Airflow control systems and methods using model predictive control

• US 9,376,965 B2
• Filed: 06/06/2013
• Issued: 06/28/2016
• Est. Priority Date: 04/23/2013
• Status: Active Grant

• Current Assignee: GM Global Technology Operations LLC (General Motors Company)
• Original Assignee: GM Global Technology Operations LLC (General Motors Company)
• Inventors: Whitney, Christopher E., Storch, Sharon L.
• Primary Examiner(s): Vo, Hieu T
• Assistant Examiner(s): Manley, Sherman
• Application Number:
  US13/911,121
• Publication Number:
  US 20140316681A1
• Time in Patent Office: 1,118 Days
• US Class Current: 1/1
• CPC Class Codes: F01L 1/344 changing the angular relationship between crankshaft and camshaft, e.g. using helicoidal gear
• CPC Class Codes: F01L 2800/11 Fault detection, diagnosis
• CPC Class Codes: F02D 11/105 characterised by the function converting demand to actuation, e.g. a map indicating relations between an accelerator pedal position and throttle valve opening or target engine torque
• CPC Class Codes: F02D 13/0219 by shifting the phase, i.e. the opening periods of the valves are constant
• CPC Class Codes: F02D 2041/001 for engines with variable valve actuation
• CPC Class Codes: F02D 2041/1412 using a predictive controller
• CPC Class Codes: F02D 2041/1433 using a model or simulation of the system
• CPC Class Codes: F02D 41/0002 Controlling intake air
• CPC Class Codes: F02D 41/005 according to engine operating conditions
• CPC Class Codes: F02D 41/123 the fuel injection being cut-off
• CPC Class Codes: F02D 41/22 Safety or indicating devices for abnormal conditions in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809
• CPC Class Codes: F02D 41/221 relating to the failure of actuators or electrically driven elements
• CPC Class Codes: F02M 25/0809 Judging failure of purge control system
• CPC Class Codes: F02M 26/49 Detecting, diagnosing or indicating an abnormal function of the EGR system
• CPC Class Codes: Y02T 10/12 Improving ICE efficiencies
• CPC Class Codes: Y02T 10/40 Engine management systems

Abstract

A torque requesting module generates a first torque request for a spark ignition engine based on driver input. A torque conversion module converts the first torque request into a second torque request. A setpoint control module, based on the second torque request, generates a mass of air per cylinder (APC) setpoint, an exhaust gas recirculation (EGR) setpoint, an intake valve phasing setpoint, and an exhaust valve phasing setpoint. A model predictive control (MPC) module: identifies sets of possible target values based on the APC, EGR, intake valve phasing, and exhaust valve phasing setpoints; generates predicted parameters based on a model of the spark ignition engine and the sets of possible target values, respectively; selects one of the sets of possible target values based on the predicted parameters; and sets target values based on the possible target values of the selected one of the sets.

Claims

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

a torque requesting module that generates a first torque request for a spark ignition engine based on driver input;

a torque conversion module that converts the first torque request into a second torque request;

a setpoint control module that, based on the second torque request, generates a mass of air per cylinder (APC) setpoint, an exhaust gas recirculation (EGR) setpoint, an intake valve phasing setpoint, and an exhaust valve phasing setpoint;

a model predictive control (MPC) module that identifies sets of possible target values based on the APC, EGR, intake valve phasing, and exhaust valve phasing setpoints, that generates predicted parameters based on a model of the spark ignition engine and the sets of possible target values, respectively, that selects one of the sets of possible target values based on the predicted parameters, and that sets target values based on the possible target values of the selected one of the 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 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 MPC module selects the one of the sets of possible target values further based on the APC, EGR, intake valve phasing, and exhaust valve phasing setpoints.

4. The engine control system of claim 3 wherein the MPC module selects the one of the sets of possible target values based on comparisons of the APC, EGR, intake valve phasing, and exhaust valve phasing setpoints with the predicted parameters, respectively.

5. The engine control system of claim 1 wherein the MPC module:

determines costs for the sets based on;

first comparisons of the APC setpoint with predicted APCs determined for the sets, respectively;

second comparisons of the EGR setpoint with predicted EGRs determined for the sets, respectively;

third comparisons of the intake valve phasing setpoint with predicted intake valve phasing values determined for the sets, respectively; and

fourth comparisons of the exhaust valve phasing setpoint with predicted exhaust phasing values determined for the sets, respectively; and

selects the one of the sets of possible target values based on the costs.

6. The engine control system of claim 5 wherein the MPC module applies first, second, third, and fourth weighting values to the first, second, third, and fourth comparisons, respectively, to determine the costs, and

wherein the first weighting value is one of greater than and less than all of the second, third, and fourth weighting values.

7. The engine control system of claim 1 wherein the MPC module sets the target values to within predetermined ranges for the target values, respectively.

8. The engine control system of claim 1 wherein the setpoint module generates the APC, EGR, intake valve phasing, and exhaust valve phasing setpoints further based on desired combustion phasing.

9. The engine control system of claim 1 wherein the setpoint module generates the APC, EGR, intake valve phasing, and exhaust valve phasing setpoints further based on predetermined ranges for the APC, EGR, intake valve phasing, and exhaust valve phasing setpoints, respectively.

10. The engine control system of claim 1 wherein the setpoint module generates the APC, EGR, intake valve phasing, and exhaust valve phasing setpoints further based on a number of deactivated cylinders.

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

generating a first torque request for a spark ignition engine based on driver input;

converting the first torque request into a second torque request;

generating, based on the second torque request, a mass of air per cylinder (APC) setpoint, an exhaust gas recirculation (EGR) setpoint, an intake valve phasing setpoint, and an exhaust valve phasing setpoint;

using a model predictive control (MPC) module;

identifying sets of possible target values based on the APC, EGR, intake valve phasing, and exhaust valve phasing setpoints;

generating predicted parameters based on a model of the spark ignition engine and the sets of possible target values, respectively;

selecting one of the sets of possible target values based on the predicted parameters; and

sets target values based on the possible target values of the selected one of the 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 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 selecting the one of the sets of possible target values further based on the APC, EGR, intake valve phasing, and exhaust valve phasing setpoints.

14. The engine control method of claim 13 further comprising selecting the one of the sets of possible target values based on comparisons of the APC, EGR, intake valve phasing, and exhaust valve phasing setpoints with the predicted parameters, respectively.

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

determining costs for the sets based on;

first comparisons of the APC setpoint with predicted APCs determined for the sets, respectively;

second comparisons of the EGR setpoint with predicted EGRs determined for the sets, respectively;

third comparisons of the intake valve phasing setpoint with predicted intake valve phasing values determined for the sets, respectively; and

fourth comparisons of the exhaust valve phasing setpoint with predicted exhaust phasing values determined for the sets, respectively; and

selecting the one of the sets of possible target values based on the costs.

16. The engine control method of claim 15 further comprising applying first, second, third, and fourth weighting values to the first, second, third, and fourth comparisons, respectively, to determine the costs, and

wherein the first weighting value is one of greater than and less than all of the second, third, and fourth weighting values.

17. The engine control method of claim 11 further comprising setting the target values to within predetermined ranges for the target values, respectively.

18. The engine control method of claim 11 further comprising generating the APC, EGR, intake valve phasing, and exhaust valve phasing setpoints further based on desired combustion phasing.

19. The engine control method of claim 11 further comprising generating the APC, EGR, intake valve phasing, and exhaust valve phasing setpoints further based on predetermined ranges for the APC, EGR, intake valve phasing, and exhaust valve phasing setpoints, respectively.

20. The engine control method of claim 11 further comprising generating the APC, EGR, intake valve phasing, and exhaust valve phasing setpoints further based on a number of deactivated cylinders.