Cycle Analyst Acceleration help

Motormark · Jul 17, 2016

cycle analyst V3, Grin controller.

On my project the motor is activated by the PAS and i have a Potentiometer on the aux for limiting the Power.
But i want the acceleration smoother. Les brutal.

Is there a way to start the motor with 50watt, and slowly increse the power, over a 5 sec time, to the max Power i need?

A throttle is not an option, because it's a handbike.

Thanks for anybody who can help.

teklektik · Jul 17, 2016

What kind of PAS sensor do you have (simple PAS wheel, Thun BB, TDCM BB, etc)?
What kind of motor (DD, geared)?

There are a few adjustments that can help, but it would be good to get the sensor and motor questions cleared up first to set the stage. Also, if you have a setup file that you can post up as an attachment, that would clarify your present situation - not necessary, but handy if you have it.

Motormark · Jul 17, 2016

Teklekik,

I don't have a setup file. I program the CA by the buttons on the lcd screen.
My Pas is a 12magnet PasV7
And i have a rearwheel motor with 9 speed casette on it Crystalyte G series.

Thanks in advance.

teklektik · Jul 17, 2016

Ok.
With that sensor and the standard AutoPas configuration you will get a fixed assist level once cranking is detected.

PAS assist uses the CA power PID controller so you can reduce PLim->WGain to get a softer engagement off the line and generally softer or more laggy response across the board. Generally, this can be an issue for folks with both throttle and PAS because of the compromise between throttle response and gentle PAS engagement - in your case the task is simplified substantially with only PAS. You could try setting this down to 10-15 or so. Obviously at this end of the adjustment range, small changes will have a big effect.
ThrO->FastRate and ThrO->UpRate have global impact over any power application - including PAS - and are provided to limit the rate of change of the Throttle Output voltage. If the throttle changes slowly, they have no effect, but if it changes quickly, the rate is clamped so there is not a big jolt of power. This is described in "4.8 Adjust Throttle Ramping" of the Unofficial Guide.

To keep this simple, I would recommend reducing ThrO->FastThrsh=0 to deactivate FastRate so you can address UpRate more simply. Reducing UpRate will reduce the rate at which the throttle can change. You might try running this down to 0.5V/sec. For a normal throttle voltage spread of about 1V-4V or 3V, this will restrict the throttle to take 3V/(0.5V/sec) = 6 seconds to go from ZERO to WOT.
As is always the case, torque-based PAS gives a better feel and is more repsonsive to actual rider input than a simple PAS wheel. The former scales power application with torque and rpm while the second has a fixed assist level. In both cases the max assist is scalable using the Aux input, but the torque system requires less fequent adjustment. Depending on your riding situation, you can adjust the CA with a simple PAS wheel to give a sort of hybrid PAS effect that is rpm based. This would give a power boost when you downshifted for a hill, etc. It's not the best system for wildly varying terrain, but it can be tried with no new hardware, so....

This is discussed in "6.5 AutoTorqPAS – AutoPAS with RPM-Proportional Assist" of the Guide. Because you have a hand cycle and lower cadence, some minor adjustments to the scheme in the Guide can help - post back if you want to try that.
Needless to say, make small adjustments and change only one setting at a time so you are sure exactly what caused the effect. Run the same test stretch over and over so the test conditions are more or less invariant. I have burned off entire battery charges tweaking things in and running over the same strip of road again and again - but it's worth it to get everything tuned up.
You may wish to investigate the new v3.1 firmware linked throught the Guide download page >>>here<<<. This firmware is in beta test and is not a production release. What may make it interesting for you is that it supports a digital step UP/DOWN method of adjusting the PAS level using buttons instead of a pot. I believe this is a better situation for hand cycles where thumbing a button for a power boost is easy to do while still retaining grip on the cranks. The wiring can be flown from the cranks by running it along a brake or shift cable. So - just a thought to get PAS Assist sort of 'at your fingertips'...

Motormark · Jul 17, 2016

Thank you very much. This is the info i need.

Just to picture what i need:

I train with another competition handbiker from a higher category
He can produce 170watt human power, and i can do only 120watt

So i want electric support for 50watt, so we can both do our training, and still ride together.

I don't have a throttle. Only a PASS and a pot on the aux input to limit the power.
But i'm going to install a Volt devider and put 3,6 volt on the input of the trottle. So this must be the WOT position. Then i can use the throttle ramping.

Thank you!

teklektik · Jul 17, 2016

Motormark said:
...the motor is activated by the PAS...i want the acceleration smoother. Les brutal.
Is there a way to start the motor with 50watt, and slowly increse the power, over a 5 sec time, to the max Power i need?

Motormark said:
But i'm going to install a Volt divider and put 3,6 volt on the input of the throttle. So this must be the WOT position. Then i can use the throttle ramping.

No.
'Throttle ramping' refers to the Throttle OUT signal not the Throttle IN signal. It refers to the CA throttle output to the controller - and does not require that a throttle be connected to the CA.

teklektik said:
B. ThrO->FastRate and ThrO->UpRate have global impact over any power application - including PAS and are provided to limit the rate of change of the Throttle Output voltage.

So - UpRate has direct effect on the rate at which your PAS-generated power is allowed to change and so directly does what you requested - apply power more slowly over a period of time.

As far as the throttle resistor divider trick, there are alternative strategies that may be more desirable if you want a no-PAS method of applying power.
What situation or Use Case are you trying to address?

Motormark · Jul 17, 2016

'Throttle ramping' refers to the Throttle OUT signal not the Throttle IN signal. It refers to the CA throttle output to the controller - and does not require that a throttle be connected to the CA.

teklektik wrote:
B. ThrO->FastRate and ThrO->UpRate have global impact over any power application - including PAS and are provided to limit the rate of change of the Throttle Output voltage.

So - UpRate has direct effect on the rate at which your PAS-generated power is allowed to change and so directly does what you requested - apply power more slowly over a period of time.

Now i get it. I can leave the thottle out on "0,00V WOT"

Motormark · Jul 17, 2016

Throttle in, i mean

teklektik · Jul 17, 2016

Motormark said:
Now i get it. I can leave the thottle in on "0,00V WOT"

Cool.
Ya, you should have the throttle deactivated with ThrI->CntrlMode=Off(0V)

FWIW:

This selection is actually changed in v3.1 to ThrI->CntrlMode=Off(ZERO) to be consistent with ThrI->CntrlMode=Off(WOT) since the actual Throttle OUT voltage is set to ThrO->MinOut not 0V...

Motormark · Jul 17, 2016

It should be great if the new 3.1 firmware worked with the Shimano Di2 knobs.
The brake shifter, or the TT shifters.

teklektik · Jul 17, 2016

I looked at the Di2 brake shifter and it seems that they may work - although at $130, it seems a little steep. The technical info is a little thin on those, but if you look at the documentation linked above on the Guide download page you will see that any two momentary contact switches will work. Follow the links to the firmware and you will see a couple of examples using common Wuxing components. In your case, you might just insert a common momentary switch into the butt top of each hand crank that you can press with your thumb - UP on one hand DOWN on the other. Sort of depends on your cranks...

Motormark · Jul 22, 2016

I only have wires on one side. But thanks for all the help.

teklektik · Jul 22, 2016

Wow! Quite a ride!

If sometime you happen to get a shot of the the cranks up high so the controls are clearer, it might be neat to post it up. We get a small but measurable stream of hand crank folks and I think ideas in that vein would be welcome. Not a pressing matter, but maybe keep it pending...

Cycle Analyst Acceleration help

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