SYSTEM FOR DETECTING AN AIR FILTER CONDITION, IN PARTICULAR FOR COMBUSTION ENGINE

• US 20160018288A1
• Filed: 06/25/2015
• Published: 01/21/2016
• Est. Priority Date: 06/27/2014
• Status: Active Grant

• Current Assignee: FPT Motorenforschung AG (Iveco Group NV)
• Original Assignee: FPT Motorenforschung AG (Iveco Group NV)
• Inventors: Eckhardt, Thomas
• Granted Patent: US 10,126,203 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B01D 46/0086 Filter condition indicators
• CPC Class Codes: B01D 46/446 by pressure measuring
• CPC Class Codes: F02M 35/024 using filters, e.g. moistened F02M35/026 takes precedence; cleaning of the filtering material F02M35/08
• CPC Class Codes: F02M 35/08 with means for removing dust, particles or liquids from cleaners; with means for indicating clogging; with by-pass means; Regeneration of cleaners
• CPC Class Codes: F02M 35/09 Clogging indicators ; Diagnosis or testing of air cleaners sensors therefore F02M35/10373
• CPC Class Codes: F02M 35/10373 Sensors for intake systems throttle position sensors F02D9/105
• CPC Class Codes: G01M 15/09 by monitoring pressure in fluid ducts, e.g. in lubrication or cooling parts

Abstract

Method for detecting an air filter condition, in particular for combustion engines, comprising the following steps

• • calculation of a linear regression over data-couples values, each comprising pressure drop value at the air filter and square of air flow value crossing the air filter, corresponding to said pressure drop value, in order to obtain an angular coefficient of the linear regression, comparison of the angular coefficient or of the function construed on the angular coefficient with at least one threshold in order to detect an operative condition of the air filter (FIG. 1).

Claims

1. Method for detecting an air filter condition, in particular for combustion engines, comprising the following steps

(ik) calculation of a linear regression over data-couples values, each comprising

pressure drop value (ia) at the air filter

square of air flow value (ib) crossing the air filter, corresponding to said pressure drop value,

in order to obtain an angular coefficient (k) of the linear regression,

(iki) comparison of said angular coefficient or of a function construed on said angular coefficient with at least one threshold ((ThL, Th1, ThH), (kMin, kMax), ({dot over (V)}_min², {dot over (V)}_max²)) in order to detect (ikii) an operative condition of the air filter.

2. Method according to claim 1, wherein, when (iki) said angular coefficient (k) or said function construed on said angular coefficient exceeds a higher threshold (ThU) (k or f(k)>

ThU;

YES), the air filter is acknowledged (ikii) as clogged.

3. Method according to claim 1, wherein, when (iki) said angular coefficient (k) or said function construed on said angular coefficient is lower that a lower threshold (ThL) (k or f(k)<

ThL;

YES), the air filter is acknowledged (ikii) as tampered or absent or the intake pipe is acknowledged as leaking.

4. Method according to claim 1, wherein (iki) said angular coefficient (k) or said function construed on said angular coefficient is compared with at least three thresholds ThL<

Th 1 <

ThU in order to detect one of the following at least four conditions;

First condition;

ThL<

k<

Th1;

filter is acknowledged as new and/or in good conditions;

Second condition;

Th1<

k<

ThU;

filter is acknowledged as dirty, but not yet dangerously clogged;

Third condition;

ThU<

k;

filter is acknowledged as dangerously clogged;

Fourth condition;

k<

ThL;

the angular coefficient k is acknowledged as too low even for a new filter, thus a severe dangerous condition is acknowledged;

no filter cartridge present,

wrong filter cartridge present,

intake leakage.

5. Method according to claim 4, comprising a step of detecting (ikiii) of a Fifth condition, when said angular coefficient (k) or a function construed on said angular coefficient suddenly passes from said Second or Third condition to the Fourth condition, indicating a tampering approach.

6. Method according to claim 4, wherein, when said Fourth or Fifth condition is detected, the method comprises a further step (x) wherein the engine in turned into a recovery mode, with a limited power/torque/speed.

7. Method according to claim 1, wherein, said function construed on said angular coefficient (k) is a theoretical maximal pressure drop (Δ

p_max) corresponding to a predefined theoretical maximal air flow value ({dot over (V)}_max).

8. Method according to claim 7, wherein said theoretical maximal pressure drop Δ

p_max is given by

Δ

p_max=k·

{dot over (V)}_max²  

 

Eq. 3

where {dot over (V)}_max coincides with said predefined theoretical maximal air flow value.

9. Method according to claim 1, wherein said drop pressure is acquired (v) by a differential pressure sensor or by subtracting

a first measured absolute pressure, measured by means of a first absolute pressure sensor arranged downstream of the air filter according to air flow direction, from

a second measured absolute pressure, measured by means of a second absolute pressure sensor arranged in the ambient.

10. Method according to claim 1, wherein an applicable range [{dot over (V)}_min, {dot over (V)}_max], of air flows is subdivided (iii) into a predefined number of adjacent intervals (0-7), then, said data-couples values Δ

p, {dot over (V)}² are grouped (iv) on the basis of the respective interval belonging the air flow value {dot over (V)} and associated to the respective interval,

and wherein said angular coefficient k is calculated (ik) by means of the following formula

11. Method according to claim 10, further comprising a preliminary step (v) of acquisition of said data-couples Δ

p, {dot over (V)}² and a subsequent step of inhibition (vi) of said linear regression calculation, until at least a predefined number of intervals is associated with at least one data-couple.

12. Apparatus for detecting an air filter condition, in particular for combustion engines, comprising

means for acquire (v) a pressure drop value at the air filter,

means for acquire (v) an air flow value crossing the air filter, corresponding to said pressure drop value

elaborating means (ECU) adapted to carry out all the steps (ik-ikiii, x, iii, iv, v) of claim 1.

13. Computer program comprising computer program code means adapted to perform all the steps (ik-ikiii) of claim 1, when said program is run on a computer.

14. A computer readable medium having a program recorded thereon, said computer readable medium comprising computer program code means adapted to perform all the steps (ik-ikiii) of claim 1, when said program is run on a computer.

15. Combustion engine comprising an air filter and an apparatus for detecting its operative conditions according to claim 12.

16. Terrestrial vehicle comprising a combustion engine according to claim 15.