Method for compensating rotational irregularities of an internal combustion engine of a drive train of a hybrid vehicle

In a drive train of a hybrid vehicle which includes an electric motor and an internal combustion engine, the electric motor being connected to drive wheels by a drive shaft and to the internal combustion engine by an engine shaft, wherein a drive controller controls the electric motor by applying a controlling torque (Tstell) thereto, a method of compensating for rotational irregularities introduced into the drive train by the internal combustion engine which comprises:

• determining a shaft torque (TW(n)) of the engine shaft of a current work cycle (n) of the internal combustion engine, feeding the shaft torque (TW) to a compensation controller in which is stored a shaft torque (TW(n−1)) of a previous work cycle (n−1), calculating a compensated shaft torque (Tcomp) from the shaft torque (TW(n)) of the current work cycle (n), the shaft torque (TW(n−1)) of the previous work cycle (n−1), and a shaft torque of a previous work cycle (n−1) shifted by a system delay, and adjusting a predefined target torque (Tsoll) with the compensated shaft torque (Tcomp) to provide the controlling torque (Tstell) and thereby compensate for the rotational irregularities of the internal combustion engine by using the electric motor.