Method to control an electromechanical linear actuator device for an internal combustion engine

Patent metadata

Field	Value
Publication number	US-10563607-B2
Application number	US-201815975357-A
Country	US
Kind code	B2
Filing date	May 9, 2018
Priority date	May 10, 2017
Publication date	Feb 18, 2020
Grant date	Feb 18, 2020

Abstract

A method is described to control an actuation profile of an electromechanical linear actuator device of an internal combustion engine designed to control the movement of a component; the internal combustion engine comprises a sensor, which faces the actuator device and is designed to detect the noise generated by the movement of the component; the method comprises the steps of acquiring, by means of the sensor, the intensity of a signal generated by the impact of the component against a limit stop; identifying a first listening window of the signal associated with said impact; calculating a noise index inside the listening window; comparing the noise index with a reference value; and controlling the actuation profile of the actuator device based on this comparison.

First claim

The invention claimed is:

1. A method to control an actuation profile of an electromechanical linear actuator device ( 20 ) for an internal combustion engine (ICE); wherein the actuator device ( 20 ) is designed to control the movement of a movable armature ( 27 ) moving towards a first limit stop position defined by a fixed mechanical abutment ( 25 ) and vice versa; the internal combustion engine (ICE) comprises a sensor ( 31 ), which is arranged close to the actuator device ( 20 ) and is designed to detect the noise generated by the movement of the movable armature ( 27 ); the method comprises the steps of:
acquiring, by means of the sensor ( 31 ), the intensity of a signal (S) generated by the impact of the movable armature ( 27 ) against the fixed mechanical abutment ( 25 );
identifying a first listening window (OW) in the signal (S) detected by the sensor ( 31 ); wherein the first listening window (OW) identifies the impact of the movable armature ( 27 ) against the fixed mechanical abutment ( 25 );
calculating a first noise index (IDRC) of the signal (S) detected by the sensor ( 31 ) inside the first listening window (OW);
comparing the first noise index (IDRC) with at least one first reference value (I REF ); and
changing a time (T ON-MAIN ) needed to reach the maximum value of the current absorbed by the actuator device ( 20 ) based on the comparison between the first noise index (IDRC i ) and the first reference value (I REF ), namely
decreasing said time (T ON-MAIN ) needed to reach the maximum absorbed current value by a first value (Δt 2 ), in case the first noise index (IDRC) exceeds the respective first reference value (I REF ); or
increasing said time (T ON-MAIN ) needed to reach the maximum absorbed current value by a second value (Δt 3 ), in case the first noise index (IDRC) is smaller than or equal to the respective first reference value (I REF ); and
diagnosing a fault of the actuator device ( 20 ), in case said time (T ON-MAIN ) needed to reach the maximum absorbed current value exceeds a maximum value (T ON-MAINmax ).

2. The method according to claim 1 , wherein the actuator device ( 20 ) is designed to slow down the movement of a piston ( 14 ) moving towards a second limit stop position defined by a fixed closing disc ( 15 ); and the sensor ( 31 ) is suited to detect the noise generated by the movement of the piston ( 14 );
and comprising the further steps of:
acquiring, by means of the sensor ( 31 ), the intensity of a signal (S) generated by the impact of the piston ( 14 ) against the fixed closing disc ( 15 );
dividing the signal (S) detected by the sensor ( 31 ) into a plurality of listening windows (CW i );
calculating a second noise index (IDRC i ) of the signal (S) detected by the sensor ( 31 ) for each listening window (CW i );
comparing the maximum value (IDRC MAX ) of the second noise indexes (IDRC i ) with at least one second reference value (IDRR); and
changing the times of the actuation profile of the actuator device ( 20 ) based on the comparison between the maximum value (IDRC MAX ) and the second reference value (IDRR).

3. The method according to claim 2 and comprising the further step of:
identifying the listening window (CWi) containing the maximum value (IDRC MAX );
changing the times of the actuation profile of the actuator device ( 20 ) based on the position of the listening window (CW i ) having the maximum value (IDRC MAX ) in the actuation profile.

4. The method according to claim 3 and comprising the further step of changing a time (T OFF2 ) needed to reduce the speed of the piston ( 14 ) by a third value (Δt) based on the position of the listening window (CW i ) having the maximum value (IDRC MAX ) in the actuation profile.

5. The method according to claim 4 and comprising the further steps of:
increasing said time (T OFF2 ) needed to reduce the speed of the piston ( 14 ) by a quantity equal to the third value (Δt), in case the listening window (CW i ) having the maximum value (IDRC MAX ) in the actuation profile proceeds with a closing command; or
decreasing said time (T OFF2 ) needed to reduce the speed of the piston ( 14 ) by a quantity equal to the third value (Δt), in case the listening window (CW i ) having the maximum value (IDRC MAX ) in the actuation profile follows the closing command.

6. The method according to claim 1 , wherein the first noise index (IDRC) and the second noise index (IDRC i ) may be calculated using the following formula:
IDRC=MAXs( t ) t2 t1 −MINs( t ) t2 t1 , where

IDRC is the noise index in the respective listening window (OW; CW i );
s(t) is the signal detected by the sensor ( 31 ); and
t 1 , t 2 represents the time instants defining the respective listening window (OW; CW i ).

7. The method according to claim 1 , wherein the first noise index (IDRC) and the second noise index (IDRC i ) may be calculated using the following formula:

IDRC
=

1
N

⁢

∑

t
=

t
1

t
N

⁢

⁢



S
^

⁡

(
t
)



,

where
IDRC is the noise index in the respective listening window (OW; CW i );
Ŝ(t) is the signal detected by the sensor ( 31 ) and filtered in time; and
t 1 , t N represents the time instants defining the respective listening window (OW; CW i ).

8. The method according to claim 1 , wherein the first noise index (IDRC) and the second noise index (IDRC i ) may be calculated using the following formula:

IDRC
=

MAX

f
0

≤
f
≤

f
1

⁢



S
^

⁡

(
f
)



,

where
IDRC is the noise index in the respective listening window (OW; CW i );
Ŝ(f) is the signal detected by the

Assignees

• Magneti Marelli Spa

Inventors

• De Cesare Matteo
• Brugnoni Enrico
• Torcolini Nicola
• Monti Federico

Classifications

• F02M37/043

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