A vehicle theft protecting system includes a vehicle-onboard device mounted on a vehicle and a management station installed at a predetermined location, each including narrow area wireless communication unit capable of communication with encryption in a range of a predetermined distance to perform regular mutual communication to monitor each other’s condition. The method may also include receiving computed RF feedback, correlated with one or more processing states of the object; and monitoring the computed RF feedback during the processing to detect the one or more processing states of the object. A first relief surface adjacent the primary cutting edge has a first relief angle and a second relief adjacent the two wipers has a second relief angle that is greater than the first relief angle.