Airflow control systems and methods using model predictive control

• US 9,429,085 B2
• Filed: 06/06/2013
• Issued: 08/30/2016
• 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., Jin, Ning, Genslak, Robert J., Chen, Jyh-Shin, Wong, Kevin C.
• Primary Examiner(s): Cronin, Stephen K
• Assistant Examiner(s): Steckbauer, Kevin R
• Application Number:
  US13/911,148
• Publication Number:
  US 20140311446A1
• Time in Patent Office: 1,181 Days
• US Class Current: 1/1
• CPC Class Codes: F02B 37/18 by bypassing exhaust from the inlet to the outlet of turbine or to the atmosphere
• 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 11/107 Safety-related aspects
• 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 2250/18 Control of the engine output torque
• CPC Class Codes: F02D 37/02 one of the functions being ignition
• CPC Class Codes: F02D 41/0002 Controlling intake air
• 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 41/005 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 41/221 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 25/0836 Arrangement of valves controlling the admission of fuel vapour to an engine, e.g. valve being disposed between fuel tank or absorption canister and intake manifold
• CPC Class Codes: F02M 26/05 High pressure loops, i.e. wherein recirculated exhaust gas is taken out from the exhaust system upstream of the turbine and reintroduced into the intake system downstream of the compressor
• CPC Class Codes: F02M 26/49 Detecting, diagnosing or indicating an abnormal function of the EGR system
• 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 module generates setpoints for the spark ignition engine based on the second torque request. A model predictive control (MPC) module: identifies sets of possible target values based on the 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. A first constraint module selectively sets a predetermined range for first one of the target values. The MPC module limits the first one of the target values to within the predetermined range.

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 module that generates air and exhaust setpoints for the spark ignition engine based on the second torque request;

a model predictive control (MPC) module that (i) identifies sets of possible target values based on the air and exhaust setpoints, that (ii) generates predicted parameters for the sets of possible target values, respectively, based on (a) a model of the spark ignition engine and (b) the sets of possible target values, respectively, that (iii) selects one of the sets of possible target values based on comparisons of the predicted parameters with the air and exhaust set points, and that (iv) sets target values based on the possible target values of the selected one of the sets;

a first constraint module that selectively sets a predetermined range for a first one of the target values,

wherein the MPC module limits the first one of the target values to within the predetermined range; and

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

2. The engine control system of claim 1 wherein the first and second target values are each a different one of the target values.

3. The engine control system of claim 1 wherein the first constraint module sets the predetermined range in response to a determination that actuation of the throttle valve is impeded.

4. The engine control system of claim 1 wherein the first constraint module sets the predetermined range in response to a determination that actuation of a camshaft phaser is impeded.

5. The engine control system of claim 1 wherein the first constraint module sets the predetermined range in response to a determination that actuation of an exhaust gas recirculation (EGR) valve is impeded.

6. The engine control system of claim 1 further comprising a second constraint module that selectively sets a second predetermined range for a first one of the air and exhaust setpoints, and

wherein the setpoint module limits the first one of the air and exhaust setpoints to within the second predetermined range.

7. The engine control system of claim 6 wherein the second constraint module sets the second predetermined range based on the predetermined range set for the first one of the target values.

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

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

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

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

9. The engine control system of claim 1 wherein the first constraint module adjusts the predetermined range for the first one of the target values from a first boundary to a second boundary of a predetermined range of actuation of an associated engine actuator.

10. The engine control system of claim 1 wherein the first constraint module adjusts the predetermined range for the first one of the target values from a first boundary to a second boundary of a second predetermined range around the first one of the target values.

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 air and exhaust setpoints for the spark ignition engine based on the second torque request;

using a model predictive control (MPC) module;

identifying sets of possible target values based on the air and exhaust setpoints;

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

selecting one of the sets of possible target values based on comparisons of the predicted parameters with the air and exhaust set points; and

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

selectively setting a predetermined range for a first one of the target values;

limiting the first one of the target values to within the predetermined range; and

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

12. The engine control method of claim 11 wherein the first and second target values are each a different one of the target values.

13. The engine control method of claim 11 further comprising setting the predetermined range in response to a determination that actuation of the throttle valve is impeded.

14. The engine control method of claim 11 further comprising setting the predetermined range in response to a determination that actuation of a camshaft phaser is impeded.

15. The engine control method of claim 11 further comprising setting the predetermined range in response to a determination that actuation of an exhaust gas recirculation (EGR) valve is impeded.

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

selectively setting a second predetermined range for a first one of the air and exhaust setpoints; and

limiting the first one of the air and exhaust setpoints to within the second predetermined range.

17. The engine control method of claim 16 further comprising setting the second predetermined range based on the predetermined range set for the first one of the target values.

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

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

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

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

19. The engine control method of claim 11 further comprising adjusting the predetermined range for the first one of the target values from a first boundary to a second boundary of a predetermined range of actuation of an associated engine actuator.

20. The engine control method of claim 11 further comprising adjusting the predetermined range for the first one of the target values from a first boundary to a second boundary of a second predetermined range around the first one of the target values.