Traction Control Settings

As you can immagine, I'm continuosly thinking on how to tune the Traction Control (TC). One idea could be to flash some key parameters or to control it more easily. Looking around I've seen this very interesting solution:
(Bazzaz)
I like since seems user frendly... I try to go for it!

Step 1
first is to select the adjustment switch: I go for a 10K potentiometer since it is cheap and I think it ca do all what I need. In order to give fashion to it, I like to call it as "MANETTINO" like Ferrari does for a similar stuff they have on the dashboard (by the way, manettino means "tiny handle").

Step 2
I try to define what I really need: I like to be able to change the TC threshold (I mean when it starts to work) and the sensibility (I mean how much strongly reduces the engine tourque).

Step 3
Potentiometer working definition:
- each 40° of potentiometer revolution I like to change the TC threshold as:

Fig.1) depending on manettino position, the potentiometer output voltage is changed from 0V to 5V corresponding to OFF, 110%, 120%, 130%, 140%, 150% and 160% threshold factors.

- inside each 40° of potentiometer revolution I like to modulate the TC sensitivity giving a progressive change in both sensitivity:

Fig.2) depending on manettino position, the TC threshold is changed from OFF, 110%, 120%, 130%, 140%, 150% and 160%. Once the threshold is selected, the sensibility can be adjusted from 0 to 1

Step 4
The circuit to be added is quite easy: I add just one potentiometer from 5V to GND, the cursor is connected to the ADC_1 channel 0.

Step 5
Off-line calculation: in order to write the software I need to write down all the variables and try to build up a model: I use a spreadsheet - what else!
This is what I generate, I know is not so easy to understand, but it shows how the manettino position is converted to voltage and to ADC value and then to TC threshold and TC sensitivity:


Step 6
Now is time to think about the software changes. First I need a couple of new static variables:
- uiTC_Threshold
- uiTC_Slope
and then I need to configure the ADC_2 for cntinuous conversions, I use DAvE as usual:

I like to limit the "manettino" changes only when the bike is not running, therefore, in the OFF state I add the following lines:

uiTmp = ADC1_RESRA0; // Get latest Manettino value
if ( uiTmp > 150 )
{
uiTC_Threshold = 1000 + ((unsigned int)( uiTmp / 151 ) * 100); // 110% is 0.74V
uiTC_Slope = ( uiTmp % 151 ); // Remainder
} else {
uiTC_Threshold = 0;
uiTC_Slope = 0;
}

Step 7
I need now another timer to modulate the engine tourque as calculated by the TC, I use Timer_7 from the CC2 unit:

The selected resolution is 15.515 usec, therefore to conver the ADC value into timer counter value, I just need to multiply by 432:

// Traction Control Timer Calculation
CC2_vLoadTmr ( CC2_TIMER_7, uiTC_Slope*432 );

The last stuff is to toggle port P10.7: the software turns it on, the Timer 7 Interrupt Service Routine turns it off:

IO_vSetPin( IO_P10_7 ); // TC-OFF to HIGH

...

void CC2_viTmr7(void) interrupt CC2_T7INT
{
// TC-OFF signal to LOW after timer expires
IO_vResetPin( IO_P10_7 ); // TC-OFF to LOW
} // End of function CC2_viTmr7

Step 8
well, last step is to test it! I'll do tomorrow...