| 摘要 |
A double remote control loop contains a second lambda probe (S' lambda ) which measures the oxygen concentration in the exhaust gases downstream of the catalytic pot. A regulator (15) controls the richness calculated from the downstream probe and based on a second richness level (C' lambda ) optimal for treating pollutants to permanently control the first richness level (C lambda ) in the single loop. The spark and injection of the engine are electronically controlled and the engine has a set number of cylinders and a catalytic converter. A single remotely controlled loop contains a first lambda probe (S lambda ) to measure the oxygen concentration in the exhaust gases from the engine (10) upstream of the catalytic pot (11). The chip calculates the richness of the mixture supplied to the engine using the probe measurements. A regulator (13) controls the richness calculated from the probe upstream and based on a first richness level (C lambda ). This gives the correction (Tc) to be added to the standard injection time (ti) by an adding machine (14) to determine the fuel injection duration (Ti) required to obtain the desired air-fuel richness in the engine cylinders. The regulator in the single loop receives at its inlet the difference ( epsilon 1) between the voltage (U lambda ) from the single loop probe, giving the air-fuel mixture richness upstream of the catalyst, and a level (C lambda ) determined by the regulator of the double loop from the difference ( epsilon 2) between the voltage (U' lambda ) from the double loop probe (S' lambda ), giving the air-fuel mixture richness downstream of the catalyst and a voltage level (C' lambda ) in the double loop corresponding to an optimal richness for treating nitrous oxides by the catalytic pot. A fixed voltage is added to the difference ( epsilon 1) in an adding circuit (16) to compensate for the static error proportional to the response time of the remote control system. A circuit (17) limiting the amplitude of the voltage to between a minimum and maximum value is connected at the inlet to the adding circuit (16) in the single loop. The voltage level (C' lambda ) in the double loop and the proportional and integral parameters of the regulators (13, 15) are adjusted as a function of the operating conditions of the engine and the vehicle. The regulators in the two loops are proportional integral (PI), derived proportional integral (DPI) or Smith predictor type.
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