System and a method for adapting control of a reducing agent dosing unit
AssigneeScania CV AB
InventorsKurt Källkvist, Emanuel Remmo, Joakim Sommansson
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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.
Claims17
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.
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.
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.
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.
Dependencies are inferred from the claim text.