L6470与我的电机不兼容

在这种情况下，您可以将INT_SPEED参数设置为最大值。
 
如果您需要有关电压模式的更多详细信息，请参阅具体的应用说明http://www.st.com/st-web-ui/static/active/en/resource/technical/document/application_note/DM00061093.pdf
。
 
问候
恩里科



以下为原文





In this case you can set the INT_SPEED parameter to the maximum value.

If you need more details to the voltage mode, you can consult the specific application note http://www.st.com/st-web-ui/static/active/en/resource/technical/document/application_note/DM00061093.pdf
.

Regards
Enrico

我懂了。
 
您可以发布应用和电机的参数（目标电流，电源电压，Rm，Lm，ke等）吗？
 
恩里科



以下为原文





I see.

Can you post the parameters of your application and motor (target current, supply voltage, Rm, Lm, ke, etc)?

Enrico

当然。
 
目标电流 - 1A
电源电压 - 24V
Rm - 6.2欧姆
Lm - 1.88 mH
ke - 0.009 V / Hz
 
这给出了大约2100步/秒的INT_SPEED，但我限制在~1000步/秒。
 
例如，如果我想以6000步/秒的速度运行，我可以计算一个变通方法的最终斜率，它将以该速度给出所需的电流（通过交叉图形），并获得高达1000步/秒的稳定电流，但是从1000到6000步/秒我得到一个过流，因为最后的斜率开始得太早。
 
 
谢谢。



以下为原文





Sure.

target current - 1A
supply voltage - 24V
Rm - 6.2 Ohm
Lm - 1.88 mH
ke - 0.009 V/Hz

This gives an INT_SPEED of ~2100 step/s, but I'm limited to ~1000 step/s.

If I want to run at 6000 step/s for example, I can calculate a workaround final slope that will give the wanted current at that speed (by intersecting the graphs), and I get a steady current up to 1000 step/s, but from 1000 to 6000 step/s I get an overcurrent since the final slope starts too early.


Thank you.

好，
 
 
我做了一些计算。
首先，使用“理想”补偿曲线，器件在6000步/秒速度之前达到占空比的100％（约为4600步/秒）。高于此速度的测量不会进一步增加施加到电动机的电压正弦波。
 
试试这个配置，让我知道它是如何工作的：
kval_acc = kval_dec = kval_run = 0x42
st_slp = 0x06
fn_slp_acc = fn_slp_dec = 0x0b
int_spd = 0x3fff
 
恩里科



以下为原文





Ok,


I made some calculations.
First of all also using the ''ideal'' compensation curve the device reaches the 100% of duty cycle before the 6000 step/s speed (at about 4600 step/s). That meas that above this speed the voltage sinewave applied to the motor is not further increased.

Try this configuration and let me know how it work:
kval_acc = kval_dec = kval_run = 0x42
st_slp = 0x06
fn_slp_acc = fn_slp_dec = 0x0b
int_spd = 0x3fff

Enrico

嗨恩里科，
 
 
回复晚了非常抱歉。
 
你是对的，由于缺少BEMF补偿（驱动器最大化），我确实遇到从大约5000步/秒开始减小的相电流。
我知道除了使用更高的电机电压（我目前不想做）之外，我无法解决这个问题。
 
L6472能否以相同的规格驱动我的电机？还是它也无法高速达到目标相电流？
 
谢谢，
然。



以下为原文





Hi Enrico,


Sorry for the late response.

You are right, and I do encounter a decreasing phase current starting from around 5000 steps/sec due to lack of BEMF compensation (driver is maxed out).
I understand there's nothing I can do to resolve this issue, except for using higher motor voltage (which I don't want to do currently).

Will the L6472 be able to drive my motor with the same specifications? or would it also be unable to reach the target phase current at high speed?

Thanks,
Ran.

嗨冉，
 
 
 L6472中实现的不同控制模式可以为您提供一些额外的电流（和扭矩）。然而，限制是由于电源电压，因此它仍然存在。
 
 恩里科



以下为原文





Hi Ran,


The different control mode implemented in the L6472 could give you a bit of extra current (and torque). However the limitation is due to the supply voltage, so it is still present.

Enrico

嗨恩里科，
 
 
我尝试使用L6470的设置（使用SPIN评估软件）进行更多操作，以查看我是否可以高速获得更好的结果，并且我发现如果我将步骤模式更改为完整步骤我确实实现了高速时所需的相电流。
但是，如果在将全步速度设置为远低于预期速度的值时使用除“全步”以外的任何其他值，则不会获得所需的相电流（尽管它确实更改为步进模式）。
这有点出乎意料，因为我认为在通过全步速度之后进入全步，其行为与从一开始使用全步模式相同。
这一发现还表明，通过电子方式可以以我想要的速度实现所需的相电流，这只是一个驱动问题。
 
我很感激您对我的发现的反馈。
 
谢谢，
然。



以下为原文





Hi Enrico,


I tried to play a little more with the settings of the L6470 (using the SPIN eval software) to see if I can get better results at high speed, and I found out that if I change the Step Mode to Full Step I do achieve the desired phase current at high speed.
However, if I use anything other than Full Step while setting Full-Step Speed to a value much lower than the intended speed, I do not get the wanted phase current (although it does change to step mode).
This is a bit unexpected, as I would assume going to full step after passing the Full-Step Speed would behave the same as using Full Step mode from the start.
This finding also show that electronically it is possible to achieve the wanted phase current at my desired speed, it's just a driver issue.

I would appreciate your feedback on my finding.

Thanks,
Ran.

嗨冉，
 
 
 当器件使用全步进速度阈值在微步和全步之间切换时，电压方波（全步）的幅度受到限制，以避免不连续（参见器件数据手册中的相应章节）。
 所以你的发现是正确的：自动全步骤给出了正常全步骤的较低电压（然后是较低的电流）。
 
 恩里科



以下为原文





Hi Ran,


When the device switches between microstep and full-step using the Full Step Speed threshold the amplitude of the voltage squarewave (Full-step) il limited in order to avoid discontinuities (see respective section in the device datasheet).
So your finds are correct: the automatic full-step gives a lower voltage (and then a lower current) that the normal full-step.

Enrico