METHOD FOR CONTROLLING A VEHICLE HYBRID PROPULSION SYSTEM DURING TRANSIENT BEHAVIOUR

The method involves constructing a nitrogen oxide (NOx) emission model for estimation of emissions of a diesel engine as a function of torque of the diesel engine. A dynamic NOx emission setpoint is calculated from the emission model and a static torque setpoint of the engine. A dynamic torque setpoint of the engine is determined from the NOx emission setpoint. A dynamic torque setpoint of an electric machine is determined as a function of the dynamic torque setpoint of the engine. The dynamic torque setpoints are applied to a hybrid drive system. Independent claims are also included for the following: (1) a computer product having a set of instructions for a method for controlling a hybrid drive system (2) a hybrid drive system for a vehicle.