Alcohol concentration estimation and detection apparatus for an engine

Patent metadata

Field	Value
Publication number	US-9777649-B2
Application number	US-201113011287-A
Country	US
Kind code	B2
Filing date	Jan 21, 2011
Priority date	Feb 1, 2010
Publication date	Oct 3, 2017
Grant date	Oct 3, 2017

Abstract

In an alcohol concentration estimation apparatus for an engine, a first crank angular speed (ω 1 ) within a first predetermined interval overlapping with the compression top dead center is calculated, and a first variation amount (Δω 1 ) is calculated by subtracting ω 1 from an average engine speed. A second crank angular speed (ω 2 ) within a second predetermined interval overlapping with the combustion bottom dead center is calculated, and a second variation amount (Δω 2 ) is calculated by subtracting ω 1 from ω 2 . In a relationship between air fuel ratio A/F and an indicated mean effective pressure (IMEP)/charging efficiency (ηc) of the engine when the engine is operated with a predetermined fuel injection map indicating a relationship between A/F and IMEP/ηc for each desired alcohol concentration, IMEP/ηc is substituted by Δω 2/Δω1 ratio to estimate an alcohol concentration in fuel. The alcohol concentration estimation apparatus eliminates requirement of sensors for detecting an intake air mass.

First claim

What is claimed is:

1. An alcohol concentration estimation apparatus which receives a crank pulse supplied from a pickup coil which detects passing of a plurality of reluctors provided on a crank pulse rotor which rotates in synchronism with a crankshaft of an engine,
said alcohol concentration estimation apparatus comprising:
an NeA calculation section adapted to calculate an average engine speed (NeA) of the engine based on crank pulse output;
a Δω 1 , Δω 2 calculation section operable:
to calculate a first crank angular speed (ω 1 ) within a first predetermined interval (τ 1 ) overlapping with a compression top dead center (TDC) of the engine,
and to subtract the first crank angular speed (ω 1 ) from the average engine speed (NeA) to calculate a first variation amount (Δω 1 ) and to calculate a second crank angular speed (ω 2 ) within a second predetermined interval (τ 2 ) overlapping with a combustion bottom dead center (BDC) of the engine and to subtract the first crank angular speed (ω 1 ) from the second crank angular speed to calculate a second variation amount (Δω 2 );

an ignition controlling section configured to drive and control an ignition system of the engine; and
a fuel injection controlling section configured to drive and control a fuel injection system of the engine,
wherein said alcohol concentration estimation apparatus is operable to estimate an alcohol concentration of a fuel based on the values of the first variation amount (Δω 1 ) and the second variation amount (Δω 2 ), and
wherein the ignition controlling section controls the ignition system based on the estimated alcohol concentration and the fuel injection controlling section controls the fuel injection system based on the estimated alcohol concentration.

2. The alcohol concentration estimation apparatus according to claim 1 , wherein at least one of the reluctors of the crank pulse rotor is formed so as to stretch over the one of the compression top dead center (TDC) and the combustion bottom dead center (BDC).

3. The alcohol concentration estimation apparatus according to claim 1 , wherein:
the first predetermined interval (τ 1 ) is an interval from a falling point (C 1 ) of a crank pulse (P 1 ) positioned just before the compression top dead center (TDC) to another falling point (C 2 ) of another crank pulse (P 2 ) positioned just after the compression top dead center (TDC); and
the second predetermined interval (τ 2 ) is an interval from a falling point (C 3 ) of a crank pulse (P 3 ) positioned just before the combustion bottom dead center (BDC) to another falling point (C 4 ) of another crank pulse (P 4 ) positioned just after the combustion bottom dead center (BDC).

4. The alcohol concentration estimation apparatus according to claim 3 , wherein at least one of the reluctors of the crank pulse rotor is formed so as to stretch over the one of the compression top dead center (TDC) and the combustion bottom dead center (BDC).

5. The alcohol concentration estimation apparatus according to claim 1 , further comprising:
a fuel injection map set so as to operate the engine with a stoichiometric air fuel ratio where the engine is operated with a fuel having a predetermined alcohol concentration;
a Δω 2 /Δω 1 calculation section operable to calculate, when the engine is operated with the setting of said fuel injection map, a ratio between the first variation amount (Δω 1 ) and the second variation amount (Δω 2 ); and
an alcohol concentration estimation map group comprising a plurality of maps, each corresponding to individual predetermined engine speeds and indicative of a plurality of relationships between a plurality of alcohol concentrations and a parameter which increases in proportion to the alcohol concentration;
wherein said alcohol concentration estimation apparatus is operable to select one of alcohol concentration estimation maps which coincides with the average engine speed (NeA), and to determine the parameter from the ratio between the first variation amount (Δω 1 ) and the second variation amount (Δω 2 ) to estimate the alcohol concentration.

6. The alcohol concentration estimation apparatus according to claim 5 , wherein:
the first predetermined interval (τ 1 ) is an interval from a falling point (C 1 ) of a crank pulse (P 1 ) positioned just before the compression top dead center (TDC) to another falling point (C 2 ) of another crank pulse (P 2 ) positioned just after the compression top dead center (TDC); and
the second predetermined interval (τ 2 ) is an interval from a falling point (C 3 ) of a crank pulse (P 3 ) positioned just before the combustion bottom dead center (BDC) to another falling point (C 4 ) of another crank pulse (P 4 ) positioned just after the combustion bottom dead center (BDC).

7. The alcohol concentration estimation apparatus according to claim 5 , wherein at least one of the reluctors of the crank pulse rotor is formed so as to stretch over the one of the compression top dead center (TDC) and the combustion bottom dead center (BDC).

8. The alcohol concentration estimation apparatus according to claim 5 , wherein:
each of said alcohol concentration estimation maps indicates a relationship between the alcohol concentration and an indicated mean effective pressure (IMEP)/charging efficiency (ηc) of the engine under a condition that the engine is operated with a fuel injection map set so that the engine is operated in a stoichiometric air fuel ratio where the engine is operated with a fuel having a predetermined alcohol concentration; and
said alcohol concentration estimation apparatus is operable to associate the first variation amount (Δω 1 ) with the charging efficiency (ηc) and also operable to associate the second variation amount (Δω 2 ) with the indicated mean effective pressure (IMEP) to use the associated parameters as the parameters.

9. The alcohol concentration estimation apparatus according to claim 8 , wherein:
the first predetermined interval (τ 1 ) is an interval from a falling point (C 1 ) of a crank pulse (P 1 ) positioned just before the compression top dead center (TDC) to another falling point (C 2 ) of another crank pulse (P 2 ) positioned just after the compression top dead center (TDC); and
the second predetermined interval (τ 2 ) is an interval from a falling point (C 3 ) of a crank pulse (P 3 ) positioned just before the combustion bottom dead center (BDC) to another falling point (C 4 ) of another crank pulse (P 4 ) positioned just after the combustion bottom dead center (BDC).

10. The alcohol concentration estimation apparatus according to claim 8 , wherein at least one of the reluctors of the crank pulse rotor is formed so as to stretch over the one of the compression top dead center (TDC) and the combustion bottom dead center (BDC).

11. An alcohol concentration estimation apparatus which receives a crank pulse supplied from a pickup coil which detects passing of a plurality of reluctors provided on a crank pulse rotor which rotates in synchronism with a crankshaft of an engine, said alcohol concentration estimation apparatus comprising:
a Δω 1 , Δω 2 calculation section operable to calculate:
a first variation amount (Δω 1 ) from a difference between an angular speed upon starting of a compression stroke of the engine and an angular speed in the proximity of the compression top dead center (TDC), and
a second crank angular speed (ω 2 ) within a second predetermined interval (τ 2 ) overlapping with the combustion bottom dead center (BDC) of the engine, and to subtract a first crank angular speed (ω 1 ) from the second crank angular speed (ω 2 ) to calculate a second variation amount (Δω 2 );

an ignition controlling section configure

Assignees

• Nishida Kenji
• Fukuzawa Kazuto
• Kaneko Tetsuya
• Saito Kenjiro
• Honda Motor Co Ltd

Inventors

• Nishida Kenji
• Fukuzawa Kazuto
• Kaneko Tetsuya
• Saito Kenjiro

Classifications

• 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

• F02D41/2422

  Selective use of one or more tables · CPC title

• F02P5/1502

  using one central computing unit · CPC title

• F02D41/0097

  using means for generating speed signals · CPC title

• F02D19/084

  Blends of gasoline and alcohols, e.g. E85 · CPC title