Torque simulation controllers do not control torque

[avandalen]

Torque simulation controllers do not control torque​

In recent times, there has been a surge in the marketing of motor controllers as torque simulation controllers. This led me to assume that these controllers control the motor torque rather than its speed. However, this turned out to be false, I discovered that these controllers merely regulate the motor voltage, just like regular motor controllers.
See my full article here:

Torque simulation

Here, I share technical solutions that arised during the development of my solar-bike.

www.avdweb.nl

 

[amberwolf]

Thanks for the article; yes this has been discussed here over the years to correct various people's misconceptions because of their incorrect marketing terms.

 

[stancecoke]

However, this turned out to be false

Interesting finding, but I think the control strategy is much simpler. The Kunteng normally just controls the battery current to the value, that is assigned to the recent assist level, with a cadence dependent ramp from standstill. The mechanical output power characteristic you are showing, is simply caused by the effiency vs. speed behaviour of any BLDC motor...

The throttle behaviour can be set in the menu of the display

 

[Comrade]

mechanical output power characteristic you are showing, is simply caused by the effiency vs. speed behaviour of any BLDC motor

And that's why they are even called torque simulation controller, not torque controller.

 

[Blacklite]

However, this turned out to be false, I discovered that these controllers merely regulate the motor voltage, just like regular motor controllers.
See my full article here:

Torque simulation

Here, I share technical solutions that arised during the development of my solar-bike.

www.avdweb.nl

Nowhere does your article show that these controllers are just controlling voltage.
You are showing a relationship between cadence and power.
Do you have further data showing the control paradigm is voltage? I would assume it is actually current instead, and torque is directly proportional to current.

 

[AHicks]

There's speed based PAS, and there's power based PAS. KT's "imitation torque control" is chinglish for power based PAS. It's that simple.....

 

[richj8990]

There's speed based PAS, and there's power based PAS. KT's "imitation torque control" is chinglish for power based PAS. It's that simple.....

It affects throttle response too. That's why I'm going to turn it off later after I put the battery back on for this new build in the garage.

Instead of these replies reminding everyone that imitation torque is not torque, maybe someone (mua) should describe what really happens out on the road or trail with imitation torque. Like, you know, real-world application experience?

I like speed control because you know what you are getting, and the power application is consistent. With imitation torque, the controller senses that the speed is slowing down even though the power is constant, therefore the controller quickly ramps up the power to compensate for the slower speed. So if you go from a flat surface to an incline, imitation torque will ramp up the power to compensate for the incline. Sounds nice in theory, and yes it can be nice in reality. Sometimes it ramps up the power too much and the wheel will spin. The thing I find annoying about it though (and this may or may not be helped by reprogramming the controller) is that when you are on a level surface or going slightly downhill...not enough where you can gravity coast, but enough that you'd want to max out your gears and have just a little bit of e-power to cruise at 20-25 mph, suddenly the throttle is unresponsive. Because it's doing the opposite of what it does on an incline: it's cutting back (all or almost all) of the power because it senses additional speed w/o any extra wattage. I don't like that. Some imitation torque functions are smoother than others, but speed control is consistent and I like that better.

 

[AHicks]

It affects throttle response too. That's why I'm going to turn it off later after I put the battery back on for this new build in the garage.

Instead of these replies reminding everyone that imitation torque is not torque, maybe someone (mua) should describe what really happens out on the road or trail with imitation torque. Like, you know, real-world application experience?

I like speed control because you know what you are getting, and the power application is consistent. With imitation torque, the controller senses that the speed is slowing down even though the power is constant, therefore the controller quickly ramps up the power to compensate for the slower speed. So if you go from a flat surface to an incline, imitation torque will ramp up the power to compensate for the incline. Sounds nice in theory, and yes it can be nice in reality. Sometimes it ramps up the power too much and the wheel will spin. The thing I find annoying about it though (and this may or may not be helped by reprogramming the controller) is that when you are on a level surface or going slightly downhill...not enough where you can gravity coast, but enough that you'd want to max out your gears and have just a little bit of e-power to cruise at 20-25 mph, suddenly the throttle is unresponsive. Because it's doing the opposite of what it does on an incline: it's cutting back (all or almost all) of the power because it senses additional speed w/o any extra wattage. I don't like that. Some imitation torque functions are smoother than others, but speed control is consistent and I like that better.

Between the wife and I, we currently have 6 bikes, and I ride every day. 4 of these bikes are set up with KT controllers, and all have the "imitation torque control" enabled. The other 2 bikes use Bafang mid drives, one of which is UART based (an Ultra), where they give you the choice or power or speed based. Based on my experience with KT (8 bikes dating back to 2017), and after trying it both ways, THAT bike is set to speed based.

None of my KT based bikes, dating back to 2017, will add uncommanded power in ANY mode, let alone when "imitation torque control" is enabled. The KT's do have cruise control, but even that will shut down/cancel if it slows more than a couple of miles an hour.

"Sometimes it ramps up the power too much and the wheel will spin."

This is getting pretty creative based on my experience. One of my bikes is powered by a 1000w MAC 12t, one of the most powerful geared hubs available. That bike has wheelied, but I've NEVER experienced wheel spin.....

"The thing I find annoying about it though (and this may or may not be helped by reprogramming the controller) is that when you are on a level surface or going slightly downhill...not enough where you can gravity coast, but enough that you'd want to max out your gears and have just a little bit of e-power to cruise at 20-25 mph, suddenly the throttle is unresponsive. Because it's doing the opposite of what it does on an incline: it's cutting back (all or almost all) of the power because it senses additional speed w/o any extra wattage.

With the speed limit set to 99 mph, down hill runs on any of my KT bikes will be WAY faster than MOST will ever want to go. Even on the flat and level, the MAC 12t powered bike will run well over 30mph. Down hill, I once saw something close to 40, but I'm too old to enjoy anything like that any more.

Point being, they do not shut the motor down.

If your experience contradicts any of my results, I'd suggest you might want to try some different parameter settings..... like I did when figuring all that out......