Advanced Torque Estimation and Control Algorithm of Diesel Engines

Electronic diesel engine control is one of the most important research subjects on automotive engines. This paper presents the research results achieved by the authors on the issue of mean torque closed-loop feedback control of diesel engines. To achieve mean torque feedback, momentary flywheel speed is processed and a new symbolic index is presented in this paper. The relationship between the symbolic index and mean effective torque is investigated. On the natural aspiration diesel engine, mean effective torque is proportional to the index when engine speed does not change. On the turbo-charged diesel engine, as the variation of the intake air mass, the compression pressure changes at different mean torque. Hence the relationship between the index and mean torque is not linear. The boost pressure sensor is used to compensate the influence of the compression pressure. Then the mean torque is identified by the index and the closed-loop control system is built. The experimental results verify the feasibility, flexibility and accuracy of the mean torque feedback control system of diesel engines.