SMART TIRE PRESSURE SENSOR, SMART TIRE PRESSURE MONITORING SYSTEM USING SAME

A smart tire pressure monitoring system includes a plurality of smart tire pressure sensors respectively installed in one respective tire of a vehicle for communication with an electronic control unit in the vehicle through a wireless communication protocol. Each smart tire pressure sensor includes a LF receiver for receiving a low frequency communication signal from the electronic control unit, an encoding identification unit for recognizing the low frequency communication signal and fetching and modulating a corresponding ID code, and a RF transmitter for transmitting the modulated ID code to the electronic control unit to establish communication.

DETAILED DESCRIPTION OF THE INVENTION

Prior to reading the description of a preferred embodiment provided hereinafter for illustrating the concept of the present invention, it is to be understood that the components of the embodiment shown in the accompanying drawings are depicted for the sake of easy explanation and need not to be made to exact scale.

Referring toFIGS. 1-3, a smart tire pressure monitoring system in accordance with the present invention is shown installed in a vehicle1. In this embodiment, the vehicle1is a car having four tires2. The smart tire pressure monitoring system comprises a smart tire pressure sensor100installed in each tire2, an electronic control unit4mounted in the vehicle1at a selected location (for example, the dashboard), a LF antenna3mounted in the vehicle1corresponding to one respective tire2and electrically connected to the electronic control unit4, and a plurality of RF receiver5mounted in the vehicle1and electrically connected to the electronic control unit4.

Each smart tire pressure sensor100comprises a housing10, an air valve20mounted at one side of the housing10, and a microcontroller11, a pressure sensor12, an accelerometer sensor13, a temperature sensor14, a LF receiver15, a RF transmitter16, a battery unit17and an encoding identification unit18mounted within the housing10.

The pressure sensor12is electrically connected to the microcontroller11and adapted to detect the tire pressure value of the respective tire2. The accelerometer sensor13is electrically connected to the microcontroller11and adapted to detect the acceleration value of the respective tire2. The temperature sensor14is electrically connected to the microcontroller11and adapted to detect the temperature value of the respective tire2. The battery unit17and the encoding identification unit18are respectively electrically connected to the microcontroller11.

The LF receiver15is electrically connected to the microcontroller11and adapted to receive a low frequency communication signal from one respective LF antenna3to wake up the respective smart tire pressure sensor100. Upon receipt of a low frequency communication signal from the respective LF antenna3, the LF receiver15converts the signal into an induction voltage to wake up the microcontroller11. The low frequency in this embodiment is of 125 KHz. Further, the LF antennas3can be independent devices outside the vehicle1adapted for waking up the smart tire pressure sensors100.

The encoding identification unit18has built therein a plurality of D codes, and is electrically connected to the microcontroller11. After having been woken up by a low frequency communication signal, the microcontroller11fetches and modulates the corresponding ID code from the encoding identification unit18, and then transmits the modulated ID code to the electronic control unit4in the vehicle1via the RF transmitter16. Upon receipt of the ID code, the electronic control unit4establishes communication with the respective smart tire pressure sensor100to obtain the detected tire pressure, temperature and speed data of the respective tire2from the respective smart tire pressure sensor100.

Further, if the accelerometer sensor13detects an acceleration value of the respective tire2(i.e., the vehicle1starts to move) during operation of the RF transmitter16of each smart tire pressure sensor100to transmit a modulated signal to the electronic control unit4, the encoding identification unit18immediately runs a locking procedure to stop working, preventing communication with other vehicles. Further, the acceleration value of the vehicle1can be, for example, 20 km/hour.

FIG. 4is a circuit block diagram of the encoding identification unit18in each smart tire pressure sensor100of the smart tire pressure monitoring system in accordance with the present invention. As illustrated, the encoding identification unit18comprises a microprocessor181, a data bank182, a decoder183, and an encoder184. When the LF receiver15receives a low frequency communication signal, the decoder183amplifies the signal and converts it into a digital ID code for enabling the microprocessor181to recognize its waveform and to fetch the corresponding ID code from the data bank182, for example, the ID code of A123 of the electronic control unit4. After fetched the ID code of A123 from the data bank182, the microprocessor181controls the encoder184to encode this ID code into a modulated signal and then controls the RF transmitter16to send out this modulated signal.

Hereinafter, we explain how each smart tire pressure sensor100and the electronic control unit4of the vehicle1to restart the matching procedure:

At first, each tire2and each respective smart tire pressure sensor100are properly installed in the vehicle1, and then the electronic control unit4is operated to transmit a low frequency communication signal through each LF antenna3to each smart tire pressure sensor100to wake up or trigger the microcontroller11of each smart tire pressure sensor100, enabling the encoding identification unit18of each smart tire pressure sensor100to fetch and modulate the corresponding ID code and then to transmit the modulated ID code through the respective RF transmitter16to the RF receiver5, and thus the electronic control unit4can establish communication with each smart tire pressure sensor100to automatically determine the location of each tire2after receipt of the respective ID code.

It is particularly worth mentioning that to avoid signal interference by other vehicles during matching, the encoding identification unit18of each smart tire pressure sensor100immediately enters a locking procedure to stop operation after establishment of communication with the electronic control unit4and after the accelerometer sensor13detected an acceleration value, prohibiting the respective smart ire pressure sensor100from establishing communication with the electronic control unit4of any other vehicle and avoiding losing contact with the electronic control unit4of the vehicle1.

In conclusion, the smart tire pressure monitoring system of the invention enables each smart tire pressure sensor to automatically recognize the ID of the electronic control unit and provides its ID code to the electronic control unit to establish communication, so that the electronic control unit can obtain the tire pressure value of each tire. Thus, the invention can be used in different vehicles of different models or from different providers.