Claims Analysis
Total Claims: 22
Claim 1
Independent Claim
186 words
For a turbocharged engine having an engine control module operable to control engine operation in response to data received from a plurality of sensors, a method for diagnosing abnormal turbocharger compressor operation, comprising the steps of: storing, in a memory, data corresponding to a compressor operation map defining a region of normal compressor operation between a surge line and a choke line, a surge region outside the surge line and a choke region outside the choke line, the surge line and choke line being defined according to a predetermined relationship between a first and a second compressor operating parameter; conducting a rationality test on the data received from selected ones of the plurality of sensors and generating an error signal if one or more of the selected sensors fails the rationality test; if all sensors pass the rationality test, generating actual values for the first and second operating parameters from the sensor data; and comparing the actual values with the compressor operation map and generating an abnormal operation signal if the actual values fall outside a predetermined relationship with the choke line or the surge line.
Claim 2
Dependent Claim
186 words
For a turbocharged engine having an engine control module operable to control engine operation in response to data received from a plurality of sensors, a method for diagnosing abnormal turbocharger compressor operation, comprising the steps of: storing, in a memory, data corresponding to a compressor operation map defining a region of normal compressor operation between a surge line and a choke line, a surge region outside the surge line and a choke region outside the choke line, the surge line and choke line being defined according to a predetermined relationship between a first and a second compressor operating parameter; conducting a rationality test on the data received from selected ones of the plurality of sensors and generating an error signal if one or more of the selected sensors fails the rationality test; if all sensors pass the rationality test, generating actual values for the first and second operating parameters from the sensor data; and comparing the actual values with the compressor operation map and generating an abnormal operation signal if the actual values fall outside a predetermined relationship with the choke line or the surge line.
Claim 3
Dependent Claim
27 words
The method according to claim 1 , wherein said step of conducting a rationality test includes conducting the tests in a predetermined order among the selected sensors.
Claim 4
Dependent Claim
32 words
The method according to claim 2 , wherein the rationality test for successive sensors in the predetermined order utilize data from one or more of the prior sensors in the predetermined order.
Claim 5
Dependent Claim
36 words
The method according to claim 3 , wherein the selected ones of the sensors include, in said predetermined order, sensors for boost pressure, ambient pressure, turbo speed and mass air flow at the engine air intake.
Claim 6
Dependent Claim
26 words
The method according to claim 4 , wherein the rationality test for the turbo speed sensor utilizes data from the boost pressure and ambient pressure sensors.
Claim 7
Dependent Claim
27 words
The method according to claim 4 , wherein the rationality test for the mass air flow sensor utilizes data from the boost pressure and ambient pressure sensors.
Claim 8
Dependent Claim
105 words
The method according to claim 1 , wherein the rationality test includes: storing, in the memory, data corresponding to a sensor rationality map defining a region of acceptable sensor performance between an upper boundary line and a lower boundary line, the upper and lower boundary lines being defined according to a predetermined relationship between a third and a fourth compressor operating parameter; generating, from the sensor data, actual values for the third and fourth compressor operating parameters; and comparing the actual values with the sensor rationality map and generating a failure signal if the actual values fall outside either the upper or lower boundary line.
Claim 9
Dependent Claim
29 words
The method according to claim 7 , wherein the upper and lower boundary lines are defined by a second order polynomial relationship between the third and fourth operating parameters.
Claim 10
Dependent Claim
76 words
The method according to claim 8 , wherein: a selected one of the plurality of sensors is the turbo speed sensor; the third compressor operating parameter is the compressor pressure ratio (PR); the fourth compressor operating parameter is the turbo speed (N c ); and the second order polynomial has the form; PR=c i N c 2 +c j N c +c k , where c i , c j and c k are predetermined constants.
Claim 11
Dependent Claim
77 words
The method according to claim 8 , wherein: a selected one of the plurality of sensors is the mass air flow sensor; the third compressor operating parameter is the turbo speed (N c ); the fourth compressor operating parameter is the mass air flow (MAF); and the second order polynomial has the form; MAF=c i N c 2 +c j N c +c k , where c i , c j and c k are predetermined constants.
Claim 12
Dependent Claim
44 words
The method according to claim 10 , wherein the third compressor operating parameter is a corrected turbo speed in which the actual turbo speed value from the turbo speed sensor is normalized as a function of the sensor value from the ambient temperature sensor.
Claim 13
Dependent Claim
76 words
The method according to claim 7 , wherein: the upper and lower boundary lines are defined by a predetermined relationship between the third and fourth operating parameters; and the step of comparing the actual values with the sensor rationality map includes; applying the actual value for the third operating parameter to the predetermined relationship to obtain a calculated value for the fourth operating parameter; and comparing the actual and calculated values for the fourth operating parameter.
Claim 14
Dependent Claim
30 words
The method according to claim 1 , wherein the surge line and the choke line are defined by a third order polynomial relationship between the first and second operating parameters.
Claim 15
Dependent Claim
70 words
The method according to claim 13 , wherein: the first compressor operating parameter is the mass air flow (MAF) at the engine air intake; the second compressor operating parameter is the compressor pressure ratio (PR); and the third order polynomial relationship has the form; MAF=c i PR 3 +c j PR 2 +c k PR+c l , where c i ,c j ,c k and c l are predetermined constants.
Claim 16
Dependent Claim
103 words
The method according to claim 1 , wherein: the first compressor operating parameter is the mass air flow (MAF) at the engine air intake; the second compressor operating parameter is the compressor pressure ratio (PR); and the step of comparing the actual values with the compressor operation map includes; obtaining an actual value for the mass air flow from the sensor data; calculating an actual compressor pressure ratio from the sensor data; applying the actual compressor ratio to the predetermined relationship to obtain a calculated value for the mass air flow; and comparing the actual and calculated values for the mass air flow.
Claim 17
Dependent Claim
52 words
The method according to claim 15 , wherein the step of comparing the actual values with the compressor operation map further includes detecting a surge or choke trend by comparing the absolute value of the difference between the actual and calculated values for the mass air flow to a predetermined limit value.
Claim 18
Dependent Claim
66 words
The method according to claim 15 , wherein the step of comparing the actual values with the compressor operation map further includes detecting a surge or choke cycle by comparing the difference between the actual and calculated values for the mass air flow at a first time with the difference between the actual and calculated values for the mass air flow at a second different time.
Claim 19
Dependent Claim
48 words
The method according to claim 17 , wherein the step of comparing the actual values with the compressor operation map includes generating an abnormal operation signal if the sign of the difference at the first time is different from the sign of the difference at the second time.
Claim 20
Dependent Claim
161 words
For a turbocharged engine having an engine control module operable to control engine operation in response to data received from a plurality of sensors, a method for diagnosing abnormal turbocharger compressor operation, comprising the steps of: storing, in a memory, data corresponding to a compressor operation map defining a region of normal compressor operation between a surge line and a choke line, a surge region outside the surge line and a choke region outside the choke line, the surge line and choke line being defined according to a predetermined relationship between a first and a second compressor operating parameter; generating actual values for the first and second operating parameters from the sensor data; and applying the actual value for the first operating parameter to the predetermined relationship to obtain a calculated value for the second operating parameter; comparing the actual and calculated values for the second operating parameter and generating an abnormal operation signal if the comparison exceeds a predetermined limit.
Claim 21
Dependent Claim
161 words
For a turbocharged engine having an engine control module operable to control engine operation in response to data received from a plurality of sensors, a method for diagnosing abnormal turbocharger compressor operation, comprising the steps of: storing, in a memory, data corresponding to a compressor operation map defining a region of normal compressor operation between a surge line and a choke line, a surge region outside the surge line and a choke region outside the choke line, the surge line and choke line being defined according to a predetermined relationship between a first and a second compressor operating parameter; generating actual values for the first and second operating parameters from the sensor data; and applying the actual value for the first operating parameter to the predetermined relationship to obtain a calculated value for the second operating parameter; comparing the actual and calculated values for the second operating parameter and generating an abnormal operation signal if the comparison exceeds a predetermined limit.
Claim 22
Dependent Claim
37 words
The method according to claim 19 , wherein the step of comparing the actual and calculated values includes comparing the difference between the actual and calculated values for the second operating parameter to a predetermined limit value.