize current images to show exact difference ...  compensation off ferror = 0.125mm at 15m/min ...  compensation on ferror = 0.00009028mm at 1m/min and multiply it by 15 we get 0,0013542mm which is significantly less then 0.125 ..

What I remember from testing by my short eyes it whas something near 0.001mm during that 15m/min testing was done with bentch top setup without any load presented... just AX5106 with AM8xxx motor 

but I can go home for testing this weekend to create exact speed difference testing if it is neccessary

No apologies needed [img]/media/kunena/emoticons/wink.png[/img]

 

I can understand You and YangYang, its added job, but I openly disagree ... its the best time to improve lcnc and solve it at native level for ever, no other proforma hobby solution as now my is...

it should be solution for everyone who not understand it soo well as you guys... my solution of compensation will be even more inaccurate when scurve will be done and implemented ... 

I can not say you what to do, your job, your rules, your output ... thanks for your upgrade to curving
 

grandixximo wrote:

The CiA 402 standard provides feedforward objects exactly for this: 0x60B1 (velocity offset) and 0x60B2 (torque offset). The master can send position plus velocity feedforward so the drive can anticipate acceleration. This is the standard's solution, it just needs to be mapped in lcec.
Also, good drives interpolate internally. The servo loop runs faster than the bus cycle (Maxon runs 0.4ms internal vs 1ms bus). The drive doesn't jump between positions, it interpolates. That's what 0x60C2 configures.
 

Can we explore this on another topic when I get to it? I wanted to rewrite dominic's cia402 component to make it easier to maintain and properly deal with homing so it comes into line with the custom homing that wasn't around when it was written. So it would be perfect for inclusion. Could the new TP have output pins that could be taken as input to calculate these?   Or how would we do it? Any conversion/massaging would be done in the revised component.