To provide a method for preventing incorrect judgment of a slip of a vehicle.

A method for judging the slip includes a step of comparing wheel speeds of drive wheels 28a, 28b detected directly by wheel speed sensors 34a, 34b with wheel speeds of drive wheels 28a, 28b, calculated based on the rotary position θr of a drive shaft 26 (the rotary shaft of a motor 22) detected by an accurate resolver 32 used to control the drive of the motor 22; and a step of monitoring detecting errors of the wheel speed sensors 34a, 34b. The method further includes a step of judging whether deviations of the wheel speeds of non-drive wheels 29a, 29b detected by the wheel speed sensors 36a, 36b from wheel speeds of the drive wheels 28a, 28b based on the resolver 32 are threshold value or more or not when both the wheel speeds are not in an allowing range, and detecting errors of the wheel speed sensors 34a, 34b are large; and a step of judging whether the slip occurs or not. Thus, the incorrect judgment of the slip can be prevented even when the detecting errors of the wheel speed sensors 34a, 34b are relatively large.

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