Dynamic indicated torque prediction for turbocharged diesel engine based on combustion model

For accurately estimating the indicated torque of turbocharged diesel engine under transient operation, a new on-line prediction algorithm based on the 0-D combustion model was proposed. Firstly, the factors that affect transient indicated torque were analyzed through transient combustion characteristics. The experiment under steady and transient operation was conducted to obtain the heat release and state parameters. These data were subsequently used to train the neural networks to get the function of state parameters and heat release. The combustion model can predict heat release in both steady and transient states. The in-cylinder thermodynamic process is numerically calculated using the combustion model. To implement its online, the numerical algorithm was simplified and shows good real-time capability. Due to the decoupling of the strong nonlinear correlation between state parameters and indicated torque, the algorithm possesses high predictability. Bench test result shows the mean average relative error (MARE) of torque estimation is 2% in the steady state, and 5% in transient state.