US 6,298,718 B1 · Turbocharger compressor diagnostic system

Abstract

A system and method for detecting abnormal operation of a turbocharger compressor reads data from a plurality of sensors and first conducts a series of rationality tests on the sensor data. The tests determine whether the data generated by certain ones of the sensors is accurate or compromised. If a particular sensor fails its corresponding rationality test, an error signal is generated. On the other hand, if all sensor data passes the rationality tests, the compressor performance data is compared to a compressor operation map, and more particularly to surge and choke regions defined by boundary lines on the map. If certain compressor performance data falls into either the surge or choke region, an appropriate abnormal performance signal is generated. In certain embodiments of the invention, the sensor rationality tests are based on a predetermined second order polynomial relationship between two compressor operating parameter, such as mass air flow, boost pressure, turbo speed, etc. In another aspect, a third order polynomial relationship between mass air flow and compressor pressure ratio is used to diagnose an abnormal compressor condition.

Claims20

Dependent claims

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.

2 more elements

Dependencies are inferred from the claim text.

Turbocharger compressor diagnostic system

Life of this patent

Turbocharger compressor diagnostic system

Life of this patent

Abstract

Claims20