#$%^&*AU2013202167B220150129.pdf#####MOTION STABILIZER FOR TRACTOR ABSTRACT In a pendular motion determination unit (100) of a motion stabilizer (SA) for a tractor (TR), a parameter computation unit (120) computes a determination parameter PA indicative of a quantity of change in an actual yaw rate Y, a threshold value setting unit (140) computes a threshold value PAth for the parameter PA, and a determination unit (150) determines that a pendular motion caused by swaying motion of a trailer (TL) is imparted, if the parameter PA is greater than the threshold value PAth. Based upon at least one of a value related to the actual yaw rate Y and a value related to the standard yaw rate Ys, an evaluation value computation unit (130) computes a steering-back maneuver evaluation value TS (indicative of a possibility of making periodical steering-back maneuvers), based upon which at least one of the threshold value PAth and the parameter PA is changed.
