Adaptive calibration method for electric air pumps for new energy trucks

Abstract

The present invention discloses an adaptive calibration method for an electric air pump for a new energy truck, including triggering the entry into the air pump calibration mode after determining that the calibration conditions are met, and after verifying that the brake air pressure meets the requirements, enabling the electric air pump to work and continuously monitoring the brake pressure changes; when the dryer is exhausted for the first time, recording the lowest point of the air pressure; when the dryer is exhausted again, recording the lowest point of the air pressure again, and calculating the time interval between the two lowest points; if the difference between the two lowest points is less than the pressure difference threshold, then the calibration is terminated and the shutdown air pressure value and the delayed shutdown time represented by the above time interval are obtained. 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 entire vehicle, and significantly reducing research and development costs such as manpower; in addition, after the aging of the components, the above calibration scheme can also be implemented according to the current state to correct the working state of the air 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 supply for pneumatically braked pure electric trucks comes from the matching electric air pump, which is typically a high-pressure component. Generally, the air pump's operation involves draining and backflushing, both designed to prevent condensed water from freezing in sub-zero temperatures, which could cause dryer malfunctions and potentially lead to accidents.

[0003] The timing of the air pump's start and stop requires vehicle-wide control. For example, on certain vehicle models, the air pump's start and stop are controlled by a high-voltage distribution box, which collects two brake pressure values ​​(pressure 1 and pressure 2) fed back from an instrument and then controls the pump's start and stop according to established control logic.

[0004] The dryer drainage backflush pressure is 1MPa in the above example (schematically, the dryer drainage backflush pressure is 1MPa. When the air pressure reaches the VCU and the two brake air pressure values ​​detect that exceed 0.94MPa, the inflation volume is delayed by 20S, which can not only ensure that the pressure exceeds 1MPa to cause the dryer to drain and backflush, 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, then under the two indicators of shutdown air pressure value (such as the aforementioned 0.94Mpa) and delayed shutdown time (such as the aforementioned 20s), the dryer drainage backflush pressure may not be reached. 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 backflush, the pressure is reached again after continuous inflation to continue drainage and backflush, 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 pressure of the drainage backflush may be 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 during the calibration of 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 in the present invention is as follows:

[0010] The present invention provides a method for adaptive calibration of 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, check whether the brake pressure meets the requirements;

[0013] After determining that the brake 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 and the air pressure is reduced, 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, where the shutdown mark includes a shutdown air pressure value and a delayed shutdown time, where 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 entire vehicle air pressure below a predetermined first alarm air pressure threshold.

[0021] In at least one possible implementation, the calibration condition further 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 verification of whether the brake pressure meets the conditions 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 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 at the same time; 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 entire vehicle, and significantly reducing research and development costs such as manpower; in addition, even after the components 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] The following describes embodiments of the present invention in detail. 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 intended only to explain the present invention and are not to be construed as limiting the present invention.

[0028] The present invention proposes an embodiment of a method for adaptive calibration of 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 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, of course, other pre-calibration 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] Regarding triggering the calibration mode, in some preferred embodiments of the present invention, a dedicated calibration switch can be configured in the instrument system, enabling a single-touch activation of the calibration mode. This concept further illustrates that, in actual operation, the user may first activate the calibration switch, and then the vehicle will determine whether the aforementioned calibration conditions are met. If the conditions are met, the calibration process can be initiated again.

[0032] Step S2: Before enabling the electric air pump, 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 lasts for more than 1s, it can be considered to meet the inflation requirements.

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

[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 the time interval from the first air pressure value to the second air pressure value is calculated and recorded;

[0037] Specifically, the above three steps may refer to the VCU enabling the air pump to start working, and then the air pressure continues to rise. When the dryer is exhausted for the first time, the instrument indicates that the air pressure will suddenly drop, and the VCU records 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 records 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 ended and a shutdown mark of the electric air pump is obtained, where the shutdown mark includes a shutdown air pressure value and a delayed shutdown time, where 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, the VCU can set C=(B-0.01)Mpa as the shutdown pressure value, and the aforementioned interval time is used as the delayed shutdown time, thereby completing the calibration of key parameters, that is, after starting the air pump to make the brake pressure reach C pressure, it continues to work for S1 time, and then executes the 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 at the same time; 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 entire vehicle, and significantly reducing research and development costs such as manpower; in addition, even after the components 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 directions are mentioned in the embodiments of the present invention, they are relative concepts based on the embodiments. In addition, "at least one" refers to one or more, and "more" refers to two or more. "And / or" describes the association relationship of the 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 represent: a, b, c, a and b, a and c, b and c or a, b and c, where 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 modes 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 scope of implementation of the present invention is not limited to what is shown in the drawings. Any 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 description and drawings, should be within the scope of protection 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, check whether the brake pressure meets the requirements; After determining that the brake 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 and the air pressure is reduced, 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, where the shutdown mark includes a shutdown air pressure value and a delayed shutdown time, where the delayed shutdown time is the time interval.

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

5. The self-adaptive calibration method for electric air pump for new energy trucks 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 and there is no fault.

6. The self-adaptive calibration method for the electric air pump of a new energy truck according to claim 1, characterized in that: The checking whether the brake pressure meets the conditions 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 adaptive calibration method for an electric air pump for a new energy truck according to any one of claims 1 to 6, characterized in that: 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 the entry into the air pump calibration mode after the calibration conditions are met.

Images