Method for determining a value of a current

Patent metadata

Field	Value
Publication number	US-9638377-B2
Application number	US-201214345281-A
Country	US
Kind code	B2
Filing date	Aug 6, 2012
Priority date	Sep 20, 2011
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

A method for determining a value of a current, which is required for changing a switching state of a pressure control valve of a fuel delivery system, in which the current flowing through the pressure control valve is varied from a starting value up to a target value, and a time curve of the current is analyzed, the value required for changing the switching state being reached when the curve of the current has a change in slope, this change being detected via a first derivation over time of the current.

First claim

What is claimed is:

1. A method for determining a value of a current, which is required for changing a switching state of a pressure control valve of a fuel delivery system, the method comprising:
varying the current flowing through the pressure control valve from a starting value up to a target value; and
analyzing a time curve of the current, which time curve results from the varying, the analyzing including detecting for which value of the current the curve undergoes a change in slope and determining this current value as the value required for changing the switching state;
wherein the change in slope is detected based on a first derivation over time of the current.

2. The method of claim 1 , wherein the value required for changing the operating state is reached when the first derivation over time of the current has a plateau and/or a peak.

3. The method of claim 1 , wherein the current is for a fuel delivery system of an internal combustion engine of a motor vehicle when the motor vehicle is in coasting mode.

4. The method of claim 1 , wherein a change in the switching state of the pressure control valve includes an opening or a closing of the pressure control valve.

5. The method of claim 1 , wherein the current flowing through the pressure control valve is increased or decreased from a starting value up to the target value for changing the switching state of the pressure control valve.

6. The method of claim 1 , wherein the current is varied in steps or continuously.

7. The method of claim 1 , wherein a value for the pressure at which the switching state of the pressure control valve is changed is assigned to the at least one value of the current, and wherein there is a characteristic of the pressure control valve which includes at least one pair of a value for the current and a value for the pressure.

8. A system to determine a value of a current, comprising:
a control unit configured to determine the value of the current, which is required for changing a switching state of a pressure control valve of a fuel delivery system,
wherein the control unit changes a current, which flows through the pressure control valve, from a starting value up to a target value and checks a resulting time curve of the current,
wherein the control unit checks for which value of the current the curve of the current undergoes a change in slope and identifies this value as the value required for changing the switching state,
and wherein the control unit detects this change in the slope based on a first derivation over time of the current.

9. The configuration of claim 8 , further comprising:
at least one pressure sensor which is configured as a component of the fuel delivery system, wherein the control unit assigns a value for a pressure, at which the pressure control valve changes the switching state and which is measured by the at least one pressure sensor, to the value of the current, and the control unit provides a characteristic of the pressure control valve, including at least one pair of a value for the current and the value for the pressure.

10. The configuration of claim 9 , wherein the control unit internally corrects the characteristic of the pressure control valve.

Assignees

• Sommerer Andreas
• Chatelain Sebastien
• Combe Raphael
• Viereck Markus
• Bosch Gmbh Robert

Inventors

• Sommerer Andreas
• Chatelain Sebastien
• Combe Raphael
• Viereck Markus

Classifications

• F02D41/3863 Primary

  by controlling the flow out of the common rail, e.g. using pressure relief valves · CPC title

• F02D2041/2058

  using information of the actual current value · CPC title

• F17D3/01 Primary

  for controlling, signalling, or supervising the conveyance of a product · CPC title

• Y10T137/0379

  By fluid pressure · CPC title

• Y10T137/7784

  Responsive to change in rate of fluid flow · CPC title