MOTION DETERMINATION DEVICE AND MOTION DETERMINATION METHOD

Provided are a motion determination device and a motion determination method capable of correctly determining a kicking motion performed by a user about to open or close a rear gate or the like of a vehicle. The motion determination device includes two or more sensors respectively mounted on positions which are spaced apart from each other and have a relative vertical relationship in a vehicle, and detecting approach of an object, and a determination device. The determination device determines that the predetermined kicking motion has been performed, when each of the detection values shows a pattern in which the detection value becomes equal to or more than a first threshold value and then equal to or more than a second threshold value greater than the first threshold value, and thereafter becomes less than the second threshold value and then less than the first threshold value, a time until each of the detection values becomes less than the first threshold value after it becomes equal to or more than the first threshold value is within a predetermined time, and a ratio of a maximum value of the detection value by a first sensor among the two or more sensors and a maximum value of the detection value by a second sensor different from the first sensor among the two or more sensors is within a predetermined range.