Transient-state control method for a hybrid drive system for vehicles

A computer-implemented method of controlling a hybrid drive system including at least one electric machine and at least one diesel engine, wherein a static torque setpoint of the diesel engine is acquired, comprising:

• constructing a NOx emission model allowing estimation of the emissions of the diesel engine as a function of a torque of the diesel engine;
• calculating a dynamic NOx emission setpoint from the NOx emission model and from the static torque setpoint of the diesel engine, a NOx reduction factor parameter ξ being set, and the NOx emission setpoint NOxsp being calculated as a function of the NOx reduction factor ξ according to the equations:
• NO
• x
• sp
• =
• NO
• x
• s
• +
• Δ
• ⁢
• ⁢
• NO
• x
• ⁡
• (
• 1
• -
• ξ
• 100
• )
• wherein NOxs is a level of the NOx emissions under static conditions and ΔNOx is the NOx peak amplitude with respect to static conditions and
• ΔNOx=NOx−NOxs
• wherein NOx is the maximum dynamic peak value and NOxs is the NOx emission level under static conditions;
• determining a dynamic torque setpoint of the diesel engine from the NOx emission setpoint;
• determining a dynamic torque setpoint of the electric machine as a function of the dynamic torque setpoint of the diesel engine;
• and
• applying the dynamic torque setpoints to the drive system.