TRANSMITTER OF TIRE AIR PRESSURE SIGNAL AND TIRE POSITION DETERMINATION SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a transmitter of tire air pressure signals and a tire position determination system that can precisely detect positions in a tire rotation direction.SOLUTION: A transmitter 4 of tire air pressure signals comprises a digital filter 12 that filters a gravity detection signal Sgr outputted from a gravity detector 9. The digital filter 12 removes a signal component related with bad road running or a centrifugal force. A transmitter position determination part 20 determines a position in the tire rotation direction of the transmitter 4 of tire air pressure signals. A transmission control part 21 makes a transmission antenna 10 transmit auto location radio waves when the transmitter 4 of tire air pressure signals takes a specified position (e.g. peak position).