Controller for internal combustion engine

Patent metadata

Field	Value
Publication number	US-10982642-B2
Application number	US-201916390037-A
Country	US
Kind code	B2
Filing date	Apr 22, 2019
Priority date	Jun 1, 2018
Publication date	Apr 20, 2021
Grant date	Apr 20, 2021

Abstract

Aspects of the disclosure are directed to controller for an internal combustion engine. The controller can, in each combustion cycle that composes a change cycle, calculate an average of control amounts from a first combustion cycle to an nth (1<=n<=N) combustion cycle and calculate an error of the average with respect to an average of a reference normal population. Further, the controller can set both a positive threshold and a negative threshold based on a standard error of the reference normal population in the case where the number of data is n. Subsequently, the controller can change the operation amount to make the error approach the positive threshold or the negative threshold when the error exceeds neither the positive threshold nor the negative threshold at any combustion cycle.

First claim

What is claimed is:

1. A controller for an internal combustion engine comprising:
at least one processor; and
at least one memory coupled to the at least one processor, the at least one memory including at least one computer-executable program that upon execution causes the at least one processor to execute;
control amount calculation processing of calculating a control amount relating to combustion of the internal combustion engine for each combustion cycle, based on information from a sensor which detects a state of the internal combustion engine; and
operation amount change processing of changing an operation amount affecting the control amount for each change cycle, one change cycle consisting of N combustion cycles, where N is greater than or equal to 2;
wherein, in the operation amount change processing, the at least one processor operates to:
choose a reference normal population of the control amount under a current operating condition of the internal combustion engine from a plurality of reference normal populations set for each operating condition of the internal combustion engine;
execute, in each combustion cycle from a first combustion cycle to an Nth combustion cycle that composes the change cycle,
average calculation processing of calculating a n-cycle average that is an average of the control amounts from the first combustion cycle to an nth combustion cycle, where n is greater than or equal to 1 and less than or equal to N
error calculation processing of calculating an n-cycle error that is an error of the n-cycle average with respect to an average of the reference normal population, and
threshold set processing of setting both a positive change determination threshold and a negative change determination threshold with respect to the n-cycle error, based on a standard error of the reference normal population in a case where number of data is n,

change the operation amount to make the n-cycle error approach the positive change determination threshold or the negative change determination threshold, when the n-cycle error doesn't exceed the positive change determination threshold at any combustion cycle and doesn't exceed the negative change determination threshold at any combustion cycle,
calculate an unbiased variance of the control amounts from the first combustion cycle to the Nth combustion cycle, when the n-cycle error doesn't exceed the positive change determination threshold at any combustion cycle and doesn't exceed the negative change determination threshold at any combustion cycle, and
change the operation amount to make the n-cycle error approach the positive change determination threshold or the negative change determination threshold, when the unbiased variance is smaller than a variance of the reference normal population by a predetermined value or more, and

further wherein the at least one processor operates to:
in the control amount calculation processing, calculate as the control amount a crank angle at which a combustion ratio becomes a predetermined ratio, based on information from a combustion pressure sensor, and
in the operation amount change processing, change an opening of an EGR valve of the internal combustion engine to an open side, when the unbiased variance is smaller than the variance of the reference normal population by the predetermined value or more.

2. The controller according to claim 1 ,
wherein the at least one processor operates to, in the operation amount change processing, change the operation amount gradually by stepwise change to make the n-cycle error approach the positive change determination threshold or the negative change determination threshold.

Assignees

• Toyota Motor Co Ltd

Inventors

• Urano Shigeyuki
• Sata Kota

Classifications

• F02D41/0052

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

• F02D37/02

  one of the functions being ignition · CPC title

• F02P5/1516 Primary

  with means relating to exhaust gas recirculation, e.g. turbo · CPC title

• F02D41/2477

  characterised by the method used for learning · CPC title

• F02D35/028

  by determining the combustion timing or phasing · CPC title