DEVICE AND METHOD FOR CONTROLLING PRIME MOVER

An increase in angular acceleration alpha of a rotating shaft of a motor, which outputs a torque to a drive shaft linked to drive wheels, may cause a skid on the drive wheels. In response to detection of a skid, the control procedure of the invention sets a maximum torque Tmax according to a preset map representing a relation between the angular acceleration alpha and the maximum torque Tmax, and restricts an output torque level to the drive shaft. The map is set to decrease the maximum torque Tmax with an in crease in angular acceleration alpha . The restricted output torque level is restored at a zero cross timing of the angular acceleration alpha after a negative peak in the course of convergence of the skid. This arrangement makes the direction of the torque restored from the torque restriction identical with the direction of the angular acceleration, thus effectively reducing torsions of the drive shaft and thereby preventing potential torsional vibrations of the drive shaft.