Method for determining the angular position of an engine by way of a crankshaft sensor and a camshaft sensor

Patent metadata

Field	Value
Publication number	US-10240550-B2
Application number	US-201615769984-A
Country	US
Kind code	B2
Filing date	Oct 20, 2016
Priority date	Oct 26, 2015
Publication date	Mar 26, 2019
Grant date	Mar 26, 2019

Abstract

A method for determining the angular position of an engine by a crankshaft sensor and a camshaft sensor. The method includes production by the crankshaft sensor of a revolution event, determination of the angular position of the camshaft by identifying the start-of-tooth and end-of-tooth events following the revolution event, in rapid mode, over at most one revolution of the crankshaft, if a no tooth event occurs after the revolution event and if the determination of the angular position of the camshaft fails, the method continues with a step of determining the angular position of the camshaft by identification, in slow mode, over at least two crankshaft revolutions.

First claim

The invention claimed is:

1. A method for determining an angular position of an engine by way of a crankshaft sensor comprising a crankshaft detector facing a crankshaft toothed wheel, performing two revolutions per engine cycle, and comprising a large number of regular teeth and a revolution marker, the crankshaft detector being able to produce a ‘tooth’ event corresponding to an edge for each of said teeth, a ‘revolution’ event for the revolution marker, and a ‘missing tooth’ event when two successive ‘tooth’ events are abnormally far apart, and of a camshaft sensor comprising a camshaft detector facing a camshaft toothed wheel, performing one revolution per engine cycle, and comprising a small number of irregular teeth, the camshaft detector being able to produce a ‘tooth start’ event for each rising edge and a ‘tooth end’ event for each falling edge, the method comprising:
producing the ‘revolution’ event by the crankshaft sensor,
determining with the camshaft sensor the angular position of the camshaft by identifying the ‘tooth start’ and ‘tooth end’ events produced by the camshaft detector following said ‘revolution’ event, in a fast mode, over at most one crankshaft revolution, wherein if a ‘missing tooth’ event is produced by the crankshaft detector after the ‘revolution’ event and if the determination of the angular position of the camshaft fails, the method continues with a step of:
determining with the camshaft sensor the angular position of the camshaft by identifying the ‘tooth start’ and ‘tooth end’ events produced by the camshaft detector, in a slow mode, over at least two crankshaft revolutions.

2. The method as claimed in claim 1 , wherein the crankshaft toothed wheel is regularly angularly divided into 60 teeth positions and comprises a large number of teeth equal to 58, and 2 consecutive missing teeth forming the revolution marker.

3. The method as claimed in claim 1 , wherein the camshaft toothed wheel comprises a small number of teeth equal to 4, comprising a first small tooth, followed by a first small cavity, followed by a first large tooth, followed by a second small cavity, followed by a second large tooth, followed by a first large cavity, followed by a second small tooth, followed by a second large cavity.

4. The method as claimed in claim 1 , wherein a ‘missing tooth’ is not able to be produced within a window whose extent is said large number of teeth toleranced by +/− a tolerance of 2 teeth following a ‘revolution’ event.

5. The method as claimed in claim 1 , wherein a ‘missing tooth’ is not able to be produced within a window whose extent is said large number of teeth toleranced by +/− a tolerance of teeth following a ‘revolution’ event.

6. The method as claimed in claim 5 , wherein the crankshaft toothed wheel is regularly angularly divided into 60 teeth positions and comprises a large number of teeth equal to 58, and 2 consecutive missing teeth forming the revolution marker.

7. The method as claimed in claim 1 , wherein the determination of the angular position of the camshaft by identification in the slow mode is continued in the slow mode for as long as the determination of the angular position of the camshaft fails.

8. The method as claimed in claim 7 , wherein a ‘missing tooth’ is not able to be produced within a window whose extent is said large number of teeth toleranced by +/− a tolerance of teeth following a ‘revolution’ event.

9. The method as claimed in claim 7 , wherein the crankshaft toothed wheel is regularly angularly divided into 60 teeth positions and comprises a large number of teeth equal to 58, and 2 consecutive missing teeth forming the revolution marker.

10. The method as claimed in claim 7 , wherein a ‘missing tooth’ is not able to be produced within a window whose extent is said large number of teeth toleranced by +/− a tolerance of 2 teeth following a ‘revolution’ event.

Assignees

• Continental Automotive France
• Continental Automotive Gmbh

Inventors

• Mazenc Christophe

Classifications

• G01D5/00

  Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable (G01D3/00 takes precedence; specially adapted for apparatus giving results other than momentary value of variable G01D1/00) · CPC title

• F02D2250/06

  Reverse rotation of engine · CPC title

• G01D5/142

  using Hall-effect devices (measuring magnetic variables using Hall-effect or other galvanomagnetic devices G01R33/06) · CPC title

• G01D5/2457

  Incremental encoders having reference marks · CPC title

• F02D41/22 Primary

  Safety or indicating devices for abnormal conditions {(in air/fuel ratio feedback systems F02D41/1495, in electric control linkage F02D11/107, in purge control systems F02M25/0809)} · CPC title