Method for controlling a hybrid drive which drives a vehicle

Method for controlling a hybrid drive that drives a vehicle, the hybrid drive including an internal combustion engine and at least one electric motor which can be driven via an electrical energy source, the method comprising the steps:

• switching the electric motor over to a generator mode when a present requirement to generate electric energy is present;
• operating the internal combustion engine substantially at a torque corresponding to ideal operation of the internal combustion engine with respect to at least one of efficiency and exhaust gas behavior when the internal combustion engine is in operating ranges in which an amount of torque to be output by the internal combustion engine for overcoming instantaneous tractive resistances lies below a torque corresponding to the ideal operation of the internal combustion engine;
• and
• using a differential torque between the torque corresponding to the ideal operation and the torque to be output by the internal combustion engine for overcoming the instantaneous tractive resistances to drive the electric motor operated as a generator;
• wherein the internal combustion engine is a diesel engine which is coupled to a soot filter via an exhaust gas line, and further comprising the step of controlling the amount of torque taken up by the electric motor operating in the generator mode such that, as a function of operating parameters, exhaust gas temperatures are reached which causes automatic burning off of the soot filter.