The commencement of a developing period of slip is detected by the fact that a time-differential value vs of a creep velocity Ns (a relative velocity between a peripheral velocity Nm of a driving wheel and a vehicle velocity Nt) exceeds a predetermined reference delta 1. The termination of the developing period is detected by the fact that a time-differential value vm of the peripheral velocity vm becomes equal to zero. During the developing period, a torque command Tp to a main motor controller is decreased by a re-adhesion control signal Tfd which is formed by the combination of a time-dependent component e1 and a slip-dependent component e2. After termination of the developing period, the torque command Tp is decreased with time at an appropriate time constant. According to the present invention, the arithmetic logic operation for control can be much simplified without any deterioration of a adhesion performance of an electric vehicle. |