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

• US 20060289314A1
• Filed: 06/21/2006
• Published: 12/28/2006
• Est. Priority Date: 06/22/2005
• Status: Active Grant

• Current Assignee: Robert Bosch GmbH
• Original Assignee: Robert Bosch GmbH
• Inventors: Hein, Reinhard, Kowol, Frank, Moser, Thomas, Schnaibel, Eberhard, Kanters, Johannes, Junginger, Erich
• Granted Patent: US 8,075,759 B2
• Time in Patent Office: Days
• US Class Current: 205/782
• 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. The method of determining a Lambda value with a wideband Lambda sensor of an internal combustion engine of a motor vehicle, the method including measuring a first oxygen concentration in a lean operation and a second oxygen deficit in rich operation from a measured pumping electricity and sensitivities of the wideband Lambda sensor to gasses detected and gas concentration rations;

and determining the Lambda value from the first and second oxygen concentrations.

2. The method according to claim 1, further including determining an alternative pumping current from a measured pumping current based on a ration of a concentration of hydrogen to a concentration of carbon monoxide and sensitivities of the sensor to oxygen, hydrogen and carbon monoxide gasses by using the equation

$I_{p-\mathrm{Alternative}}=\frac{-I_{\mathrm{pMeasured}}}{2}$

( K + 1 ) ·

ɛ

_O 2 K ·

ɛ

_H 2 + ⁢

ɛ

_CO

3. The method according to claim 1, wherein the sensitivities of oxygen, hydrogen, and carbon monoxide have been previously determined.

4. The method according to claim 1, wherein the ration of the concentration of hydrogen to carbon monoxide has been previously determined.

5. The method according to claim 1 further including recording gas concentrations in an exhaust of the internal combustion engine against a number of revolutions-load-range and the Lambda value in characteristic fields.