Procedure for the determination of the Lambda values with a broadband Lambda probe

• US 8,075,759 B2
• Filed: 06/21/2006
• Issued: 12/13/2011
• Est. Priority Date: 06/22/2005
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Schnaibel, Eberhard, Junginger, Erich, Kanters, Johannes, Moser, Thomas, Kowol, Frank, Hein, Reinhard
• Primary Examiner(s): Hendricks, Keith
• Assistant Examiner(s): DINH, BACH T
• Application Number:
  US11/472,144
• Publication Number:
  US 20060289314A1
• Time in Patent Office: 2,001 Days
• Field of Search: 204424-429, 2057835-785, 73 2331- 2332
• US Class Current: 205/784.5
• CPC Class Codes: G01N 27/419 Measuring voltages or currents with a combination of oxygen pumping cells and oxygen concentration cells

Abstract

A procedure to calculate the Lambda value with a wideband Lambda sensor of an internal combustion engine of a motor vehicle is thereby characterized, in that from the measured pumping electricity and the sensitivities of the wideband Lambda sensor as well as the gas concentration ratios, in the lean operation an oxygen concentration and in the rich operation an oxygen deficit are determined and from these respectively a conclusion is drawn about the Lambda value using the Pischinger Formula.

Claims

1. A method of determining a Lambda value of internal combustion engine exhaust gas with a wideband Lambda sensor, the method comprising:

measuring a pumping current, wherein the pumping current is a function of oxygen concentration in the exhaust gas;

calculating a first oxygen concentration when the pumping current is cathodic, corresponding to an air-fuel mixture in a lean condition, the first oxygen concentration calculated from the measured pumping current and an oxygen sensitivity parameter;

otherwise, calculating a second oxygen concentration when the pumping current is anodic, corresponding to the air-fuel mixture in a rich condition, the second oxygen concentration calculated from a hydrogen sensitivity parameter, a carbon monoxide sensitivity parameter, a gas concentration ratio, the measured pumping current, and the oxygen sensitivity parameter utilizing an equation

2. The method according to claim 1, wherein the oxygen sensitivity parameter, the hydrogen sensitivity parameter, and the carbon monoxide sensitivity parameter are predetermined parameters of the Lambda sensor.

3. The method according to claim 1, further comprising recording gas concentrations in the exhaust gas of the internal combustion engine against a number of revolutions-load-range.