Control systems and methods for estimating engine coolant heat loss
View Patent ↗A control system for an engine includes an air calculation module that determines, based on a plurality of first coolant temperatures sensed during a period of engine operation, a first cumulative mass of intake air combusted by the engine during the period that corresponds to an estimated amount of heat dissipated by a cooling system of the engine during the period, and that determines, based on the first cumulative mass, a second cumulative mass of intake air of the engine that is required to raise a temperature of the engine from an initial temperature at a start of the period to a target temperature. The control system further includes a control module that selectively adjusts one of a diagnostic condition and an operating condition of the engine based on the second cumulative mass. A related method for controlling an engine is also provided.
1. A control system for an engine comprising:
an air calculation module that determines, based on a plurality of first coolant temperatures sensed during a period of engine operation, a first cumulative mass of intake air combusted by said engine during said period that corresponds to an estimated amount of heat dissipated by a cooling system of said engine during said period, and that determines, based on said first cumulative mass, a second cumulative mass of intake air of said engine that is required to raise a temperature of said engine from an initial temperature at a start of said period to a target temperature; and
a control module that selectively adjusts one of a diagnostic condition and an operating condition of said engine based on said second cumulative mass.
2. The control system of claim 1 , wherein said control module selectively adjusts said one of said diagnostic condition and said operating condition based on a comparison of said target temperature and a second coolant temperature sensed when a total cumulative mass of intake air combusted by said engine is greater than or equal to said second cumulative mass.
3. The control system of claim 2 , wherein said diagnostic condition is a diagnostic result that indicates one of a stuck thermostat and a skewed coolant temperature sensor output when said second coolant temperature is less than said target temperature.
4. The control system of claim 2 , wherein said operating condition is an estimated engine temperature, and wherein said control module adjusts said estimated engine temperature based on a default coolant temperature estimate when said second coolant temperature is less than said target temperature.
5. The control system of claim 1 , wherein said first cumulative mass is determined based on a first difference between an average of said plurality of first coolant temperatures and an estimated ambient temperature.
6. The control system of claim 5 , wherein said first cumulative mass is further determined based on said period.
7. The control system of claim 1 , wherein said second cumulative mass is further determined based on a second difference between said target temperature and said initial temperature.
8. A method for controlling an engine comprising:
determining, based on a plurality of first coolant temperatures sensed during a period of engine operation, a first cumulative mass of intake air combusted by said engine during said period that corresponds to an estimated amount of heat dissipated by a cooling system of said engine during said period;
determining, based on said first cumulative mass, a second cumulative mass of intake air of said engine that is required to raise a temperature of said engine from an initial temperature at a start of said period to a target temperature; and
selectively adjusting one of a diagnostic condition and an operating condition of said engine based on said second cumulative mass.
9. The method of claim 8 , wherein said selectively adjusting includes selectively adjusting one of said diagnostic condition and said operating condition based on a comparison of said target temperature and a second coolant temperature sensed when a total cumulative mass of intake air combusted by said engine is greater than or equal to said second cumulative mass.
10. The method of claim 9 , wherein said diagnostic condition is a diagnostic result and said selectively adjusting includes adjusting said diagnostic result to indicate one of a stuck thermostat and a skewed coolant temperature sensor output when said second coolant temperature is less than said target temperature.
11. The method of claim 9 , wherein said operating condition is an estimated engine temperature, and wherein said selectively adjusting includes adjusting said estimated engine temperature based on a default coolant temperature estimate when said second coolant temperature is less than said target temperature.
12. The method of claim 8 , wherein said determining said first cumulative mass includes determining said first cumulative mass based on a first difference between an average of said plurality of first coolant temperatures and an estimated ambient temperature.
13. The method of claim 12 , wherein said determining said first cumulative mass further includes determining said first cumulative mass based on said period.
14. The method of claim 8 , wherein said determining said second cumulative mass further includes determining said second cumulative mass based on a second difference between said target temperature and said initial temperature.