over a broad range the rotational speed of the slave drive is set such that it runs synchronously with the rotational speed of the master drive a correction value being added however this value is determined as a function of the torques of the slave and master drive a first simple implementation is thus a controller provided in the slave drive which receives information about the torque or motor current from the master drive in particular via a communication medium such as for example a field bus such as a can bus an interbus or profibus devicenet or ethernet or a wireless data transmission system such as bluetooth or the like the controller then determines the setpoint rotational speed of the slave in the following manner where n_slave_setpoint is the setpoint rotational speed of the slave drive k is a factor that produces identical revolution speeds if there is no system deviation that is when the bracketed expression is zero n_master_actual is the actual rotational speed of the slave drive b is the proportional share of the p controller where i_slave_actual corresponds to the actual motor current of the slave drive that is to the torque of the slave drive c is the weighting of the setpoint torque ratio of the two drives i_master_actual is the actual motor current of the master drive thus corresponding to the torque of the master drive the center of gravity p of the vehicle is at a constant height h 2 in additional exemplary embodiments according to the present invention instead of the proportional element or in addition to the latter further elements such integrating elements or differential elements are added precontrols may be.