Imitation torque controller Kunteng

[vladobac]

I would like to share my experience with this type of controller.
The controller does not respond to the pedaling force, nor to its cadence. Hence the “imitation”. It would be better to describe it as a “power mode”. It works in such a way that after selecting the assistance level, the motor constantly helps you with the programmed force, regardless of the riding speed. Conventional controllers have a so-called “speed mode” and at each assistance level they only help up to a fixed speed programmed by the manufacturer. In practice, this is usually around 10 km/h at assistance level 1, a little more at level 2 and the maximum at level 5. So if you want to ride such a bike briskly, e.g. 25 km/h, you have to choose assistance level 5. Unfortunately, with such strong assistance you will not be able to do any sports at all, because the bike will do all the work for you. Of course, at the expense of range. That's why I prefer power-limited controllers over speed-limited ones. This allows me to achieve high average speeds and maximize range with minimal motor support.
On my bike with a "no name" motor with a 36V/250W rear gear, I originally had a very cheap 15A controller with torque simulation. In principle, it suited me and I wouldn't want another system. However, the motor was not running smoothly, so I was looking for a better quality, but not too expensive controller. I couldn't find any specific tips for such a controller on professional forums, so I contacted several sellers on Aliexpress. One seller wrote back to me that the Kunteng KT36/48V SVPR controller with the KT-LCD5 display has the option of such a setting. It even works in the so-called sine mode, which should guarantee smooth motor operation. I purchased it and installed it on my bike. After setting the necessary parameters and testing it, I confirm that it met my requirements. The motor runs smoothly and quietly at higher speeds than with the previous controller.
I repeat again that the controller is suitable for cyclists who do not want all the work from the bike, but also actively help it. The speed limit is the same for all assistance levels and can be easily set with one parameter (theoretically up to 72 km/h). The resulting riding speed therefore depends only on the cyclist's performance and the selected assistance level. If you are not lazy, you can move briskly (25-30 km/h) with minimal engine support and thus increase your range. Below I will list the parameters with which this mode is set:
The current mode is selected by setting parameter P3=1 (if you set P3=0, the bike will be in classic speed control mode).
Parameter C14 sets three sets of assistance power:
C14=1 support power for assistance 1-5 is approximately 6/17/30/45/100% of the maximum motor power
C14=2 support power for assistance 1-5 is approximately 12/22/40/55/100% of the maximum motor power
C14=3 support power for assistance 1-5 is approximately 17/30/45/66/100% of the maximum motor power
The level of individual stages cannot be changed, but I believe that everyone will find one that suits them in the default settings.
Parameter C5 allows you to gently (in eight stages) reduce the maximum current of the controller by up to 50%. All support stages will react proportionally to the current reduction.
The controller has the ability to connect throttle, brakes, front and rear lights.
I am attaching a link to the purchased controller with display, PAS sensor and 1T5 cable (which is unnecessarily long). The price for these 4 components was less than 77€.

https://www.aliexpress.com/item/1005010106837004.html?spm=a2g0o.order_list.order_list_main.5.23861802q2jC9O

 

[amberwolf]

If it's helpful:

The controller does not respond to the pedaling force, nor to its cadence.

Virtually all controllers are like this--they simply apply the full amount of whatever the presently chosen assist level allows, as soon as any pedalling is detected.

Some have settings to modify various things in the assist levels, but those aren't user-controllable via pedals (only in menus on the screen or sometimes via a separate program or app).

If you do want to use cadence or torque pedal control, there are options to add this to many existing controllers (any of them that will operate solely from it's throttle input and has a mode that allows it's full range of assist from the throttle without any other inputs).

One is the Cycle Analyst from ebikes.ca but this is not cheap and it takes significant time investment to learn how to set it up for your specific system and usage, and tuning the results for a perfect ride. In most cases that perfect ride is possible, though, so worth it if you're willing and have the money. I use one to do cadence-controlled operation of a 2WD system on the heavy heavy-cargo trike SB Cruiser.

There is at least one DIY arduino (or other MCU) project here to take a cadence sensor and make a throttle signal from it.

There's another that will take a torque sensor voltage and convert it to a throttle voltage.

Some of the Erider TS BB's have a throttle-range voltage output that can be directly connected to the throttle input of a controller, but beware that without something to calibrate this to remain below the starting threshold of the controller input when not being used, it can drift over time and in different environmental conditions enough to start out above the throttle-off condition, and the bike could take off without a rider as soon as it's turned on if the controller has no protections against this (has to be tested on each one as virtually none tell you if they do in any useful way).

For some versions of some controllers, there are OSF OSFW Open source Firmware available in various threads here on ES and on Github, etc., that you can flash over the OEM firmware to completely change how the controller works, and some of these then allow direct cadence and/or torque control.




There are a few controllers that have a direct way to use torque sensors; most of the "kit" types work directly with some of the Erider TS BB versions.

Some versions of the Phaserunners from ebikes.ca can do it; others can do it using the Superharness also from ebikes.ca, or the cycle analyst.

The PR is based on the ASI BAC controller series, so if you're willing to figure out all the bajillion settings of those, without the easy Phaserunner Setup Suite software then you can do about anything in the ASI that you can do in the PR, eventually.


If you look around at Stancecoke's posts and threads, there are other methods in those.

 

[vladobac]

Thanks for the additional information. I am also attaching the results from a practical ride with the new controller. My bike is a comfortable 26" touring bike with a suspension front fork. Today I rode it 77.8 km on flat terrain. First time with the new controller. During this ride I measured the energy consumption. I have a battery capacity meter and the result of my measurement was that I consumed 315.8 Wh (8361 mAh) on those 77.8 km. That is a nice 4.06 Wh/km. Average speed 23.0 km/h. The minimum with the old controller was 5.1 Wh/km. The theoretical range with my 672 Wh battery would be about 165 km. I am very satisfied and looking forward to summer. But I will have to wait at least half a year for that, because winter has not even started yet...

 

[docw009]

That battery consumption level of 4.06 Wh/km (6.2 Wh/mile). is very good. Are you letting the controller go at the full 20A or have you set C5 less than 10?

I run 20A KT controllers on several hub motors. My lowest numbers are around 5 WH/km. I'm 86 kg, but my 53 kg wife might do 4.3 Wh/km, We're riding slower then you too,

Most cadence controllers treat the prescence of PAS pulse train as an on/off switch, but they do ignore it when the pedals spin backwards. I feel KT has a good algorithm for PAS in that they prorate the current flor assist levels with some ability to adjust. I know there are better controllers for more powerful applications, but KT's work for me. Most of my bikes use the LCD3 but also have the small color LCD7. Hard to see in sun, and buttons are stiff. I like having the wattage show on the display,

 

[vladobac]

Sorry for the late reply. I did not limit the maximum current. Today I rode 76.7 km (flat, no wind, temperature 7°C) and at an average speed of 23.8 km/h I achieved a consumption of 3.67 Wh/km. I achieve low consumption with low assistance. I only used assistance modes 1 and 2. I have a current mode set where the current consumption was only 1.4A with assistance 1 and 3.4A with assistance 2. The consumption is constant, independent of cadence and speed. I weigh 82 kg, I am 68 years old.