Method for estimating a physical stoppage of a motor vehicle internal combustion engine

Patent metadata

Field	Value
Publication number	US-10920706-B2
Application number	US-201716466757-A
Country	US
Kind code	B2
Filing date	Dec 12, 2017
Priority date	Dec 13, 2016
Publication date	Feb 16, 2021
Grant date	Feb 16, 2021

Abstract

Disclosed is a method for estimating a physical stoppage of an engine of a motor vehicle, subject to bounce-back, a target equipped with teeth being borne by the crankshaft and successive passes of the teeth past a sensor being detected, a first time count incrementing since a last detection of the passing of a tooth and being associated with a first time threshold with the first count being reset to zero when the time between passes of two successive teeth is below the first threshold. A second count associated with a second time threshold is performed, with this count being suspended when and for as long as a time between the passes of two successive teeth is below the second threshold, the engine being estimated to have stopped as soon as the counts have respectively reached the first and second thresholds.

First claim

The invention claimed is:

1. A method for estimating a physical stoppage of an internal combustion engine of a motor vehicle where the engine is subject, during stopping, to at least one bounce-back that temporarily reverses a crankshaft of the engine, said crankshaft including a target equipped with teeth, and where a sensor detects successive passes of the teeth past the sensor during rotation of the crankshaft, the method comprising:
incrementing a first time count (compt 1 ) since a last detection of a passing of a tooth (D) of the target, the first count (compt 1 ) being associated with a first time threshold (S 1 );
in the event that a time between passes of two successive teeth of the target is less than the first time threshold (S 1 ), resetting the first time count (compt 1 ) to zero;
incrementing a second time count (compt 2 ) when the engine operates below a predetermined engine speed threshold (S), and suspending the second time count (compt 2 ) when and for as long as the time between the passes of two successive teeth is below a second time threshold (S 2 );
upon the first and second time counts (compt 1 , compt 2 ) respectively reaching the first and second time thresholds (S 1 , S 2 ), determining that the engine has stopped; and
upon detection that a time elapsed between two detected consecutive passes is below the second time threshold (S 2 ) and a direction of rotation of the crankshaft is in a direction of forward progress of the vehicle, an engine speed averaged over a predetermined number of successive teeth being higher than the predetermined engine speed threshold (S), resetting the second time count (compt 2 ) to zero and determining that the engine as starting.

2. The method as claimed in claim 1 , wherein the predetermined engine speed threshold (S) is 100 revolutions per minute.

3. The method as claimed in claim 2 , wherein the second time threshold is higher than the first time threshold.

4. The method as claimed in claim 3 , wherein the first time threshold is equal to 125 milliseconds and the second time threshold is equal to 250 milliseconds.

5. The method as claimed in claim 2 , wherein the first and second time thresholds can be calibrated.

6. A motor vehicle comprising an internal combustion engine, a crankshaft driven by the engine, and the crankshaft bearing a target that is coaxial with the crankshaft and having teeth at a periphery thereof and an angular marker, a rotation of the target monitored by a crankshaft position sensor that transmits measurements to a processing unit, wherein physical stoppage of the engine is determined by an estimating method as claimed in claim 2 , the processing unit comprising first and second counters that respectively perform the first and second time counts.

7. The method as claimed in claim 1 , wherein the second time threshold (S 2 ) is higher than the first time threshold (S 1 ).

8. The method as claimed in claim 7 , wherein the first time threshold (S 1 ) is equal to 125 milliseconds and the second time threshold (S 2 ) is equal to 250 milliseconds.

9. The method as claimed in claim 8 , wherein the first and second time thresholds can be calibrated.

10. A motor vehicle comprising an internal combustion engine, a crankshaft driven by the engine, and the crankshaft bearing a target that is coaxial with the crankshaft and having teeth at a periphery thereof and an angular marker, a rotation of the target monitored by a crankshaft position sensor that transmits measurements to a processing unit, wherein physical stoppage of the engine is determined by an estimating method as claimed in claim 8 , the processing unit comprising first and second counters that respectively perform the first and second time counts.

11. The method as claimed in claim 7 , wherein the first and second time thresholds can be calibrated.

12. A motor vehicle comprising an internal combustion engine, a crankshaft driven by the engine, and the crankshaft bearing a target that is coaxial with the crankshaft and having teeth at a periphery thereof and an angular marker, a rotation of the target monitored by a crankshaft position sensor that transmits measurements to a processing unit, wherein physical stoppage of the engine is determined by an estimating method as claimed in claim 7 , the processing unit comprising first and second counters that respectively perform the first and second time counts.

13. The method as claimed in claim 1 , wherein the first and second time thresholds (S 1 , S 2 ) can be calibrated.

14. The method as claimed in claim 13 , wherein the second threshold (S 2 ) is dependent on a temperature of the engine.

15. A motor vehicle comprising an internal combustion engine, a crankshaft driven by the engine, and the crankshaft bearing a target that is coaxial with the crankshaft and having teeth at a periphery thereof and an angular marker, a rotation of the target monitored by a crankshaft position sensor that transmits measurements to a processing unit, wherein physical stoppage of the engine is determined by an estimating method as claimed in claim 14 , the processing unit comprising first and second counters that respectively perform the first and second time counts.

16. A motor vehicle comprising an internal combustion engine, a crankshaft driven by the engine, and the crankshaft bearing a target that is coaxial with the crankshaft and having teeth at a periphery thereof and an angular marker, a rotation of the target monitored by a crankshaft position sensor that transmits measurements to a processing unit, wherein physical stoppage of the engine is determined by an estimating method as claimed in claim 13 , the processing unit comprising first and second counters that respectively perform the first and second time counts.

17. A motor vehicle comprising an internal combustion engine, a crankshaft driven by the engine, and the crankshaft bearing a target that is coaxial with the crankshaft and having teeth at a periphery thereof and an angular marker, a rotation of the target monitored by a crankshaft position sensor that transmits measurements to a processing unit, wherein physical stoppage of the engine is determined by an estimating method as claimed in claim 1 , the processing unit comprising first and second counters that respectively perform the first and second time counts (compt 1 , compt 2 ).

18. The motor vehicle as claimed in claim 17 , wherein the target is a gear wheel with a plurality of teeth, and the angular marker is a long tooth which is obtained by omitting at least one of the teeth of the gear wheel.

19. The motor vehicle as claimed in claim 18 , equipped with an automatic stop/start system for the internal combustion engine and/or is a hybrid vehicle.

20. The motor vehicle as claimed in claim 17 , equipped with an automatic stop/start system for the internal combustion engine and/or is a hybrid vehicle.

Assignees

• Continental Automotive France
• Continental Automotive Gmbh

Inventors

• Joseph Fabien
• Marconato Benjamin
• Eloy Stéphane

Classifications

• F02D2200/021

  Engine temperature · CPC title

• F02N11/0814

  comprising means for controlling automatic idle-start-stop · CPC title

• F02N2250/04

  Reverse rotation of the engine · CPC title

• F02D2250/06

  Reverse rotation of engine · CPC title

• F02D2200/101

  Engine speed · CPC title