ASI BAC2000 and Sempu

[jeje]

I am running a system with an ASI BAC2000 controller and a Sempu T4.3 quadrature torque sensor. I've scheduled a few meeting with ASI support already and I still can't get it to work properly. They (ASI support) did say that Sempu is a problematic sensor for them. Since it's a fairly popular sensor, I thought I'll try my luck here to see if anyone has experience with the two.

I've scoped all signal wires to confirm my Sempu is working as it should, my controller detects the two speed channels fine with the PFS and Cruise inputs (digital inputs bit 3 and bit 4). I am able to use the Sempu as a throttle input, so the torque signal is definitely fine too. The problem is that the average pedal cadence and average pedal torque reading are always 0.

My Setup
Bacdoor version: 1.15.3.0
Controller software revision: 6.012

Command Inputs tab
Control command source: 3 (BB torque sensor)

Pedal Torque Sensor tab
Pedal sensor type: 3 (Quadrature torque)
Pedalec Torque symmetry: 2 (Quarter cycle)
Pedal speed sensor pulses per rev: 24 ppr
Pedal sense delay: 2 counts
Pedalec power gain: 4
Torque sensor gain: 60 Nm/Vo
Pedalec deadband torque: 1 Nm
Pedalec initial torque: 0 Nm
Pedal speed map offset: 0.75 pu
Torque sensor offset: 1.5 Volts

Control Loops & Tuning tab
Speed regulator mode: 2 (torque mode with speed limiting)

Can someone also explain how "torque reference" and "torque command" are calculated? I've also been seeing the mention of a 65 page BacDoor user manual, but I am unable to find it. Can someone provide a link? Thanks!

 

[amberwolf]

I've also been seeing the mention of a 65 page BacDoor user manual, but I am unable to find it. Can someone provide a link?

Searching on that exact phrase gives this result:
https://www.google.com/search?newwindow=1&q=65+page+BacDoor+user+manual
which includes links to some, but I haven't looked at the actual stuff linked there to test if they are what you are looking for.

 

[jeje]

Searching on that exact phrase gives this result:
https://www.google.com/search?newwindow=1&q=65+page+BacDoor+user+manual
which includes links to some, but I haven't looked at the actual stuff linked there to test if they are what you are looking for.

Doh! Why didn't I think of trying that. Thanks amberwolf! One of the results is a 65 page user manual for the BAC500, but I'm sure the setup should be the same. Hopefully this will help me with some of my issues.

 

[OnlyEbay]

Had the same error on the 6.012 software revision. Martin from ASI told me to go to revision 6.014 and the problem got resolved!

 

[neutro]

I am running a system with an ASI BAC2000 controller and a Sempu T4.3 quadrature torque sensor.

Hi, from the components it looks like you're doing a high power torque sensing build.

Could you outline the build and your experiences with torque sensing briefly if you have time? Very interested in the torque sensing aspect and looking to start a build.

I'm considering a BAC2000 with a X1 PRO GEN2 on a RISUN type EEB/enduro frame.

 

[jeje]

Hey neutro,

I end up not having a lot of luck with the Sempu/ASI combo. I can get it to work during the first few pedal strokes, but once it tries to go full power, the sensor stops working and I feel my power cut out. I think it's noise, but I've done everything I can think of to try to isolate/shield my torque sensor.

I switched to an older TDCM sensor and it seems to work fine. Because of the lower resolution, the sensor doesn't kick in until a certain number of pulses is detected when using control command source #2 (pedal sensor). Because of this, hill starts are a problem since you need serious man power to get the pedals to spin for a heavier bike. There is a new mode called "throttle OR pedal sensor" with the latest update, and it automatically switches from a throttle input to a pedal sensor input once a cadence signal is detected. I used this mode for a short period of time with no problems. I don't really have anything else to offer since I've switched to a Bafang mid motor, but I did purchase Bafang's pedal sensor as well, so I might test a ASI/Bafang combo when I have time.

 

[neutro]

Thanks for the reply jeje, very relevant insight there.

If you have a moment, I'd appreciate any comment you may have on a higher power, torque PAS, EEB build I'm trying to figure out.

Basically, what's the best torque PAS option on an EEB with a large battery, to approach the torque PAS on an LMX if possible.

The thread is here:

https://endless-sphere.com/forums/viewtopic.php?f=3&t=107705&sid=3b8ab09996573854d7b239dcb6f9aaee