CN114046985B

CN114046985B - Single valve PI test method in ESC assembly and electronic stability control system

Info

Publication number: CN114046985B
Application number: CN202111319251.2A
Authority: CN
Inventors: 陶喆; 刘海珍; 余茂奎; 张日波; 张晨鸣; 陆锋
Original assignee: Nason Automotive Technology Hangzhou Co ltd
Current assignee: Nason Automotive Technology Hangzhou Co ltd
Priority date: 2021-11-05
Filing date: 2021-11-05
Publication date: 2024-06-04
Anticipated expiration: 2041-11-05
Also published as: CN114046985A

Abstract

The invention provides a single valve PI test method in an ESC assembly and an electronic stability control system, wherein the single valve PI test in the ESC assembly comprises the following steps: starting a motor, opening an oil supply valve, closing a pressure regulating valve, enabling a brake cylinder to supply liquid to the ESC, and controlling the ESC to perform active pressure building; controlling the duty ratio of a first booster valve to be detected to be a first interval, and acquiring the pressure difference of the front end and the rear end of the first booster valve through a pressure detection device; and respectively recording the pressure difference of the first pressure boosting valve under different duty ratios in the first interval to obtain a PI curve of the first pressure boosting valve. According to the invention, the automatic test of PI can be realized mainly by driving the plunger pump piston to move and build pressure through the motor rotation according to the active pressure building function of the ESC, and then the corresponding single valve in the tested assembly is controlled in sequence, so that excessive human participation is not needed, and the test efficiency and accuracy of the PI of the ESC assembly are greatly improved.

Description

Single valve PI test method in ESC assembly and electronic stability control system

Technical Field

The invention relates to the technical field of vehicle safety, in particular to a single valve PI test method in an ESC assembly and an electronic stability control system.

Background

With the development and popularization of the automobile industry, the stability of the electronic products on the chassis of the automobile is also important. The ESC product has an extremely important effect on the whole control of the whole vehicle. Because the control effect of the ESC product on the whole vehicle is mainly based on the accuracy of the single valve PI written by software in the ESC assembly, and no quick and effective test method for testing the single valve PI in the ESC assembly exists in the whole industry at present, how to quickly and efficiently test the single valve PI in the ESC assembly is also a problem to be solved urgently in the industry at present.

At present, most of conventional test methods for testing single valve PI in an ESC assembly are manual test methods, and test pipelines are manually connected by testers, and because 6 single valves (2 pressure limiting valves and 4 pressure increasing valves) in the ESC assembly need to be tested, the testers need to manually replace the test pipelines after each single valve is tested, the whole test period can be prolonged, and the test efficiency of the whole PI is affected. Because the testers need to frequently disassemble and assemble the test pipelines and can not ensure that the installation positions of the test pipelines can be completely consistent each time, the whole test accuracy of the conventional manual test method is low, and the conventional manual test method needs to have external power source participation.

The foregoing description is provided for general background information and does not necessarily constitute prior art.

Disclosure of Invention

Aiming at the technical problems, the invention provides the single valve PI test method and the electronic stability control system in the ESC assembly, which can improve the test efficiency and accuracy of the PI of the ESC assembly, and are simple to operate without the participation of an external power source.

In order to solve the technical problems, the invention provides a single valve PI test method in an ESC assembly, which is applied to an electronic stability control system and comprises the following steps:

The motor is started to drive the plunger pump to move, so that the ESC carries out active pressure building; controlling the duty ratio of a valve to be tested to be a first interval, and acquiring the pressure difference of the front end and the rear end of the valve to be tested through a pressure detection device; and respectively recording the pressure differences of the tested valve under different duty ratios in the first interval to obtain a PI curve of the tested valve.

Optionally, the method further comprises: before testing the PI curve, the ESC is subjected to exhausting operation through a motor plunger pump, so that the gas in a pipeline in the ESC is completely exhausted.

Optionally, the step of starting the motor to drive the plunger pump to move to enable the ESC to actively build pressure comprises the following steps: the motor speed is fixed and a fixed current duty cycle is set for the oil supply valve and the pressure regulating valve in the ESC.

Optionally, after the step of starting the motor to drive the plunger pump to move and make the ESC perform active pressure building, the method further comprises: and setting a fixed duty ratio for a pressure relief valve on the same side as the tested valve, so that the pressure value at the lower end of the tested valve is zero.

Optionally, the valve under test is a booster valve.

Optionally, the step of controlling the duty ratio of the measured valve to be a first interval and acquiring the pressure difference between the front end and the rear end of the measured valve through the pressure detection device includes: in the test process, the duty ratio of the valve to be tested is increased or decreased according to a fixed slope in the first interval range.

The invention also provides an electronic stability control system for executing the method, wherein the electronic stability control system is respectively connected with the brake cylinder and the brake wheel set through pipelines, and the electronic stability control system comprises a motor plunger pump, an oil supply valve, a pressure regulating valve, a pressure relief valve, a pressure increasing valve and a pressure detecting device;

the oil supply valve is connected to a first pipeline between the brake cylinder and the motor plunger pump;

the pressure regulating valve is connected to a second pipeline between the brake cylinder and the brake wheel set;

the pressure increasing valve is connected to a second pipeline between the pressure regulating valve and the brake wheel set;

the pressure release valve is connected to a third pipeline between the brake wheel set and the motor plunger pump;

The motor plunger pump is also connected between the pressure regulating valve and the braking wheel set through a fourth pipeline;

the motor plunger pump includes: motor and plunger pump, the braking wheelset includes: a first wheel cylinder and a second wheel cylinder, the pressure-increasing valve including: a first pressure increasing valve and a second pressure increasing valve;

The pressure detection device includes: the brake system comprises a first pressure sensor, a second pressure sensor and a third pressure sensor, wherein the first pressure sensor is installed at an outlet of a brake cylinder, the second pressure sensor is installed on a pipeline between a first pressure increasing valve and a first wheel cylinder, and the third pressure sensor is installed on a pipeline between a second pressure increasing valve and a second wheel cylinder.

Optionally, when the first booster valve is a tested valve, the second booster valve is kept open, so that the brake fluid reaches the second pressure release valve through the second booster valve.

Optionally, the motor maintains a fixed rotational speed.

As described above, the method for testing the PI of the single valve in the ESC assembly is applied to an electronic stability control system, and mainly comprises the steps of driving a plunger pump piston to move and build pressure through motor rotation according to the active pressure building function of the ESC, and then sequentially controlling the corresponding single valve in the tested assembly to realize the automatic test of the PI. By the mode, external power source participation is not needed, one-key starting can be achieved without artificial excessive participation, and the testing efficiency and accuracy of the PI of the ESC assembly are greatly improved.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and together with the description, serve to explain the principles of the invention. In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the description of the embodiments will be briefly described below, and it will be obvious to those skilled in the art that other drawings can be obtained from these drawings without inventive effort.

Fig. 1 is a flow chart of a single valve PI test method within an ESC assembly, in accordance with an embodiment of the present invention;

FIG. 2 is a diagram illustrating a test path of a PI curve of a booster valve according to an embodiment of the present invention;

FIG. 3 is a diagram illustrating another boost valve PI curve test path according to an embodiment of the present invention;

fig. 4 is a schematic structural diagram of an electronic stability control system according to an embodiment of the present invention.

The achievement of the objects, functional features and advantages of the present invention will be further described with reference to the accompanying drawings, in conjunction with the embodiments. Specific embodiments of the present invention have been shown by way of the above drawings and will be described in more detail below. The drawings and the written description are not intended to limit the scope of the inventive concepts in any way, but rather to illustrate the inventive concepts to those skilled in the art by reference to the specific embodiments.

Detailed Description

Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. When the following description refers to the accompanying drawings, the same numbers in different drawings refer to the same or similar elements, unless otherwise indicated. The implementations described in the following exemplary examples do not represent all implementations consistent with the invention. Rather, they are merely examples of apparatus and methods consistent with aspects of the invention as detailed in the accompanying claims.

It should be noted that, in this document, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, the element defined by the phrase "comprising one … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element, and furthermore, elements having the same name in different embodiments of the invention may have the same meaning or may have different meanings, the particular meaning of which is to be determined by its interpretation in this particular embodiment or by further combining the context of this particular embodiment.

It should be understood that although the terms first, second, third, etc. may be used herein to describe various information, these information should not be limited by these terms. These terms are only used to distinguish one type of information from another. For example, first information may also be referred to as second information, and similarly, second information may also be referred to as first information, without departing from the scope herein. The term "if" as used herein may be interpreted as "at … …" or "at … …" or "in response to a determination", depending on the context. Furthermore, as used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes," and/or "including" specify the presence of stated features, steps, operations, elements, components, items, categories, and/or groups, but do not preclude the presence, presence or addition of one or more other features, steps, operations, elements, components, items, categories, and/or groups. The terms "or", "and/or", "including at least one of", and the like, as used herein, may be construed as inclusive, or mean any one or any combination. For example, "including at least one of: A. b, C "means" any one of the following: a, A is as follows; b, a step of preparing a composite material; c, performing operation; a and B; a and C; b and C; a and B and C ", again as examples," A, B or C "or" A, B and/or C "means" any of the following: a, A is as follows; b, a step of preparing a composite material; c, performing operation; a and B; a and C; b and C; a and B and C). An exception to this definition will occur only when a combination of elements, functions, steps or operations are in some way inherently mutually exclusive.

It should be understood that, although the steps in the flowcharts in the embodiments of the present invention are shown in order as indicated by the arrows, these steps are not necessarily performed in order as indicated by the arrows. The steps are not strictly limited in order and may be performed in other orders, unless explicitly stated herein. Moreover, at least some of the steps in the figures may include multiple sub-steps or stages that are not necessarily performed at the same time, but may be performed at different times, the order of their execution not necessarily occurring in sequence, but may be performed alternately or alternately with other steps or at least a portion of the other steps or stages.

The words "if", as used herein, may be interpreted as "at … …" or "at … …" or "in response to a determination" or "in response to a detection", depending on the context. Similarly, the phrase "if determined" or "if detected (stated condition or event)" may be interpreted as "when determined" or "in response to determination" or "when detected (stated condition or event)" or "in response to detection (stated condition or event), depending on the context.

It should be noted that, in this document, step numbers such as S1 and S2 are adopted, and the purpose of the present invention is to more clearly and briefly describe the corresponding content, and not to constitute a substantial limitation on the sequence, and those skilled in the art may execute S2 first and then execute S1 when implementing the present invention, which is within the scope of protection of the present invention.

It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.

In the following description, suffixes such as "module", "part" or "unit" for representing elements are used only for facilitating the description of the present invention, and have no specific meaning per se. Thus, "module," "component," or "unit" may be used in combination.

The invention discloses a single valve PI test method in an ESC assembly, which is applied to an electronic stability control system (ESC), and is mainly used for automatically realizing the test according to the active pressure building function of the ESC assembly without external power source participation. The whole test can be started by one key without excessive human participation, and the test efficiency and accuracy of the ESC assembly PI are greatly improved. Optionally, the method for testing the single valve PI in the ESC assembly according to the present invention may be implemented by the electronic stability control system of the vehicle provided by any embodiment of the present invention, and the system may be implemented by software and hardware, and may be integrated in a vehicle such as an automobile.

First embodiment

Referring to fig. 1, as shown in fig. 1, the method for testing the single valve PI in the ESC assembly of the present invention comprises the following steps:

step S11: the motor is started to drive the plunger pump to move, so that the ESC can actively build pressure.

Step S12: and controlling the duty ratio of the valve to be tested to be a first interval, and acquiring the pressure difference of the front end and the rear end of the valve to be tested through a pressure detection device.

Step S13: and respectively recording the pressure differences of the tested valve under different duty ratios in the first interval to obtain a PI curve of the tested valve.

In one embodiment, the method of the present invention further comprises: before formally testing the PI curve, the ESC is subjected to exhaust operation through a motor plunger pump, and the gas of a test pipeline in the ESC is completely exhausted.

In one embodiment, step S11: the motor starts to drive the plunger pump to move, so that the ESC actively builds pressure, comprising: the motor rotation speed is fixed, and fixed current duty ratios are respectively set for an oil supply valve and a pressure regulating valve in the ESC assembly.

In one embodiment, step S11: the motor starts to drive the plunger pump to move, so that the ESC actively builds pressure, and then the method further comprises the following steps: and setting a fixed duty ratio for a pressure relief valve on the same side as the tested valve, so that the pressure value at the lower end of the tested valve is zero.

In one embodiment, the valve under test is a booster valve.

In one embodiment, step S12: the duty ratio of the valve to be tested is controlled to be a first interval, and the pressure difference of the front end and the rear end of the valve to be tested is obtained through a pressure detection device, and the method comprises the following steps: the duty ratio of the valve to be tested is increased or decreased according to a fixed slope in the first interval range.

The following is an illustration in connection with the method steps described above:

referring to fig. 2, fig. 2 is a PI curve test path of a side boost valve in an ESC assembly.

For example: the PI curve of the rr_iv (RR side boost valve, reference 15 in fig. 2) in the ESC assembly was automatically tested at 1000rpm for the motor (reference 12 in fig. 2 and 3).

The PI curve of the RR_IV valve corresponds to the pressure difference curve of the front end and the rear end of the RR_IV valve under different current duty ratios. I.e. the pressure difference between sensor 2 and sensor 3 in fig. 2, the pressure collected by sensor 3 remains zero throughout the test, and the pressure collected by sensor 2 is varied. Alternatively, sensor 2 may be an RR-end pressure sensor; the sensor 3 may be a FL-side pressure sensor.

First, the ESC assembly requires a systematic exhaust of gas before the PI curves are formally tested, and the gas in each circuit formed by the pipe connection of each component (such as a brake cylinder, each valve, a motor plunger pump, each wheel cylinder group and the like) in the ESC assembly is completely exhausted.

Alternatively, the negative pressure can be created by the movement of a motor plunger pump and the cooperation between the valves in the ESC assembly to vent the gas from the circuits in the ESC assembly. In the whole exhaust process of the electronic stability control system, the motor rotates at a certain rotating speed to drive the plunger pump to perform piston movement so as to form negative pressure, so that brake liquid in the brake cylinder enters the ESC assembly, and gas in each loop in the ESC assembly is discharged. The motor rotation speed is not limited and can be set according to actual requirements.

Secondly, after the exhaustion is completed, the motor is controlled to operate at a rotation speed to be tested, namely, a rotation speed of 1000rpm, and a fixed current duty ratio of an oil supply valve (11 shown in fig. 2) and a pressure regulating valve (13 shown in fig. 2) is set, so that the ESC assembly is in an active pressure building state.

Alternatively, the current duty cycle is fixed by a given oil supply valve and pressure regulating valve, and brake fluid is passed from the brake cylinder to the motor-plunger pump via the oil supply valve. And then the motor rotates to drive the plunger pump to move to form negative pressure, so that the ESC actively builds pressure.

Finally, after the duty ratio of the tested booster valve, namely RR_IV, is set by software, the pressure difference between the front end and the rear end of the RR_IV valve, namely the PI value, is obtained. The PI value is the PI value at the set duty cycle. Wherein rr_ov (RR side relief valve, 19 in fig. 2) needs to be given a fixed duty cycle all the time throughout the test such that rr_iv lower end pressure is zero (i.e. the pressure measured by sensor 3 is 0 bar). Therefore, the PI value is the pressure value measured by the sensor 2.

Specifically, by setting the duty cycle of the boost valve, the pressure inside the ESC can be regulated.

Alternatively, the brake fluid reaches rr_iv (i.e., the valve under test) and fl_iv (FL-side pressure-increasing valve, reference numeral 14 in fig. 2) via the motor plunger pump, respectively, and then enters fl_wheel cylinder (front left wheel, reference numeral 17 in fig. 2) via fl_iv, and finally reaches fl_ov (fl_pressure-releasing valve, reference numeral 18 in fig. 2).

Alternatively, if the PI curve of rr_iv within a certain duty cycle range is to be directly tested, the duty cycle output of the valve under test is directly set by software. For example, if the PI curve of rr_iv is tested within the range of 10% -50%, the duty cycle output of the given rr_iv of the software is directly set to rise or fall according to a certain slope within the range of 10% -50%.

It is noted that when testing an IV boost valve PI curve over a certain range of duty cycles, care needs to be taken to give a larger duty cycle current to the corresponding side TV pressure regulating valve (reference 13 in fig. 2). For example, when testing PI curves with RR_IV in the range of 10% to 50%, it is necessary to give a 15% to 55% duty cycle current to the side TV pressure regulator valve.

Similarly, if the PI curve of fl_iv at the motor speed of 1000rpm is to be tested, the test method can be performed according to the PI curve test path shown in fig. 3, and the test method is the same as that of the above embodiment.

According to the invention, the automatic test of PI can be realized by driving the plunger pump piston to move and build pressure through the rotation of the motor according to the active pressure building function of the ESC and then sequentially controlling the corresponding single valve in the tested assembly, the participation of an external power source is not needed, the whole test can be started by one key, the artificial excessive participation is not needed, and the test efficiency and accuracy of the PI of the ESC assembly are greatly improved.

Second embodiment

The invention also provides a method for performing any of the above embodiments.

Referring to fig. 4, as shown in fig. 4, an electronic stability control system according to an embodiment of the present invention includes: an oil supply valve 11, a motor plunger pump 12, a pressure regulating valve 13, a pressure increasing valve, a pressure releasing valve and a pressure detecting device. The pressure-increasing valve includes at least: a first pressure increasing valve 15 and a second pressure increasing valve 14. The relief valve includes at least: a first pressure relief valve 19 and a second pressure relief valve 18. The pressure detection device at least comprises: a first pressure sensor 1, a second pressure sensor 2 and a third pressure sensor 3. The motor-plunger pump 12 includes: the motor is connected with the plunger pump 2 through complete mechanical contact, and the motor drives the plunger pump therein to move the piston when rotating.

Optionally, the electronic stability control system is connected to the brake cylinder 10 and the brake wheel set via pipes, respectively.

The oil supply valve 11 is connected to a first line between the brake cylinder 10 and the motor-plunger pump 12.

The pressure regulating valve 13 is connected to a second line between the brake cylinder 10 and the brake wheel set.

The pressure release valve is connected to a third line between the brake set and the motor-plunger pump 12.

The motor-plunger pump 12 is also connected between the pressure regulating valve and the brake wheel set by a fourth line.

Wherein the pressure increasing valve is connected to the second line between the pressure regulating valve 13 and the brake wheel set. The brake wheelset includes: a first wheel cylinder 16 and a second wheel cylinder 17. The pressure regulating valve 13 is connected to the first wheel cylinder 16 and the second wheel cylinder 17 via second lines, respectively. The first pressure increasing valve 15 is connected to a line between the first wheel cylinder 16 and the pressure regulating valve 13, and the second pressure increasing valve 14 is connected to a line between the second wheel cylinder 17 and the pressure regulating valve 13. The first pressure release valve 19 is connected to a line between the first wheel cylinder 16 and the motor-plunger pump 12, and the second pressure release valve 18 is connected to a line between the second wheel cylinder 17 and the motor-plunger pump 12. The first pressure sensor 1 is provided on the outlet line of the brake cylinder 10, the second pressure sensor 2 is provided on the line between the second pressure-increasing valve 14 and the second wheel cylinder 17, and the third pressure sensor 3 is provided on the line between the first pressure-increasing valve 15 and the first wheel cylinder 16.

In one embodiment, during the test, if the valve under test is the first pressure increasing valve, the second pressure increasing valve is required to be kept open, so that the brake fluid reaches the second pressure releasing valve through the second pressure increasing valve.

In one embodiment, during the test, the motor is always kept at a fixed speed, such as 1000rpm, and the PI curve tested is the PI curve at the set duty cycle at 1000 rpm.

The invention also provides a vehicle, and the electronic stability control system is mounted on the vehicle.

The invention also provides a computer readable storage medium, wherein the computer readable storage medium is stored with a single valve PI test program in the ESC assembly, and the single valve PI test program in the ESC assembly realizes the steps of the single valve PI test method in the ESC assembly in any embodiment when being executed by a processor.

In the embodiments of the mobile terminal and the computer readable storage medium provided by the present invention, all technical features of each embodiment of the above method are included, and the expansion and explanation contents of the description are basically the same as those of each embodiment of the above method, which are not repeated herein.

Embodiments of the present invention also provide a computer program product comprising computer program code which, when run on a computer, causes the computer to perform the method as in the various possible embodiments described above.

The embodiment of the invention also provides a chip, which comprises a memory and a processor, wherein the memory is used for storing a computer program, and the processor is used for calling and running the computer program from the memory, so that the device provided with the chip executes the method in the various possible implementation manners.

The foregoing embodiment numbers of the present invention are merely for the purpose of description, and do not represent the advantages or disadvantages of the embodiments.

The steps in the method of the embodiment of the invention can be sequentially adjusted, combined and deleted according to actual needs.

The units in the device of the embodiment of the invention can be combined, divided and deleted according to actual needs.

In the present invention, the same or similar term concept, technical solution and/or application scenario description will be generally described in detail only when first appearing and then repeatedly appearing, and for brevity, the description will not be repeated generally, and in understanding the present invention technical solution and the like, reference may be made to the previous related detailed description thereof for the same or similar term concept, technical solution and/or application scenario description and the like which are not described in detail later.

In the present invention, the descriptions of the embodiments are emphasized, and the details or descriptions of the other embodiments may be referred to.

The technical features of the technical scheme of the invention can be arbitrarily combined, and all possible combinations of the technical features in the above embodiment are not described for the sake of brevity, however, as long as there is no contradiction between the combinations of the technical features, the invention shall be considered as the scope of the description of the invention.

From the above description of the embodiments, it will be clear to those skilled in the art that the above-described embodiment method may be implemented by means of software plus a necessary general hardware platform, but of course may also be implemented by means of hardware, but in many cases the former is a preferred embodiment. Based on such understanding, the technical solution of the present invention may be embodied essentially or in a part contributing to the prior art in the form of a software product stored in a storage medium (e.g. ROM/RAM, magnetic disk, optical disk) as above, comprising instructions for causing a terminal device (which may be a mobile phone, a computer, a server, a controlled terminal, or a network device, etc.) to perform the method of each embodiment of the present invention.

In the above embodiments, it may be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, the processes or functions in accordance with embodiments of the present invention are produced in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable devices. The computer instructions may be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center by a wired (e.g., coaxial cable, fiber optic, digital subscriber line), or wireless (e.g., infrared, wireless, microwave, etc.). Computer readable storage media can be any available media that can be accessed by a computer or data storage devices, such as servers, data centers, etc., that contain an integration of one or more available media. Usable media may be magnetic media (e.g., floppy disks, storage disks, magnetic tape), optical media (e.g., DVD), or semiconductor media (e.g., solid state storage disk Solid STATE DISK (SSD)), etc.

The foregoing description is only of the preferred embodiments of the present invention, and is not intended to limit the scope of the invention, but rather is intended to cover any equivalents of the structures or equivalent processes disclosed herein or in the alternative, which may be employed directly or indirectly in other related arts.

Claims

1. The utility model provides a single valve PI test method in ESC assembly is applied to electronic stability control system, characterized in that, single valve PI test in the ESC assembly includes:

Exhausting the ESC through a motor plunger pump to completely exhaust the gas of a pipeline in the ESC;

starting a motor to drive a plunger pump to move, controlling the motor to rotate at a fixed speed, and setting a fixed current duty ratio for an oil supply valve and a pressure regulating valve in the ESC to enable the ESC to perform active pressure building;

controlling the duty ratio of a tested valve to be a first interval, and acquiring the pressure difference of the front end and the rear end of the tested valve through a pressure detection device, wherein the tested valve is a booster valve;

setting a pressure release valve on the same side as the tested valve as a fixed duty ratio to enable the pressure value at the lower end of the tested valve to be zero;

and controlling the duty ratio of the tested valve to rise or fall according to a fixed slope in the range of the first interval, and respectively recording the pressure differences of the tested valve under different duty ratios in the first interval to obtain a PI curve of the tested valve.

2. An electronic stability control system for performing the method of claim 1, the electronic stability control system being connected to the brake cylinder and the brake wheel set by pipelines, respectively, the electronic stability control system comprising a motor plunger pump, an oil supply valve, a pressure regulating valve, a pressure relief valve, a pressure increasing valve, and a pressure detecting device;

3. The electronic stability control system of claim 2 wherein when the first boost valve is a valve under test, the second boost valve remains open allowing brake fluid to pass through the second boost valve to the second pressure relief valve.

4. The electronic stability control system of claim 2 wherein the motor maintains a fixed rotational speed.