MOTEC m800 Half Upshift

[ajax827]

We've been working with a MOTEC m800 ecu and an ADL.

We're running a motorcycle engine (CBR 600) for our Formula SAE car where neutral lies halfway between first and second gear. We've been having issues shifting into neutral from first because a whole power (100% duty cycle) up-shift skips over it. We think the best way to combat this is to add in a half up-shift that actuates at half the power of a normal up-shift.

We have a button as a normal digital input running into the ecu that triggers the aux output that up-shifts using the gear up-shift function. But when we try to use the half shift button (that is sent via CAN from the ADL) we aren't sure how to use these two different inputs to trigger the up-shift at two different powers. Is the best way to do making a new function to half shift as our output? We've tried this but whenever we set up two functions neither button would actuate an up-shift despite the up-shift working normally.

Is there a way to do this on the same output function? We've tried using an aux table to either full- or half-shift depending on which button or which combination of buttons is pushed but it hasn't worked very well. Sensing the digital input button for upshift is hard to do as a 0/1 value (we've mainly been taking the period or duration pushed which doesn't work great) and the actual shifter output for full and half shift takes too long and sometimes bounces back and forth oddly.

We've been working on this for a while and haven't been able to make much headway so any help is appreciated. If there's any information that I forgot to put in that would be helpful please let me know.

Thanks.

[David Ferguson]

I don't think the duty cycle is as important as the length of time of the shift pulse (BTW - are you controlling an electric solenoid, or air or hydraulic control valve?)

Please tell us how you control the length of time of the pulse... If the output solenoid is just controlled by whenever the input signal is true -- can you try making shorter pulses with your switch?

Would it be possible to have either manual interlock, or a manual activation cable that you pull to just move do a half-shift. I was thinking of something with a slotted yoke at the transmission shift lever, so it doesn't move in normal operation. But you could downshift to 1st, then pull the cable to find neutral every time.

[ajax827]

We are controlling an electric solenoid and haven't messed with the pulse time length. For working upshift we simply used the built in MOTEC function for upshift which has a 250 msec pulse time length. We haven't found a way to use the auxiliary table output function to control the length of time for the shift pulse as opposed to the duty, how exactly would this be done? That would probably help greatly.

A manual/physical solution is not really optimal for our situation and it would be better to have working upshift and downshift with no halfshift than to have to run a manual cable to find neutral.

[David Ferguson]

The length of the Shift Pulse is defined in Adjust->Functions->Gear Shift->Up Shift in the "Up Output Duration" field. If you are getting 250ms you must have a 250 in that field.

OK, assuming you have configured the aux outputs for low-side drive (Adjust->Auxiliary Output Functions->Aux Out x->Parameters Output Mode = 0), then the table contains the duty cycle that the output uses. (BTW if you use Hi-Side drive, then only some of the AUX outputs can do that, see Output Mode F1 for details).

As a test, I created an user channel named "Shift Duty" (abbrev ShiftD) Input Source ADL 1, Calibration 1-to-1 % 1 decimal place. I setup the X axis the Up Shift table to use that channel. I filled the axis value with just two values 0, 100. Then the table contains the same value 0 and 100. Now the ADL can define what strength the shift should occur at by sending a new value when a "neutral request" condition is active (say when the gear == 1, speed == 0 and the brake is on). I would probably do that with a table in the ADL, which had 100% for non-neutral reques, and whatever weaker duty cycle was required ( try 30%) for when the Neutral Request was active.

Hope that helps.