阅读说明：本技术 一种胎压监测方法及装置 (Tire pressure monitoring method and device ) 是由 许盛中 肖丹丹 于 2018-08-02 设计创作，主要内容包括：本发明涉及一种胎压监测方法及装置,包括以下步骤：采集四个车轮的角速度信号和载荷信号；根据采集的四个车轮的角速度信号的关系,初步判断轮胎是否处于欠压状态；然后判断欠压状态的轮胎的载荷信号是否异于其他轮胎的载荷信号,若不同,则该轮胎不欠压,反之,该轮胎欠压。即本发明能够有效避免由于载荷不均匀引起的胎压监测误报警的问题。(The invention relates to a tire pressure monitoring method and a tire pressure monitoring device, which comprise the following steps: collecting angular speed signals and load signals of four wheels; preliminarily judging whether the tire is in an undervoltage state or not according to the relationship of the collected angular speed signals of the four wheels; and then judging whether the load signal of the tire in the undervoltage state is different from the load signals of other tires, if so, judging that the tire is not undervoltage, otherwise, judging that the tire is undervoltage. Namely, the invention can effectively avoid the problem of tire pressure monitoring false alarm caused by uneven load.)

1. A tire pressure monitoring method, characterized by comprising the steps of:

1) collecting angular speed signals and load signals of four wheels;

2) preliminarily judging whether the tire is in an undervoltage state or not according to the relationship of the collected angular speed signals of the four wheels;

3) and then judging whether the load signal of the tire in the undervoltage state is different from the load signals of other tires, and if the load signals are different, judging that the tire is not undervoltage.

2. The tire pressure monitoring method according to claim 1, wherein the preliminary judgment of the tire under-pressure state in step 2) is:

if w₁>w₂＝w₃＝w₄I.e. r>0, the left front wheel is in an undervoltage state;

if w₂>w₁＝w₃＝w₄I.e. r<0, the right front wheel is in an undervoltage state;

if w₃>w₄＝w₁＝w₂I.e. r<0, the left rear wheel is in an undervoltage state;

if w₄>w₁＝w₂＝w₃I.e. r>0, the right rear wheel is in an undervoltage state;

wherein w₁、w₂、w₃、w₄The angular velocity signals of the wheels of the left front wheel, the right front wheel, the left rear wheel and the right rear wheel are respectively indicated, and r is a set threshold value.

3. The tire air pressure monitoring method according to claim 2, wherein the threshold value r is set by the expression:

wherein w₁、w₂、w₃、w₄Which respectively refer to angular velocity signals of the wheels of the left front wheel, the right front wheel, the left rear wheel and the right rear wheel.

4. The tire pressure monitoring method according to claim 3, wherein the determination in step 3) is:

when the left front wheel is in the undervoltage state in the initial judgment, if z is₁>z₂＝z₃＝z₄And is and

when the front right wheel is initially judged to be in an undervoltage state, if z is the condition₂>z₁＝z₃＝z₄And is and

when the left rear wheel is in the undervoltage state in the initial judgment, if z₃>z₂＝z₁＝z₄And is and

when the rear right wheel is judged to be in the undervoltage state in the initial step, if z is the undervoltage state₄>z₂＝z₃＝z₁And is and

wherein z is₁、z₂、z₃、z₄Which refer to the load signals of the left front wheel, the right front wheel, the left rear wheel and the right rear wheel, respectively.

5. A tire pressure monitoring device comprising a controller, a memory, and a program stored in the memory and executable on the controller, the controller executing the program to perform the steps of:

1) collecting angular speed signals and load signals of four wheels;

2) preliminarily judging whether the tire is in an undervoltage state or not according to the relationship of the collected angular speed signals of the four wheels;

3) and then judging whether the load signal of the tire in the undervoltage state is different from the load signals of other tires, and if the load signals are different, judging that the tire is not undervoltage.

6. The tire pressure monitoring device according to claim 5, wherein the preliminary determination of the tire under-pressure condition in step 2) is:

if w₁>w₂＝w₃＝w₄I.e. r>0, the left front wheel is in an undervoltage state;

if w₂>w₁＝w₃＝w₄I.e. r<0, the right front wheel is in an undervoltage state;

if w₃>w₄＝w₁＝w₂I.e. r<0, the left rear wheel is in an undervoltage state;

if w₄>w₁＝w₂＝w₃I.e. r>0, the right rear wheel is in an undervoltage state;

wherein w₁、w₂、w₃、w₄The angular velocity signals of the wheels of the left front wheel, the right front wheel, the left rear wheel and the right rear wheel are respectively indicated, and r is a set threshold value.

7. The tire pressure monitoring device according to claim 6, wherein the threshold value r is set by the expression:

wherein w₁、w₂、w₃、w₄Which respectively refer to angular velocity signals of the wheels of the left front wheel, the right front wheel, the left rear wheel and the right rear wheel.

8. The tire pressure monitoring device according to claim 7, wherein the determination in step 3) is:

when the left front wheel is in the undervoltage state in the initial judgment, if z is₁>z₂＝z₃＝z₄And is and

when the front right wheel is initially judged to be in an undervoltage state, if z is the condition₂>z₁＝z₃＝z₄And is andthe right front wheel is not undervoltage;

when the left rear wheel is in the undervoltage state in the initial judgment, if z₃>z₂＝z₁＝z₄And is and

when the rear right wheel is judged to be in the undervoltage state in the initial step, if z is the undervoltage state₄>z₂＝z₃＝z₁And is and

wherein z is₁、z₂、z₃、z₄Which refer to the load signals of the left front wheel, the right front wheel, the left rear wheel and the right rear wheel, respectively.

Technical Field

The invention belongs to the field of tire pressure monitoring of vehicle engineering, and particularly relates to a tire pressure monitoring method and device.

Background

In order to prevent the tire deformation caused by the fact that the tire pressure of the vehicle tire is lower than a normal value, the energy consumption and even the driving safety problem exist, the tire pressure needs to be monitored in real time, and an alarm is given when the tire is abnormal, namely, the tire pressure monitoring technology is called.

Currently, the tire pressure monitoring technology is classified into a direct type and an indirect type. The direct type is generally to install a pressure sensor inside the tire, directly measure the tire pressure, and alarm when the tire pressure reaches a set limit value. The indirect mode is mainly through the rotational speed difference between the fast sensor comparison tire of car ABS system, and when the atmospheric pressure of certain tire reduced, the rolling radius that the weight of vehicle can make this tire diminishes, and the rotational speed can accelerate, can judge whether tire pressure is normal.

Disclosure of Invention

The invention aims to provide a tire pressure monitoring method and a tire pressure monitoring device, which are used for solving the problem that the angular velocity signal of a tire with a large corresponding load is increased to generate a tire pressure monitoring false alarm due to the fact that the load of a vehicle is not uniform in the conventional passenger car.

In order to achieve the above object, the present invention provides a tire pressure monitoring method, which specifically includes the following steps:

the first method scheme is as follows: the method comprises the following steps:

1) collecting angular speed signals and load signals of four wheels;

2) preliminarily judging whether the tire is in an undervoltage state or not according to the relationship of the collected angular speed signals of the four wheels;

3) and then judging whether the load signal of the tire in the undervoltage state is different from the load signals of other tires, and if the load signals are different, judging that the tire is not undervoltage.

In the second method, on the basis of the first method, the preliminary judgment of the tire under-pressure state in the step 2) is as follows:

if w₁>w₂＝w₃＝w₄I.e. r>0, the left front wheel is in an undervoltage state;

if w₂>w₁＝w₃＝w₄I.e. r<0, the right front wheel is in an undervoltage state;

if w₃>w₄＝w₁＝w₂I.e. r<0, the left rear wheel is in an undervoltage state;

if w₄>w₁＝w₂＝w₃I.e. r>0, the right rear wheel is in an undervoltage state;

wherein w₁、w₂、w₃、w₄The angular velocity signals of the wheels of the left front wheel, the right front wheel, the left rear wheel and the right rear wheel are respectively indicated, and r is a set threshold value.

In the third method, on the basis of the second method, the expression of the threshold r is set as follows:

wherein w₁、w₂、w₃、w₄Which respectively refer to angular velocity signals of the wheels of the left front wheel, the right front wheel, the left rear wheel and the right rear wheel.

In the fourth method, based on the third method, the judgment in the step 3) is as follows:

when the left front wheel is in the undervoltage state in the initial judgment, if z is₁>z₂＝z₃＝z₄And is andthe left front wheel is not undervoltage;

when the front right wheel is initially judged to be in an undervoltage state, if z is the condition₂>z₁＝z₃＝z₄And is and

the right front wheel is not undervoltage;

when the left rear wheel is judged to be in an undervoltage stateWhen z is present, if₃>z₂＝z₁＝z₄And is and

the left rear wheel is not undervoltage;

when the rear right wheel is judged to be in the undervoltage state in the initial step, if z is the undervoltage state₄>z₂＝z₃＝z₁And is and

the right rear wheel is not undervoltage;

wherein z is₁、z₂、z₃、z₄Which refer to the load signals of the left front wheel, the right front wheel, the left rear wheel and the right rear wheel, respectively.

The invention also provides a tire pressure monitoring device, which specifically comprises the following scheme:

the first device scheme comprises a controller, a memory and a program which is stored in the memory and can run on the controller, wherein the controller executes the program to realize the following steps:

1) collecting angular speed signals and load signals of four wheels;

2) preliminarily judging whether the tire is in an undervoltage state or not according to the relationship of the collected angular speed signals of the four wheels;

3) and then judging whether the load signal of the tire in the undervoltage state is different from the load signals of other tires, and if the load signals are different, judging that the tire is not undervoltage.

In the second device scheme, on the basis of the first device scheme, the preliminary judgment of the tire under-pressure state in the step 2) is as follows:

if w₁>w₂＝w₃＝w₄I.e. r>0, the left front wheel is in an undervoltage state;

if w₂>w₁＝w₃＝w₄I.e. r<0, the right front wheel is in an undervoltage state;

if w₃>w₄＝w₁＝w₂I.e. r<0, the left rear wheel is in an undervoltage state;

if w₄>w₁＝w₂＝w₃I.e. r>0, the right rear wheel is in an undervoltage state;

wherein w₁、w₂、w₃、w₄The angular velocity signals of the wheels of the left front wheel, the right front wheel, the left rear wheel and the right rear wheel are respectively indicated, and r is a set threshold value.

In the third device solution, on the basis of the second device solution, the expression of the threshold r is set as:

wherein w₁、w₂、w₃、w₄Which respectively refer to angular velocity signals of the wheels of the left front wheel, the right front wheel, the left rear wheel and the right rear wheel.

The device scheme four, on the basis of the device scheme three, the judgment in the step 3) is as follows:

when the left front wheel is in the undervoltage state in the initial judgment, if z is₁>z₂＝z₃＝z₄And is and

the left front wheel is not undervoltage;

when the front right wheel is initially judged to be in an undervoltage state, if z is the condition₂>z₁＝z₃＝z₄And is and

the right front wheel is not undervoltage;

when the left rear wheel is in the undervoltage state in the initial judgment, if z₃>z₂＝z₁＝z₄And is and

the left rear wheel is not undervoltage;

when the rear right wheel is judged to be in the undervoltage state in the initial step, if z is the undervoltage state₄>z₂＝z₃＝z₁And is and

the right rear wheel is not undervoltage;

wherein z is₁、z₂、z₃、z₄Which refer to the load signals of the left front wheel, the right front wheel, the left rear wheel and the right rear wheel, respectively.

The invention has the beneficial effects that: the tire pressure monitoring method firstly carries out preliminary judgment of tire underpressure through indirect tire pressure monitoring, adds a confirming part of tire underpressure on the basis of the preliminary judgment, namely, the direct tire pressure monitoring is carried out, a vehicle load signal is introduced, the influence of the vehicle load signal is eliminated by judging the relation between the vehicle load signal and the angular speed signal of the wheel, the actual underpressure state of the tire can be judged more accurately, and the problem of false alarm caused by uneven load distribution is avoided.

Drawings

FIG. 1 is a schematic view of a tire pressure monitoring system for a passenger vehicle according to the present invention;

fig. 2 is a flowchart of a tire pressure monitoring control method for a passenger vehicle according to the present invention.

Detailed Description

Embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

Specifically, the description of the tire pressure monitoring method is taken as an example of a passenger car, but the present invention is not limited to the passenger car given in the embodiment, and is also applicable to tire pressure monitoring of other vehicles.

Fig. 1 is a schematic view of a tire pressure monitoring system for a passenger vehicle, which includes a wheel speed sensor, a tire strain sensor, a tire pressure monitoring controller, and an instrument module. The wheel speed sensors are arranged on each wheel of the vehicle, and can monitor the angular speed signals of the wheels of each tire in real time; the tire strain sensor is arranged in an air spring or an oil-gas spring cavity of a vehicle, and can measure the pressure in the spring, namely the stress condition of each tire of the vehicle, namely a load signal; the tire pressure monitoring controller can read the information of relevant load signals and angular speed signals of wheels from the tire strain sensors and the wheel speed sensors of all tires of the vehicle, and the information is used for calculation and analysis of tire pressure monitoring.

The wheel speed sensor and the tire strain sensor in the embodiment transmit monitored data to the tire pressure monitoring controller through the CAN bus, and report the data to the instrument module through the CAN bus after calculation and analysis, and the instrument module judges according to the received signals and gives an early warning prompt in an acousto-optic form to a driver.

Specifically, as shown in fig. 2, when the system is powered on, the wheel speed sensors collect angular velocity signals of four wheels, the tire pressure monitoring controller receives the angular velocity signals of each wheel, and performs corresponding calculation and analysis according to the relationship between the angular velocity signals of each wheel, and the specific steps are as follows:

1. angular velocity signals and load signals of four wheels are collected.

2. And preliminarily judging whether the tire is in an undervoltage state or not according to the relationship of the collected angular speed signals of the four wheels.

Wherein, let l1, l2, l3, l4 respectively indicate left front wheel, right front wheel, left rear wheel and right rear wheel, preliminary judgement tire underpressure state has following four kinds of situations specifically:

if w₁>w₂＝w₃＝w₄I.e. r>0, the left front wheel l1 is in an under-voltage state;

if w₂>w₁＝w₃＝w₄I.e. r<0, the right front wheel l2 is in an under-voltage state;

if w₃>w₄＝w₁＝w₂I.e. r<0, the left rear wheel l3 is in an under-voltage state;

if w₄>w₁＝w₂＝w₃I.e. r>0, the right rear wheel l4 is in an undervoltage state;

the set threshold r in this embodiment is a difference between a ratio of collected angular velocity signals of two front wheel wheels and a ratio of collected angular velocity signals of two rear wheel wheels, and its expression is:

wherein, w₁、w₂、w₃、w₄Which refer to the angular velocity signals of the wheels of the left front wheel l1, the right front wheel l2, the left rear wheel l3 and the right rear wheel l4, respectively.

In conclusion, according to the formula, when r>0, indicating that the left front wheel l1 or the right rear wheel l4 is under-pressurized, using wheel angular velocity correction if w₁>w₂＝w₃＝w₄If the left front wheel l1 is under-voltage, otherwise, the right rear wheel l4 is under-voltage; when r is<0, indicating an under-pressure of the front right wheel l2 or the rear left wheel l3, likewise if w₂>w₁＝w₃＝w₄The explanation is that the right front wheel l2 is undervoltage, and the reverse explains that the left rear wheel l3 is undervoltage.

The set threshold r in the present embodiment refers to a difference value based on a non-linear change of the static wheel speed, and when the set threshold r is equal to 0, that is, when the tire pressure is optimal, it is determined that the tire is normal. When the set threshold r is not 0, it can be preliminarily determined that a certain wheel tire is in an underpressure state.

As other embodiments, the tire underpressure monitoring method disclosed in the chinese patent application "tire pressure monitoring method and apparatus based on OBD" with application publication number "CN 105691121A" may also be used in the present invention to preliminarily determine whether the tire is in an underpressure state.

3. And judging whether the load signal of the tire in the undervoltage state is different from the load signals of other tires, and if so, judging that the tire is not undervoltage.

Because the angular speed of the tire is influenced by the vehicle load, in order to further ensure the accuracy of tire pressure monitoring, the invention acquires the load signals z of four wheels by using the tire strain sensor₁、z₂、z₃、z₄Which correspond to the left front wheel l1, the right front wheel l2, the left rear wheel l3 and the right rear wheel l4, respectively, and further confirm the tire underpressure conditions of the four cases in step 2.

When the load of the vehicle is uniform, namely the collected load signals z of four wheels₁、z₂、z₃、z₄Equal, the above four cases are explainedEither condition corresponds to the tire being in fact under-pressurized condition.

When the load of the vehicle is not uniform, specifically, taking the case that the preliminary judgment in step 2 monitors that the right front wheel l2 is in an undervoltage state as an example, the load signal condition of the right front wheel l2 is judged, if z is₂>z₁＝z₃＝z₄And is andif the monitoring result is due to the influence of the load, namely the right front wheel l2 is not undervoltage, the alarm is not given, otherwise, the right front wheel l2 is undervoltage, namely the alarm is given.

Of course, the judgment of whether the left front wheel l1, the left rear wheel l3 and the right rear wheel l4 are under-pressure or not in the other three cases is similar to the judgment method of the right front wheel l 2:

when the left front wheel l1 is under-voltage, if z₁>z₂＝z₃＝z₄And is and

the left front wheel l1 is not undervoltage;

when the left rear wheel l3 is under-voltage in the preliminary judgment, if z₃>z₂＝z₁＝z₄And is and

the left rear wheel l3 is not under-pressurized;

when the rear right wheel l4 is preliminarily judged to be in the undervoltage state, if z is₄>z₂＝z₃＝z₁And is and

the right rear wheel l4 is not underpressurized.

Formulas in the present embodiment

The actual meaning of the representation can be that the ratio of the two is consistent, or the corresponding precision range is set according to the actual requirementThe ratio of the two can be regarded as equal as long as the ratio is within the set precision range; and the specific precision range thereof needs real vehicle calibration. Likewise, the formula

The meaning of the expression is the same as above.

In the above embodiment, the wheel is sequentially determined in the order of the front left wheel, the front right wheel, the rear left wheel, and the rear right wheel. In another embodiment, the order may be different, and the set threshold r may be calculated and analyzed according to the order of the wheels.

The tire pressure monitoring method is divided into two parts, wherein the first part is a primary judgment and detection part; secondly, confirming the underpressure of the tyre; the preliminary judgment detection part is used for preliminary judgment of tire underpressure through indirect tire pressure monitoring, but the method is not limited to the specific means in the step 2, and tire pressure monitoring methods in the prior art can be used as the preliminary judgment method; the key of the invention is a confirming part of the tire underpressure, which is based on the first part, directly monitors the tire pressure, namely introduces a vehicle load signal, and eliminates the influence of the vehicle load signal by judging the relation between the vehicle load signal and the angular velocity signal of the wheel, thereby more accurately judging the actual underpressure state of the tire and avoiding the problem of false alarm caused by uneven load.

The invention also provides a tire pressure monitoring device, which comprises a controller, a memory and a program stored in the memory and capable of running on the controller, wherein the controller executes the program to realize the following steps:

1) collecting angular speed signals and load signals of four wheels;

2) preliminarily judging whether the tire is in an undervoltage state or not according to the relationship of the collected angular speed signals of the four wheels;

3) and then judging whether the load signal of the tire in the undervoltage state is different from the load signals of other tires, and if the load signals are different, judging that the tire is not undervoltage.

The specific embodiments are given above, but the present invention is not limited to the described embodiments. The basic idea of the present invention is to provide the above basic solution, and those skilled in the art can make changes, modifications, substitutions and variations to the embodiments without departing from the principle and spirit of the present invention.