| 摘要 |
<p>The first phase for the second catalyst is offset by a preset time relative to the other catalyst. The two upstream and the two downstream lambda probes are connected so that, for a number of cycles, the upstream probe for the second catalyst modifies the exhaust gases upstream of the upstream probe of the first catalyst, and the downstream probe of the second catalyst modifies the exhaust gases upstream of the downstream probe of the first catalyst. - A post-treatment device for the exhaust gas is placed in the exhaust pipe of the engine, containing at least one catalyst (114, 214), a first lambda probe (112, 212) upstream of the catalyst and a second lambda probe (116, 216) downstream of the catalyst. In a first phase, the lambda value is controlled actively upstream of the catalyst to be a value less than 1 to determine the oxygen accumulation capacity of the catalyst until the oxygen in the catalyst is completely evacuated. In a second phase the lambda value upstream of the catalyst is actively controlled to be a value greater than 1 until the catalyst is completely loaded with oxygen. The oxygen accumulation capacity of the catalyst is determined using an oxygen balance. The post-treatment device contains at least two catalysts in parallel in the exhaust gas flow, with respectively first and second lambda probes upstream and downstream of the two catalysts.</p> |
