Model predictive control systems and methods for internal combustion engines

• US 9,347,381 B2
• Filed: 03/26/2014
• Issued: 05/24/2016
• Est. Priority Date: 03/26/2014
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Long, Ruixing, Cygan, Gary Robert Jr., Verdejo, Julian R., Whitney, Christopher E., Jin, Ning, Bemporad, Alberto, Bernardini, Daniele
• Primary Examiner(s): HUYNH, HAI H
• Application Number:
  US14/225,502
• Publication Number:
  US 20150275772A1
• Time in Patent Office: 790 Days
• Field of Search: 123/436, 123/399, 701/103, 701/110, 731/141.5
• US Class Current: 1/1
• CPC Class Codes: F02B 37/12 Control of the pumps
• CPC Class Codes: F02D 13/02 during engine operation
• CPC Class Codes: F02D 2009/0235 Throttle control functions
• CPC Class Codes: F02D 2041/0017 by simultaneous control of throttle and exhaust gas recirculation
• CPC Class Codes: F02D 2041/1433 using a model or simulation of the system
• CPC Class Codes: F02D 21/04 with circulation of exhaust gases in closed or semi-closed circuits
• CPC Class Codes: F02D 2250/18 Control of the engine output torque
• CPC Class Codes: F02D 2250/22 by keeping a torque reserve, i.e. with temporarily reduced drive train or engine efficiency
• CPC Class Codes: F02D 23/00 Controlling engines characterised by their being supercharged
• CPC Class Codes: F02D 41/0007 for control of turbo-charged or super-charged engines control of the pumps per se F02B37/12
• CPC Class Codes: F02D 41/0047 Controlling exhaust gas recirculation [EGR] temperature control with cooler in recirculation circuit F02M26/33
• CPC Class Codes: F02D 41/005 according to engine operating conditions
• CPC Class Codes: F02D 41/0087 Selective cylinder activation, i.e. partial cylinder operation deceleration cut-off F02D41/123
• CPC Class Codes: F02D 41/04 Introducing corrections for particular operating conditions F02D41/14 takes precedence
• CPC Class Codes: F02D 41/1406 with use of a optimisation method, e.g. iteration
• CPC Class Codes: F02D 9/02 concerning induction conduits throttle valves, or arrangements thereof in conduits F02D9/08
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

An engine control method includes: generating a first predicted engine output torque and a first predicted mass of air per cylinder (APC) based on a model of the spark ignition engine and a first set of possible target values determined based on an engine torque request; generating a second predicted engine output torque and a second predicted mass of APC based on the model of the spark ignition engine and a second set of possible target values determined based on the engine torque request; determining a first cost for the first set of possible target values; determining a second cost for the second set of possible target values; selecting one of the first and second sets based on the first and second costs; and setting target values based on the possible target values of the selected one of the first and second sets.

Claims

1. An engine control system for a vehicle, comprising:

a prediction module that generates a first predicted engine output torque and a first predicted mass of air per cylinder (APC) based on a model of a spark ignition engine and a first set of possible target values determined based on an engine torque request and that generates a second predicted engine output torque and a second predicted mass of APC based on the model of the spark ignition engine and a second set of possible target values determined based on the engine torque request;

a cost module that;

determines a first cost for the first set of possible target values based on a first predetermined weighting value, the first predicted engine output torque, the engine torque request, a second predetermined weighting value, and the first predicted mass of APC; and

determines a second cost for the second set of possible target values based on the first predetermined weighting value, the second predicted engine output torque, the engine torque request, the second predetermined weighting value, and the second predicted mass of APC;

a selection module that selects one of the first and second sets based on the first and second costs and that sets target values based on the possible target values of the selected one of the first and second sets; and

a throttle actuator module that controls opening of a throttle valve based on a first one of the target values.

2. The engine control system of claim 1 further comprising:

a boost actuator module that controls opening of a wastegate of a turbocharger based on a second one of the target values;

an exhaust gas recirculation (EGR) actuator module that controls opening of an EGR valve based on a third one of the target values; and

a phaser actuator module that controls intake and exhaust valve phasing based on fourth and fifth ones of the target values.

3. The engine control system of claim 1 wherein the cost module:

determines the first cost based on;

a first product of the first predetermined weighting value and a magnitude of a first difference between the first predicted engine output torque and the engine torque request; and

a second product of the second predetermined weighting value and a second difference between the first predicted mass of APC and a predetermined minimum APC; and

determines the second cost based on;

a third product of the first weighting value and a magnitude of a third difference between the second predicted engine output torque and the engine torque request; and

a fourth product of the second weighting value and a magnitude of a fourth difference between the second predicted mass of APC and the predetermined minimum APC.

4. The engine control system of claim 3 wherein the cost module:

determines the first cost based on a sum of the first and second products; and

determines the second cost based on a sum of the third and fourth products.

5. The engine control system of claim 3 wherein the first predetermined weighting value is greater than the second predetermined weighting value.

6. The engine control system of claim 1 wherein the selection module selects the first set when the first cost is less than the second cost, and the selection module selects the second set when the second cost is less than the first cost.

7. The engine control system of claim 1 wherein the cost module:

determines the first cost further based on a third predetermined weighting value, a first predicted crankshaft angle where a predetermined percent of injected fuel will be burned, a predetermined minimum crankshaft angle, and a predetermined maximum crankshaft angle; and

determines the second cost further based on the third predetermined weighting value, a second predicted crankshaft angle where the predetermined percent of injected fuel will be burned, the predetermined minimum crankshaft angle, and the predetermined maximum crankshaft angle.

8. The engine control system of claim 7 wherein the prediction module further:

generates the first predicted crankshaft angle based on the model of the spark ignition engine and the first set of possible target values; and

generates the second predicted crankshaft angle based on the model of the spark ignition engine and the second set of possible target values.

9. The engine control system of claim 1 wherein the cost module:

determines the first cost further based on a fourth predetermined weighting value, a first predicted coefficient of variation (COV) of indicated mean effective pressure (IMEP), a predetermined minimum COV of IMEP, and a predetermined maximum COV of IMEP; and

determines the second cost further based on the fourth predetermined weighting value, a second predicted COV of IMEP, the predetermined minimum COV of IMEP, and the predetermined maximum COV of IMEP.

10. The engine control system of claim 9 wherein the prediction module further:

generates the first predicted COV of IMEP based on the model of the spark ignition engine and the first set of possible target values; and

generates the second predicted COV of IMEP based on the model of the spark ignition engine and the second set of possible target values.

11. An engine control method for a vehicle, comprising:

generating a first predicted engine output torque and a first predicted mass of air per cylinder (APC) based on a model of a spark ignition engine and a first set of possible target values determined based on an engine torque request;

generating a second predicted engine output torque and a second predicted mass of APC based on the model of the spark ignition engine and a second set of possible target values determined based on the engine torque request;

determining a first cost for the first set of possible target values based on a first predetermined weighting value, the first predicted engine output torque, the engine torque request, a second predetermined weighting value, and the first predicted mass of APC;

determining a second cost for the second set of possible target values based on the first predetermined weighting value, the second predicted engine output torque, the engine torque request, the second predetermined weighting value, and the second predicted mass of APC;

selecting one of the first and second sets based on the first and second costs;

setting target values based on the possible target values of the selected one of the first and second sets; and

controlling opening of a throttle valve based on a first one of the target values.

12. The engine control method of claim 11 further comprising:

controlling opening of a wastegate of a turbocharger based on a second one of the target values;

controlling opening of an exhaust gas recirculation (EGR) valve based on a third one of the target values; and

controlling intake and exhaust valve phasing based on fourth and fifth ones of the target values.

13. The engine control method of claim 11 further comprising:

determining the first cost based on;

a first product of the first predetermined weighting value and a magnitude of a first difference between the first predicted engine output torque and the engine torque request; and

a second product of the second predetermined weighting value and a second difference between the first predicted mass of APC and a predetermined minimum APC; and

determining the second cost based on;

a third product of the first weighting value and a magnitude of a third difference between the second predicted engine output torque and the engine torque request; and

a fourth product of the second weighting value and a magnitude of a fourth difference between the second predicted mass of APC and the predetermined minimum APC.

14. The engine control method of claim 13 further comprising:

determining the first cost based on a sum of the first and second products; and

determining the second cost based on a sum of the third and fourth products.

15. The engine control method of claim 13 wherein the first predetermined weighting value is greater than the second predetermined weighting value.

16. The engine control method of claim 11 further comprising:

selecting the first set when the first cost is less than the second cost; and

selecting the second set when the second cost is less than the first cost.

17. The engine control method of claim 11 further comprising:

determining the first cost further based on a third predetermined weighting value, a first predicted crankshaft angle where a predetermined percent of injected fuel will be burned, a predetermined minimum crankshaft angle, and a predetermined maximum crankshaft angle; and

determining the second cost further based on the third predetermined weighting value, a second predicted crankshaft angle where the predetermined percent of injected fuel will be burned, the predetermined minimum crankshaft angle, and the predetermined maximum crankshaft angle.

18. The engine control method of claim 17 further comprising:

generating the first predicted crankshaft angle based on the model of the spark ignition engine and the first set of possible target values; and

generating the second predicted crankshaft angle based on the model of the spark ignition engine and the second set of possible target values.

19. The engine control method of claim 11 further comprising:

determining the first cost further based on a fourth predetermined weighting value, a first predicted coefficient of variation (COV) of indicated mean effective pressure (IMEP), a predetermined minimum COV of IMEP, and a predetermined maximum COV of IMEP; and

determining the second cost further based on the fourth predetermined weighting value, a second predicted COV of IMEP, the predetermined minimum COV of IMEP, and the predetermined maximum COV of IMEP.

20. The engine control method of claim 19 further comprising:

generating the first predicted COV of IMEP based on the model of the spark ignition engine and the first set of possible target values; and

generating the second predicted COV of IMEP based on the model of the spark ignition engine and the second set of possible target values.