BoostControl is relatively simple compared to WideBand or OnlineCourse/VeLearning implementation
The trick is the very well mappable boost-target.
Actuation implementation
Since the solenoids people kept finding were on/off type with 20..30 Hz max frequency, the original high frequency softpwm implementation had to be changed.
3 parts:
- initialize
- pid (userspace) calculations. Ideally best to calculate pid just before actuation (eg. always before falling edge - since the rising edge timing varies).
- actuation (userspace or interrupt or combo)
- DROPPED: actuation of both edges in interrupt with EventQueue the same way as OutputTrigger mst..msp..msq..
- pid() calculation called from (userspace) vems.c mainloop every N msec using softelapsed(). We do the activation edge right from there. The other edge is scheduled via eventqueue (unless the output is railed at 0 or 100%). Take care with duty overflow (similar way as for injection).
PID tuning
PID parameter tuning of such a system is not trivial.
- I want to do some measurements on the valve and restriction on the table. Especially since it's almost impossible to get proper datasheet from solenoid valve manufacturers.
- I cannot measure the wastegate's effect without the engine though
- compressor
- compressor supply
- solenoid valve
- restriction
- noise (another restriction and pneumatic switch?) to disturb the controller
- pressure sensors
- controller (GenBoard/VerThree)
- datalogging
- el. connections
- pneumatic connections
Compressor supply
My tire inflating compressor eats 11..12A from 12V supply, so my power supplies are not up to the job. (The PC ATX supply is >25A at 3.3V but not at 12V).
I got a dry Lead-acid battery that I should fill and charge for the experiments. Looking for the sulphuric acid concentration to fill up originally with. I'll have to slowly charge and discharge a few times.
- google: lead acid battery fill sulphuric acid concentration charge
- http://www.ibmwr.org/otech/newbattery.html
- http://www.du.edu/~jcalvert/phys/lead.htm#Batt history and "electrolyte of dilute sulphuric acid of specific gravity 1.28. This is a 37% solution, with 472.5 g/l of H2SO4. At full discharge, the electrolyte is of specific gravity 1.05, an 8% solution containing 84.18 g/l of acid. Both plates are coated with PbSO4"