Numerical and Experimental Analysis of the Momentum and Heat Transfer in Exhaust Gas Sensors

Recursive parameter estimation of exhaust gas oxygen sensors with input-dependent time delay and linear parameters

“…In fact, the working principle and the positioning of the widerange oxygen sensor imply that its parameters and time delay show a distinctive dependency on the exhaust mass flow (Brück, 2010;Klett et al, 2005;Moser et al, 2013). Hence, the exhaust mass flow represents the operating point that has to be considered as an input to the sensor.…”

“…The design of the protection tube implies that the gas exchange inside the protection tube is a function of the gas flow conditions around the protection tube (Brück, 2010;Klett et al, 2005;Moser et al, 2013). Large exhaust mass flows imply a fast reaction of the sensor and vice versa.…”

“…According to Moser et al (2013), Brück (2010), Klett et al (2005) the sensor dynamics show a distinctive dependency on the exhaust mass flow. Furthermore, it is known from the literature (Moser et al, 2013) that the behavior of a wide-range oxygen sensor in the exhaust pipe of a diesel engine at a constant exhaust mass flow can be modeled accurately as a time-delayed first-order system.…”

“…The working principle and the positioning of these sensors in the exhaust pipe imply that they are subject to input-dependent time delays and inputdependent linear parameters as shown in Moser, Onder, and Guzzella (2013), Brück (2010), Klett et al (2005) and experimentally investigated in this paper. Due to drift, clogging, aging and manipulation the input-dependent time delays and linear parameters can be subject to variation during the lifetime of the sensor.…”

Using exhaust pressure pulsations to detect deteriorations of oxygen sensor dynamics

“…high values of N eng , induce a large pressure difference p(x). More details on the first effect can be found in [18]. The second effect that contributes to the gas exchange in the PT are the pressure oscillations p exh (t) in the exhaust pipe around the mean pressure levelp exh…”