1. Field of the Invention
The invention generally relates to a smart antenna system and method of the same, in particular to a smart antenna system and method of the same for tire pressure monitoring using a plurality of antennas.
2. Description of Prior Art
When the pressure applied to a tire (referred as tire pressure in the following) is abnormal, there are disadvantages such as affecting brake performance or increasing possibility of tires going flat while driving causing car accident in addition to decreasing tire service life and increasing fuel consumption. Therefore, a tire pressure monitor system (Tire Pressure Monitoring System, referred as TPMS in the following) is gradually applied in cars to assure driving safety so as to effectively avoid car accidents caused by driving in a car having abnormal tire pressures.
Normal tire pressure monitor system comprises a tire pressure monitoring module installed in the tire, and a vehicle controller installed in a car. The tire pressure monitoring module measures tire pressure data of a tire, then wirelessly transmits the tire pressure data to a vehicle controller installed in a car. The tire pressure data is displayed as a reference to the driver.
The currently-available tire pressure monitoring module is installed in the tire and uses a set of fixed antennas to send tire pressure data. However, if the pressure monitoring module within the tire is located in the signal reception dead zone of the vehicle controller in the car during vehicle operation, the vehicle controller in the car may not be able to receive the tire pressure data precisely because signals for carrying the tire pressure data are too weak.
In order to overcome the disadvantages of above mentioned prior art, an objective of the present invention is to provide a smart antenna system for tire pressure monitoring to overcome the signal reception dead zone problem of a vehicle controller.
In order to overcome the disadvantages of above mentioned prior art, another objective of the present invention is to provide a smart tire pressure monitoring system to overcome the signal reception dead zone problem of a vehicle controller.
In order to overcome the disadvantages of above mentioned prior art, still another objective of the present invention is to provide a smart antenna method for tire pressure monitoring to overcome the signal reception dead zone problem of a vehicle controller.
In order to achieve the above objective of the present invention, the smart antenna system of the present invention is used in a vehicle controller and comprises at least a tire pressure monitoring module. Each tire pressure monitoring module comprises: a tire micro control unit, a tire RF transmit unit electrically connected to the tire micro control unit, a tire RF receive unit electrically connected to the tire micro control unit, a tire pressure inspecting unit electrically connected to the tire micro control unit and a plurality of antennas electrically connected to the tire RF transmit unit and the tire RF receive unit. The tire micro control unit selects a default antenna among the a plurality of antennas to send a tire pressure data signal to the vehicle controller for displaying a tire pressure data via the default antenna of the smart tire pressure monitoring module after a default antenna signal sent by the vehicle controller is received.
In order to achieve the above another objective of the present invention, the smart tire pressure monitoring system of the present invention comprises: a vehicle controller disposed in a vehicle, and at least a tire pressure monitoring module, disposed in a vehicle tire. Each tire pressure monitoring module comprises a tire micro control unit, a tire RF transmit unit electrically connected to the tire micro control unit, a tire RF receive unit electrically connected to the tire micro control unit, a tire pressure inspecting unit electrically connected to the tire micro control unit, and a plurality of antennas electrically connected to the tire RF transmit unit and the tire RF receive unit. The vehicle controller elects the antenna transmitting test signals with highest received signal strength indication (RSSI) among the antennas as a default antenna. The tire micro control unit sends a tire pressure data signal to the vehicle controller for displaying a tire pressure data via the default antenna.
In order to achieve the above still another objective of the present invention, the smart antenna method for tire pressure monitoring of the present invention is used in a vehicle controller and at least a tire pressure monitoring module. The tire pressure monitoring module comprises a plurality of antennas. One of the antennas sends a tire pressure data signal to the vehicle controller for displaying a tire pressure data. The smart antenna method comprises: the antenna of the tire pressure monitoring module transmitting a test signal respectively to the vehicle controller, the vehicle controller receiving the test signal transmitted by the antenna and recording the RSSI of the test signal, the vehicle controller comparing RSSI strength of the test signal and elects the antenna transmitting test signals with highest received signal strength indication (RSSI) among the antennas as a default antenna, the vehicle controller transmitting data of the default antenna to the tire pressure monitoring module and the tire pressure monitoring module selecting the antenna to send the tire pressure data signal according to data of the default antenna.
The features of the invention believed to be novel are set forth with particularity in the appended claims. The invention itself, however, may be best understood by reference to the following detailed description of the invention, which describes an exemplary embodiment of the invention, taken in conjunction with the accompanying drawings, in which:
According to present invention, the smart antenna system and method for tire pressure monitoring use a tire pressure monitoring module having multi antennas and installed in a tire.
The vehicle controller disposed in the car receives signals from various antennas and selects the antenna used by tire pressure monitoring module for sending tire pressure data signal based on the Received Signal Strength Indication (RSSI) of signals. Such mechanism is effective in lowering the error rate of the tire pressure data signal received by the vehicle controller so as to offer immediate and precise tire pressure data.
The tire pressure monitoring module 20 comprises a tire RF transmit unit 202, a tire RF receive unit 204, a tire pressure inspecting unit 206, a power unit 208, a tire micro control unit 210 and a plurality of antennas 212A˜212E. the tire micro control unit 210 is electrically connected to the tire RF transmit unit 202, the tire RF receive unit 204, the tire pressure inspecting unit 206 and the power unit 208. The antenna 212A˜212E is electrically connected to the tire RF transmit unit 202 and the tire RF receive unit 204. The tire micro control unit 210 of the tire pressure monitoring module 20 sends a tire pressure data signal to the vehicle controller 10 for displaying a tire pressure data via one of the antenna 212A˜212E.
It follows that the vehicle controller 10 compares RSSI strength of the test signal and selects the antenna transmitting test signals with highest received signal strength indication (RSSI) among the antennas as the default antenna to send the test signal among antennas 212A˜212E (S30). Consequently, the vehicle controller 10 transmits a default antenna signal with default antenna data to the tire pressure monitoring module 20 (S40). Then, the tire micro control unit 210 of the tire pressure monitoring module 20 selects a default antenna to send the tire pressure data signal according to the data of the default antenna (S50). Lastly, if the Bit Error Rate (BER) of the tire pressure data signal sent by the default antenna increases, the process moves back to step S10; if the BER of the tire pressure data signal sent by the default antenna default antenna is normal, then the process moves back to step S50.
The possible implementations of the antennas 212A˜212E include an air tap of the tire, a steel band for fixing the tire pressure monitoring module 20, an air tap cover of the tire, an external antenna on the tire pressure monitoring module 20 (for example a helical external antenna as shown in
The smart antenna system and method for tire pressure monitoring of the present invention uses tire pressure monitoring module with multi-antenna installed in a tire. The vehicle controller in the car selecting the antenna transmitting the test signals with highest RSSI among the antenna as a default antenna. The tire pressure monitoring module sends the tire pressure data signals to the vehicle controller for displaying the tire pressure data as user's reference via the default antenna
As the skilled person will appreciate, various changes and modifications can be made to the described embodiments. It is intended to include all such variations, modifications and equivalents which fall within the scope of the invention, as defined in the accompanying claims.