# US 2022/0034249 A1 · Control of pre-scr ammonia dosing based on look-ahead data

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- Number: US 2022/0034249 A1
- Document ID: US20220034249A1
- Status: Published application
- Kind: A1
- Application number: 17/278,749
- Filed: 2019-09-17
- Published: 2022-02-03
- Earliest claimed: 2018-10-04
- Assignees: Scania CV AB
- Applicants: Scania CV AB
- Inventors: Björn HARNEMO
- Web page: https://patentgrep.com/patent/US20220034249A1

## CPC

- F01N 3/2073: {Means for generating a reducing substance from the exhaust gases}
- F01N 3/021: by means of filters
- F01N 3/023: using means for regenerating the filters, e.g. by burning trapped particles
- F01N 3/0231: {using special exhaust apparatus upstream of the filter for producing nitrogen dioxide, e.g. for continuous filter regeneration systems [CRT]}
- F01N 3/0814: {combined with catalytic converters, e.g. NOx absorption/storage reduction catalysts}
- F01N 3/20: specially adapted for catalytic conversion (F01N3/22 takes precedence)
- F01N 3/2066: {Selective catalytic reduction [SCR]}
- F01N 3/208: {Control of selective catalytic reduction [SCR], e.g. by adjusting the dosing of reducing agent}
- F01N 9/005: {using models instead of sensors to determine operating characteristics of exhaust systems, e.g. calculating catalyst temperature instead of measuring it directly}
- F01N 13/009: {having two or more separate purifying devices arranged in series}
- F01N 13/0093: {the purifying devices are of the same type}
- F01N 3/035: with catalytic reactors
- F01N 2260/04: for regeneration or reactivation, e.g. of catalyst
- F01N 2560/026: for measuring or detecting NOx
- F01N 2610/02: the substance being ammonia or urea
- F01N 2900/102: Travelling distance
- F01N 2900/1402: Exhaust gas composition
- F01N 2900/1621: Catalyst conversion efficiency
- F01N 2900/1622: Catalyst reducing agent absorption capacity or consumption amount
- Y02A 50/20: Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
- Y02T 10/12: Improving ICE efficiencies
- Y02T 10/40: Engine management systems
- F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16)
- Y02A: TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A method for controlling an exhaust gas aftertreatment system, wherein the system includes a first selective catalytic reduction (SCR) device, a catalytic particulate filter arrangement arranged downstream of the first SCR device, and a second selective catalytic reduction (SCR) device arranged downstream of the catalytic particulate filter arrangement. The method includes estimating future exhaust conditions based upon predicted vehicle operating conditions (s4103); —estimating a future NOx conversion demand based on the estimated future exhaust conditions (s405); —dosing a reducing agent from a first reducing agent dosing device at a rate based at least on the estimated future NOx conversion demand (s406).

## Claims

### Claim 1

A method for controlling an exhaust gas aftertreatment system, wherein the exhaust gas aftertreatment system comprises
a first reducing agent dosing device;
a first selective catalytic reduction (SCR) device arranged downstream of the first reducing agent dosing device;
a catalytic particulate filter arrangement arranged downstream of the first SCR device, wherein the catalytic particulate filter assembly comprises a catalysed particulate filter, or wherein the catalytic particulate filter assembly comprises an oxidation catalyst and a particulate filter arranged downstream of the oxidation catalyst;
a second reducing agent dosing device arranged downstream of the catalytic particulate filter arrangement; and
a second selective catalytic reduction (SCR) device arranged downstream of the second reducing agent dosing device;
and wherein the method comprises the steps of:
estimating future exhaust conditions based upon predicted vehicle operating conditions (s403);
estimating a future NOx conversion demand based on the estimated future exhaust conditions (s405); and
dosing a reducing agent from the first reducing agent dosing device at a rate based at least on the estimated future NOx conversion demand (s406).

### Claim 2 (depends on 1)

A method according to claim 1, wherein the step (s406) of dosing a reducing agent from the first reducing agent dosing device at a rate based at least on the estimated future NOx conversion demand comprises:
comparing the estimated future NOx conversion demand with a predetermined first threshold limit for NOx conversion demand (s407); and
dosing a reducing agent from the first reducing agent dosing device, wherein
if the estimated future NOx conversion demand is within the first threshold limit, then the reducing agent is dosed at a predetermined baseline rate (s409); and
if the estimated future NOx conversion demand is beyond the first threshold limit, then the reducing agent is dosed at an adapted rate (s411), wherein the adapted rate differs from the baseline rate.

### Claim 3 (depends on 2)

A method according to claim 2, wherein the first threshold limit is an upper threshold limit, and wherein the adapted rate is an elevated rate that is higher than the baseline rate.

### Claim 4 (depends on 3)

A method according to claim 3, further comprising comparing the estimated future NOx conversion demand with a predetermined lower threshold limit for NOx conversion demand, wherein
if the estimated future NOx conversion demand is beyond the lower threshold limit, then a reducing agent is dosed at a lower rate from the first reducing agent dosing device, wherein the lower rate is lower than the baseline rate.

### Claim 5 (depends on 2)

A method according to claim 2, wherein the first threshold limit is a lower threshold limit, and wherein the adapted rate is a lower rate that is lower than the baseline rate.

### Claim 6 (depends on 2)

A method according to claim 2, wherein
the baseline rate is adapted to correspond to from 20% to 60% of estimated future NOx conversion demand; and/or
the elevated rate is adapted to correspond to from 60% to 90% of estimated future NOx conversion demand; and/or
the lower rate is adapted to correspond to from 0% to 30% of estimated future NOx conversion demand.

### Claim 7 (depends on 2)

A method according to claim 2, wherein the elevated rate and/or the lower rate varies based at least partially on the estimated future NOx conversion demand.

### Claim 8 (depends on 1)

A method according to claim 1, comprising dosing a reducing agent from the second reducing agent dosing device at a rate based at least partially on the estimated future NOx conversion demand.

### Claim 9 (depends on 1)

A method according to claim 1, wherein the exhaust gas aftertreatment system further comprises a NOx sensor, and wherein the method comprises dosing a reducing agent from the first and/or second reducing agent dosing devices at a rate based at least partially on a value provided by the NOx sensor.

### Claim 10 (depends on 1)

A method according to claim 1, wherein the predicted vehicle operating conditions are based on information from at least one of an engine management system of the internal combustion engine, a gearbox management system, a navigation system, a cruise control system and/or a radar system configured to determine traffic conditions.

### Claim 11

An exhaust gas aftertreatment system comprising:
a first reducing agent dosing device;
a first selective catalytic reduction (SCR) device arranged downstream of the first reducing agent dosing device;
a catalytic particulate filter arrangement arranged downstream of the first SCR device, wherein the catalytic particulate filter assembly comprises a catalysed particulate filter, or wherein the catalytic particulate filter assembly comprises an oxidation catalyst and a particulate filter arranged downstream of the oxidation catalyst;
a second reducing agent dosing device arranged downstream of the catalytic particulate filter arrangement;
a second selective catalytic reduction (SCR) device arranged downstream of the second reducing agent dosing device;
a means arranged to estimate future exhaust conditions based upon predicted vehicle operating conditions; and
a means arranged to estimate a future NOx conversion demand based on the estimated future exhaust conditions;
wherein the exhaust gas aftertreatment system is arranged to dose a reducing agent from the first reducing agent dosing device based at least on the estimated future NOx conversion demand.

### Claim 12 (depends on 11)

An exhaust gas aftertreatment system according to claim 11, further comprising:
a means arranged to compare the estimated future NOx conversion demand with a predetermined first threshold limit for NOx conversion demand;
wherein the exhaust gas aftertreatment system is arranged to dose a reducing agent from the first reducing agent dosing device at a predetermined baseline rate if the estimated future NOx conversion demand is within the first threshold limit;
and wherein the exhaust gas aftertreatment system is arranged to dose a reducing agent from the first reducing agent dosing device at an adapted rate if the estimated future NOx conversion demand is beyond the first threshold limit, wherein the adapted rate differs from the baseline rate.

### Claim 13 (depends on 11)

A vehicle comprising an internal combustion engine, wherein the vehicle further comprises an exhaust gas aftertreatment system according to claim 11.

### Claim 14 (depends on 1)

A computer program (P), comprising program code for causing a control unit or a computer connected to the control unit to perform the method according to claim 1.

### Claim 15 (depends on 1)

A computer-readable medium comprising instructions, which when executed by a control unit or a computer connected to the control unit cause the control unit or the computer to perform the method according to claim 1.

### Claim 16 (depends on 3)

The method according to claim 3, wherein the elevated rate is at least 10% higher than the baseline rate.

### Claim 17 (depends on 4)

The method according to claim 4, wherein the lower rate is at least 10% lower than the baseline rate.

### Claim 18 (depends on 5)

The method according to claim 5, wherein the lower rate is at least 10% lower than the baseline rate.