rusefillc
commented
3 years ago launch control overall idea: launch car on bad traction conditions changing rapidly (mud race)
Big picture: we want to target turbo speed not boost
We have some sort of hardware input device with CAN bus output. Knobs buttons whatever. Or rotary pot with analog input. 4 knobs/sets of buttons total
preparation phase before grid 1) driver set launch rpm (a), launch turbospeed (boost) (b) (60kRPM or 80kPRM or 100kPRM) and launch ramp (c) - rate of RPM increase (8 values, 1000 PRM per second - ish) turbo speed ramp (d)
actual launch
2) driver depress clutch and put car in launch gear (first or second) no communication with rusEFI
3) driver hold launch button on steering wheel which actuates brake via handbrake solenoid or handbrake apply handbrake to stop car from unwanted movement
there should be a timer (10ms to 50ms) to engage clutch actuator a bit later after brake actuator was releases. brake actuator could be theoretically controlled directly by button without ECU but for practical wiring reasons it's better to control both from ECU
4) on 'ready to race' driver give car full throttle (human puts pedal down) and wait for 'green light' - ecu needs to build desired target turbo speed and hold launch rpm, green light will come in 2-5sec from now
ECU has to limit RPM. preferably by retarding timing but open question if ignition cut would necessary
Just full ignition cut "if RPM> target then do full ignition cut" is NOT an option, we have to be smarter. There has to be a closed-loop control of ignition skip rate, with feed-forward 8x8 map
2-5 seconds due to reality
5) on 'green light' driver release button clutch and brake
steering wheel button, digital input into rusEFI
6) button release starts post launch timer and launch rpm limiter and launch turbo speed control need to be released and ecu need to go to post launch ramp RPM and turbo speed control
7) ecu have to maintain rising boost and rising rpm according to selected ramp
8) after gear change ecu should control engine as normally or maybe second ramp can control second gear after launch driver selectors 8 positions for boost(turbospeed) 8 positions for rpm and 8 ramps
4:29 here we go :)
on the one hand we have #203 but users like Martin Matousek would always want variations, so we need all the Lua hooks to allow custom strategies
hold launch button on steer wheel and clutch and full throttle while in launch gear ( first on second) and ecu should maintain desired RPM and Boost
launch! relapse button and clutch, start timer and gradually increase boost and rpm in controlled manner to keep traction