Bottom bracket torque sensors

[fabiograssi]

In theory, is it possible to install a POT 0~5v and a THUN torque sensor, all paired with a cycle analist v3 to do a "throttle less" setup?

Do I really need the CA v3, or I can use the PAS input of the stock controller and install a POT 0~5v instead of the throttle?

I am really tempted to build this next bike without throttle, if this THUN torque sensor provide a smooth response....

Any inputs?

- Fabio

 

[Miles]

I am really tempted to build this next bike without throttle, if this THUN torque sensor provide a smooth response....

Any inputs?

How could it provide a "smooth response"? It's monitoring the torque on the lefthand crank.... Do you pedal smoothly?

 

[adrian_sm]

I am really tempted to build this next bike without throttle, if this THUN torque sensor provide a smooth response....

Any inputs?

How could it provide a "smooth response"? It's monitoring the torque on the lefthand crank.... Do you pedal smoothly?

I am not sure what Thun do, but many off their competitors average/smooth the output for just that reason.

 

[Miles]

I am not sure what Thun do, but many off their competitors average/smooth the output for just that reason.

AFAIK, you get the raw output from the sensor. Obviously, it needs to be averaged. Have you got links for the competitors you referred to, Adrian? It would be good to get together a list of what's available now.

 

[adrian_sm]

Have you got links for the competitors you referred to, Adrian? It would be good to get together a list of what's available now.

My previous comment was based on some brief discussion with a few suppliers at Eurobike. It was only a passing interest for me, so I haven't research it properly. But Ultramotors was definitely claiming it of their BB torque sensor. This 2010 press release suggests they had patents pending, so it should be public by now.
http://www.trademarkpr.eu/ultramotor/external/Background/Ultra%20Motor%20Corporate%20Profile.pdf

I can't remember the name other company I talked to, but it was not a well known one, is was some chinese or taiwan mob.

I'll search through the brochures I picked up and send you a list of the ones I stumbled across if you really want.

- Adrian

 

[Miles]

But Ultramotors was definitely claiming it of their BB torque sensor. This 2010 press release suggests they had patents pending, so it should be public by now.

But is it available for OEM? I don't doubt that their "system" smooths "as sensored" force. The real question is: Are there any torque sensor systems available to us which have a smoothed output?

 

[adrian_sm]

But Ultramotors was definitely claiming it of their BB torque sensor. This 2010 press release suggests they had patents pending, so it should be public by now.

But is it available for OEM? I don't doubt that their "system" smooths "as sensored" force. The real question is: Are there any torque sensor systems available to us which have a smoothed output?

Yes. From what the guy I spoke to said, they are available to OEMs, and they smooth the output from the BB sensor.

 

[Miles]

Thanks Adrian.

This is all I've found, so far: http://www.taipeicycle.com.tw/en_US/product/info.html?id=1A7A69EF6AEEAAFEF11132E7D17F7222

From Adrian's link:

At the Eurobike Show in September the company will launch
its next-generation propulsion system for pedelecs, featuring a patent-pending torque sensor
located directly in the bottom bracket cartridge. The Ultra Motor bottom bracket torque sensor
reacts directly to chain tension and is not subject to left/right signal variations due to irregular
pedalling. It incorporates force, rotation and position sensors for the ultimate in torque sensing
accuracy and responsiveness.

Nothing among the Ultra Motor patents published, relating to the sensor, yet.

 

[adrian_sm]

This is all way off topic, and should probably be moved to a different thread but.... yep, that is the model I saw. Here is my happy snap.

 

[fabiograssi]

Sorry for the hijack in that thread, but the aim of the discussion was not the "smooth response". I only mentioned that if the torque sensor could provide a smooth response, I will choose to use...

The main question, that remais without reply is:

Is that possible to pair this Thun BB torque sensor with a controller without the use of a cycle analist v3?

The RT model appears to have a rotational sensor, a positional sensor (16 positions), and a torque sensor (0,10mV/Nm).

Some tech info about this BB can be found here:

http://www.thun.de/fileadmin/user_u...rlagen/0040_X-CELL_Datenblatt_GB_20120626.pdf

http://www.thun.de/en/marketing/sales-documents/

 

[adrian_sm]

Not directly. The outputs of the Thun are not suited to be a throttle signal. If you are happy to solder a few wires, and program a little bit, it would be pretty easy to put a little micro controller in between to do the job (Arduino, Picaxe). Just need to decide how to map the THUN outputs to a throttle signal. Most popular method seems to be setting a certain pedal torque to equate to 100% throttle. But you could get fancier than that if you want.

[EDIT] Here is a link to the sort of Arduino boards I use. An Arduino Nano. ~$13, connects to your computer via USB, the software is free, and easy to use, with heaps of examples.
http://www.ebay.com.au/itm/Arduino-Nano-V3-0-Compatible-Mega328-ATMega328P-Headers-Non-Soldered-00985-/261098094514?pt=LH_DefaultDomain_15&hash=item3ccaa8bfb2#ht_1155wt_1397
http://www.arduino.cc/

 

[adrian_sm]

Just read your original post. What controller do you have, and what sort of signal is it expecting from the PAS input. You might get lucky.