Trigger hysteresis using avload instead of load?

A forum for discussing applications and implementations of the MegaShift transmission controller code for the GPIO from B&G. This can control up to 8-speeds and 6 shift solenoids (plus a 16x9 table for controlling a PWM line pressure valve). It has manual and fully automatic modes (16x9 load x speed table), with under and over rev-limit protection, and full data logging of all inputs and outputs (among many other abilities). A TransStim to test your completed board is also available.
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Addicted
Posts: 188
Joined: Mon Oct 14, 2013 7:14 am
Location: Winchester, England

Trigger hysteresis using avload instead of load?

Post by Addicted »

Have you tried this Lance? currently shifts are controlled by avload, but the hysteresis by instantaneous load, how do you think it would behave if both were controlled by avload?
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: Trigger hysteresis using avload instead of load?

Post by Bernard Fife »

Addicted,

This should be easy to do, I will have a look.

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: Trigger hysteresis using avload instead of load?

Post by Bernard Fife »

Addicted,

Attached is 5.099z code that allows you to select to use either the instant load or the average load for shift hysteresis:
Monitor_5099z.abs.s19
(83 KiB) Downloaded 609 times
GPIO_MShift_5099.ini
(278.02 KiB) Downloaded 603 times
The setting is under 'General Settings -> Shift Factors -> Load value for Hysteresis' where the options are to:
- Use instant Load
- Use the short-term Load average

There is some interaction between the average load and the decel settings, so this might not work the way you want it to. You might want to try disabling the decel mode by setting the 'General Settings -> Throttle and Load Factors - > Max. sLoad in Decel Mode' to zero (0).

The code attached is also virtually untested (except briefly on my bench). If you want to give it a try, let me know how it works for you.

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Addicted
Posts: 188
Joined: Mon Oct 14, 2013 7:14 am
Location: Winchester, England

Re: Trigger hysteresis using avload instead of load?

Post by Addicted »

Thanks Lance, I'll give it a try. Like you say, it may not work very well at all, but I wanted to be able to try something before you release 5.1 :)
Addicted
Posts: 188
Joined: Mon Oct 14, 2013 7:14 am
Location: Winchester, England

Re: Trigger hysteresis using avload instead of load?

Post by Addicted »

Is avload the same as sload?
Addicted
Posts: 188
Joined: Mon Oct 14, 2013 7:14 am
Location: Winchester, England

Re: Trigger hysteresis using avload instead of load?

Post by Addicted »

Hmmmm. Hysteresis is still being turned off sooner than I expect. What other factors will turn off hysteresis?
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: Trigger hysteresis using avload instead of load?

Post by Bernard Fife »

For shifting, the hysteresis is based on load and speed: http://www.msgpio.com/manuals/mshift/V5tune.html#gs
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Addicted
Posts: 188
Joined: Mon Oct 14, 2013 7:14 am
Location: Winchester, England

Re: Trigger hysteresis using avload instead of load?

Post by Addicted »

There must be other factors that turn of hysteresis as mine always turns off almost as soon as the shift is completed and the speed and load figure deltas are within the the hysteresis limits. I've even tried doubling the limits but it still turns off.

Annoyingly something has stopped working in the megasquirt unit so at the moment I cannot start the car so trans testing is on hold so I cannot test the new CAN wiring ( beldin shielded twisted pair) as I'm hoping its CAN issues turning hysteresis off (decel spikes?)
Bernard Fife
Posts: 1696
Joined: Fri Apr 04, 2008 1:28 pm

Re: Trigger hysteresis using avload instead of load?

Post by Bernard Fife »

Addicted,

Do you happen to have a log with the latest code?

Lance.
"Never wrestle with pigs. You both get dirty and the pig likes it." - George Bernard Shaw
Addicted
Posts: 188
Joined: Mon Oct 14, 2013 7:14 am
Location: Winchester, England

Re: Trigger hysteresis using avload instead of load?

Post by Addicted »

Lance wrote:Addicted,

Do you happen to have a log with the latest code?

Lance.
5.099z? no.. it was while loading it that the megasquirt ecu died.. (coincidence!)

Until I can drive again with the new code and the new CANbus wiring all bets are off.... ;)
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