ENGINE SYSTEM UTILIZING MODAL WEIGHTED ENGINE OPTIMIZATION

• US 20160131068A1
• Filed: 11/10/2014
• Published: 05/12/2016
• Est. Priority Date: 11/10/2014
• Status: Active Grant

• Current Assignee: Caterpillar Incorporated
• Original Assignee: Caterpillar Incorporated
• Inventors: HARDY, William L., WACKERLE, Christopher K., RIBORDY, Jeffrey J., APPLEGREN, Timothy E., BOND, Michael S.
• Granted Patent: US 9,689,336 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F02D 2041/1425 using a bond graph model or models with nodes
• CPC Class Codes: F02D 2200/1002 Output torque
• CPC Class Codes: F02D 2200/101 Engine speed
• CPC Class Codes: F02D 41/1406 with use of a optimisation method, e.g. iteration
• CPC Class Codes: F02D 41/2422 Selective use of one or more tables
• CPC Class Codes: F02D 41/2429 Methods of calibrating or learning
• CPC Class Codes: F02D 41/2438 Active learning methods
• CPC Class Codes: F02D 41/2477 characterised by the method used for learning

Abstract

An engine system is disclosed. The engine system may have an engine. The engine system may also have a sensor configured to generate a sensor signal indicative of an amount of power generated by the engine and a speed sensor configured to generate a speed signal indicative of a speed of the engine. The engine system may also have a controller configured to receive the sensor signal and the speed signal. The controller may also be configured to generate an operating histogram based on the sensor signal and the speed signal. Further the controller may be configured to receive modal points for the engine, the modal points having associated emissions limits. The controller may also be configured to generate a calibration parameter set for the operating histogram based on the weights. In addition, the controller may be configured to apply the calibration parameter set to the engine.

Claims

1. An engine system, comprising:

an engine;

a sensor configured to generate a sensor signal indicative of a power generated by the engine;

a speed sensor configured to generate a speed signal indicative of a speed of the engine; and

a controller configured to;

receive the sensor signal and the speed signal;

generate an operating histogram based on the sensor signal and the speed signal;

receive modal points for the engine, the modal points having associated emissions limits, each modal point including the speed of the engine and an amount of output power of the engine corresponding to the speed;

assign weights to the modal points based on the operating histogram;

generate a calibration parameter set for the operating histogram based on the weights; and

apply the calibration parameter set to the engine.

2. The engine system of claim 1, wherein the modal points include steady state emissions cycle modal points, transient emissions cycle modal points, and not to exceed emissions boundary points, and the emissions limits include:

a first limit on a weighted average of amounts of emissions generated by the engine when operating at the steady state emissions cycle modal points;

a second limit on a weighted total amount of emissions generated by the engine when operating at the transient emissions cycle modal points; and

a third limit on a maximum amount of emissions generated by the engine when operating within a boundary determined by the not to exceed emissions boundary points.

3. The engine system of claim 1, wherein the controller is configured to generate the operating histogram by:

initializing a timer for a first period of time;

receiving the sensor signal and the speed signal during the first period of time; and

identifying a plurality of engine operating points based on the sensor signal and the speed signal, each operating point including;

the speed of the engine;

an amount of power generated by the engine at the speed; and

an amount of time of engine operation at the speed.

4. The engine system of claim 3, wherein the controller is configured to assign the weights to the modal points by:

identifying at least a first operating point at which the engine spends a maximum amount of time;

identifying at least a second operating point at which the engine spends a minimum amount of time;

identifying a first modal point adjacent the first operating point;

identifying a second modal point adjacent the second operating point;

assigning a first weight to the first modal point based on a first amount of time associated with the first operating point; and

assigning a second weight to the second modal point based on a second amount of time associated with the second operating point.

5. The engine system of claim 4, wherein the controller is configured to generate the calibration parameter set by determining control parameters for the engine that:

reduce a first fuel consumption amount at one of the first modal point and the second modal point based on the first weight and the second weight; and

reduce a first amount of emissions at an other of the first modal point and the second modal point.

6. The engine system of claim 5, wherein the first weight is greater than the second weight when the first amount of time is greater than the second amount of time.

7. The engine system of claim 5, wherein the controller is further configured to generate the calibration parameter set by:

identifying at least a third operating point for the engine;

identifying a third modal point adjacent the third operating point;

identifying a fourth modal point adjacent the third operating point;

determining a first set of control parameters for the third modal point;

determining a second set of control parameters for the fourth modal point;

determining a third set of control parameters by interpolating between the first set of control parameters and the second set of control parameters; and

associating the third set of control parameters with the third operating point.

8. The engine system of claim 3, wherein the controller is further configured to:

initializes the timer for a second period of time;

receive the sensor signal and the speed signal during the second period of time; and

update the operating histogram after the second period of time.

9. The engine system of claim 1, wherein the sensor is a fuel sensor.

10. A method of optimizing an operation of an engine, comprising:

receiving, from a sensor, a sensor signal indicative of an amount of power generated by the engine;

receiving, from a speed sensor, a speed signal indicative of a speed of the engine;

generating, using a controller, an operating histogram based on the sensor signal and the speed signal, the operating histogram;

defining modal points for the engine, the modal points having associated emissions limits, each modal point including the speed of the engine and an amount of output power of the engine corresponding to the speed;

assigning weights to the modal points based on the operating histogram;

generating a calibration parameter set for the operating histogram based on the weights;

applying the calibration parameter set to the engine.

11. The method of claim 10, wherein the modal points include steady state emissions cycle modal points, transient emissions cycle modal points, and not to exceed emissions boundary points, and the emissions limits include:

a first limit on a weighted average of amounts of emissions generated by the engine when operating at the steady state emissions cycle modal points;

a second limit on a weighted total amount of emissions generated by the engine when operating at the transient emissions cycle modal points; and

a third limit on a maximum amount of emissions generated by the engine when operating within a boundary determined by the not to exceed emissions boundary points.

12. The method of claim 11, wherein generating the operating histogram includes:

initializing a timer for a first period of time;

receiving the sensor signal and the speed signal during the first period of time;

identifying a plurality of engine operating points based on the sensor signal and the speed signal, each operating point corresponding to an amount of power generated by the engine and the speed of the engine; and

determining an amount of time spent by the engine at the each operating point.

13. The method of claim 12, wherein assigning weights to the modal points includes:

identifying at least a first operating point at which the engine spends a maximum amount of time;

identifying at least a second operating point at which the engine spends a minimum amount of time;

identifying a first modal point adjacent the first operating point;

identifying a second modal point adjacent the second operating point;

assigning a first weight to the first modal point based on a first amount of time associated with the first operating point; and

assigning a second weight to the second modal point based on a second amount of time associated with the second operating point.

14. The method of claim 13, wherein generating the calibration parameter set includes determining control parameters that:

reduce a first fuel consumption amount at one of the first modal point and the second modal point based on the first weight and the second weight; and

reduce a first amount of emissions at an other of the first modal point and the second modal point.

15. The method of claim 14, wherein the first weight is greater than the second weight when the first amount of time is greater than the second amount of time.

16. The method of claim 14, wherein generating the calibration parameter set further includes:

identifying a third operating point for the engine;

identifying a third modal point adjacent the third operating point;

identifying a fourth modal point adjacent the third operating point;

determining a first set of control parameters for the third modal point;

determining a second set of control parameters for the fourth modal point;

determining a third set of control parameters by interpolating between the first set of control parameters and the second set of control parameters; and

associating the third set of control parameters with the third operating point.

17. The method of claim 12, further including:

initializing the timer for a second period of time;

receiving the sensor signal and the speed signal during the second period of time; and

updating the operating histogram after the second period of time.

18. An engine, comprising:

a crankshaft;

a combustion chamber;

a fuel injector configured to inject fuel into the combustion chamber;

a piston disposed reciprocatingly within the combustion chamber, the piston being configured to rotate the crankshaft;

a sensor configured to generate a sensor signal indicative of power output by the engine;

a speed sensor configured to generate a speed signal indicative of a speed of the engine; and

a controller configured to;

receive the sensor signal and the speed signal;

generate an operating histogram based on the sensor signal and the speed signal;

receive modal points for the engine, the modal points having associated emissions limits, each modal point including the speed of the engine and an amount of output power of the engine corresponding to the speed;

assign weights to the modal points based on the operating histogram;

generate a calibration parameter set for the operating histogram based on the weights; and

apply the calibration parameter set to the engine.

19. The engine of claim 18, wherein the controller is configured to select engine ratings by:

identifying at least a first operating point at which the engine spends a maximum amount of time;

identifying at least a second operating point at which the engine spends a minimum amount of time;

identifying a first modal point adjacent the first operating point;

identifying a second modal point adjacent the second operating point;

assigning a first weight to the first modal point based on a first amount of time associated with the first operating point;

assigning a second weight to the second modal point based on a second amount of time associated with the second operating point;

determining control parameters that;

reduce a first fuel consumption amount at one of the first modal point and the second modal point based on the first weight and the second weight; and

reduce a first amount of emissions at an other of the first modal point and the second modal point.

20. The engine of claim 19, wherein the controller is configured to reduce the fuel consumption amount at the first modal point when the first weight is greater than the second weight.