Self-adaptive calibration method for electric inflation pump of new energy truck

Abstract

The invention discloses a new energy truck electric inflating pump self-adaptive calibration method, which comprises the following steps: triggering to enter an inflating pump calibration mode after judging that a calibration condition is met, and enabling an electric inflating pump to work and continuously monitoring the change of brake pressure after verifying that the brake pressure meets the requirement; when the dryer exhausts for the first time, recording the lowest air pressure point; when the dryer exhausts air again, the lowest points of the air pressure are recorded again, and the time interval between the two lowest points is calculated; if the difference between the two lowest points is smaller than the pressure difference threshold value, calibration is ended, and the shutdown air pressure value and the delay shutdown time represented by the time interval are obtained. According to the self-adaptive calibration scheme provided by the invention, the shutdown node of the inflating pump can be calibrated to a relatively optimal state, so that the air pressure in the system is closest to an exhaust value, the cost of the whole vehicle does not need to be increased, and the research and development cost such as manpower is remarkably reduced; in addition, after the parts are aged, the calibration scheme can be implemented according to the current state so as to correct the working state of the inflating pump.

Description

Technical Field

[0001] The present invention relates to the technical field of vehicle air brake technology, and in particular to a self-adaptive calibration method for an electric air pump for a new energy truck. Background Art

[0002] The air source of the pneumatic brake pure electric truck comes from the electric air pump matched with the vehicle model, which is usually a high-pressure component. Generally speaking, the working process of the air pump includes drainage and backwashing, both of which are to prevent condensed water from freezing in an environment below zero degrees, causing the dryer to work abnormally and thus cause an accident.

[0003] The start and stop timing of the air pump needs to be controlled by the whole vehicle. For example, the start and stop of the air pump of a certain vehicle model is controlled by the high-voltage distribution box through collecting two brake air pressure values ​​(first brake pressure pressure1, second brake pressure pressure2) fed back from the instrument, and controlling the start and stop of the air pump according to the established control logic.

[0004] The dryer drainage backwashing pressure is 1MPa in the above example (schematically, the dryer drainage backwashing pressure is 1Mpa. When the air pressure reaches the VCU and the two brake air pressure values ​​exceed 0.94MPa, the inflation volume is delayed by 20S, which can not only ensure that the pressure exceeds 1MPa to drain and backwash the dryer, but also replenish some air pressure to the system after drainage and unloading). However, there is actually a pressure deviation of about 0.05Mpa. If it is an upper deviation, the dryer drainage backwashing pressure may not be reached under the two indicator settings of the shutdown air pressure value (such as the aforementioned 0.94Mpa) and the delayed shutdown time (such as the aforementioned 20s). At this time, the calibration personnel need to adjust the program and re-write the calibration. If it is a lower deviation, it is possible that after drainage and backwashing, the pressure is reached again after continuous inflation to continue drainage and backwashing, resulting in frequent unloading of the dryer and excessive inflation of the air pump, resulting in power loss.

[0005] Furthermore, the pressure after backblowing may drop significantly, generally 0.1Mpa. If the delay time indicator is set insufficiently, the air pressure of the entire vehicle will be low, which will affect the braking system.

[0006] In addition, as the vehicle ages, the dryer will age and the drainage backwash pressure may be partially reduced. At this time, the air pump working control program may need to be changed synchronously.

[0007] From the above analysis, it can be found that in the process of calibrating the working logic of the air pump, the artificially set thresholds and delay indicators and the pressure deviation of the dryer exhaust will affect the calibration results, making it difficult to achieve the optimal state. Summary of the invention

[0008] In view of the above, the present invention aims to provide an adaptive calibration method for an electric air pump for a new energy truck to solve the above-mentioned technical problems.

[0009] The technical solution adopted by the present invention is as follows:

[0010] The present invention provides a method for adaptively calibrating an electric air pump for a new energy truck, which includes:

[0011] After determining that the preset calibration conditions are met, the vehicle controller is triggered to enter the air pump calibration mode;

[0012] Before enabling the electric air pump to work, check whether the brake air pressure meets the requirements;

[0013] After determining that the brake air pressure meets the conditions, the electric air pump is triggered to work and the brake pressure changes are continuously monitored;

[0014] When the dryer is exhausted for the first time to reduce the air pressure, the current first air pressure value is recorded;

[0015] When the dryer is exhausted again to reduce the air pressure, the current second air pressure value is recorded, and the time interval from the first air pressure value to the second air pressure value is calculated and recorded;

[0016] Comparing the first air pressure value with the second air pressure value, and determining whether the difference between the two is less than a preset pressure difference threshold;

[0017] If the difference between the two is less than the pressure difference threshold, the calibration is terminated and a shutdown mark of the electric air pump is obtained, wherein the shutdown mark includes a shutdown air pressure value and a delayed shutdown time, wherein the delayed shutdown time is the time interval.

[0018] In at least one possible implementation manner, the shutdown air pressure value is: the difference between the second air pressure value and the pressure difference threshold.

[0019] In at least one possible implementation manner, the first air pressure value and the second air pressure value recorded during exhaust are both the lowest value of the first brake pressure or the lowest value of the second brake pressure at the corresponding moment.

[0020] In at least one possible implementation, the calibration condition includes: placing the air pressure of the entire vehicle below a predetermined first alarm air pressure threshold.

[0021] In at least one possible implementation, the calibration condition also includes: the vehicle key position is in the ON position, and the high-voltage accessory relay is closed without fault.

[0022] In at least one possible implementation, the verifying whether the brake pressure meets the condition includes: collecting the first brake pressure and the second brake pressure on the instrument, and determining whether the two do not exceed a predetermined second alarm pressure threshold at the same time and last for a predetermined period of time.

[0023] In at least one possible implementation, triggering the vehicle controller to enter the air pump calibration mode includes: receiving an instruction from a dedicated calibration switch configured in the instrument system, and triggering entry into the air pump calibration mode after the calibration conditions are met.

[0024] Compared with the prior art, the main design concept of the present invention is that after judging that the calibration conditions are met, the air pump calibration mode is triggered, and after verifying that the brake pressure meets the requirements, the electric air pump is enabled to work and the brake pressure changes are continuously monitored; when the dryer is exhausted for the first time to reduce the air pressure, the current first air pressure value is recorded; when the dryer is exhausted again to reduce the air pressure, the current second air pressure value is recorded, and the time interval from the first air pressure value to the second air pressure value is recorded; if the difference between the first air pressure value and the second air pressure value is less than the pressure difference threshold, the calibration is terminated and the shutdown mark of the electric air pump is obtained, including the shutdown air pressure value and the delayed shutdown time represented by the above time interval. The adaptive calibration scheme provided by the present invention can calibrate the shutdown node of the air pump to a relatively optimal state, so that the air pressure in the system is closest to the exhaust value, without increasing the cost of the whole vehicle, and significantly reducing the research and development costs such as manpower; in addition, even after the parts are aged, the calibration scheme proposed by the present invention can be implemented according to the current state to correct the working state of the air pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be further described below with reference to the accompanying drawings, in which:

[0026] Figure 1 A schematic diagram of an adaptive calibration method for an electric air pump for a new energy truck provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0027] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention.

[0028] The present invention proposes an embodiment of a method for adaptively calibrating an electric air pump for a new energy truck. Specifically, Figure 1 shown, including:

[0029] Step S1: After determining that the preset calibration conditions are met, trigger the vehicle controller to enter the air pump calibration mode;

[0030] The calibration conditions mentioned here mainly refer to whether the vehicle air pressure is below the established first alarm pressure threshold (usually it can be indicated in the instrument, such as setting the first alarm pressure threshold to 0.4Mpa, the vehicle air pressure can be set below 0.4Mpa first). In addition to this, other calibration pre-conditions can also be included, such as the vehicle key ON position is valid, the high-voltage accessory relay is closed without fault, etc.

[0031] As for the implementation method of triggering the calibration mode, in some preferred embodiments of the present invention, a dedicated calibration switch can be configured in the instrument system, so that the calibration mode can be started with one button. This concept can further illustrate that in actual operation, the user can first operate the calibration switch, and then the vehicle can determine whether the aforementioned calibration conditions are met. When the conditions are met, the calibration process can be started again.

[0032] Step S2: before enabling the electric air pump to work, verify whether the brake air pressure meets the conditions;

[0033] The brake pressure verification described here can, as mentioned above, collect the first brake pressure and the second brake pressure of the instrument to determine whether the two do not exceed the second alarm pressure threshold at the same time and last for a predetermined period of time. For example, if pressure1≤0.6Mpa, pressure2≤0.6Mpa, and this state is maintained for more than 1s, it can be considered to meet the inflation requirements.

[0034] Step S3: after determining that the brake air pressure meets the conditions, trigger the electric air pump to work, and continuously monitor the change of the brake pressure;

[0035] Step S4, when the dryer is exhausted for the first time to reduce the air pressure, the current first air pressure value is recorded;

[0036] Step S5, when the dryer is exhausted again to reduce the air pressure, the current second air pressure value is recorded, and at the same time, the time interval from the first air pressure value to the second air pressure value is obtained and recorded;

[0037] The above three steps may specifically refer to that the VCU enables the air pump to start working, and then the air pressure continues to rise. When the dryer is exhausted for the first time, the air pressure indicated by the instrument will suddenly drop, and the VCU will record the first air pressure value A at this time (preferably the lowest value of the current first brake pressure or the second brake pressure); the air pump does not stop but continues to work, and then when the dryer is exhausted again, the instrument air pressure will drop again, and the VCU will record the current second air pressure value B (preferably the lowest value of the current first brake pressure or the second brake pressure); synchronously, calculate and record the time S1 from value A to value B.

[0038] Step S6, comparing the first air pressure value and the second air pressure value, and determining whether the difference between the two is less than a preset pressure difference threshold;

[0039] Step S7: If the difference between the two is less than the pressure difference threshold, the calibration is terminated and a shutdown mark of the electric air pump is obtained, wherein the shutdown mark includes a shutdown air pressure value and a delayed shutdown time, wherein the delayed shutdown time is the time interval.

[0040] For the above steps, after comparing the two air pressure values ​​AB, if the difference between the two air pressure values ​​is less than 0.01Mpa (the set pressure difference threshold), the calibration is determined to be successful. At this time, VCU can set C=(B-0.01)Mpa as the shutdown air pressure value, and the aforementioned interval time is used as the delayed shutdown time, thereby completing the key parameter calibration, that is, after starting the air pump to make the brake pressure reach C pressure, continue to work for S1 time, and then execute shutdown.

[0041] In summary, the main design concept of the present invention is that after judging that the calibration conditions are met, the air pump calibration mode is triggered, and after verifying that the brake pressure meets the requirements, the electric air pump is enabled to work and the brake pressure changes are continuously monitored; when the dryer is exhausted for the first time to reduce the air pressure, the current first air pressure value is recorded; when the dryer is exhausted again to reduce the air pressure, the current second air pressure value is recorded, and the time interval from the first air pressure value to the second air pressure value is recorded; if the difference between the first air pressure value and the second air pressure value is less than the pressure difference threshold, the calibration is terminated and the shutdown mark of the electric air pump is obtained, including the shutdown air pressure value and the delayed shutdown time represented by the above time interval. The adaptive calibration scheme provided by the present invention can calibrate the shutdown node of the air pump to a relatively optimal state, so that the air pressure in the system is closest to the exhaust value, without increasing the cost of the whole vehicle, and significantly reducing the research and development costs such as manpower; in addition, even after the parts are aged, the calibration scheme proposed by the present invention can be implemented according to the current state to correct the working state of the air pump.

[0042] If the expressions expressing orientation are mentioned in the embodiments of the present invention, they are relative concepts based on the embodiments. In addition, "at least one" means one or more, and "plurality" means two or more. "And / or" describes the association relationship of associated objects, indicating that three relationships may exist. For example, A and / or B can represent the existence of A alone, the existence of A and B at the same time, and the existence of B alone. Among them, A and B can be singular or plural. The character " / " generally indicates that the previous and next associated objects are in an "or" relationship. "At least one of the following" and similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b and c can be represented by: a, b, c, a and b, a and c, b and c, or a and b and c, wherein a, b, c can be single or multiple.

[0043] The above describes in detail the structure, features and effects of the present invention based on the embodiments shown in the drawings, but the above is only a preferred embodiment of the present invention. It should be noted that the technical features involved in the above embodiments and their preferred methods can be reasonably combined and matched into a variety of equivalent schemes by those skilled in the art without departing from or changing the design ideas and technical effects of the present invention; therefore, the present invention is not limited to the scope of implementation shown in the drawings, and all changes made in accordance with the concept of the present invention, or modifications to equivalent embodiments with equivalent changes, which still do not exceed the spirit covered by the specification and drawings, should be within the protection scope of the present invention.

Claims

1. A self-adaptive calibration method for an electric air pump for a new energy truck, characterized in that: include: After determining that the preset calibration conditions are met, the vehicle controller is triggered to enter the air pump calibration mode; Before enabling the electric air pump to work, check whether the brake air pressure meets the requirements; After determining that the brake air pressure meets the conditions, the electric air pump is triggered to work and the brake pressure changes are continuously monitored; When the dryer is exhausted for the first time to reduce the air pressure, the current first air pressure value is recorded; When the dryer is exhausted again to reduce the air pressure, the current second air pressure value is recorded, and the time interval from the first air pressure value to the second air pressure value is calculated and recorded; Comparing the first air pressure value with the second air pressure value, and determining whether the difference between the two is less than a preset pressure difference threshold; If the difference between the two is less than the pressure difference threshold, the calibration is terminated and a shutdown mark of the electric air pump is obtained, wherein the shutdown mark includes a shutdown air pressure value and a delayed shutdown time, wherein the delayed shutdown time is the time interval.

2. The self-adaptive calibration method for electric air pump for new energy trucks according to claim 1 is characterized in that: The shutdown air pressure value is: the difference between the second air pressure value and the pressure difference threshold.

3. The self-adaptive calibration method for electric air pump for new energy truck according to claim 1, characterized in that: The first air pressure value and the second air pressure value recorded during exhaust are both the lowest value of the first brake pressure or the lowest value of the second brake pressure at the corresponding moment.

4. The self-adaptive calibration method for electric air pump for new energy truck according to claim 1, characterized in that: The calibration condition includes: placing the air pressure of the entire vehicle below a predetermined first alarm air pressure threshold.

5. The self-adaptive calibration method for electric air pump for new energy truck according to claim 4 is characterized in that: The calibration conditions also include: the vehicle key position is in the ON position, and the high-voltage accessory relay is closed without fault.

6. The self-adaptive calibration method for electric air pump for new energy trucks according to claim 1, characterized in that: The checking whether the brake pressure meets the condition includes: collecting the first brake pressure and the second brake pressure on the instrument, and determining whether the two do not exceed the predetermined second alarm pressure threshold at the same time and last for a predetermined time period.

7. The self-adaptive calibration method of the electric air pump for new energy trucks according to any one of claims 1 to 6, characterized in that: The triggering of the vehicle controller to enter the air pump calibration mode includes: receiving an instruction from a special calibration switch configured in the instrument system, and triggering to enter the air pump calibration mode after the calibration conditions are met.

Images