METHOD (VERSIONS) AND SYSTEM FOR SELF-DIAGNOSIS OF NITROGEN OXIDES SENSOR Russian patent published in 2020 - IPC F01N11/00 

FIELD: control and measuring equipment; transport machine building.

SUBSTANCE: invention relates to methods and systems for reducing toxicity of exhaust gases in exhaust systems of vehicles. System for detecting degradation of characteristics of a nitrogen oxide sensor (NO) based on results of self-diagnostic (SD) inspection of NO sensor comprises a first NO sensor located in an exhaust system of an engine upstream of selective-reduction catalytic (SRC) neutraliser; a second sensor NO located downstream of the SRC neutraliser; a first temperature sensor located on the same axis with the first NO sensor relative to the exhaust gas flow in the exhaust system, for measuring the temperature of the exhaust gases flowing past the first NO sensor; a second temperature sensor located on the same axis with the second NO sensor relative to the exhaust gas flow in the exhaust system, for measuring the temperature of the exhaust gases flowing past the second NO sensor; controller with possibility of SPL bus communication with first and second NO sensors, wherein the controller comprises computer-readable instructions for: determining the deterioration of the first NO sensor and/or the second NO sensor characteristics, based on the readings from the first NO sensor and the first temperature sensor and the second NO sensor and the second temperature sensor, respectively, wherein said readings are generated during self-test after ignition of vehicle; and generating a warning on the vehicle screen in response to determining degradation of characteristics of the first and/or second sensor NO.

EFFECT: high sensitivity of determining the presence or absence of deterioration of characteristics of the sensor NO and high efficiency of the system for reducing NO emissions.

20 cl, 7 dwg