Patent ID: 6223735
Filing Date: 2001-05-01
Classification: G01N

Abstract:
Method for controlling an oxygen linear sensor arrangement including an oxygen linear sensor, located along an exhaust duct of an internal combustion engine, the sensor having at least a first electrolytic cell, a second electrolytic cell and a diffusion chamber receiving an exhaust gas flowing in the exhaust duct, the sensor supplying a first signal correlated to a difference between a composition of the exhaust gas within the diffusion chamber and a reference stoichiometric composition, the method comprising the steps of:sensing the first signal;supplying a controlled current, as a function of the first signal, to the sensor to activate oxygen ions draining between the diffusion chamber, the first electrolytic cell and the second electrolytic cell, in a manner to vary the composition of the gas within the diffusion chamber for canceling the difference between the composition of the exhaust gas within the diffusion chamber and the reference stoichiometric composition;using the controlled current to generate a first output signal (Vout.sub.m) correlated to an oxygen content of the exhaust gas;supplying a controlled gas to the sensor, the controlled gas having a controlled composition;recording a behavior of the first output signal (Vout.sub.m) during an interval of time in which the sensor is surrounded by the controlled gas;averaging the first output signal (Vout.sub.m) during the time interval to obtain a mean value;calculating a correction parameter on the basis of the mean value and of a nominal value representing a theoretical value of the first output signal (Vout.sub.m) in the presence of the controlled gas; andcorrecting the first output signal (Vout.sub.m) by using the correction parameter to produce a corrected output signal proportional to the exhaust gas oxygen content.