US 6,218,936 B1 · Tire air pressure monitoring system

Abstract

A tire air pressure monitoring system includes transmitters and a receiver. The transmitters wirelessly transmit data regarding the inner pressure of tires and the receiver receives the data from the transmitters. Each transmitter has its own ID code and includes a pressure sensor for measuring the inner pressure of the corresponding tire. Every time each pressure sensor measures the pressure, the corresponding transmitter generates a time interval by performing a pseudorandom number calculation based on the measured pressure and its ID code. The pressure sensor will measure the pressure each time the obtained time interval elapses. When each pressure sensor measures the pressure for a predetermined number of times, the corresponding transmitter wirelessly transmits data. This system prevents the transmitters from interfacing with one another and facilitates the manufacture of the transmitters.

Claims15

Dependent claims

A transmitter for wirelessly transmitting data regarding the inner pressure of a tire, comprising:

a pressure sensor for measuring the inner pressure of the tire;
transmitting means for wirelessly transmitting data including the measured pressure;
first commanding means for commanding the pressure sensor to measure the pressure, wherein, every time the pressure sensor measures the pressure, the first commanding means obtains a time interval based on a pseudorandom number calculation using at least data representing the pressure measured by the pressure sensor, and wherein the first commanding means commands the pressure sensor to measure the pressure after the computed time interval has elapsed;
and
second commanding means for commanding the transmitting means to wirelessly transmit the data every time the pressure sensor measures the pressure for predetermined number of times.

2 more elements

A tire air pressure monitoring apparatus having a plurality of transmitters for wirelessly transmitting data regarding the inner pressures of respective vehicle tires and a receiver for receiving the data wirelessly transmitted by the transmitters, wherein each transmitter has its own ID code, and wherein the data transmitted from each transmitter represents at least the measured pressure and the ID code, the apparatus comprising:

a memory located in the receiver, wherein the memory includes a registration ID table for registering the ID codes of the transmitters and reception count values, each reception count value corresponding to one of the ID codes, wherein each reception count value is used for judging whether the corresponding ID code registered in the registration ID table is valid;
an initializing switch connected to the receiver, wherein the initializing switch is manipulated for initially registering the ID codes, which are contained in data received by the receiver, in the registration ID table;
and
a controller located in the receiver, wherein, when a registration based on the manipulation of the initializing switch is performed, the controller sets each reception count value, which corresponds to one of the initially registered ID codes, to predetermined maximum count value.

1 more element

Dependencies are inferred from the claim text.

Tire air pressure monitoring system

Life of this patent

Tire air pressure monitoring system

Life of this patent

Abstract

Claims15