1. 1 HW/SW codesign of a multiple- injections driver for engine control systems Alessandra Nardi Fan Mo Mentor : Alberto Ferrari

2. 2 OUTLINE Problem definition Driver specifications Behavioral model Functional simulation results

3. 3 PROBLEM DEFINITION - I HW/SW Driver for fuel injection Direct injection engine – 2 to 4 cylinders One injector for every cylinder – independent – max 5 strokes for engine cycle Tight time constraints

4. 4 PROBLEM DEFINITION - I INTAKECOMPRESSIONEXPANSIONEXHAUSTED 120° 320° 440° 570° CRANKSHAFT ANGLE Massimo Baleani, Alberto Ferrari

5. 5 PROBLEM DEFINITION - II Engine phase  Engine angle 00 180  360  540  ExhaustExplosionCompressionIntake

6. 6 PROBLEM DEFINITION - III Fuel sub-system – sensor for fuel temperature (FT) – sensor for fuel pressure (FP) Engine angle – fly-wheel (FW) - every 6  – phase-wheel (PW)

7. 7 DRIVER INPUT/OUTPUT INPUTS FW, PW, FT, FP Stroke fuel quantities (Q1,…,Q5) Stroke opening angles (T1,…,T5) every TDC Exhaust PARAMETERS: Stroke angle ranges : ( _o_k, _c_k) Minimum closure time : T cmin

8. 8 DRIVER INPUT/OUTPUT OUTPUTS Engine angle position (ALPHA90) - every 90  Engine speed (SRPM90) - every 90  DC events Injector signal J Fuel injected in the last cycle: F1, F2, F3, F4, F5

9. 9 DRIVER SPECIFICATIONS - I Max 5 strokes for each cycle of each cylinder k-th Injection Stroke (ISk) only in ( _o_k, _c_k) Guarantee : IS1 < IS2 < IS3 < IS4 < IS5 Overlapped strokes: – injector closed for a minimum amount of time T cmin

10. 10 DRIVER SPECIFICATIONS - II Tk  ( _o_k, _c_k) ? IF Tk < _o_k THEN  _o_k = _o_k IF Tk > _o_k THEN ISk not scheduled IF Tk  ( _o_k, _c_k) THEN  _o_k = Tk

11. 11 DRIVER SPECIFICATIONS - III In case of overlapped strokes: Minimum Closure Time IS1 IS2

12. 12 IMPLEMENTATION CONSTRAINTS Injection open angle resolution : +/- 0.2  Injected fuel quantity precision : 0.1mg – if not cut All computation must be integer Only basic mathematical instructions (no sqrt) Use IC/OC to implement timed functionality

13. 13 IMPLEMENTATION CONSTRAINTS Injection open angle resolution : +/- 0.2  Constant speed model  =  ·  t Constant acceleration model  =  0 ·  t + 1/2 · a  ·  t 2 Error :   = 1/2 · a  ·(  /  0 ) 2 Example:  = 6   0 = 1,000 rpm a  = 10,000 rpm/s    = 0.03 

14. 14 IMPLEMENTATION CONSTRAINTS Injected fuel quantity resolution : +/- 0.1mg  V =  Q / D = 0.1mg/(0.76mg/mm 3 ) = 0.131mm 3    t = 13.1  s Example:   = 0.03    t =   /  0  0 = 1,000 rpm    t = 5  s  Counter Precision  0 = 8,000 rpm   t = 125  s  T clock = 0.5  s  0 = 500 rpm   t = 2 ms  # ticks = 4000  # bits = 12

15. 15 FUNCTIONAL/ARCHITECTURE CODESIGN Behavioral Model – Behavioral Decomposition #1   resources – Behavioral Decomposition #2  resources optimization

16. 16 BEHAVIORAL DECOMPOSITION #1

17. 17 BEHAVIORAL DECOMPOSITION #2

18. 18 BEHAVIORAL DECOMPOSITION #2

19. 19 DRIVER SYSTEM

20. 20 ENGINE DETECTION Description of the modules: - FRC - DETECTOR - SAMPLE90

21. 21 CYLINDER DRIVER

22. 22 CYL_DRIVER/OPEN_INJECTION_ANGLES Tk  ( _o_k, _c_k) ? IF Tk < _o_k THEN  _o_k = _o_k IF Tk > _o_k THEN Isk not scheduled IF Tk  ( _o_k, _c_k) THEN  _o_k = Tk

23. 23 CYL_DRIVER/TIMER_SYSTEM_MNG

24. 24 TIMER_SYSTEM_MNG/ V_T_S_CONVERTER

25. 25 DESIGN FLOW ESTEREL Description ESTEREL COMPILER C SIMULATION Platform TESTBENCH PART DESIGN MODULE PART TESTBENCH Description C COMPILER Executable File OUTPUT DATA Record COMPARE

26. 26 SIMULATION RESULTS: RPM Time [  s] Speed [rpm]

27. 27 SIMULATION RESULTS: INJECT PULSE Time [  s] Injector signal

28. 28 SIMULATION RESULTS: INJECT PULSE Injector signal Angle [°]

29. 29 PERFORMANCE - RPM: error < 0.3rov/min - STROKE: no functional error, angle error < 0.08 degree - CLOCK FREQUENCY: 1MHz (with reference to Testbench provided by Alberto Ferrari)