基于排气温度动态模型的在线观测器研究

As one of the most core components for diesel emission control and monitoring, the exhaust temperature sensor is widely used for electronic control of diesel engine. In order to satisfy the needs of on-line fault diagnosis and fault-tolerant control of rear temperature sensors for the two-stage turbocharging system, an engine is used to establish a dynamic model of exhaust gas temperature which reflects the combustion conditions of cylinder, and the air-fuel ratio, engine speed, and altitude are used to calibrate the exhaust gas temperature influencing factors virtually. An on-line exhaust gas temperature observer including first-order lagging links was constructed, and the effectivenesses of observer at steady state and dynamic situation were verified in typical operating conditions. The result shows that the on-line observer can be used for on-line temperature estimation, which has a high calculation accuracy and dynamic response performance with the steady state accuracy of ±3%, the dynamic accuracy of ±8%, and the response time of less than 3 s.