Optimization-based controls for an air handling system using an online reference governor

Patent metadata

Field	Value
Publication number	US-10012158-B2
Application number	US-201615363857-A
Country	US
Kind code	B2
Filing date	Nov 29, 2016
Priority date	Nov 29, 2016
Publication date	Jul 3, 2018
Grant date	Jul 3, 2018

Abstract

System, apparatus, and methods are disclosed for controlling one or more actuators of an air handling system of an internal combustion engine. The one or more actuators are controlled in response to one or more feedforward references that are adjusted by a reference governor that predicts one or more operating parameters and imposes constraints on the one or more feedforward references to reduce the potential for violating limits on the one or more operating parameters.

First claim

What is claimed is:

1. A method comprising:
operating a system including an internal combustion engine and an air handling system, the air handling system including an exhaust system and an intake system, the intake system structured to provide a charge flow to the internal combustion engine, wherein the charge flow includes a fresh air flow and an exhaust gas recirculation (EGR) flow;
determining one or more feedforward references for the charge flow and the EGR flow based on a first set of operational parameters of the system;
adjusting the one or more feedforward references in response to a second set of operational parameters predictive of one or more of a transient condition and a disturbance of the system;
determining one or more control commands for one or more actuators of the air handling system that control at least one of the charge flow and the EGR flow based on the adjusted one or more feedforward references and a current reference of each of the one or more actuators; and
positioning the one or more actuators of the air handling system in response to the one or more control commands.

2. The method of claim 1 , wherein the one or more feedforward references indicate an EGR valve position and an exhaust throttle position.

3. The method of claim 2 , wherein the EGR valve positon includes a high pressure EGR valve position and a low pressure EGR valve position.

4. The method of claim 1 , wherein determining and adjusting the one or more feedforward references and determining the one or more control commands are repeated over a plurality of time periods over which the first set of operational parameters and the second set of operational parameters are time variant.

5. The method of claim 1 , wherein the adjusted one or more feedforward references and the current reference of each of the one or more actuators are provided to a feedback controller that determines the one or more control commands in response to a difference between the adjusted one or more feedforward references and the current reference of each of the one or more actuators.

6. The method of claim 5 , further comprising adjusting the one or more feedforward references in response to the second set of operational parameters with a reference governor.

7. The method of claim 6 , wherein the reference governor is configured to adjust the one or more feedforward references in response to one or more physical constraints on the output of the internal combustion engine.

8. The method of claim 7 , wherein the one or more physical constraints include a NOx limit.

9. The method of claim 7 , wherein the reference governor includes a predictive model to predict at least one operating parameter based on the second set of operational parameters and the at least one operating parameter is subject to the one or more physical constraints.

10. The method of claim 6 , wherein the one or more feedforward references are determined from one or more reference tables based on the first set of operational parameters.

11. The method of claim 1 , wherein the first and second sets of operational parameters each include at least one of an air to fuel ratio, a mass air flow, an ambient air pressure, an EGR mass flow rate, a compressor mass flow rate, a turbine mass flow rate, a charge flow, an EGR fraction, an exhaust manifold pressure, an intake manifold temperature, an intake manifold pressure, and an engine-out NOx state.

12. A system, comprising:
an internal combustion engine;
an air handling system including an exhaust system and an intake system, the intake system structured to provide a charge flow to the internal combustion engine, the air handling system including an exhaust gas recirculation (EGR) system connecting the intake system and the exhaust system, the air handling system including a plurality of actuators for controlling the charge flow, an exhaust flow, and an EGR flow; and
a controller operatively coupled with the air handling system and the internal combustion engine;
wherein the controller is structured to perform the following operations during operation of the engine:
determine one or more feedforward references for the charge flow and the EGR flow based on a first set of operational parameters of the system;
adjust the one or more feedforward references in response to a second set of operational parameters;
determine one or more control commands for one or more actuators of the air handling system that control at least one of the charge flow, the exhaust flow and the EGR flow based on the adjusted one or more feedforward references; and
control positioning of the plurality of actuators of the air handling system based at least in part upon the one or more control commands.

13. The system of claim 12 , wherein the controller includes a reference governor that is configured to receive the one or more feedforward references and the second set of operational parameters, determine the adjusted one or more feedforward references, and output the adjusted one or more feedforward references to a feedback controller.

14. The system of claim 13 , wherein the feedback controller is configured to receive current references for the plurality of actuators and the adjusted one or more feedforward references, the feedback controller further being configured to determine the one or more control commands for the plurality of actuators in response to a difference between the current references and the adjusted one or more feedforward references.

15. The system of claim 12 , wherein the plurality of actuators includes at least one EGR valve in the EGR system and an exhaust throttle in the exhaust system.

16. The system of claim 15 , wherein the at least one EGR valve includes a low pressure EGR valve in a low pressure EGR loop and a high pressure EGR valve in a high pressure EGR loop.

17. The system of claim 12 , wherein:
the exhaust system includes a turbocharger and an exhaust throttle;
the EGR system includes a low pressure EGR loop including a low pressure EGR valve and a high pressure EGR loop including a high pressure EGR valve;
the plurality of actuators include actuators associated with each of the turbocharger, the exhaust throttle, the low pressure EGR valve, and the high pressure EGR valve; and
wherein the controller is configured to control a position of the plurality of actuators in response to the one or more control commands.

18. An apparatus, comprising:
an electronic controller in operative communication with a plurality of sensors operable to provide signals indicative of operational parameters of a system, the system including an engine and an air handling system operationally coupled to the engine, the air handling system including an exhaust system and an intake system connected by an exhaust gas recirculation (EGR) system, the intake system structured to provide a charge flow to the engine, wherein the electronic controller includes:
a real-time system condition module structured to determine a first set of operational parameters and a second set of operational parameters of the system based upon the signals provided by the plurality of sensors;
a reference generation module structured to determine one or more feedforward references for the charge air flow and an EGR flow in response to the first set of operational parameters;
a reference governor module structured to determine adjustments to the one or more feedforward references in response to the second set of operational parameters;
a feedback control module structured to determine one or more actuator control command

Assignees

• Cummins Inc

Inventors

• Kothandaraman Govindarajan
• Borhan Hoseinali
• Patel Bibin N

Classifications

• F02D41/146

  the characteristics being an NOx content or concentration · CPC title

• F02D41/0077 Primary

  Control of the EGR valve or actuator, e.g. duty cycle, closed loop control of position (EGR valve position sensor F02M26/48) · CPC title

• F02D41/0052

  Feedback control of engine parameters, e.g. for control of air/fuel ratio or intake air amount · CPC title

• F02D9/06

  Exhaust brakes · CPC title

• F02D41/005

  according to engine operating conditions · CPC title