# US 11,111,837 B2 · System and a method for adapting control of a reducing agent dosing unit > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,111,837 B2 - Document ID: US11111837B2 - Status: Granted - Kind: B2 - Application number: 16/646,605 - Filed: 2018-09-06 - Published: 2020-07-02 - Granted: 2021-09-07 - Earliest claimed: 2017-09-22 - Assignees: Scania CV AB - Applicants: Scania CV AB - Inventors: Kurt Källkvist; Emanuel Remmo; Joakim Sommansson - Web page: https://patentgrep.com/patent/US11111837B2 ## CPC - F01N 3/208: {Control of selective catalytic reduction [SCR], e.g. by adjusting the dosing of reducing agent} - F01N 3/2066: {Selective catalytic reduction [SCR]} - F01N 9/007: {Storing data relevant to operation of exhaust systems for later retrieval and analysis, e.g. to research exhaust system malfunctions} - F01N 2560/08: the means being a pressure sensor - F01N 2610/02: the substance being ammonia or urea - F01N 2610/1433: Pumps - F01N 2610/146: Control thereof, e.g. control of injectors or injection valves - F01N 2900/1808: Pressure - F01N 2900/1811: Temperature - F01N 2900/1821: Injector parameters - 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 Disclosed is a method for adapting control of a reducing agent dosing unit in a reducing agent provision system for emission control of a combustion engine. Characteristics relating to pressure variations associated with a dosing cycle are used for determining a first time period and a second time period. The time periods relate to a delay between activation of dosing and de-activation of dosing, respectively. The first time period and second time period are used for adapting operation of said reducing agent dosing unit. ## Claims ### Claim 1 A method for adapting control of a reducing agent dosing unit in a reducing agent provision system for emission control of a combustion engine, said reducing agent provision system comprising a pump unit for pressurizing said reducing agent to be dosed, wherein said dosing unit comprising an electrically controlled valve unit arranged to be shifted between an opened state and a closed state, comprising the steps of: continuously determining a prevailing pressure of said reducing agent in said reducing agent provision system downstream of said pump unit; initiating shifting said valve unit at a first point of time to said open state from said closed state by applying a voltage to a valve unit operation arrangement; determining a second point of time for a characteristic pressure drop due to said shifting to said open state of said valve unit; initiating shifting said valve unit at a third point of time to said closed state from said open state by turning off said voltage to said valve unit operation arrangement; determining a fourth point of time for a characteristic pressure increase due to said shifting to said closed state of said valve unit; determining a time interval between said first and said second point of time and another time interval between said third and fourth point of time; and providing the thus determined time intervals as a basis for said adaption control of said reduction agent dosing unit for obtaining an intended dosing period during a dosing cycle. ### Claim 2 (depends on 1) The method according to claim 1, comprising the steps of: continuously determining a prevailing current applied for said valve unit operation arrangement; determining a fifth point of time for a characteristic current drop due to said shifting to said open state of said valve unit; and comparing the thus determined second point of time with said thus determined fifth point of time to decide whether said second point of time appears reliable. ### Claim 3 (depends on 1) The method according to claim 1, further comprising the steps of: continuously determining a prevailing current applied for said valve unit operation arrangement; determining a sixth point of time for a characteristic current increase due to said shifting to said closed state of said valve unit; and comparing the thus determined fourth point of time with said thus determined sixth point of time to decide whether said fourth point of time appears reliable. ### Claim 4 (depends on 1) The method according to claim 1, further comprising the step of: storing said time intervals together with values for prevailing applied voltage, prevailing reducing agent temperature and prevailing pressure of said reducing agent, said values corresponding to a particular system working point. ### Claim 5 (depends on 4) The method according to claim 4, further comprising the step of: for a number of different system working points, storing corresponding determined pairs of time intervals. ### Claim 6 (depends on 5) The method according to claim 5, further comprising the step of: providing the thus stored system working point information for adapting control of said reduction agent dosing unit. ### Claim 7 (depends on 1) The method according to claim 1, further comprising the step of: providing non pre-stored determined time intervals as a basis for consecutive adaption control of said reduction agent dosing unit for obtaining an intended dosing period during a dosing cycle. ### Claim 8 A system for adapting control of a reducing agent dosing unit in a reducing agent provision system for emission control of a combustion engine, said reducing agent provision system comprising a pump unit for pressurizing said reducing agent to be dosed, wherein said dosing unit comprising an electrically controlled valve unit arranged to be shifted between an opened state and a closed state, wherein said system comprises: one or more control units; and computer program code stored on a non-transitory computer-readable medium, said computer program code comprising computer instructions to cause the one or more control units to perform the following operations: continuously determining a prevailing pressure of said reducing agent in said reducing agent provision system downstream of said pump unit; initiating shifting said valve unit at a first point of time to said open state from said closed state by applying a voltage to a valve unit operation arrangement; determining a second point of time for a characteristic pressure drop due to said shifting to said open state of said valve unit; initiating shifting said valve unit at a third point of time to said closed state from said open state by turning off said voltage to said valve unit operation arrangement; determining a fourth point of time for a characteristic pressure increase due to said shifting to said closed state of said valve unit; determining a time interval between said first and said second point of time and another time interval between said third and fourth point of time; and providing the thus determined time intervals as a basis for said adaption control of said reduction agent dosing unit for obtaining an intended dosing period during a dosing cycle. ### Claim 9 (depends on 8) The system according to claim 8, said computer program code further comprising computer instructions to cause the one or more control units to perform the following operations: continuously determining a prevailing current applied for said valve unit operation arrangement; determining a fifth point of time for a characteristic current drop due to said shifting to said open state of said valve unit; and comparing the thus determined second point of time with said thus determined fifth point of time to decide whether said second point of time appears reliable. ### Claim 10 (depends on 8) The system according to claim 8, said computer program code further comprising computer instructions to cause the one or more control units to perform the following operations: continuously determining a prevailing current applied for said valve unit operation arrangement; determining a sixth point of time for a characteristic current increase due to said shifting to said closed state of said valve unit; and comparing the thus determined fourth point of time with said thus determined sixth point of time to decide whether said fourth point of time appears reliable. ### Claim 11 (depends on 8) The system according to claim 8, said computer program code further comprising computer instructions to cause the one or more control units to perform the following operations: storing said time intervals together with values for prevailing applied voltage, prevailing reducing agent temperature and prevailing pressure of said reducing agent, said values corresponding to a particular system working point. ### Claim 12 (depends on 11) The system according to claim 11, said computer program code further comprising computer instructions to cause the one or more control units to perform the following operations: for a number of different system working points, storing corresponding determined pairs of time intervals. ### Claim 13 (depends on 12) The system according to claim 12, said computer program code further comprising computer instructions to cause the one or more control units to perform the following operations: providing the thus stored system working point information for adapting control of said reduction agent dosing unit. ### Claim 14 (depends on 8) The system according to claim 8, said computer program code further comprising computer instructions to cause the one or more control units to perform the following operations: providing non pre-stored determined time intervals as a basis for consecutive adaption control of said reduction agent dosing unit for obtaining an intended dosing period during a dosing cycle. ### Claim 15 A vehicle comprising a system for adapting control of a reducing agent dosing unit in a reducing agent provision system for emission control of a combustion engine, said reducing agent provision system comprising a pump unit for pressurizing said reducing agent to be dosed, wherein said dosing unit comprising an electrically controlled valve unit arranged to be shifted between an opened state and a closed state, wherein said system comprises: one or more control units; and computer program code stored on a non-transitory computer-readable medium, said computer program code comprising computer instructions to cause the one or more control units to perform the following operations: continuously determining a prevailing pressure of said reducing agent in said reducing agent provision system downstream of said pump unit; initiating shifting said valve unit at a first point of time to said open state from said closed state by applying a voltage to a valve unit operation arrangement; determining a second point of time for a characteristic pressure drop due to said shifting to said open state of said valve unit; initiating shifting said valve unit at a third point of time to said closed state from said open state by turning off said voltage to said valve unit operation arrangement; determining a fourth point of time for a characteristic pressure increase due to said shifting to said closed state of said valve unit; determining a time interval between said first and said second point of time and another time interval between said third and fourth point of time; and providing the thus determined time intervals as a basis for said adaption control of said reduction agent dosing unit for obtaining an intended dosing period during a dosing cycle. ### Claim 16 (depends on 15) The vehicle according to claim 15, which vehicle is any from among a truck, a bus or a passenger car. ### Claim 17 A computer program product comprising computer program code stored on a non-transitory computer-readable medium, said computer program product used for adapting control of a reducing agent dosing unit in a reducing agent provision system for emission control of a combustion engine, said reducing agent provision system comprising a pump unit for pressurizing said reducing agent to be dosed, wherein said dosing unit comprising an electrically controlled valve unit arranged to be shifted between an opened state and a closed state, said computer program code comprising computer instructions to cause one or more control units to perform the following operations: continuously determining a prevailing pressure of said reducing agent in said reducing agent provision system downstream of said pump unit; initiating shifting said valve unit at a first point of time to said open state from said closed state by applying a voltage to a valve unit operation arrangement; determining a second point of time for a characteristic pressure drop due to said shifting to said open state of said valve unit; initiating shifting said valve unit at a third point of time to said closed state from said open state by turning off said voltage to said valve unit operation arrangement; determining a fourth point of time for a characteristic pressure increase due to said shifting to said closed state of said valve unit; determining a time interval between said first and said second point of time and another time interval between said third and fourth point of time; and providing the thus determined time intervals as a basis for said adaption control of said reduction agent dosing unit for obtaining an intended dosing period during a dosing cycle.