CA3 - AutoPAS with RPM-Proportional Assist

[Htfan]

I'm in the process of reconfiguring my ebike with a new CA3.

Now I'm adding PAS to the scenario. Specifically "AutoPAS with RPM-Proportional Assist" this is section 6.5 in the V3 Guide. However, I don't own a thun torque sensor and using a traditional PAS sensor. I've added a 5k potentiometer as described in section 6.6 of the V3 Guide "DIY Virtual Torque Sensor".

My question is how to properly configure:

Trq->TrqScale
Trq->AsstFactr
Trq->Assistant

parameters. For some reason, I'm having trouble understanding. Maybe too much Easter chocolate or something...

Any comments appreciated!

 

[Htfan]

Here's a screen shot from the CA3 guide describing the DIY torque sensor.

I already have this working. Just looking for recommendations for settings for:

Trq->TrqScale
Trq->AsstFactr
Trq->Assistant

 

[Htfan]

I'm getting much closer to workable settings through trial and error. Been going for short rides adjusting settings, then repeat.

Kind of feel like I'm talking to myself however I understand that this is a very specific thread that not many ebikes address.

 

[greg_p]

I'm getting much closer to workable settings through trial and error. Been going for short rides adjusting settings, then repeat.

Kind of feel like I'm talking to myself however I understand that this is a very specific thread that not many ebikes address.

I have sent some question to teklektik about this some days ago, he wrotes a the (un)official user guide you wrote.
Actually you can base on the provided tables that are based on a max 3x power assist when going from 55rpm (x1) to 90rpm (3x).
I asked him because where I live, I have some steep hills and, and my build was potentially aiming some people that have not a lot of power in the legs, so the assistance level must go higher than 3x.

You are right saying it's not addressing too many people, because most are using throttle. But either I would like to try it, I think that many potential "electric assisted bikes" are not really interested in much power or amp figures, they are not even interested into a cycle analyst. But the CAv3 is so good that Justin and the team could try to make a single box without display, or even integrate it into a controller, because at the end, it is controlling the motor...

Here is the table from p56

and the one he generates me for x6:

 

[Htfan]

I have sent some question to teklektik about this some days ago, he wrotes a the (un)official user guide you wrote.
Actually you can base on the provided tables that are based on a max 3x power assist when going from 55rpm (x1) to 90rpm (3x).

Awesome! This is very helpful. So, it sounds like I need to enter settings from the table for my "target" at 90rpm... This was my confusion. (not the 55rpm)

You are right saying it's not addressing too many people, because most are using throttle. But either I would like to try it, I think that many potential "electric assisted bikes" are not really interested in much power or amp figures, they are not even interested into a cycle analyst. But the CAv3 is so good that Justin and the team could try to make a single box without display, or even integrate it into a controller, because at the end, it is controlling the motor...

Realize this too. Hoping that by sharing this post it will help a few others. I'm one of those people that like to install all features then use them as needed.

 

[teklektik]

So, it sounds like I need to enter settings from the table for my "target" at 90rpm... This was my confusion. (not the 55rpm)

Not exactly.

The trick to setting up this rpm-scaled assist is to get the multiplier (top row) selected so that if you pedal harder/faster the bike gets enough power on the flat to just sustain the higher speed at the increased cadence without running away. If the multiplier is too low, you don't get enough assist to actually speed up much - if the assist is too great the bike has too much assist at the higher pedal speed. Needless to say, this scheme works best on flat or near flat situations and needs some per-bike tuning.

If you chose a table cell in the first column, there is no rpm assist - it's always a fixed amount. As you move to the right, each column gives increasing assist with rpm. The trick is to NOT to just choose a column based only on 90rpm, but to pick a particular assist level at 55rpm (row), then choose a column that will give you the desired assist at 90rpm. It's difficult to know ahead of time how much assist that is - depends on weight, speed, terrain, etc.

Remember - this is the maximum assist level - you really want to use a pot so you can dial in (scale 0-100%) the actual applied assist for any given situation. So - if you set this up for a max of 500W assist at 90rpm, you may actually only dial in 75W for putzing along on the flat and looking at trees...

I find about a 2:1 assist boost works good for me with a 90rpm assist power level of about 500W. It will take a bit of experimentation to get the 'best' settings, but it's worth the trouble to be able to briefly pedal a bit faster/harder and have the bike speed up to higher speed and stay there where you are working about as hard as before but with a faster cadence. When you downshift for small inclines or to zip ahead, the rpm goes up and so does the assist, giving you an extra boost automagically.

In the end this is just a gimmick to give you are broader riding range to minimize the frequency of manual pot adjustments. Torque sensor rigs use both rpm and torque - this just uses rpm - so half the equation but much cheaper...

 

[Htfan]

Thank you very much teklektik!

This provided the missing info I needed. Makes much more sense now.