WO2009094901A1

WO2009094901A1 - A method for instant monitoring the tire pressure using a tire pressure monitoring system

Info

Publication number: WO2009094901A1
Application number: PCT/CN2009/000097
Authority: WO
Inventors: Yong Zheng
Original assignee: Suzhou Sate Auto Electronic Co., Ltd.
Priority date: 2008-01-22
Filing date: 2009-01-22
Publication date: 2009-08-06
Also published as: CN101492000A; WO2009094901A9; CN101492000B

Abstract

A method for instant monitoring the tire pressure using a tire pressure monitoring system. The tire pressure monitoring system comprises a sensing emitter and a central monitor. An acceleration sensor is disposed in the sensing emitter, which can sense and measure the rotate speed of the wheels to determine the current running state of the vehicle. If the acceleration sensor determines the vehicle is stationary, the system applies a tire pressure DEPT detecting algorithm to monitor the pressure. The tire pressure DEPT detecting algorithm means that, the sensing emitter collects the tire pressure information P once at regular intervals S; thecentral monitor stores the last tire pressure information P0 which is transmitted to the central monitor from the sensing emitter; the current tire pressure information which is actually collected by the sensing emitter is P2, while a tire pressure update fixed value M is set. If |P2-P0|>M, the sensing emitter will transmit P2 to the central monitor which then will store P2 and display it as the current tire pressure value.

Description

-l - A method for monitoring tire pressure in real time using a tire pressure monitoring system

The present invention relates to a method for real-time monitoring of tire pressure, and in particular to a method for real-time monitoring of tire pressure by a tire pressure monitoring system (TPMS). Background technique

TPMS is the abbreviation of the tire pressure monitoring system "Tire Pressure Monitoring System". It is simply used to monitor the pressure and temperature of the vehicle tires in real time when the vehicle is running or stopped, to ensure that the pressure and temperature of the tires are maintained within the standard range. , to reduce the probability of puncture and damage, reduce fuel consumption and damage to vehicle components.

TPMS monitors tire pressure, temperature and other data in real-time while driving or stationary by installing a highly sensitive sensor transmitter on each tire, and wirelessly transmits it to the receiver built into the central monitor. Central monitor Display the above data on the display or alert the driver in the form of a beep, etc., and alarm when the tire leaks and the pressure changes beyond the safety threshold (the threshold can be set by the display) to ensure driving safety.

In terms of products, TPMS is currently divided into two types, one is Wheel-Speed Based TPMS (indirect TPMS), which compares the speed difference between tires by the wheel speed sensor of the vehicle ABS system. To achieve the purpose of monitoring tire pressure, the main disadvantage of this type of system is that it is impossible to judge the situation in which two or more tires are simultaneously out of gas and the speed exceeds 100 km/h, and has been gradually eliminated.

The other is Pressure-Sensor Based TPMS (referred to as direct TPMS), which uses a pressure sensor installed in each tire to directly measure the air pressure of the tire, and display and monitor the tire pressure, when the tire pressure When the temperature is too low or there is leakage, the system will automatically alarm, which is the more commonly used technical method.

At present, the most commonly used TPMS working methods are as follows:

1. A mechanical centrifugal switch is installed in the tire to control the operation of the sensor transmitter. When the wheel reaches a certain speed or higher, the centrifugal switch is closed. At this time, the sensor transmitter starts to work, and the pressure is detected and at a fixed time interval. The central monitor sends pressure information. The disadvantage of this method is: When the car is at rest, it is impossible to know the pressure information of the tire. It can only work after the car has reached a certain speed (generally greater than 20kmh), so that the tire pressure signal cannot be monitored in real time. 2. Regardless of whether the tire pressure is normal or not, the sensor transmitter uses 24-hour real-time monitoring and sends tire pressure information to the central monitor at fixed time intervals. Although this method can achieve the 24-hour tire pressure detection function, because the vehicle is in the actual use process, the static state is basically greater than the use state, and in most of the static state, the TPMS is constantly sending tires. The pressure detection information makes the battery built in the sensor transmitter consume a lot of power and the product has a short service life.

For the above-mentioned first TPMS system, since the tire pressure cannot be monitored in real time, it is basically not used by most demanding motor vehicle manufacturers; for the second TPMS system, since the vehicle is not distinguished from the stationary state and the motion state, real-time use Pressure collection method, which can indicate tire pressure information in real time, but when the vehicle is at rest, if the pressure does not change, the sensor transmitter still sends tire pressure information to the central monitor at regular intervals. Greatly shorten the service life of the product. Based on the above situation, a new type has emerged.

The TPMS system uses the following algorithm for monitoring tire pressure changes - the sensor transmitter collects tire pressure information P every other fixed time interval S; the pressure value P collected by the previous fixed interval S, the current actual sensor transmitter The collected tire pressure information is P ₂ , and a tire pressure update fixed value M is set at the same time. When | _{2 2} | | 〉 3⁄41, the sensor transmitter sends P ₂ to the central monitor, and the central monitor will P ₂ Stored and displayed as the current pressure value of the tire on the display.

This algorithm can well avoid the vehicle's continuous sending of tire pressure information when it is at rest, resulting in unnecessary consumption of the sensor transmitter battery. However, the disadvantage of this method is: When the vehicle is at rest, the algorithm cannot detect trace amounts. In the case of leakage, if the tire pressure is slightly leaked, it is less than the rate at which the system's minimum adjacent collection interval can be monitored. When the pressure change amount has not reached the pressure update fixed value M, the last collected pressure value of the system is updated by the current pressure value of the system. The system always displays the value of the pressure information sent for the first time, so that this kind of micro-leakage event cannot be detected. In this case, the possible situation is: There is a slight leak in the tire pressure, the tire pressure has been reduced a lot, but the display The above shows the value of the vehicle tire pressure when it is in good working condition, so that it can not attract the attention of the driver, and it is very likely to cause a safety accident. Disclosure of invention

The object of the present invention is to provide a method for monitoring the tire pressure in real time by a tire pressure monitoring system, which adopts a new pressure detecting method to distinguish the vehicle from the stationary state and the moving state, and the vehicle is stationary. The state effectively avoids the situation that the system cannot be effectively monitored when the tire is slightly leaked, and prolongs the service life of the product.

In order to achieve the above technical effects, the present invention provides the following technical solutions:

A tire pressure monitoring system for monitoring tire pressure in real time, the tire pressure monitoring system includes a sensor transmitter mounted on the tire, a central monitor installed in the cab, and the sensor transmitter has a built-in pressure sensor. An acceleration sensor, the acceleration sensor can determine the current state of motion of the vehicle by sensing and measuring the rotational speed of the automobile wheel;

When the acceleration sensor determines that the car is at a standstill state, the system uses the tire pressure DEPT detection algorithm for pressure monitoring. The tire pressure DETP detection algorithm refers to: the sensor transmitter collects tire pressure information P every other fixed time interval S; The monitor stores the pressure information P that the sensor transmitter sent to the central monitor last time. The tire pressure information currently collected by the sensor transmitter is P ₂ , and a tire pressure update fixed value M is set at the same time, when | P ₂ — P. | > M, then the sensor transmitter sends P ₂ to the central monitor, which stores the P ₂ and displays it as the current pressure value of the tire on the display;

When the acceleration sensor determines that the vehicle is in motion, the system uses the tire pressure DEPT detection algorithm for pressure monitoring, and the sensor transmitter transmits the tire pressure information currently collected by the sensor transmitter to the central monitor every other fixed time interval τ. The central monitor stores the pressure information and displays it on the display as the current tire pressure value. The best way to implement the invention

The present invention is further illustrated by the following comparative test:

When the acceleration sensor determines that the vehicle is at rest - contrast conditions: The tire is deflated at a constant rate of 1KPA/S at rest, and the sensor transmitter collects tire pressure information every other fixed time interval S = 4 seconds. The tire pressure information currently collected by the sensor transmitter is P ₂ , the pressure value P collected by the previous fixed interval S, and the central monitor stores the pressure information PD that the sensor transmitter sent to the central monitor last time. The tire pressure is updated to a fixed value of M = 10 KPA. Prior art invention

吋? 2 P, 1 P -P, 1 P ₂ Po 1 P ₂ -PO 1

IS 100 101 1 100 101 1 2S 99 101 2 99 101 2

3S 98 101 3 98 101 3

4S 97 101 4 97 101 4

5S 96 97 1 96 101 5

6S 95 97 2 95 101 6

7S 94 97 3 94 101 7

8S 93 97 4 93 101 8

9S 92 93 1 92 101 9

10S 91 93 2 91 101 10

US 90 93 3 90 90 11

12S 89 93 4 89 90 1

Conclusion: In the prior art, each time the pressure signal is collected, when the tire pressure is lowered, the sensor transmitter updates the pressure signal 10KPA because it does not reach the updated fixed 10KPA, so the central monitor is dying, the central monitor stores The sensor launch directly stores the original tire pressure value device and the last sent pressure value is updated to the current pressure and cannot be updated. Therefore, for such a micro force value, the amount leak can be detected in a short time. A change in tire pressure is made so that any micro-leakage events can be detected. When the acceleration sensor determines that the car is in motion. - Contrast conditions: During the motion, the tire is deflated at an equal rate of 1KPA/S, and the sensor transmitter collects tire pressure information every other fixed time interval S=4 seconds. The tire pressure information currently collected by the sensor transmitter is P ₂ , the pressure value P collected by the previous fixed interval S, and the central monitor stores the pressure information P sent by the sensor transmitter to the central monitor last time. . The tire pressure is updated to a fixed value of M 2 10 KPA, and the sensor transmitter transmits the tire pressure information currently collected by the sensor transmitter to the central monitor every other fixed time interval T = 15 seconds. Prior art invention

Time Ρ ₂ Ρ, 1 P ₂ -P, 1 ?2 Ρο 1 Ρ "Ρ. 1

1S 100 101 1 100 101 1

2S 99 101 2 99 101 2 3S 98 101 3 98 101 3

4S 97 101 4 97 101 4

5S 96 97 1 96 101 5

6S 95 97 2 95 101 6

7S 94 97 3 94 101 7

8S 93 97 4 93 101 8

9S 92 93 1 92 101 9

10S 91 93 2 91 101 10

US 90 93 3 90 90 11

12S 89 93 4 89 90 1

13S 88 89 1 88 90 2

14S 87 89 2 87 90 3

15S 86 86 0 86 86 0

16S 85 86 1 85 86 1

Conclusion: In the prior art, in the invention, when the pressure of the tire is lowered, the sensor transmitter is updated with a pressure value of 10KPA, so the central monitor is stored, the central monitor stores the information. The sensor sends out the original tire pressure value. The last sent pressure value of the detector is updated to be unable to be updated. Only the pressure value before the sensor is transmitted, and the sensor transmitter is separated every other fixed time interval. When the pressure new pressure information is updated at a fixed time interval, the current tire pressure information of the current tire can be displayed in real time again when the information is displayed in real time. Pressure information. This shows that at the car

In the state of motion, the present invention still has certain advantages in monitoring tire pressure information in real time.

In summary, the present invention can effectively monitor tire pressure information in real time when the vehicle is at a standstill, especially for a small amount of leakage, which can be detected and displayed in a short time. The relative response time of the present invention to changes in tire pressure information is still superior to the prior art when the vehicle is in motion.

Industrial applicability The effect of the invention is: determining the current state of motion of the vehicle by the acceleration sensor, and using the tire pressure DEPT detection algorithm when the vehicle is at a standstill, so that the central monitor can monitor the tire pressure in a very short time. The leakage condition is displayed on the display, which greatly increases the safety performance of the tire pressure monitoring. However, the prior art cannot monitor the micro-leakage; when the vehicle is in motion, the tire pressure DEPT detection algorithm is still used. In conjunction with the sensor, the sensor transmitter transmits the current pressure information at regular intervals and displays it on the display. This can greatly reduce the number of times the transmitting sensor transmits information. Especially when the vehicle is at rest, this real-time monitoring method greatly reduces the energy consumption of the sensor transmitter and greatly extends the life of the product.

Claims

Rights request

A tire pressure monitoring system for monitoring tire pressure in real time. The tire pressure monitoring system includes a sensor transmitter mounted on the tire, a central monitor installed in the cab, and a built-in pressure in the sensor transmitter. Sensor

The sensor transmitter further includes an acceleration sensor, wherein the acceleration sensor can determine the current motion state of the automobile by sensing and measuring the rotation speed of the automobile wheel; when the acceleration sensor determines that the vehicle is at a static state, the system uses the tire The pressure DEPT detection algorithm performs pressure monitoring. The tire pressure DETP detection algorithm means that the sensor transmitter collects tire pressure information P every other fixed time interval S; the central monitor stores the sensor transmitter last time sent to the center Monitor pressure information P. The tire pressure information currently collected by the sensor transmitter is P ₂ , and a tire pressure update fixed value M is set at the same time, when IP ₂ —P. I >M 吋, the sensor transmitter sends P ₂ to the central monitor, the central monitor stores P ₂ as the current pressure value of the tire; when the acceleration sensor determines that the car is in motion, the system uses the tire pressure DEPT detection The algorithm performs pressure monitoring, and the sensor transmitter transmits the tire pressure information currently collected by the sensor transmitter to the central monitor every fixed time interval T, and the central monitor stores the pressure information and displays it as the current pressure value of the tire. On the display.