Urea pump bench test method and device

Abstract

The invention discloses a urea pump bench testing method and device. The method comprises the steps that a heating module of a urea pump is controlled to conduct heating according to preset testing conditions; the test conditions comprise environment temperature, heating power, test wind speed and heating time; controlling an air blower to blow air to the urea box based on the test air speed; temperature information of urea liquid in the urea box is obtained through a thermal imaging camera; liquid level information of urea liquid in the urea box is obtained through a liquid level sensor; based on the temperature information, the liquid level information and the shape of the urea box, the liquid unfreezing amount of the urea liquid in the urea box is calculated; and outputting target heating power corresponding to the test condition based on the liquid unfreezing amount. The air blower is arranged in the urea pump rack test system, so that the heat dissipation influence of natural wind on the urea box at different running speeds of a vehicle can be simulated, the urea pump rack test result is more suitable for the actual situation, and the error of the simulation analysis result is reduced.

Description

Technical Field

[0001] The present application relates to the field of automobile technology, and in particular to a urea pump bench testing method and device. Background Art

[0002] Urea systems are widely used in diesel vehicles that meet the National VI standard. They are mainly used to neutralize nitrogen oxides in exhaust gas. Urea systems are mainly composed of urea tanks, urea pumps, urea pipes and nozzles. The freezing point of national standard urea liquid is -11°C. Because the injection of urea directly affects the emission results, urea pumps are integrated with heating modules. However, because urea tanks generally need to be adjusted with the vehicle installation position and have different shapes, and the heating area of ​​urea pumps is generally not enough to cover the entire urea tank, bench test simulations are generally used for simulation analysis to confirm the heating effect of the heating module and see if it meets the thawing capacity requirements.

[0003] However, in the prior art, the simulation analysis results of bench test simulations are generally only used as a guide, and are often quite different from actual tests. In addition, current bench tests are relatively simple, and most of them are static analyses. However, the actual vehicle operation process is affected by wind speed and surrounding parts, which is more complicated and harsh. This leads to large errors in the existing simulation analysis results. Summary of the invention

[0004] In view of the above problems, the present application provides a urea pump bench test method and device that overcomes the above problems or at least partially solves the above problems. The technical solution is as follows:

[0005] A urea pump bench test method is applied to a urea pump bench test system, the urea pump bench test system comprising: a blower, a thermal imaging camera, a urea tank, a urea pump and a control module; the urea pump is used to heat and spray urea liquid, the thermal imaging camera is used to obtain temperature information of urea liquid in the urea tank, and the urea pump is integrated with a heating module and a liquid level sensor; the method comprises: controlling the heating module of the urea pump to heat according to preset test conditions; the test conditions include ambient temperature, heating power, test wind speed and heating time; based on the test wind speed, controlling the blower to blow air to the urea tank; after the heating time is reached, controlling the heating module to stop heating; obtaining temperature information of the urea liquid in the urea tank through the thermal imaging camera; obtaining liquid level information of the urea liquid in the urea tank through the liquid level sensor; calculating the liquid thawing amount of the urea liquid in the urea tank based on the temperature information, the liquid level information and the shape of the urea tank; and outputting the target heating power corresponding to the test conditions based on the liquid thawing amount.

[0006] By setting up a blower in the urea pump bench test system, the heat dissipation effect of natural wind on the urea tank at different vehicle running speeds can be simulated, so that the urea pump bench test results are more in line with the actual situation and the error of the simulation analysis results is reduced. At the same time, the temperature information of the urea liquid in the urea tank is monitored in real time through a thermal imaging camera, and the thawing amount of the urea liquid is calculated through the temperature information and liquid level information, which not only improves the calculation efficiency, but also ensures the accuracy of the calculation results.

[0007] Optionally, the calculating the amount of liquid thawed urea liquid in the urea tank based on the temperature information, the liquid level information and the shape of the urea tank specifically includes: determining, based on the thermal imaging picture, an area ratio between an area of ​​a thawed region with a temperature higher than a preset temperature threshold and a total area of ​​the urea liquid; and determining the amount of liquid thawed urea liquid in the urea tank based on the shape of the urea tank, a comparison between the liquid level height and volume of the urea tank, the area ratio and the liquid level information.

[0008] Optionally, outputting the target heating power corresponding to the test condition based on the liquid thawing amount specifically includes: repeating the following process until the liquid thawing amount under the current test condition is higher than a preset threshold value: confirming that the liquid thawing amount within the heating time is lower than the preset threshold value; controlling the heating module to stop heating, and cold-soaking the urea tank based on the ambient temperature; confirming through the thermal imaging camera that the urea liquid temperature in the urea tank drops to the ambient temperature; increasing the heating power, and recalculating the liquid thawing amount under the current test condition.

[0009] Optionally, increasing the heating power until the amount of liquid thawed under the current test conditions is higher than the preset threshold value specifically includes: determining the liquid volume difference between the first liquid thawed amount and the preset threshold value; determining the first heating power increase based on the liquid volume difference; determining the second heating power based on the first heating power increase and the first heating power; determining the second liquid thawed amount corresponding to the second heating power, if the difference between the second liquid thawed amount and the preset threshold value is greater than the preset difference, reducing the heating power increase to obtain the second heating power increase; determining the third heating power based on the second heating power increase and the first heating power, until the liquid thawed amount corresponding to the adjusted heating power is higher than the preset threshold value, and the difference with the preset threshold value is lower than the preset difference.

[0010] By adjusting the increase in heating power, it is possible to avoid increasing the heating power too much at a time, which would result in excessive heating power. Although this would make the amount of urea liquid thawed higher than the preset threshold, it would ultimately lead to a waste of resources.

[0011] Optionally, the preset threshold is positively correlated with the maximum injection rate of the urea pump at the ambient temperature.

[0012] Optionally, the urea pump bench test system also includes a tilt simulation device, which is arranged at the bottom of the urea tank and can be tilted at different angles according to the control instruction of the control module; the test condition also includes a test slope; before the control module controls the heating module of the urea pump to heat according to the preset test condition, the method also includes: controlling the tilt simulation device to tilt so that an angle corresponding to the test slope is formed between the urea tank and the horizontal plane; before obtaining the temperature information of the urea liquid in the urea tank through the thermal imaging camera, the method also includes: controlling the tilt simulation device to return to a horizontal state.

[0013] Optionally, the urea tank is a transparent urea tank, so that the thermal imaging camera can monitor the temperature information of the urea liquid in the urea tank.

[0014] Optionally, a simulated air duct is provided between the blower and the urea tank, and the simulated air duct is a corresponding air duct between a vent and the urea tank on a vehicle type where the urea tank is located.

[0015] Optionally, a plurality of simulation components are provided in the simulation air duct, and the layout positions and temperatures of the simulation components are the same as the layout positions and temperatures of components within a preset range on the vehicle model where the urea tank is located under corresponding working conditions.

[0016] Optionally, after calculating the liquid thawing amount of urea liquid in the urea tank based on the temperature information, the liquid level information and the shape of the urea tank, the method further includes: determining similarities between the liquid thawing amounts of multiple sample urea tanks and the target urea tank based on the liquid thawing amounts corresponding to the target urea tank under multiple groups of test conditions; determining similar urea tanks of the target urea tank among the multiple sample urea tanks based on the similarities of the liquid thawing amounts; and determining the heating powers corresponding to the target urea tank under different test conditions based on historical test data of the similar urea tanks.

[0017] By calculating similar urea tanks of the target urea tank, the heating power of similar urea tanks under different test conditions can be used as a reference to reduce the number of tests of the target urea tank during testing, thereby greatly saving time and test consumption. At the same time, the heating power change trend of the target urea tank can be fitted according to the heating power change trend of the sample urea tank under different test conditions, and the fitting result can be directly used as the heating power of the target urea tank, thereby reducing the number of tests.

[0018] A urea pump bench test device is applied to the above-mentioned urea pump bench test system, the device comprising: a heating module, controlling a heating module of a urea pump to heat according to preset test conditions; the test conditions comprising ambient temperature, heating power, test wind speed and heating time; an air blowing module, controlling the blower to blow air to the urea tank based on the test wind speed; a time module, controlling the heating module to stop heating after the heating time is reached; a temperature information module, acquiring temperature information of urea liquid in the urea tank through a thermal imaging camera; a liquid level information module, acquiring liquid level information of the urea liquid in the urea tank through the liquid level sensor; a liquid thawing amount module, calculating the liquid thawing amount of the urea liquid in the urea tank based on the temperature information, the liquid level information and the shape of the urea tank; and a heating power module, outputting a target heating power corresponding to the test conditions based on the liquid thawing amount.

[0019] By means of the above technical solution, the present disclosure provides a urea pump bench test method and device, which can simulate the heat dissipation effect of natural wind on the urea tank at different running speeds of the vehicle by setting a blower in the urea pump bench test system, so that the urea pump bench test results are more in line with the actual situation and reduce the error of the simulation analysis results. At the same time, the temperature information of the urea liquid in the urea tank is monitored in real time by a thermal imaging camera, and the thawing amount of the urea liquid is calculated by the temperature information and the liquid level information, which not only improves the calculation efficiency, but also ensures the accuracy of the calculation results.

[0020] The above description is only an overview of the technical solution of the present disclosure. In order to more clearly understand the technical means of the present disclosure, it can be implemented according to the contents of the specification. In order to make the above and other purposes, features and advantages of the present disclosure more obvious and easy to understand, the specific implementation methods of the present disclosure are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only used for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Moreover, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0022] Figure 1 This is a structural schematic diagram of a urea pump bench test system in an embodiment of the present application;

[0023] Figure 2 This is a flow chart of a urea pump bench test method in an embodiment of the present application;

[0024] Figure 3 This is a schematic diagram of the overall process of a urea pump bench test in an embodiment of the present application;

[0025] Figure 4 This is a structural schematic diagram of a urea pump bench test device in an embodiment of the present application;

[0026] Figure 5 This is a structural schematic diagram of a urea pump bench test equipment in an embodiment of the present application.

[0027] Among them, 1. blower, 2. thermal imaging camera, 3. urea tank, 4. urea pump, 5. control module, 6. tilt simulation device. DETAILED DESCRIPTION

[0028] The exemplary embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present disclosure and to enable the scope of the present disclosure to be fully communicated to those skilled in the art.

[0029] Urea systems are widely used in diesel vehicles that meet the National VI standard. They are mainly used to neutralize nitrogen oxides in exhaust gas. Urea systems are mainly composed of urea tanks, urea pumps, urea pipes and nozzles. The freezing point of national standard urea liquid is -11°C. Because the injection of urea directly affects the emission results, urea pumps are integrated with heating modules. However, because urea tanks generally need to be adjusted with the vehicle installation position and have different shapes, and the heating area of ​​urea pumps is generally not enough to cover the entire urea tank, bench test simulations are generally used for simulation analysis to confirm the heating effect of the heating module and see if it meets the thawing capacity requirements.

[0030] However, in the prior art, the simulation analysis results of bench test simulations are generally only used as a guide, and are often quite different from actual tests. In addition, current bench tests are relatively simple, and most of them are static analyses. However, the actual vehicle operation process is affected by wind speed and surrounding parts, which is more complicated and harsh. This leads to large errors in the existing simulation analysis results.

[0031] To this end, the present application provides a urea pump bench test method, wherein the urea pump bench test method is applied to Figure 1 In the urea pump bench test system shown, Figure 1 The arrow in the middle indicates the direction of data transmission and control command transmission. The system includes a blower, a thermal imaging camera, a urea tank, a urea pump, and a control module. Specifically, the urea pump and urea liquid are carried in the urea tank, the thermal imaging camera is arranged above the urea tank, and the urea pump is integrated with a heating module and a liquid level sensor. In a practical solution, the urea pump, as the core component of the urea system, will be integrated with a pressure sensor, a temperature sensor, and a concentration sensor in addition to a heating module and a liquid level sensor. Figure 1The direction of the arrow in the middle is the data transmission direction between the various components. Specifically, the thermal imaging camera will shoot the objects in the urea tank from top to bottom, so as to monitor the temperature change of the urea liquid in the urea tank, record it, and then feed it back to the control module. The urea tank is the carrier of the urea pump and the urea liquid. During the bench test, in order to facilitate camera monitoring, a transparent urea tank can be used. The recommended material is acrylonitrile-styrene-butadiene copolymer (ABS). Here is an explanation of the ABS material: ABS is a thermoplastic polymer material structure with high strength, good toughness, and easy processing and molding. ABS is a general-purpose thermoplastic engineering plastic developed in the 1940s. It is a plastic variety with excellent comprehensive mechanical properties. It not only has good rigidity, hardness and processing fluidity, but also has high toughness. It can be injection molded, extruded or thermoformed, and is suitable as a material for the urea tank during the urea pump bench test. The blower is used to receive instructions from the control module to achieve switching of different wind speeds to simulate the natural wind corresponding to the vehicle at different driving speeds. The control module is used to receive the thermal imaging transmission image, and combined with the liquid level signal transmitted by the pump, calculate the amount of urea thawed, and can also control the blower wind speed and the heating power adjustment of the pump.

[0032] Based on the above-mentioned urea pump bench test system, in order to solve the problem that in the prior art, the simulation analysis results of bench test simulation are generally only used as a guide, and the gap with the actual test is often quite large, and the current bench test is relatively simple, most of which are static analysis, but the actual vehicle operation process is affected by wind speed and surrounding parts, which is more complicated and severe, resulting in large errors in the existing simulation analysis results, the present application provides a urea pump bench test method and device, Figure 2 1 is a schematic flow chart of a urea pump bench test method provided in an embodiment of the present application. The method can be applied to a processing module in a urea pump bench test system. The method includes:

[0033] S201: Controlling a heating module of a urea pump to heat according to preset test conditions; the test conditions include ambient temperature, heating power, test wind speed, and heating time.

[0034] First, the control module receives the test conditions set by the tester, which include ambient temperature, heating power, test wind speed and heating time. The parameters of each functional module are controlled according to the above test conditions to meet the test conditions. It should be noted that, except for the ambient temperature, which needs to be adjusted by other equipment in the test scene, such as the indoor temperature control device, other test conditions, such as heating power and heating time, can be completely adjusted by controlling the heating module integrated on the urea pump.

[0035] Here is a brief explanation of the significance of the urea pump bench test. Based on industry regulations, different models of vehicles face different ambient temperatures and have different set thawing times. The vehicle needs to thaw the frozen urea liquid within the set thawing time, and the thawing amount of the urea liquid can meet the normal operation of the emission control system. If only the thawing amount of the urea liquid meets the normal operation of the emission control system, then the heating power corresponding to the heating module on the urea pump must be as high as possible. However, in order to save energy and avoid waste of resources, the minimum heating power that can meet the demand at different ambient temperatures should be determined. On the basis of the thawing amount of the urea liquid meeting the normal operation requirements of the emission control system, the heat generation of the urea tank is reduced to prevent the heat of the urea tank from spreading to other components in the vehicle, causing the temperature of various components in the vehicle to rise, and increasing the working pressure of the air conditioning / heat pump system in the vehicle, thereby avoiding waste of resources as much as possible.

[0036] Here is an example of the original text of the above industry regulations. Manufacturers should ensure that the emission control system can guarantee its emission control function under all normal environmental conditions, especially in low temperature environments. This includes taking measures to prevent the reactants in a vehicle with 50% reactant tank from completely freezing at 258K (-15℃) during parking time of up to 7 days. If the reactants freeze, the manufacturer should ensure that the reactants can be used within 20 minutes after the vehicle is started at 258K (-15℃) (measured in the reactant tank) to ensure the normal operation of the emission control system. Therefore, during the urea pump bench test, the heating time of different models or different urea pumps can refer to the set thawing time specified in the industry regulations. For example, the requirements for the thawing of reducing agents and urea in the light-duty vehicle pollutant emission limits and measurement methods require that the urea liquid thawing and injection work be completed within 20 minutes at -15℃.

[0037] S202: Based on the test wind speed, control the blower to blow air toward the urea tank.

[0038] The test wind speed here refers to the wind speed corresponding to the vehicle during driving, that is, the wind speed after the vehicle's driving speed is combined with the natural wind speed. When the vehicle is driving, the wind speed can be measured by a car anemometer. At the same time, different models correspond to different test wind speeds, that is, the wind speed value can be adjusted according to the model. For example, pickup trucks are generally limited to 80-100km / h at high speed, while SVU can reach 120km / h. When testing, the wind speed can be set to several levels, such as 30km / h for low speed, 50km / h or 80km / h for medium speed, and 110km / h for high speed.

[0039] Here is an explanation of the control of the blower: Since the function of the blower is to blow air to the urea tank to simulate the cooling effect of the wind on the urea tank when the vehicle is moving, so as to avoid the cooling effect of the wind on the urea tank during driving, so that the heating power of the heating module cannot meet the normal working requirements of the emission control system. Therefore, in order to avoid multiple attempts at the heating power of different wind speeds when conducting a urea pump bench test, when conducting a urea pump bench test, you can first test the situation of zero wind speed to determine the corresponding heating power when the vehicle is stationary at this ambient temperature. In this way, when testing the heating power at different wind speeds, you only need to increase the heating power based on the corresponding heating power when the vehicle is stationary.

[0040] S203: After the heating time is reached, controlling the heating module to stop heating.

[0041] The timing is started when the heating module starts working. When the heating time in the test condition is reached, the heating module immediately stops heating and determines whether the heating power of the heating module meets the heating demand based on the amount of urea liquid thawed in the urea tank at this time.

[0042] S204: obtaining temperature information of the urea liquid in the urea tank through the thermal imaging camera; and obtaining liquid level information of the urea liquid in the urea tank through the liquid level sensor.

[0043] When calculating the amount of urea liquid to be defrosted, it is necessary to obtain the temperature information of the urea liquid in the urea tank and the liquid level information of the urea liquid in the urea tank. The temperature information can be obtained by photographing a thermal imaging sensor disposed above the urea tank. It should be noted that the thermal imaging sensor can not only take a picture of the temperature of the urea liquid in the urea tank when the heating time is reached, but also monitor the temperature change of the urea liquid in the urea tank at all times during heating and record it. When the temperature information is to be obtained, the temperature information corresponding to the heating time point can be taken out and the temperature information corresponding to this point can be used for calculation. The liquid level information can be obtained through the liquid level sensor integrated in the urea pump.

[0044] S205: Calculating the amount of thawed urea liquid in the urea tank based on the temperature information, the liquid level information, and the shape of the urea tank.

[0045] Since most urea tanks are irregular in shape, when calculating the amount of thawing urea liquid, in addition to temperature information and liquid level information, calculations must also be performed based on the shape of the urea tank.

[0046] Specifically, since the shapes of urea tanks are different, different liquid levels in the urea tanks correspond to different urea liquid volumes. When calculating, the following can be used as the basis: Figure 3 The liquid level volume comparison chart shown is used to determine the urea liquid volume corresponding to the urea tank to be tested at different liquid level heights.

[0047] S206: Based on the amount of liquid thawing, output the target heating power corresponding to the test condition.

[0048] After calculating the amount of urea liquid thawing corresponding to the current heating power, if the amount of liquid thawing does not meet the thawing amount requirement, the heating power of the heating module needs to be adjusted to the target heating power so that the corresponding amount of liquid thawing under the test conditions is higher than the preset threshold, thereby meeting the urea liquid thawing requirement.

[0049] After the urea pump heating power test is passed at different test wind speeds and ambient temperatures, the heating module outputs the target heating power corresponding to different ambient temperatures and test wind speeds for design reference. At the same time, the thermal imaging camera can synchronously output the entire image record. The experimenter can further examine whether there are any items that can be improved during the process and conduct more targeted retests.

[0050] When outputting the target heating power, a chart can be generated based on the relationship between the ambient temperature (T), the test wind speed (V), and the target heating power (P) for output. The chart structure is shown in the following table:

[0051] Target heating power (W) at different ambient temperatures and different test wind speeds

[0052]

[0053] The above chart is only used to illustrate the relationship between ambient temperature (T), test wind speed (V), and target heating power (P). For example, when the test wind speed is 30 km / h and the ambient temperature is -20°C, the corresponding target heating power is P15.

[0054] In one embodiment, when calculating the amount of urea liquid thawed in the urea tank based on the temperature information, the liquid level information and the shape of the urea tank, the thaw area detected by the thermal imaging camera can be used to calculate the ratio of the thaw area to the total area, thereby calculating the approximate volume of melted urea. For example, if the freezing point of urea liquid is known to be -11°C, the area with a temperature higher than -7°C in the thermal imaging image can be used as the area where the urea liquid is completely thawed, thereby simply calculating the amount of urea liquid thawed through the area ratio and the volume corresponding to the current urea tank liquid level. Figure 3 As shown in the figure, when the liquid level is 100 mm, the volume of the urea tank is 6.91 L. If the ratio of the thawing area to the total area is 50%, the thawing amount of the urea liquid can be approximately calculated to be 3.46 L. By comparing the temperature information, liquid level height, and the liquid level volume measured in advance in the target urea tank, the thawing amount of the urea liquid can be quickly calculated, and less computing resources are required.

[0055] In one embodiment, when determining the target heating power corresponding to the test conditions, if the amount of urea liquid thawed corresponding to the heating time does not exceed the preset threshold, it means that the heating power cannot meet the normal working requirements of the emission control system at this time, and the heating power needs to be increased again to thaw more urea liquid.

[0056] At this time, the following process needs to be repeated until the amount of liquid thawed under the current test conditions is greater than the preset threshold:

[0057] If the amount of liquid thawed during the heating time is lower than the preset threshold, the heating module is controlled to stop heating, and the urea tank is cold-soaked based on the ambient temperature until the temperature of the urea liquid in the urea tank is confirmed to drop to the ambient temperature through the thermal imaging camera. Cold soaking here refers to cooling the urea tank by other coolants set outside the urea tank. The temperature of the coolant can be set to be equal to or lower than the ambient temperature. The temperature of the urea liquid in the urea tank can be quickly lowered to the ambient temperature by cold soaking, so that multiple experiments can be repeated in a short time. At this time, the heating power is increased, and the amount of liquid thawed under the current test conditions is recalculated, that is, the urea liquid in the urea tank is re-thawed according to the increased heating power, and the amount of liquid thawed corresponding to the current heating power is calculated at the heating time.

[0058] Now, the preset threshold is explained. Generally, the preset threshold is positively correlated with the maximum injection rate of the urea pump at the ambient temperature. For example, the preset threshold can be the urea liquid injection amount corresponding to the maximum injection rate maintained by the target vehicle at the ambient temperature within eight hours.

[0059] Specifically, when increasing the heating and thawing amount, in order to avoid the increase of the heating power being too high, resulting in a waste of resources, after increasing the heating power, when the amount of liquid thawing of the urea solution is higher than the preset threshold, the difference between the amount of liquid thawing and the preset threshold is calculated. If the difference is higher than the preset difference, it means that the increased heating power is too high at this time, and the heating power can be slightly reduced. For the convenience of calling, the first heating power is used as the initial heating power, the second heating power is used as the heating power after the increase, and the difference between the first heating power and the second heating power is used as the first heating power increase. The reduced heating power is called the third heating power. At this time, it is necessary to ensure that the third heating power is between the first heating power and the second heating power, such as the average of the two. If the difference between the third heating power and the first heating power is the second heating power increase, the second heating power increase should be less than the first heating power increase. In the process of repeatedly measuring the heating power, by adjusting the heating power increase, it is possible to avoid a single excessive increase in the heating power, resulting in a too high heating power. Although the amount of liquid thawing of the urea solution is higher than the preset threshold, it ultimately leads to a waste of resources.

[0060] In one embodiment, although the above process can find a more suitable heating power, it may result in too many tests and a long time. In this case, if an initial heating power close to the target heating power can be provided, the above situation can be avoided. Specifically, a sample urea tank database can be constructed to store the liquid thawing amount of urea liquid corresponding to different test conditions in each sample urea tank during the urea pump bench test. When it is necessary to calculate the initial heating power close to the target heating power, the liquid thawing amount corresponding to different test conditions measured by the target urea tank can be used to find the sample cloth urea tank closest to the test result of the target urea tank in the sample urea tank database. When looking for the closest sample urea tank, the similarity of the liquid thawing amount of multiple sample urea tanks with the target urea tank can be determined based on the liquid thawing amount corresponding to the target urea tank under multiple groups of test conditions. Specifically, the test conditions and liquid thawing can be quantified into a multidimensional matrix, where the number of rows of the multidimensional matrix is ​​the number of times the target urea tank has been tested, and the number of columns is the number of dimensions of the test conditions and test results, which includes five dimensions: heating time, ambient temperature, heating power, test wind speed, and liquid thawing amount. Thus, the similarity between high-dimensional matrices is used as the similarity of the liquid thawing amount between the target urea tank and the sample urea tank. Or in a high-dimensional space, the test conditions and liquid thawing amount of the target urea tank and the sample urea tank are abstracted into a single coordinate point, and the coordinate points corresponding to multiple tests of each urea tank are connected into a broken line segment, so as to calculate the broken line segment similarity of the broken line segments corresponding to the target urea tank and each sample urea tank, respectively. Here, the broken line segment similarity is related to the distance between each point in the broken line segment. The closer the distance of the broken line segment, the higher the broken line segment similarity. The broken line segment similarity can be used as the similarity of the liquid thawing amount between the target urea tank and the sample urea tank. Then, based on the similarity of the liquid thawing amount, the sample urea tank with the highest thawing amount similarity can be selected from multiple sample urea tanks as the similar urea tank of the target urea tank. At the same time, based on the historical test data of similar urea tanks, the reference heating power corresponding to the target urea tank under different test conditions can be determined, and the reference heating power can be used as the initial heating power of the target urea tank under the corresponding test conditions. By calculating the similar urea tanks of the target urea tank, the heating power of the similar urea tanks under different test conditions can be used as a reference to reduce the number of tests of the target urea tank during the test, thereby greatly saving time and test consumption.

[0061] In the above process, after determining the similar urea tank of the target urea tank, in order to further reduce the number of tests, the heating power change trend of the target urea tank can also be fitted according to the change trend of the heating power of the similar urea tank under different test conditions. For example, it is known that when the ambient temperature of the similar urea tank is -15℃ and the wind speed is 0km / h, 10km / h, 20km / h, 30km / h, 40km / h, and 50km / h, the corresponding heating power is 10w, 11w, 12w, 13w, 14w, and 15w respectively, and it is known that when the ambient temperature of the target urea tank is -15℃ and the wind speed is 0km / h and 20km / h, the heating power is 8.8w and 10.7w. At this time, it can be known that when the ambient temperature of the similar urea tank is -15℃, the relationship between the heating power and the wind speed can be approximated as: Where P is the heating power and V is the wind speed. At this time, the known test data of the target urea tank can be substituted for fitting to obtain the relationship between the heating power and wind speed corresponding to the target urea tank. Here, the relationship between the heating power and wind speed of the target urea tank can be approximated as: It can be understood that the more known test data of the target urea tank is and the higher the similarity between the target urea tank and the similar urea tank is, the more accurate the fitting result is. Whether the heating power of the similar urea tank is used as a reference or used to fit the heating power of the target urea tank, the number of tests can be reduced, thereby shortening the test time.

[0062] In one embodiment, considering that the vehicle may be parked on a slope when stationary, and at this time, due to the inclination of the vehicle, the thawed urea liquid will move, thereby affecting the thawing efficiency. Therefore, in order to ensure that the vehicle can also meet the thawing requirements of the urea liquid on the slope, a tilt simulation device can be set at the bottom of the urea tank. The tilt simulation device here can present different angles of inclination according to the control instructions of the control module. The type of the tilt simulation device is not limited here, as long as it can meet the inclination requirements during the simulation test. At this time, the test slope can be added to the test conditions, and before the heating module thaws the urea liquid, the tilt simulation device is controlled to tilt, so that the urea tank and the horizontal plane form an angle corresponding to the test slope. Then, the heating module is used for heating. When the heating time is reached, the tilt simulation device is controlled to return to a horizontal state, and the temperature information in the urea tank is obtained by a thermal imaging camera. By adding a tilt simulation device, the thawing situation when the vehicle is parked on a slope can be simulated, thereby improving the accuracy of the test process and ensuring that the measured heating power can meet the thawing requirements of the urea liquid when the vehicle is parked on a slope. In actual application, when the vehicle is parked on a slope, the slope angle can be determined by setting up a gyroscope and other equipment in the vehicle to determine the corresponding heating power.

[0063] In one embodiment, in order to increase the authenticity of the simulation, a simulated air duct may be added between the urea tank and the blower, and the simulated air duct here needs to correspond to the air duct between the front vent of the vehicle where the urea tank is located and the urea tank. If the authenticity of the simulation is to be further increased, a simulated air duct may be added between the urea tank and the rear of the vehicle. It should be noted that the simulated air duct will affect the heat dissipation of the urea tank, but if the simulated air duct is not provided, the air volume of the blower will blow directly to the urea tank. If the thawing requirement is met at this time, then under the condition that the simulated air duct interferes with the heat dissipation efficiency, the heat in the urea tank will only be higher, that is, the amount of thawing of the urea liquid will increase. Therefore, after adding the simulated air duct, the corresponding target heating power under different test conditions will be reduced accordingly.

[0064] For the same reason, multiple simulation components can be set in the simulated air duct to simulate multiple components around the urea tank in the actual vehicle, and during the test, the temperature of the simulated components needs to be set to the temperature of each component during the actual driving process to increase the authenticity of the test process and ensure the accuracy of the test results. Similar to the simulated air duct, after adding simulation components, the corresponding target heating power under different test conditions will be reduced accordingly.

[0065] It should be noted that the above-mentioned sample urea tank database can be pre-stored in a storage device of a computer device, and when it is necessary to determine the reference heating power, the computer device can select the sample urea tank data from the storage device. Of course, the computer device can also obtain the sample urea tank data from other external devices. For example, the sample urea tank database is stored in the cloud, and when it is necessary to determine the reference heating power, the computer device can obtain the sample urea tank data from the cloud. This embodiment does not limit the method for obtaining the sample urea tank data. Among them, when calculating the similarity between the liquid thawing amount of the sample urea tank and the target urea tank, the calculation can be performed using a mathematical model constructed based on a machine learning algorithm, and the constructed similarity calculation model can be pre-trained using a training data set. When the set training precision and accuracy are reached, it is determined that the similarity calculation model of the current training has completed the training so that it can be used for prediction processing.

[0066] like Figure 4 As shown, the embodiment of the present application also provides a urea pump bench test device, including:

[0067] The heating module 401 controls the heating module of the urea pump to heat according to preset test conditions; the test conditions include ambient temperature, heating power, test wind speed and heating time.

[0068] The blowing module 402 controls the blower to blow air toward the urea tank based on the test wind speed.

[0069] The time module 403 controls the heating module to stop heating after the heating time is reached.

[0070] The information acquisition module 404 acquires the temperature information of the urea liquid in the urea tank through the thermal imaging camera; and acquires the liquid level information of the urea liquid in the urea tank through the liquid level sensor.

[0071] The liquid thawing amount module 405 calculates the liquid thawing amount of the urea liquid in the urea tank based on the temperature information, the liquid level information and the shape of the urea tank.

[0072] The heating power module 406 outputs a target heating power corresponding to the test condition based on the amount of liquid thawing.

[0073] like Figure 5 As shown, the embodiment of the present application also provides a urea pump bench test device, including:

[0074] at least one processor; and a memory in communication with the at least one processor; wherein the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to:

[0075] The heating module of the urea pump is controlled to heat according to preset test conditions; the test conditions include ambient temperature, heating power, test wind speed and heating time; based on the test wind speed, the blower is controlled to blow air to the urea tank; after the heating time is reached, the heating module is controlled to stop heating; the temperature information of the urea liquid in the urea tank is obtained through a thermal imaging camera; the liquid level information of the urea liquid in the urea tank is obtained through the liquid level sensor; based on the temperature information, the liquid level information and the shape of the urea tank, the liquid thawing amount of the urea liquid in the urea tank is calculated; based on the liquid thawing amount, the target heating power corresponding to the test conditions is output.

[0076] The embodiment of the present application further provides a non-volatile computer storage medium storing computer executable instructions, wherein the computer executable instructions are configured as follows:

[0077] The heating module of the urea pump is controlled to heat according to preset test conditions; the test conditions include ambient temperature, heating power, test wind speed and heating time; based on the test wind speed, the blower is controlled to blow air to the urea tank; after the heating time is reached, the heating module is controlled to stop heating; the temperature information of the urea liquid in the urea tank is obtained through a thermal imaging camera; the liquid level information of the urea liquid in the urea tank is obtained through the liquid level sensor; based on the temperature information, the liquid level information and the shape of the urea tank, the liquid thawing amount of the urea liquid in the urea tank is calculated; based on the liquid thawing amount, the target heating power corresponding to the test conditions is output.

[0078] Each embodiment in this application is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, for the device and medium embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the partial description of the method embodiments.

[0079] The devices and media provided in the embodiments of the present application correspond one-to-one to the methods. Therefore, the devices and media also have similar beneficial technical effects as the corresponding methods. Since the beneficial technical effects of the methods have been described in detail above, the beneficial technical effects of the devices and media will not be repeated here.

[0080] Those skilled in the art will appreciate that the embodiments of the present application may be provided as methods, systems, or computer program products. Therefore, the present application may adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application may adopt the form of a computer program product implemented in one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that include computer-usable program code.

[0081] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to generate a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0082] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0083] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0084] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0085] The memory may include non-permanent storage in a computer-readable medium, random access memory (RAM) and / or non-volatile memory in the form of read-only memory (ROM) or flash RAM. The memory is an example of a computer-readable medium.

[0086] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include transitory media such as modulated data signals and carrier waves.

[0087] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0088] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A urea pump bench test method, characterized in that: Applied to a urea pump bench test system, the urea pump bench test system comprises: a blower, a thermal imaging camera, a urea tank, a urea pump and a control module; the urea pump is used to heat and spray urea liquid, the thermal imaging camera is used to obtain the temperature information of the urea liquid in the urea tank, and the urea pump is integrated with a heating module and a liquid level sensor; the method comprises: Controlling the heating module of the urea pump to heat according to preset test conditions; the test conditions include ambient temperature, heating power, test wind speed and heating time; Based on the test wind speed, controlling the blower to blow air toward the urea tank; After the heating time is reached, controlling the heating module to stop heating; The temperature information of the urea liquid in the urea tank is obtained by a thermal imaging camera; the liquid level information of the urea liquid in the urea tank is obtained by the liquid level sensor; calculating a thawing amount of the urea liquid in the urea tank based on the temperature information, the liquid level information, and the shape of the urea tank; Based on the amount of liquid thawing, a target heating power corresponding to the test condition is output.

2. The method according to claim 1, characterized in that The calculating the amount of thawing liquid of the urea liquid in the urea tank based on the temperature information, the liquid level information and the shape of the urea tank specifically includes: Based on the thermal imaging image, determine the area ratio between the area of ​​the thawed area with a temperature higher than a preset temperature threshold and the total area of ​​the urea liquid; The amount of thawing liquid of the urea liquid in the urea tank is determined based on the shape of the urea tank, the comparison between the liquid level height and the volume of the urea tank, the area ratio, and the liquid level information.

3. The method according to claim 1, characterized in that: The outputting the target heating power corresponding to the test condition based on the amount of liquid thawing specifically includes: Repeat the following process until the amount of liquid thawed under the current test conditions is higher than the preset threshold: confirming that the amount of liquid thawed within the heating time is lower than the preset threshold; Controlling the heating module to stop heating, and cold-soaking the urea tank based on the ambient temperature; Confirming, by means of the thermal imaging camera, that the temperature of the urea liquid in the urea tank drops to the ambient temperature; Increase the heating power and recalculate the amount of liquid to be defrosted under the current test conditions.

4. The method according to claim 3, characterized in that The step of increasing the heating power until the amount of liquid thawed under the current test condition is higher than the preset threshold value specifically includes: Determining a liquid amount difference between the first liquid thawing amount and the preset threshold; determining a first heating power increase amount based on the liquid amount difference; determining a second heating power based on the first heating power increase and the first heating power; determining a second liquid thawing amount corresponding to the second heating power, and if a difference between the second liquid thawing amount and the preset threshold is greater than a preset difference, reducing the heating power increase to obtain a second heating power increase; Based on the second heating power increase and the first heating power, a third heating power is determined until the amount of liquid thawing corresponding to the adjusted heating power is higher than the preset threshold and the difference with the preset threshold is lower than the preset difference.

5. The method according to claim 3, characterized in that: The preset threshold is positively correlated with the maximum injection rate of the urea pump at the ambient temperature.

6. The method according to claim 1, characterized in that The urea pump bench test system also includes a tilt simulation device, which is arranged at the bottom of the urea tank and can present different angles of tilt according to the control instructions of the control module; The test conditions also include a test slope; Before the control module controls the heating module of the urea pump to heat according to the preset test conditions, the method further includes: Controlling the tilt simulation device to tilt so that an angle corresponding to the test slope is formed between the urea tank and the horizontal plane; Before acquiring the temperature information of the urea liquid in the urea tank by the thermal imaging camera, the method further includes: The tilt simulation device is controlled to return to a horizontal state.

7. The method according to claim 1, characterized in that The urea tank is a transparent urea tank.

8. The method according to claim 1, characterized in that A simulated air duct is arranged between the blower and the urea tank, and the simulated air duct is a corresponding air duct between a vent and the urea tank on a vehicle type where the urea tank is located.

9. The method according to claim 8, characterized in that A plurality of simulation components are arranged in the simulation air duct, and the layout positions and temperatures of the simulation components are the same as the layout positions and temperatures of components within a preset range on the vehicle model where the urea tank is located under corresponding working conditions.

10. The method according to claim 1, characterized in that After calculating the amount of thawing liquid of the urea liquid in the urea tank based on the temperature information, the liquid level information and the shape of the urea tank, the method further includes: Determining similarities between the thawing amounts of liquid in a plurality of sample urea tanks and the target urea tank based on the thawing amounts of liquid in the target urea tank under a plurality of test conditions; Determining a similar urea tank to the target urea tank among the plurality of sample urea tanks based on the similarity of the amount of liquid thawed; Based on the historical test data of the similar urea tank, the heating powers corresponding to the target urea tank under different test conditions are determined.

11. A urea pump bench test device, characterized in that: Applied to the urea pump bench test system as claimed in claim 1, the device comprises: A heating module controls the heating module of the urea pump to heat according to preset test conditions; the test conditions include ambient temperature, heating power, test wind speed and heating time; A blowing module, based on the test wind speed, controls the blower to blow air toward the urea tank; A time module controls the heating module to stop heating after the heating time is reached; The information acquisition module acquires the temperature information of the urea liquid in the urea tank through the thermal imaging camera; and acquires the liquid level information of the urea liquid in the urea tank through the liquid level sensor; a liquid thawing amount module, which calculates the liquid thawing amount of the urea liquid in the urea tank based on the temperature information, the liquid level information and the shape of the urea tank; The heating power module outputs a target heating power corresponding to the test condition based on the amount of liquid thawing.

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