KR100748891B1 - Sensor position learning method of tpms high line - Google Patents

Abstract

A method for identifying a sensor position of a TPMS High Line is provided to reduce the weight of the TPMS without using an LFI by changing a logic which identifies the position of an air pressure sensor in a tire. A method for identifying a sensor position of a TPMS High Line comprises a step of receiving RF messages, such as a sensor ID, air pressure, angular acceleration, temperature through a receiver(S204). The RF messages are transmitted from air pressure sensors at an initial state. The method comprises a step of deciding whether the air pressure sensor is installed at left or right of a vehicle by using a phase difference between a normal acceleration and a tangential acceleration(S206). The method comprises a step of deciding and memorizing whether the air pressure sensor is installed in front or back of the vehicle.

Description

Sensor Position Learning Method of TPMS High Line

1 is a view schematically showing the configuration of a conventional TPMS,

2 is a flowchart of a sensor position recognition method of a TPM high line according to the present invention;

3A and 3B are diagrams illustrating waveforms of angular acceleration of a left tire and acceleration received by a receiver for right and left distinct logic of the air pressure sensor shown in FIG. 2;

4A and 4B are diagrams illustrating waveforms of angular acceleration of the right tire and acceleration received by a receiver for right and left logic of the pneumatic sensor shown in FIG. 2;

FIG. 5 is a diagram illustrating RF reception strength for front and rear division logic of the air pressure sensor shown in FIG. 2; FIG.

<Description of the symbols for the main parts of the drawings>

20a, 20b, 20c, 20d: Tire 30a, 30b, 30c, 30d: Pneumatic sensor

40: receiver

The present invention relates to a sensor position recognition method of a TPMS high line, and more particularly, in the TPMS high line type, it is not necessary to use the LFI for identifying the position of the pneumatic sensor by changing the logic for recognizing the position of the pneumatic pressure sensor in the tire. It relates to a sensor position recognition method of the TPMS high line.

The Tire Pressure Monitoring System (hereinafter referred to as TPMS) is a system that measures the air pressure in a car's tires and informs the driver and alerts the driver when the pressure has dropped below a specified pressure. )to be.

The TPMS is classified into indirect and direct methods. The indirect method detects the tire state by detecting the rotation speed of each wheel through an anti-lock brake system (ABS) sensor, and the direct method uses the wheel (tire). The built-in air pressure sensor detects the tire pressure.

The indirect method is not reliable and currently does not allow the use of the system. Accordingly, the TPMS of the direct method has been commercialized.

There are two types of direct TPMS: high-line and low-line.

The low line can only warn that there is a tire outside the prescribed pressure, whereas the high line shows four low frequency near each tire 1a, 1b, 1c, 1d, as shown in FIG. Initiators (3a, 3b, 3c, 3d) can be added to indicate the position of the tire where the pressure is out of specification.

In other words, the receiver 4 mounted on the control panel board in the center of the vehicle's dashboard between the driver's seat and the passenger seat, ie the center fascia, has four LFIs (3a, 3b, 3c, 3d) connected by hardwire. Give a trigger command to

The four LFIs are 125kHz low frequency field strength signals with sequential (FL-> FR-> RL-> RR) to air pressure sensors (2a, 2b, 2c, 2d) mounted on each tire (1a, 1b, 1c, 1d). Wake up the corresponding air pressure sensors 2a, 2b, 2c, and 2d.

The air pressure sensors 2a, 2b, 2c, and 2d, which are sequentially woken up, send an RF signal to the receiver 4 and respond to the reception of the LFI signal.

The receiver 4, which received the response, memorizes the positions of the air pressure sensors 2a, 2b, 2c, and 2d, and uses the four LFIs 3a, 3b, 3c, and 3d in the initial state of the start key on position. Learning to find out where the tires 1a, 1b, 1c and 1d are at low pressure.

The automatic recognition logic is a unique ID of the air pressure sensors 2a, 2b, 2c, and 2d in the tires 1a, 1b, 1c, and 1d in which the receiver 4 is mounted on the vehicle in the initial state of the ignition key on position. Logic that recognizes the location of the ID.

However, the LFI (3a, 3b, 3c, 3d) had to control one air pressure sensor (2a, 2b, 2c, 2d) one-to-one for the automatic recognition logic.

Therefore, the LFIs (3a, 3b, 3c, 3d) must be provided for each tire of the tire pressure sensors (2a, 2b, 2c, 2d). Therefore, four identical LFIs must be installed in the vehicle, thereby increasing the cost of the TPMS and weight. This increases, there was a problem that takes a lot of time when assembling the line.

The present invention has been made to solve the above-mentioned problems, more specifically, by reducing the cost and weight of the TPMS by not using the LFI through the change of logic to recognize the position of the air pressure sensor in the tire in the TPMS high-line type The purpose of the present invention is to provide a method for recognizing the sensor position of a TPMS high line which can reduce the time required for the assembly process and reduce the time required.

Sensor position recognition method of the TPMS high line according to an embodiment of the present invention for achieving the above object, the sensor position in the high-line type TPMS consisting of a pneumatic sensor mounted on the front wheel left and right and rear wheel left and right tires of the vehicle, and the receiver In the method of performing recognition logic,

A first step of receiving, at the receiver, an RF message including a sensor ID, air pressure, angular acceleration, temperature, etc. sent from each air pressure sensor in an initial state where the start key of the vehicle is in the ON position; and the RF message received at the receiver. A second step of determining whether the pneumatic pressure sensor is mounted on the left side or the right side of the vehicle using the phase difference between the normal acceleration and the tangential acceleration included in the angular acceleration; and the reception sensitivity of the RF signal received from the receiver. And a third step of determining / remembering whether the air pressure sensor is mounted on the front wheel or the rear wheel of the vehicle using the difference in intensity.

Hereinafter, the configuration and operation of the present invention will be described with reference to the accompanying drawings.

As schematically shown in Fig. 5, the TPMS according to the present invention is provided with four pneumatic pressure sensors 30a, 30b and 30c respectively mounted on the tires 20a, 20b, 20c and 20d in the vehicle FR, FL, RR and RL positions. 30d and one receiver 40 receiving the air pressure sensor ID and the pressure information from the four air pressure sensors 30a, 30b, 30c, and 30d and mounted on the center fascia of the vehicle.

The air pressure sensors 30a, 30b, 30c, and 30d wirelessly transmit the sensor ID, air pressure, temperature, and acceleration, which are RF messages of the tires 20a, 20b, 20c, and 20d, to the receiver 40 during wakeup.

An acceleration sensor is mounted inside the air pressure sensors 30a, 30b, 30c, and 30d to transmit the angular acceleration, which is a vector sum of the normal acceleration and the tangential acceleration, to the receiver 40, and the receiver 40 forms the angular acceleration component. The left and right mounting positions of the pneumatic pressure sensors 30a, 30b, 30c, and 30d are distinguished by the phase difference between the acceleration and the tangential acceleration.

That is, when the tangential acceleration is 90 ° ahead of the normal acceleration, it is determined by the pneumatic sensors 30b, 30d mounted on the right side, and when the normal acceleration is 90 ° ahead of the tangential acceleration, it is determined by the pneumatic sensors 30a, 30c mounted on the left side.

In addition, the receiver 40 has a reception sensitivity strength of the RF signal transmitted from the pneumatic pressure sensors 30a and 30b located at the front wheel and an RF signal transmitted from the pneumatic pressure sensors 30c and 30d located at the rear wheel due to mounting characteristics mounted on the center fascia. There is a difference in reception strength.

In consideration of the difference in the received sensitivity of the RF signal, if the received sensitivity is relatively large, it is determined that the pneumatic sensors 30a, 30b are mounted on the front wheel of the vehicle, and if the received sensitivity is relatively small, the pneumatic sensor is mounted on the rear wheel of the vehicle. It is determined that 30a and 30b are mounted.

2 is a flowchart illustrating a sensor position recognition method of a TPS high line according to the present invention.

When the vehicle's ignition key is positioned at the ON position where all electric devices of the vehicle can be used while checking various warning lights before starting (S202), the receiver 40 of the TPMS is mounted on each tire 20a, 20b, 20c, 20d. Wake up the pneumatic pressure sensor (30a, 30b, 30c, 30d).

In such a state, the receiver 40 receives an RF message of each air pressure sensor transmitted from the wake-up air pressure sensors 30a, 30b, 30c, and 30d, that is, sensor ID, air pressure, temperature, and angular acceleration (S204).

The receiver 40 determines whether there is a phase difference between the normal acceleration and the tangential acceleration of the angular acceleration component in the RF message (S206), and determines that the phase of the normal acceleration is 90 ° ahead of the phase of the tangential acceleration in the presence of the phase difference. (S208).

When the phase of the normal acceleration is 90 ° ahead of the phase of the tangential acceleration, it is determined that the air pressure sensors 30a and 30c are mounted on the left side of the vehicle (S210).

It can be seen from the diagrams of the left tires 20a and 20c shown in FIG. 3 that the angular acceleration a is the vector sum of the normal acceleration a1 and the tangential acceleration a2 during the forward rotation of the tires 20a and 20c.

The normal acceleration a1 is rθcos (γt), and the tangential acceleration a2 is rθsin (γt), resulting in a phase difference of 90 °.

Where θ is the rotated angle, r is the companion diameter, and γ is the angle between a and a2.

As such, the phase of the normal acceleration a1 in the tires 20a and 20c mounted on the left side of the vehicle during the forward driving of the vehicle is 90 ° ahead of the phase of the tangential acceleration a2, and a1 is ahead of 90 ° in the actual vehicle state. The receiver 40 receiving the information, that is, the angular acceleration information, can be determined by the air pressure sensors 30a and 30c mounted on the left side.

After judging by the pneumatic pressure sensors 30a and 30c mounted on the left side of the vehicle, the receiver 40 compares the reception sensitivity strength of the RF signal sent from the pneumatic pressure sensors 30a and 30c mounted on the left side with a reference dB (-50 dBm). (S212), when larger than the reference dBm is mounted on the front wheel, that is, judged / memorized by the air pressure sensor 30a mounted at the FL position of the vehicle (S214), if smaller than the reference dBm is mounted on the rear wheel, that is, the vehicle The air pressure sensor 30c mounted at the RL position is determined / memorized (S222).

In FIG. 5, the distance between the pneumatic sensors 30a and 30b mounted on the front wheel and the receiver 40 due to the mounting characteristics of the receiver 40 mounted in the center fascia is the pneumatic sensors 30c and 30d mounted on the rear wheel and the receiver ( Since the reception sensitivity strength of the RF signal received at the receiver 40 is inversely proportional to the square of the distance, the reception sensitivity strength of the RF signal sent from the pneumatic sensors 30a and 30b mounted on the front wheel is less than the distance between the distances 40). The reception sensitivity of the RF signal sent from the air pressure sensors 30c and 30d mounted in the air is inevitably greater.

In fact, the reception sensitivity strength of the RF signal sent from the pneumatic sensors 30a and 30b mounted on the front wheel is about -40 dBm, and the reception sensitivity strength of the RF signal sent from the pneumatic sensors 30c and 30d mounted on the rear wheel is about -60 dBm. As a precision, by comparing the magnitude between -50 dBm, which is a value between them, as a reference dBm in the actual vehicle state, the receiver 40 can determine whether the air pressure sensor is mounted on the front wheel or the rear wheel.

Next, when the phase of the normal acceleration is not 90 ° ahead of the phase of the tangential acceleration in step S208, it is determined that the air pressure sensors 30b and 30d are mounted on the right side of the vehicle (S232).

In the diagram of the right tires 20b and 20d shown in FIG. 4, it can be seen that the angular acceleration a in the forward rotation of the tires 20b and 20d consists of a vector sum of the normal acceleration a1 and the tangential acceleration a2.

The normal acceleration a1 is rθcos (γt), and the tangential acceleration a2 is rθsin (γt), resulting in a phase difference of 90 °.

Where θ is the rotated angle, r is the companion diameter, and γ is the angle between a and a2.

As such, the phase of the tangential acceleration a2 inside the tires 20b and 20d mounted on the right side of the vehicle is 90 ° ahead of the normal acceleration a1 when the vehicle is driven forward, and a2 is ahead of 90 ° in the actual vehicle state. The receiver 40 receiving the information, that is, the angular acceleration information, can be determined by the air pressure sensors 30b and 30d mounted on the right side.

After judging by the pneumatic pressure sensors 30b and 30d mounted on the right side of the vehicle, the receiver 40 compares the reception sensitivity strength of the RF signal sent from the pneumatic pressure sensors 30b and 30d mounted on the right side with a reference dB (-50 dBm). (S234), if greater than the reference dBm is mounted on the front wheels, that is, judging / memorized by the air pressure sensor 30b mounted at the FR position of the vehicle (S236), if smaller than the reference dBm is mounted on the rear wheels, that is, the vehicle The air pressure sensor 30d mounted at the RR position is determined / memorized (S242).

As described above, the receiver 40 of the present invention determines the left and right positions of the pneumatic sensors based on the phase difference between the normal acceleration and the tangential acceleration constituting the angular acceleration, and determines the front and rear positions of the pneumatic sensors using the difference in the reception sensitivity. You can check the position of the pneumatic sensor without separately provided.

As described above, according to the present invention, it is not necessary to separately provide an LFI by changing the logic for recognizing the position of the air pressure sensor in the tire in the TPMS highline type, thereby reducing the cost of TPMS and reducing the weight, and the line assembly process. This can shorten the time it takes.

Claims (6)

The sensor position recognition logic is applied to the high-line type TPMS consisting of the pneumatic sensors 30a, 30b, 30c, and 30d mounted on the front, left and right tires 20a, 20b, 20c, and 20d of the vehicle and the receiver 40. In the method of carrying out, The receiver 40 receives an RF message including the sensor ID, air pressure, angular acceleration, temperature, and the like sent from each of the air pressure sensors 30a, 30b, 30c, and 30d in the initial state in which the start key of the vehicle is in the ON position. The first step, A second step of determining whether the pneumatic pressure sensor is mounted on the left side or the right side of the vehicle using the phase difference between the normal acceleration and the tangential acceleration constituting the angular acceleration included in the RF message received by the receiver 40; And a third step of determining / remembering whether the pneumatic sensor is mounted on the front wheel or the rear wheel of the vehicle by using the difference in the received sensitivity of the RF signal received by the receiver 40. Sensor position recognition method. The method of claim 1, And in the second step, when the phase of the normal acceleration is 90 ° ahead of the phase of the tangential acceleration, it is determined that the pneumatic sensors (30a, 30c) are mounted on the left side of the vehicle. The method of claim 2, In the third step, the reception sensitivity strength of the RF signal sent from the pneumatic pressure sensors 30a and 30c is compared with the reference dBm, and when it is larger than the reference dBm, the air pressure sensor 30a mounted at the FL position of the vehicle is determined / remembered. If less than the reference dBm sensor position recognition method of the TPMS high line, characterized in that it is determined / memorized by the air pressure sensor (30c) mounted at the RL position of the vehicle. The method of claim 1, And detecting the air pressure sensors (30b, 30d) on the right side of the vehicle when the phase of the tangential acceleration is 90 ° ahead of the phase of the normal acceleration in the second step. The method of claim 4, wherein In the third step, the reception sensitivity intensity of the RF signal sent from the pneumatic pressure sensors 30b and 30d is compared with the reference dBm, and when it is larger than the reference dBm, it is determined / memorized by the pneumatic sensor 30b mounted at the FR position of the vehicle. If less than the reference dBm sensor position recognition method of the TPMS high line, characterized in that it is determined / memorized by the pneumatic pressure sensor (30d) mounted at the RR position of the vehicle. The method according to claim 3 or 5, And a reference dBm compared with the received sensitivity strength of the RF signal is -50 dBm.

Images