Methods and systems for engine control

Patent metadata

Field	Value
Publication number	US-11092094-B2
Application number	US-201916409690-A
Country	US
Kind code	B2
Filing date	May 10, 2019
Priority date	May 11, 2018
Publication date	Aug 17, 2021
Grant date	Aug 17, 2021

Abstract

Various methods and systems are provided for adjusting fueling to groups of cylinders of an engine based on individual cylinder knock sensor outputs. As one example, a system for an engine includes: a controller with computer readable instructions stored on non-transitory memory that when executed during operation of the engine cause the controller to: deliver natural gas and diesel fuel to a first group of cylinders at amounts that produce a common, first substitution ratio of natural gas; deliver natural gas and diesel fuel to a second group of cylinders at amounts that produce a common, second substitution ratio of natural gas; and change a makeup of each of the first group of cylinders and the second group of cylinders based on individual knock sensor outputs of each cylinder of the first group of cylinders and the second group of cylinders.

First claim

The invention claimed is:

1. A system for an engine, comprising:
a controller with computer readable instructions stored on non-transitory memory that when executed during operation of the engine cause the controller to:
deliver gaseous fuel and liquid fuel to a first group of cylinders at amounts that produce a common, first substitution ratio of gaseous fuel torque to total fuel torque;
deliver gaseous fuel and liquid fuel to a second group of cylinders at amounts that produce a common, second substitution ratio of gaseous fuel torque to total fuel torque, the second substitution ratio lower than the first substitution ratio; and
change a makeup of each of the first group of cylinders and the second group of cylinders based on individual knock sensor outputs of each cylinder of the first group of cylinders and the second group of cylinders,
wherein the controller commands a plurality of fuel injectors and gas admission valves to deliver the gaseous fuel and the liquid fuel to the first group of cylinders and the second group of cylinders.

2. The system of claim 1 , wherein the first group of cylinders and the second group of cylinders include all cylinders of the engine.

3. The system of claim 1 , wherein each of the first substitution ratio and the second substitution ratio are adjustable based on the individual cylinder knock sensor outputs, wherein the first substitution ratio is a largest substitution ratio that maximizes gaseous fuel consumption at the engine, and wherein the second substitution ratio is a substitution ratio corresponding to a gas torque limit of a first cylinder that is experiencing a highest level of knock out of all cylinders of the engine.

4. The system of claim 3 , wherein changing the makeup of each of the first group of cylinders and the second group of cylinders includes moving a second cylinder from the first group of cylinders to the second group of cylinders in response to an individual knock sensor output of the second cylinder indicating the second cylinder has a greater gas torque limit than allowed by the first substitution ratio and switching to delivering gaseous fuel and liquid fuel to the second cylinder at amounts that produce the second substitution ratio.

5. The system of claim 4 , wherein the computer readable instructions further cause the controller to reduce the second substitution ratio in response to the individual knock sensor output of the second cylinder being higher than the individual knock sensor output of the first cylinder.

6. The system of claim 1 , wherein the computer readable instructions further cause the controller to:
for each cylinder, determine a gas torque limit based on the individual cylinder knock sensor output and determine a corresponding substitution ratio for the determined gas torque limit, thereby generating a determined substitution ratio for each cylinder;
set the second substitution ratio to a lowest substitution ratio of each determined substitution ratio for all cylinders of the engine and set the first substitution ratio to the determined substitution ratio that results in a highest average substitution ratio for all cylinders of the engine; and
change the makeup of each of the first group of cylinders and the second group of cylinders based on the determined substitution ratio for each cylinder and the set first substitution ratio.

7. The system of claim 6 , wherein changing the makeup of each of the first group of cylinders and the second group of cylinders based on the determined substitution ratio for each cylinder and the set first substitution ratio includes moving each cylinder with a determined substitution ratio at or greater than the first substitution ratio into the first group of cylinders and moving each cylinder with a determined substitution ratio less than the first substitution ratio into the second group.

8. The system of claim 6 , wherein the computer readable instructions further cause the controller to move all cylinders into the first group of cylinders and fuel all cylinders as a single group according to the first substitution ratio in response to the gas torque limit for each and every cylinder allowing operation at or above the set first substitution ratio.

9. The system of claim 1 , wherein the computer readable instructions further cause the controller to, upon engine-startup of the engine, move all cylinders of the engine into the first group of cylinders and set the first substitution ratio at a baseline substitution ratio.

10. The system of claim 1 , wherein the gaseous fuel is natural gas and the liquid fuel is diesel fuel, wherein the engine is a dual fuel engine including a plurality of cylinders combusting the natural gas and the diesel fuel, and wherein the total fuel torque includes a sum of natural gas fuel torque and diesel fuel torque produced by the cylinder.

11. A method for an engine, comprising:
delivering natural gas and diesel fuel at amounts that produce a common, first substitution ratio of natural gas torque to total fuel torque for each cylinder of a first group of cylinders;
delivering natural gas and diesel fuel at amounts that produce a common, second substitution ratio of natural gas torque to total fuel torque for each cylinder of a second group of cylinders, the second substitution ratio lower than the first substitution ratio; and
adjusting a makeup of the first group of cylinders and the second group of cylinders based on individual cylinder knock sensor outputs.

12. The method of claim 11 , wherein a number of cylinders in the first group of cylinders and the second group of cylinders make up a total number of cylinders of the engine.

13. The method of claim 11 , wherein adjusting the makeup of the first group of cylinders and the second group of cylinders based on individual cylinder knock sensor outputs includes adjusting the makeup of the first group of cylinders and the second group of cylinders based on individual cylinder gas torque limits, the individual cylinder gas torque limits determined for each cylinder based on the corresponding individual cylinder knock sensor outputs.

14. The method of claim 13 , further comprising setting the second substitution ratio to a level that corresponds to a lowest individual cylinder gas torque limit out of all the determined individual cylinder gas torque limits, the lowest individual cylinder gas torque limit being the individual cylinder gas torque limit for the cylinder experiencing a highest level of knock out of all cylinder of the engine.

15. The method of claim 13 , further comprising, for each cylinder, determining a weighted average substitution ratio for the first group of cylinders and the second group of cylinders, assuming a substitution ratio corresponding to the individual cylinder gas torque limit of the cylinder is selected as the first substitution ratio and further comprising setting the first substitution ratio to the substitution ratio of the cylinder with the highest determined weighted average substitution ratio.

16. The method of claim 15 , wherein adjusting the makeup of the first group of cylinders and the second group of cylinders includes moving all cylinders with a substitution ratio corresponding to the individual cylinder gas torque limit of the cylinder that is at or above the set first substitution ratio into the first group of cylinders and moving all remaining cylinders into the second group of cylinders.

17. The method of claim 15 , wherein adjusting the makeup of the first group of cylinders and the second group of cylinders includes moving a cylinder from th

Assignees

• Transp Ip Holdings Llc

Inventors

• Pedder Jacob
• Yerace Daniel

Classifications

• F02D19/081 Primary

  Adjusting the fuel composition or mixing ratio; Transitioning from one fuel to the other · CPC title

• Y02T10/30

  Use of alternative fuels, e.g. biofuels · CPC title

• F02D41/0025 Primary

  Controlling engines characterised by use of non-liquid fuels, pluralities of fuels, or non-fuel substances added to the combustible mixtures · CPC title

• F02D35/027

  using knock sensors · CPC title

• F02D41/0082

  per groups or banks (F02D41/0087 takes precedence) · CPC title