A method and system for detecting air spring leakage in air suspension vehicles.

Abstract

This invention discloses a method and system for detecting air spring leakage in vehicles with air suspension, belonging to the field of automotive suspension system development. The method includes the following steps: acquiring the vehicle's current speed to determine its current state, including a stationary state and a moving state; when the vehicle is stationary and the power is on, acquiring the current height of each air spring in the air suspension system and comparing it with a preset target height, determining whether air spring height compensation should be performed based on the comparison result, and finally determining whether the air spring is leaking based on the number of height compensation cycles within a first preset time period; when the vehicle is in motion, acquiring the height of each air spring in the air suspension system and comparing them, determining whether the air spring is leaking based on the comparison result. This invention achieves real-time automatic air spring leakage detection and improves detection accuracy.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of automobile suspension system development, and in particular, the present application relates to a method and system for detecting air spring leakage of an air suspension vehicle. BACKGROUND

[0002] With the increasing number of new energy electric vehicles, consumers' demand for vehicle intelligence and comfort is becoming increasingly apparent. Therefore, more and more new energy vehicles choose to be equipped with air suspension, which can automatically adjust the vehicle height according to different working conditions. For example, when driving at high speed, the vehicle height is actively lowered to reduce wind resistance and maintain stability; when passing through rough road surfaces, the vehicle height is actively raised to improve passability. Air spring, as an important component of air suspension, its supporting performance mainly depends on the internal air pressure.

[0003] However, air springs have a problem of air leakage, which can greatly affect driving safety. Air leakage can be divided into two cases: slow leakage and rapid leakage. Currently, there is no effective method to detect and avoid air leakage problems in China, and usually only rely on visual observation of the vehicle height after parking to determine whether there is a significant change. Traditionally, vehicle owners can only visually observe the change in vehicle height after parking to determine whether there is air leakage. This method is obviously not efficient and real-time. Therefore, developing a software or technology that can instantly identify air leakage of air suspension is expected to improve the driving safety and quality of the driving experience of new energy vehicles.

[0004] With the continuous progress of automotive technology and the growth of market demand, more advanced air leakage detection technologies may emerge in the future, which are expected to improve the reliability and safety of air suspension systems to meet consumers' demand for high-quality driving experience. SUMMARY

[0005] The present application aims to overcome the shortcomings of the prior art and proposes a method and system for detecting air spring leakage of an air suspension vehicle to achieve real-time automatic air spring leakage detection and improve detection accuracy.

[0006] To achieve the above purpose, the technical solution adopted by the present application is as follows:

[0007] A method for detecting air spring leakage of an air suspension vehicle, the method comprising the following steps:

[0008] S1, obtaining the current speed of the vehicle to determine the current state of the vehicle, the state including a stationary state and a moving state;

[0009] S2, when the vehicle is in a static state and the vehicle is not powered off, obtaining a current height of each air spring in the air suspension system and comparing the current height with a preset target height, judging whether to perform air spring height compensation according to a comparison result, and finally judging whether the air spring leaks according to a height compensation frequency within a first preset time;

[0010] S3, when the vehicle is in a moving state, obtaining the height of each air spring in the air suspension system and comparing the height with each other, and judging whether the air spring leaks according to a comparison result.

[0011] Preferably, the step S2 specifically comprises:

[0012] calculating a difference H between the current height of each air spring and the target height, that is:

[0013] H = H t1 -H t0 ;

[0014] wherein H t1 represents the target height of the air spring, and H t0 represents the current height of the air spring.

[0015] Within the first preset time, each time the H of an air spring is greater than a preset difference threshold value, the air spring will perform height compensation, and the height compensation frequency of the air spring within the first preset time is recorded. After the first preset time ends, if the height compensation frequency is greater than a preset first frequency threshold value, it is judged that the air spring leaks, otherwise the step S1 is returned.

[0016] Within the first preset time, each time the H is less than or equal to the preset difference threshold value, the step S1 is directly returned.

[0017] Preferably, the first preset time is 1 hour, the preset difference threshold value is 15 mm, and the preset first frequency threshold value is 3 times.

[0018] Preferably, the step S2 further comprises detection of a door opening, that is, within the first preset time, it is detected whether there is a door opening state; when there is a door opening, the height compensation frequency record result and the timing are cleared and the step S1 is returned; when there is no door opening, subsequent frequency judgment is continued.

[0019] Preferably, the step S2 further comprises: when the vehicle is in a static state and the vehicle is powered off, first checking whether the air spring controller is in a sleep wake-up state:

[0020] When the air spring controller is not in the sleep wake-up state, the step S1 is returned;

[0021] When the air spring controller is in the dormant wake-up state, the number of air spring height compensation times in a second preset time is recorded; if the number of air spring height compensation times in the second preset time is greater than a preset second number threshold, it is judged that there is air spring leakage, otherwise the step S1 is returned.

[0022] Preferably, the second preset time is 24 hours, and the second number threshold is 2 times.

[0023] Preferably, the step S3 specifically comprises:

[0024] The height range H1 of the air spring in the air suspension system is calculated, that is:

[0025] H1 = H max -H min ;

[0026] Wherein, H max represents the maximum height value in all air springs, and H min represents the minimum height value in all air springs.

[0027] When H1 is less than a preset range threshold, the step S1 is returned; when H1 is greater than or equal to the preset range threshold, it is judged that there is air spring leakage.

[0028] Preferably, in the step S3, the duration limit of H1 being greater than or equal to the preset range threshold is added, only when the duration is greater than or equal to a preset duration threshold, it is judged that there is air spring leakage, otherwise the step S1 is returned.

[0029] Preferably, the range threshold is 60 mm, and the duration threshold is 20 seconds.

[0030] Meanwhile, the application also proposes an air spring leakage detection system for air suspension vehicles, which is constructed according to any one of the above air spring leakage detection methods for air suspension vehicles, and comprises a vehicle speed sensor, an air spring height sensor and a controller, wherein the vehicle speed sensor and the air spring height sensor are connected with the controller respectively, the vehicle speed sensor is used for detecting real-time vehicle speed and feeding back to the controller, the air spring height sensor is used for acquiring real-time height of the air spring and feeding back to the controller, and the controller is used for controlling height compensation of the air spring and performing leakage detection.

[0031] The technical effects of the present application are: (1) The present application takes into account the difference between air spring leakage detection in the stationary state and the moving state of the vehicle, and correspondingly sets different data processing methods and judgment processes to realize automatic leakage detection. (2) The present application also takes into account the air spring leakage detection under the conditions of vehicle power-on, power-off, controller hibernation and wake-up, so that the leakage detection is suitable for various states of the vehicle and has wide application. (3) The present application also sets time limits in each detection process to avoid misjudgment caused by uneven road surface or abnormal data, improve the detection accuracy, and reduce the error. BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 A flow chart of a detection method for air spring leakage of an air suspension vehicle according to an embodiment of the present application. DETAILED DESCRIPTION

[0033] The specific embodiments of the present application will be further described below with reference to the accompanying drawings, and the purpose is to help the technical personnel in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present application, and to help its implementation. It should be noted that the terms "first", "second" and the like in the present application are only for the convenience of describing the technical solution to distinguish different components, and do not limit the present application. In order to make the technical solution of the present application more clear, the present application is explained and described by the following embodiments.

[0034] A detection method for air spring leakage of an air suspension vehicle, as shown in Figure 1 The method comprises the following steps:

[0035] S1, obtaining the current vehicle speed to determine the current state of the vehicle, the state including the stationary state and the moving state.

[0036] S2, when the vehicle is in the stationary state and the vehicle is not powered off, obtaining the current height of each air spring in the air suspension system and comparing it with the preset target height, determining whether to perform air spring height compensation according to the comparison result, and finally determining whether the air spring leaks according to the number of height compensation times within the first preset time.

[0037] S3, when the vehicle is in the moving state, obtaining the height of each air spring in the air suspension system and comparing them with each other, and determining whether the air spring leaks according to the comparison result.

[0038] Specifically, in step S1 of this embodiment, if the real-time vehicle speed (Vsd) is detected to be 0 km / h by means of a vehicle speed sensor or other means, the vehicle is considered to be stationary; if the detected vehicle speed is not 0 km / h, the vehicle is considered to be in motion. This invention supports air spring leakage detection in both stationary and moving vehicle states, expanding application scenarios and improving the real-time performance of leakage detection.

[0039] Specifically, step S2 in this embodiment includes: when the vehicle is stationary and the vehicle is not powered off (Power Down), acquiring a set of current height data for the air springs. A normal air suspension system includes four air springs; correspondingly, this embodiment can set four height sensors for height detection. Then, the difference H between the current height of each air spring and the target height is calculated, i.e.:

[0040] H = H t1 -H t0 ;

[0041] Among them, H t1 H represents the target height of the air spring. t0 This indicates the current height of the air spring. When the height H of an air spring is greater than a preset difference threshold (set to 15 mm in this embodiment, but can be flexibly selected according to actual conditions in specific implementation), the corresponding air spring will perform height compensation, and the height compensation count of the air spring will be incremented by one (assuming the initial height compensation count is i and equal to 0, the count after each height compensation is i2 equal to i+1), and the count is recorded accordingly.

[0042] To ensure data reliability and improve the accuracy of leak detection, this invention uses a timer (usually designed using software in practice) to set a first preset time (1 hour in this embodiment, but can be flexibly selected according to actual conditions in practice). Within the first preset time, whenever the height H of an air spring is greater than a preset difference threshold, the air spring will perform height compensation, and the number of height compensations of the spring within the first preset time is recorded simultaneously. After the first preset time ends, if the number of height compensations is greater than a preset first number threshold (3 times in this embodiment, but can be flexibly selected according to actual conditions in practice), then it is determined that the air spring is leaking; otherwise, the process returns to step S1 to wait for the next set of data.

[0043] Within the first preset time period, whenever H is less than or equal to the preset difference threshold, the process directly returns to step S1 to wait for the next set of data.

[0044] In consideration of the possibility of the getting on and off of the vehicle by the person when the vehicle is in the static state and the vehicle is not powered off, in this case, the getting on and off of the vehicle by the person will cause the change of the overall weight, and thus the height of the air spring will also change, so that the above detection method will have errors and cause inaccurate detection. In order to detect whether the getting on and off of the vehicle by the person, various detection means can be used in the implementation, such as the detection of the opening of the door, the setting of the pressure sensor on the seat, the setting of the weight sensor on the vehicle, etc. The embodiment adopts the detection of the opening of the door, that is, the step S2 further includes the detection of the opening of the door, specifically: in the first preset time, it is detected whether there is the state of the opening of the door; when the door is opened, the height compensation frequency record result and the timing are cleared, and the step S1 is returned to wait for the next group of data to start the detection again to reduce the error; when the door is not opened, the subsequent frequency judgment and the like of the step S2 are continued.

[0045] When the vehicle is in the static state and the vehicle is powered off and the controller is in the sleep wake-up state, the height change of the air spring can wake up the controller to perform the height compensation, but if the frequency of the height compensation is obviously excessive in a long period of time, the air spring may have a gas leakage. Therefore, the step S2 of the embodiment further includes: when the vehicle is in the static state and the vehicle is powered off, it is first checked whether the air spring controller is in the sleep wake-up state.

[0046] When the air spring controller is not in the sleep wake-up state, the step S1 is returned to wait for the next group of data.

[0047] When the air spring controller is in the sleep wake-up state, a second preset time is set by the timer, and the frequency of the height compensation of the air spring in the second preset time (the embodiment is set to 24 hours, which can be flexibly selected according to the actual situation in the implementation) is recorded (assuming that the initial height compensation frequency is i and is equal to 0, and the frequency i1 after each height compensation is equal to i+1); if the frequency of the height compensation of the air spring in the second preset time is greater than a preset second frequency threshold (the embodiment is set to 2, which can be flexibly selected according to the actual situation in the implementation), it is judged that there is the gas leakage of the air spring, otherwise the step S1 is returned to wait for the next group of data.

[0048] Specifically, the step S3 of the embodiment specifically includes: when the vehicle is in the motion state, the height change of the air spring is frequent due to the inequality of the road, so that the leakage detection method in the static state is not applicable. In order to solve the problem, the step S3 of the embodiment judges the leakage by calculating the height range H1 (the maximum value minus the minimum value) of the air spring in the air suspension system, that is:

[0049] H1 = H max -H min;

[0050] Among them, H max H represents the maximum height value among all air springs. min This represents the minimum height value among all air springs. When H1 is less than the preset range threshold (60 mm in this embodiment, but can be flexibly selected according to actual conditions in specific implementation), return to step S1 to wait for the next set of data; when H1 is greater than or equal to the preset range threshold, it is determined that there is air leakage in the air spring.

[0051] To avoid misjudgment due to uneven road surface or abnormal data, this embodiment also adds a duration limit for H1 to be greater than or equal to a preset range threshold in step S3. This can also be set by a timer. Only when the duration is greater than or equal to the preset duration threshold (set to 20 seconds in this embodiment, but can be flexibly selected according to the actual situation in specific implementation) is it determined that there is air spring leakage. Otherwise, return to step S1 to wait for the next set of data.

[0052] In this application, data such as vehicle speed and air spring height acquired through sensors and other means can be pre-processed using filtering algorithms (e.g., Kalman filtering) to improve data reliability and thus enhance the accuracy of subsequent air spring leak detection. This invention considers the differences in air spring leak detection between stationary and moving vehicle states, and sets different data processing methods and judgment procedures accordingly to achieve automatic leak detection. Furthermore, it also considers air spring leak detection during vehicle power-on, power-off, and controller sleep / wake-up scenarios, making leak detection applicable to various vehicle states and widely applicable. Moreover, this invention incorporates time limits in each detection process, improving detection accuracy and reducing errors.

[0053] Meanwhile, the application further provides an air spring leakage detection system for an air suspension vehicle, which is constructed according to any of the above air spring leakage detection methods for an air suspension vehicle, and comprises a vehicle speed sensor, an air spring height sensor and a controller, wherein the vehicle speed sensor and the air spring height sensor are connected to the controller respectively, the vehicle speed sensor is used for detecting a real-time vehicle speed and feeding back to the controller, the air spring height sensor is used for obtaining a real-time height of the air spring and feeding back to the controller, and the controller is used for receiving data uploaded by the vehicle speed sensor and the air spring height sensor, issuing a command to control height compensation of the air spring after processing, and performing leakage detection by integrating the method of the application.

[0054] The application is described above with reference to the drawings. It is obvious that the specific implementation of the application is not limited to the above method. Any non-essential improvement of the application or direct application of the above concept and technical solution of the application to other occasions without improvement is within the protection scope of the application.

Claims

1. A method of detecting air spring leaks in an air suspension vehicle, the method comprising: The method comprises the following steps: S1, acquiring the current speed of the vehicle to determine the current state of the vehicle, the state comprising a static state and a moving state; S2, when the vehicle is in the static state and the vehicle is not powered off, acquiring the current height of each air spring in the air suspension system and comparing it with the preset target height, determining whether to perform air spring height compensation according to the comparison result; finally, determining whether the air spring is leaking according to the number of height compensation times within a first preset time; wherein, within the first preset time, it is further detected whether there is a state of the vehicle door being opened; when the vehicle door is opened, the height compensation time record result and the timing are cleared and the step S1 is returned; when the vehicle door is not opened, the subsequent number of times is continued to be determined; S3, when the vehicle is in the moving state, the height of each air spring in the air suspension system is acquired and compared with each other, and it is determined whether the air spring is leaking according to the comparison result.

2. The method of claim 1, wherein: The step S2 specifically comprises: calculating a difference between the current height and the target height for each air spring i.e.: ； wherein, represents the target height of the air spring, represents the current height of the air spring; in the first preset time, each time the height difference between the target height and the current height of the air spring is greater than the preset difference threshold, the air spring performs height compensation, and the number of times of height compensation of the air spring in the first preset time is recorded; after the first preset time ends, if the number of times of height compensation is greater than a preset first number threshold, it is determined that the air spring leaks air, otherwise the step S1 is returned; in the first preset time, each time the height difference between the target height and the current height of the air spring is less than or equal to the preset difference threshold, the step S1 is directly returned. greater than the preset difference threshold, the air spring performs height compensation, and the number of times of height compensation of the air spring in the first preset time is recorded; after the first preset time ends, if the number of times of height compensation is greater than a preset first number threshold, it is determined that the air spring leaks air, otherwise the step S1 is returned; in the first preset time, each time the height difference between the target height and the current height of the air spring is less than or equal to the preset difference threshold, the step S1 is directly returned. less than or equal to the preset difference threshold, the step S1 is directly returned.

3. The method of claim 2, wherein: The first preset time is 1 hour, the preset difference threshold is 15 mm, and the preset first number of times threshold is 3 times.

4. The method of claim 1-3, wherein: The step S2 further comprises: when the vehicle is in the static state and the vehicle is powered off, first checking whether the air spring controller is in the sleep wake-up state: When the air spring controller is not in the sleep wake-up state, the step S1 is returned; When the air spring controller is in the sleep wake-up state, the number of air spring height compensation times within a second preset time is recorded; if the number of air spring height compensation times within the second preset time is greater than a preset second number of times threshold, it is determined that the air spring is leaking, otherwise the step S1 is returned.

5. The method of claim 4, wherein: The second preset time is 24 hours, and the second number of times threshold is 2 times.

6. The method of claim 1, wherein: The step S3 specifically comprises: Computing height extremes of air springs in an air suspension system i.e.: ； wherein, represents the maximum height value among all air springs, represents the minimum height value among all air springs; when if the difference is less than a preset threshold, return to the step S1; and if the difference is greater than or equal to the preset threshold, determine that there is air spring leakage.

7. The method of claim 6, wherein: In the step S3 is added The duration limit greater than or equal to the preset range threshold, only when the duration is greater than or equal to the preset duration threshold, it is judged that there is air spring air leakage, otherwise return to the step S1.

8. The method of claim 7, wherein: The range threshold is 60 mm, and the duration threshold is 20 seconds.

9. An air spring leak detection system for an air suspension vehicle, the system comprising: The system is constructed according to the air spring leakage detection method of the air suspension vehicle according to any one of claims 1-8, and the system comprises a vehicle speed sensor, an air spring height sensor, and a controller, wherein the vehicle speed sensor and the air spring height sensor are connected with the controller respectively, the vehicle speed sensor is used to detect the real-time vehicle speed and feed back to the controller, the air spring height sensor is used to acquire the real-time height of the air spring and feed back to the controller, and the controller is used to control the height compensation of the air spring and perform the leakage detection.

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