# US 2009/0266142 A1 · Systems and Methods for Sensing an Ammonia Concentration in Exhaust Gases

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- Number: US 2009/0266142 A1
- Document ID: US20090266142A1
- Status: Published application
- Kind: A1
- Application number: 12/109,405
- Filed: 2008-04-25
- Published: 2009-10-29
- Earliest claimed: 2008-04-25
- Assignees: Delphi Technologies, Inc.
- Inventors: Da Yu Wang; Sheng Yao
- Web page: https://patentgrep.com/patent/US20090266142A1

## CPC

- G01N 33/0054: {Ammonia}
- Y02A 50/20: Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)
- Y02A: TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE

## Abstract

Systems and methods for determining an NH3 concentration in exhaust gases from an engine are provided. In one exemplary embodiment, a method includes generating a first signal from an NH3 sensor fluidly communicating with the exhaust gases. The method further includes generating a second signal from an air humidity sensor disposed proximate to an air intake manifold of the engine indicating a humidity level. The method further includes determining an air/fuel ratio associated with the engine. The method further includes determining an NH3 deviation value in a calibration table based on the second signal and the air/fuel ratio, utilizing a controller. The method further includes determining an NH3 concentration value based on the first signal and the NH3 deviation value, utilizing the controller. The NH3 concentration value is indicative of the NH3 concentration in the exhaust gases. The method further includes storing the NH3 concentration value in a memory device, utilizing the controller.

## Claims

### Claim 1

A method for determining an NH3 concentration in exhaust gases from an engine, comprising:
generating a first signal from an NH3 sensor fluidly communicating with the exhaust gases;
generating a second signal from an air humidity sensor disposed proximate to an air intake manifold of the engine indicating a humidity level;
determining an air/fuel ratio associated with the engine;
determining an NH3 deviation value in a calibration table based on the second signal and the air/fuel ratio, utilizing a controller;
determining an NH3 concentration value based on the first signal and the NH3 deviation value, utilizing the controller, the NH3 concentration value indicative of the NH3 concentration in the exhaust gases; and
storing the NH3 concentration value in a memory device, utilizing the controller.

### Claim 2 (depends on 1)

The method of claim 1, wherein determining an air/fuel ratio associated with the engine comprises:
generating a third signal from an air-fuel ratio sensor fluidly communicating with the exhaust gases; and
determining the air/fuel ratio based on the third signal, utilizing the controller.

### Claim 3

A system for determining an NH3 concentration in exhaust gases from an engine, comprising:
an NH3 sensor fluidly communicating with the exhaust gases, the NH3 sensor configured to generate a first signal;
an air humidity sensor disposed proximate to an air intake manifold of the engine, the humidity sensor configured to generate a second signal indicative of a humidity level;
a controller operably communicating with the NH3 sensor and the humidity sensor, the controller configured to determine an air/fuel ratio associated with the engine;
the controller further configured to determine an NH3 deviation value in a calibration table based on the second signal and the air/fuel ratio;
the controller further configured to determine an NH3 concentration value based on the first signal and the NH3 deviation value, the NH3 concentration value indicative of the NH3 concentration in the exhaust gases; and
the controller further configured to store the NH3 concentration value in a memory device.

### Claim 4 (depends on 3)

The system of claim 3, further comprising:
an air-fuel ratio sensor fluidly communicating with the exhaust gases, the air-fuel ratio sensor configured to generate a third signal; and
the controller configured to determine the air/fuel ratio associated with the engine based on the third signal.

### Claim 5

A method for determining an NH3 concentration in exhaust gases from an engine, comprising:
generating a first signal from an NH3 sensor fluidly communicating with the exhaust gases;
retrieving an NH3 deviation value for engine operation in a predetermined climate zone, utilizing a controller, the NH3 deviation value being associated with a predetermined air/fuel ratio and a predetermined humidity level;
determining an NH3 concentration value based on the first signal and the NH3 deviation value, utilizing the controller, the NH3 concentration value indicative of the NH3 concentration in the exhaust gases; and
storing the NH3 concentration value in a memory device, utilizing the controller.

### Claim 6

A system for determining an NH3 concentration in exhaust gases from an engine, comprising:
an NH3 sensor fluidly communicating with the exhaust gases, the NH3 sensor configured to generate a first signal;
a controller operably communicating with the NH3 sensor, the controller configured to retrieve an NH3 deviation value for engine operation in a predetermined climate zone, the NH3 deviation value being associated with a predetermined air/fuel ratio and a predetermined humidity level;
the controller further configured to determine an NH3 concentration value based on the first signal and the NH3 deviation value, the NH3 concentration value indicative of the NH3 concentration in the exhaust gases; and
the controller further configured to store the NH3 concentration value in a memory device.

### Claim 7

A method for determining an NH3 concentration in exhaust gases from an engine, comprising:
generating a first signal from an NH3 sensor fluidly communicating with the exhaust gases;
retrieving an NH3 deviation value for global engine operation, utilizing the controller, the NH3 deviation value associated with a predetermined air/fuel ratio and a predetermined humidity level; and
determining an NH3 concentration value based on the first signal and the NH3 deviation value, the NH3 concentration value indicative of the NH3 concentration in the exhaust gases; and
storing the NH3 concentration value in a memory device, utilizing the controller.

### Claim 8

A system for determining an NH3 concentration in exhaust gases from an engine, comprising:
an NH3 sensor fluidly communicating with the exhaust gases, the NH3 sensor configured to generate a first signal;
a controller operably communicating with the NH3 sensor, the controller configured to retrieve an NH3 deviation value for global engine operation, the NH3 deviation value associated with a predetermined air/fuel ratio and a predetermined humidity level;
the controller further configured to determine an NH3 concentration value based on the first signal and the NH3 deviation value, the NH3 concentration value indicative of the NH3 concentration in the exhaust gases; and
the controller further configured to store the NH3 concentration value in a memory device.