Inferring temperature of a heated exhaust gas oxygen sensor
First Claim
Patent Images
1. A method of controlling the operation of an internal combustion engine producing exhaust gas wherein controlling the air to fuel ratio includes the steps of:
- establishing an exhaust gas temperature at startup to a function of time since the engine was turned off;
subtracting a temperature offset from the exhaust gas temperature;
calculating a time constant that describes the speed at which an exhaust gas oxygen (EGO) sensor heats up as a function of air mass; and
using a rolling average to predict the EGO sensor temperature as a function of said exhaust gas temperature at start-up, said temperature and said time constant.
2 Assignments
0 Petitions
Accused Products
Abstract
A method of inferring the temperature of a heated exhaust gas oxygen sensor is used in the control of the operation of an electronic engine control for an internal combustion engine.
12 Citations
19 Claims
-
1. A method of controlling the operation of an internal combustion engine producing exhaust gas wherein controlling the air to fuel ratio includes the steps of:
-
establishing an exhaust gas temperature at startup to a function of time since the engine was turned off; subtracting a temperature offset from the exhaust gas temperature; calculating a time constant that describes the speed at which an exhaust gas oxygen (EGO) sensor heats up as a function of air mass; and using a rolling average to predict the EGO sensor temperature as a function of said exhaust gas temperature at start-up, said temperature and said time constant. - View Dependent Claims (2, 3, 4)
-
-
5. A method of determining the temperature of an exhaust gas oxygen (EGO) sensor used with a heater in an electronic engine control for an engine having an exhaust utilizing a background loop including:
-
determining whether the temperatures of the EGO sensors have been initialized; if the temperatures of the EGO sensors have not been initialized, initializing the temperature of the EGO sensors; inferring the temperature of the EGO sensor by calculating a rolling average of the steady state temperature of the EGO sensor and a time constant which describes the speed at which the heat from the exhaust of a running engine will change the temperature of the tip of the EGO sensor; determining whether the EGO sensor heater is on; if the EGO sensor heater is not on, setting the amount of heat applied to the sensor to zero; if the EGO sensor heater is on, finding the amount of applied heat by using a linear equation versus the EGO sensor temperature when the EGO sensor is in an unheated state; determining the speed at which the EGO sensor tip will heat up using a calibrateable constant; inferring the temperature of the EGO sensor in the unheated state by calculating the rolling average of the amount of heat that was applied to the tip of the EGO sensor and the time constant which describes the speed at which the EGO sensor will heat in the exhaust of a running engine; inferring the temperature of the EGO sensor by adding the temperature increase due to the applied heat to the temperature of the EGO sensor in the unheated state; and updating the stored value of the temperature of the EGO sensor in the unheated state from the previous background loop with the temperature of the unheated EGO sensor from the current background loop. - View Dependent Claims (6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
-
Specification