TIRE STATE MONITORING SYSTEM AND TIRE STATE MONITORING METHOD

A tire state monitoring system comprises an acquisition device and a control device. The acquisition device is configured to repeatedly acquire a pressure and temperature inside a tire. The control device is configured to: calculate, based on ratios between the pressure and temperature acquired in a first period, a representative value of the ratios in the first period; and compare a ratio between the pressure and temperature acquired in a second period after the first period with the representative value, to determine whether the pressure inside the tire has dropped.