HW/SW codesign of a multiple-injections driver for engine control systems

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

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

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. INTAKE COMPRESSION EXPANSION EXHAUSTED 570° 320° CRANKSHAFT ANGLE 120° 440° PROBLEM DEFINITION - I Massimo Baleani, Alberto Ferrari

5. PROBLEM DEFINITION - II 180 540 Engine phase  Engine angle Compression Intake Exhaust Explosion 0 360

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. 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 : Tcmin

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. 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 Tcmin

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

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. IMPLEMENTATION CONSTRAINTS Injection open angle resolution : +/- 0.2 • Constant speed model  =  ·t • Constant acceleration model  = 0 ·t + 1/2 · a  ·t2 • Error :  = 1/2 · a  ·( / 0 )2 • Example:  = 6 0 = 1,000 rpm a  = 10,000 rpm/s   = 0.03

14. IMPLEMENTATION CONSTRAINTS • Injected fuel quantity resolution : +/- 0.1mg V = Q / D = 0.1mg/(0.76mg/mm3) = 0.131mm3  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  Tclock = 0.5s 0 = 500 rpm  t = 2 ms  # ticks = 4000  # bits = 12

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

16. BEHAVIORAL DECOMPOSITION #1

17. BEHAVIORAL DECOMPOSITION #2

18. BEHAVIORAL DECOMPOSITION #2

19. DRIVER SYSTEM

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

21. CYLINDER DRIVER

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. CYL_DRIVER/TIMER_SYSTEM_MNG

24. TIMER_SYSTEM_MNG/V_T_S_CONVERTER

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

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

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

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

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)