Method for testing pipeline pressure of hybrid transmission, computer program product and vehicle

Abstract

The embodiment of the invention provides a hybrid transmission pipeline pressure testing method, a computer program product and a vehicle. The method comprises the steps that a target working condition testing table is acquired; the target working condition test table comprises a target working condition test table in a series connection mode and a target working condition test table in a parallel connection mode; each target working condition test table comprises working condition parameters, and the working condition parameters comprise a temperature parameter, an engine rotating speed parameter and an electric pump rotating speed parameter; for each working condition parameter, acquiring pressure data acquired by the pressure acquisition device under the working condition parameter; and based on the pressure data, the pressure borne by the hybrid transmission pipeline under the working condition parameters is determined. A target working condition test table covering various working conditions of a vehicle is formulated in advance, comprehensive and efficient lubricating pipeline pressure testing is completed based on the table, and it is ensured that the system can stably work under various operation conditions.

Description

Technical Field

[0001] The present application relates to the technical field of lubrication and cooling of transmissions, and in particular to a method for testing pipeline pressure of a hybrid transmission, a computer program product, and a vehicle. Background Art

[0002] At present, in order to improve the efficiency of the transmission, the hybrid transmission adopts full active lubrication, which has become the mainstream research direction of major manufacturers. The pressure in the pipeline is an important reference parameter of the pipeline, but there is no efficient and convenient testing method. However, the transient maximum value of the pressure in the pipeline and the normal working pressure test results under harsh working conditions are particularly important. If the cooling pressure is small, the end spray oil flow may not be sprayed to the specified position according to the design direction. If the pressure is large, it may cause the pipeline to rupture and the lubrication pipeline to fail as a whole. Therefore, how to efficiently and comprehensively test the lubrication pipeline pressure of the hybrid transmission has become an urgent problem to be solved. Summary of the invention

[0003] The purpose of the embodiments of the present application is to provide a hybrid transmission pipeline pressure testing method, a computer program product and a vehicle, so as to achieve the technical effect of efficiently and comprehensively testing the hybrid transmission lubrication pipeline pressure.

[0004] In a first aspect, an embodiment of the present application provides a method for testing the pipeline pressure of a hybrid transmission, wherein an oil pump provides lubricating oil to the hybrid transmission through the pipeline; a pressure collection device is provided at the oil outlet of the oil pump; the oil pump includes a mechanical pump and an electric pump; the method includes:

[0005] Obtain a target operating condition test table; the target operating condition test table includes a target operating condition test table in a series mode and a target operating condition test table in a parallel mode; each of the target operating condition test tables includes operating condition parameters, and the operating condition parameters include temperature parameters, engine speed parameters, and electric pump speed parameters;

[0006] For each of the operating parameters, obtaining pressure data collected by the pressure collection device under the operating parameter;

[0007] Based on the pressure data, the pressure borne by the hybrid transmission pipeline under the operating parameters is determined.

[0008] In the above implementation process, by formulating in advance a target operating condition test table covering various vehicle operating conditions, a comprehensive and efficient lubrication pipeline pressure test is completed based on the table, which helps to ensure that the system can operate stably under various operating conditions.

[0009] Further, the obtaining of the target operating condition test table includes:

[0010] Obtaining an initial operating condition test table; the initial operating condition test table includes an initial operating condition test table in a series mode and an initial operating condition test table in a parallel mode; each of the initial operating condition test tables includes the operating condition parameters;

[0011] For each of the operating parameters, determining the flow demand of the hybrid transmission under the operating parameter and the actual flow output of the oil pump under the operating parameter;

[0012] Based on the difference between the flow demand and the actual flow output, the target operating condition test table is determined from the initial operating condition test table.

[0013] In the above implementation process, invalid test points are screened out based on the initial working condition test table, so as to determine the target working condition test table, which is conducive to improving the test efficiency.

[0014] Furthermore, the motor speed is positively correlated with the speed of the mechanical pump; determining the actual flow output of the oil pump comprises:

[0015] The actual flow output is determined according to the electric pump speed parameter, the displacement of the electric pump, the volumetric efficiency of the electric pump, the engine speed parameter, the displacement of the mechanical pump, and the volumetric efficiency of the mechanical pump.

[0016] In the above implementation process, since the motor speed is positively correlated with the mechanical pump speed, the mechanical pump speed can be indirectly obtained by measuring the motor speed. The actual flow output is calculated based on the speed, displacement, volumetric efficiency of the electric pump and the speed, displacement, and volumetric efficiency of the mechanical pump.

[0017] Further, the step of obtaining the pressure data collected by the pressure collection device under the operating parameters includes:

[0018] After the operating condition parameter is maintained for a preset time period, the pressure data is acquired.

[0019] In the above implementation process, each operating condition parameter simulates a corresponding operating condition, and tests are carried out according to the operating condition parameters including temperature parameters, engine speed parameters, and electric pump speed parameters, and ensure that the system runs under the operating condition for a period of time. After the system reaches a stable state, pressure data is obtained through the pressure acquisition device.

[0020] Further, the pressure borne by the hybrid transmission pipeline includes a transient maximum pressure and a stable working pressure; and determining the pressure borne by the hybrid transmission pipeline under the operating parameters based on the pressure data includes:

[0021] Calculate the peak value and average value of the pressure data within the acquisition time window;

[0022] The peak value is determined as the transient maximum pressure, and the average value is determined as the stable working pressure.

[0023] In the above implementation process, the pressure data at the pump outlet usually reflects the initial pressure state of the fluid before entering the pipeline system. In the actual system, if the pipeline design is reasonable, the pressure at the pump outlet can well reflect the pressure in the pipeline. In this case, the peak value of the pressure data at the pump outlet can be determined as the transient maximum pressure of the pipeline, and the average value can be determined as the stable working pressure of the pipeline. Of course, in some complex systems, there is a significant difference between the pressure at the pump outlet and the pressure in the pipeline. At this time, correction factors can be introduced according to system characteristics and experimental data to consider the influence of factors such as pipeline resistance on pressure. These correction factors can help estimate the pressure in the pipeline more accurately.

[0024] Furthermore, after obtaining the pressure data under each of the operating parameters, the method further includes:

[0025] The electric pump is controlled to change the rotational speed direction.

[0026] In the above implementation process, after each working condition is completed, the electric pump is controlled to reverse at a suitable speed before the next working condition test is carried out, thereby improving the accuracy of the test data.

[0027] Furthermore, the input end of the hybrid transmission is connected to a simulated input motor, and the simulated input motor is used to simulate the engine and / or the drive motor to input power to the hybrid transmission.

[0028] In the above implementation process, a variety of actual driving conditions can be reproduced by simulating the input motor.

[0029] A second aspect of an embodiment of the present application provides a computer program product, wherein the computer program product includes a computer program, and when the computer program is executed by a processor, any method described in the first aspect is implemented.

[0030] A third aspect of an embodiment of the present application provides a vehicle, which uses the method described in the first aspect to test the pipeline pressure of a hybrid transmission.

[0031] A fourth aspect of an embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement any of the methods described in the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1 A schematic flow chart of a method for testing pipeline pressure of a hybrid transmission provided in an embodiment of the present application;

[0034] Figure 2 A schematic flow chart of another hybrid transmission pipeline pressure testing method provided in an embodiment of the present application;

[0035] Figure 3 A schematic diagram of an initial working condition test provided in an embodiment of the present application;

[0036] Figure 4 A target operating condition test schematic diagram provided in an embodiment of the present application;

[0037] Figure 5 Another target operating condition test schematic diagram provided for an embodiment of the present application;

[0038] Figure 6 Another target operating condition test schematic diagram provided for an embodiment of the present application. DETAILED DESCRIPTION

[0039] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0040] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0041] The pressure in the pipeline is an important reference parameter of the pipeline, but there is no efficient and convenient testing method. How to efficiently and comprehensively test the lubrication pipeline pressure of the hybrid transmission has become an urgent problem to be solved.

[0042] In view of any of the above problems, the present application provides a method for testing the pipeline pressure of a hybrid transmission, referring to Figure 1 , Figure 1 A flow chart of a method for testing pipeline pressure of a hybrid transmission provided in an embodiment of the present application.

[0043] In this embodiment, the oil pump provides lubricating oil to the hybrid transmission through the pipeline; the oil outlet of the oil pump is equipped with a pressure collection device; the oil pump includes a mechanical pump and an electric pump; the method includes:

[0044] Step S10: obtaining a target operating condition test table; the target operating condition test table includes a target operating condition test table in a series mode and a target operating condition test table in a parallel mode; each of the target operating condition test tables includes operating condition parameters, and the operating condition parameters include temperature parameters, engine speed parameters, and electric pump speed parameters;

[0045] It should be noted that the execution subject of this embodiment may be a controller of the vehicle, such as a TCU (Transmission Control Unit) or an ECU (Electronic Control Unit).

[0046] The oil pump is a key component of the hybrid transmission lubrication system. The oil pump is in forward operation by default. The oil pump is responsible for extracting lubricating oil from the oil tank or oil pan and transporting it through pipes to various parts of the hybrid transmission that need lubrication. The pipeline system is an important channel connecting the oil pump and various lubrication points inside the hybrid transmission.

[0047] The pressure acquisition device can be a pressure sensor, a pressure transmitter, a wireless pressure collector, a multi-channel pressure data acquisition device, etc.

[0048] Before obtaining the target operating condition test table, the hybrid transmission valve body to be used is modified, a hole is opened at the pump outlet and a pressure collection device is installed; specifically, the mechanical pump and the electric pump supply oil to the pipeline through the same outlet, and a pressure collection device is installed at the outlet position, which is equivalent to the inlet position of the pipeline; the status of the sample to be tested is checked before assembly, and the sample should be a qualified sample after assembly; after confirming that the hybrid transmission is ready, it is installed on the test bench, and the test bench input motor is connected to the hybrid transmission input end; the pressure collection device is connected to the data acquisition, and this embodiment does not limit the sampling frequency. Exemplarily, the sampling frequency is not less than 10Hz.

[0049] After obtaining the target working condition test table, the test is carried out according to the test conditions in the table. In addition, multiple samples can be retested under the same working condition to obtain relevant pressure data, process and analyze the pressure data, specifically, process and analyze the pressure data and draw a curve or generate a map.

[0050] It should be understood that the target operating condition test table is a predefined table that can be stored in the execution entity and used to guide the operating condition selection during the test process.

[0051] Series mode refers to the mode in which the engine and the motor transmit power sequentially through a mechanical connection. Parallel mode refers to the mode in which the engine and the motor can provide power to the drive wheels simultaneously or individually.

[0052] In the target operating condition test table, the corresponding parameters are different according to the operating conditions represented by the test points (i.e., operating condition parameters). Specifically, if the test point represents the operating condition where only the drive motor is used as the driving source to drive the vehicle, then the engine speed parameters are all 0 or are all small values; if the test point represents the operating condition where only the engine is used as the driving source to drive the vehicle, then the electric pump speed parameters are all 0.

[0053] Of course, in addition to the target operating condition test table in series mode and the target operating condition test table in parallel mode, the target operating condition test table can also include target operating condition test tables in pure electric mode, target operating condition test tables in hybrid mode, target operating condition test tables in extended range mode and other target operating condition test tables in various driving modes of the vehicle. The temperature parameters, engine speed parameters and electric pump speed parameters contained in the target operating condition test table can be set according to specific requirements. The target operating condition test table is used to characterize various operating conditions of the vehicle. Therefore, the target operating condition test table can also include humidity parameters, vehicle speed parameters, load parameters, engine speed parameters, torque parameters, battery status parameters, transmission gear parameters and other parameters used to more comprehensively represent a working condition.

[0054] Step S20: for each of the operating parameters, obtaining pressure data collected by the pressure collection device under the operating parameter;

[0055] It is understandable that for each operating condition parameter in the target operating condition test table, pressure data needs to be collected. By collecting pressure data under each operating condition parameter, it can be ensured that the test covers different working conditions.

[0056] It should be noted that in addition to obtaining pressure data, the electric pump voltage, electric pump current and electric pump feedback speed can also be obtained. Among them, the electric pump voltage reflects the amount of energy supplied to the electric pump by the power supply, which helps to evaluate the working efficiency and power consumption of the electric pump. By comparing the voltage changes under different working conditions, it can be determined whether the electric pump is operating within the optimal working range. The electric pump current indicates the actual power consumption of the electric pump and reflects the working state and energy conversion efficiency of the electric pump. Excessive current may mean that the electric pump is overloaded, and too little current may mean that the electric pump does not achieve the expected performance. The electric pump feedback speed reflects the actual operating speed of the electric pump. The actual operating speed of the electric pump may be different from the given electric pump speed parameters. Obtaining the electric pump feedback speed to adjust the test parameters can improve the accuracy of the test.

[0057] In a specific implementation, the temperature of the system is adjusted according to the temperature parameter to ensure that the system temperature is equal to the temperature parameter, and then the engine speed and the electric pump speed are adjusted according to the engine speed parameter and the electric pump speed parameter. For example, the test bench is equipped with a temperature control system, which can adjust the temperature of the hybrid transmission and its lubrication and cooling system through a heating or cooling device. The temperature control system can be a water bath, an oil bath or other forms of heating / cooling devices.

[0058] Step S30: Based on the pressure data, determine the pressure that the hybrid transmission pipeline is subjected to under the operating parameters.

[0059] It should be noted that the pressure in the pipeline can be calculated based on the pressure data at the pump outlet, combined with system characteristics and fluid mechanics principles. As an example, a correction factor is introduced based on system characteristics and experimental data to consider the impact of factors such as pipeline resistance on pressure. The pressure in the pipeline is determined based on the pressure data at the pump outlet and the correction function.

[0060] Alternatively, if the pipeline is reasonably designed, the pressure at the pump outlet can well reflect the pressure in the pipeline. In this case, the pump outlet pressure can be determined as the pressure in the pipeline.

[0061] In this embodiment, by obtaining a target operating condition test table, collecting pressure data, and determining the pressure that the pipeline is subjected to, the accuracy and comprehensiveness of the test are improved, thereby ensuring the stability and reliability of the hybrid transmission under different operating conditions.

[0062] Based on any of the above embodiments, step S10 includes: Figure 2 Steps S01 to S03 shown:

[0063] Step S01: obtaining an initial operating condition test table; the initial operating condition test table includes an initial operating condition test table in a series mode and an initial operating condition test table in a parallel mode; each of the initial operating condition test tables includes the operating condition parameters;

[0064] It should be noted that m1×m2×m3 test points are selected in a specific test interval. The test dimensions include temperature test dimension, engine speed test dimension, and electric pump speed test dimension. m1 represents the number of temperature test dimensions, m2 represents the number of engine speed test dimensions, and m3 represents the number of electric pump speed test dimensions. Each test point contains a temperature parameter, an engine speed parameter, and an electric pump speed parameter. All test points form the initial working condition test table.

[0065] Step S02: for each of the operating parameters, determining the flow demand of the hybrid transmission under the operating parameter and the actual flow output of the oil pump under the operating parameter;

[0066] It should be noted that the theoretical flow demand can be calculated based on the design specifications and operating parameters of the hybrid transmission. The flow demand can also be estimated using empirical formulas or by referring to data from similar systems. You can also consult relevant design manuals or technical documents to find the flow demand that is suitable for the current operating conditions. This embodiment does not limit the method for determining the flow demand. For example, for different situations, such as the electric pump working alone and the mechanical pump working alone, there is a calculation module in the system, which determines the flow and pressure demand based on the flow demand when only the motor is working and the shaft gear demand when the engine participates in the work.

[0067] The actual flow output can be determined by installing a flow meter at the outlet of the oil pump to directly measure the actual flow output of the oil pump. If direct measurement is not possible, the flow output can be indirectly calculated through other parameters.

[0068] Step S03: Based on the difference between the flow demand and the actual flow output, the target operating condition test table is determined from the initial operating condition test table.

[0069] Specifically, for each operating condition parameter (ie, each test point) in the initial operating condition test table, the required flow rate is compared with the actual output flow rate. If the actual flow output meets the required flow rate, the operating condition parameter is retained; otherwise, the corresponding operating condition parameter is filtered out.

[0070] It should be noted that the purpose of determining the target operating condition test table from the initial operating condition test table is to avoid too many test points, which will affect the test efficiency, and not consider the influence of temperature (specifically, temperature will affect the viscosity of the oil and the speed of the pump), and to screen out the lower pressure conditions where the engine does not participate in the operation or runs at a low speed. In addition to using the gap between the flow demand and the actual flow output to determine the target operating condition test table from the initial operating condition test table, the target operating condition test table can also be determined based on the simulation and the actual capacity of the current oil pump at different temperatures, flow demand, mechanical pump overflow capacity, and electric pump oil pumping capacity. The target operating condition test table lists the most effective pump operation mode under a given flow demand, that is, achieving the lowest energy consumption while meeting system requirements.

[0071] Among them, the actual capacity of the oil pump at different temperatures refers to the performance data of the oil pump at different ambient temperatures or working temperatures. Through simulation and actual test data, the performance parameters of the oil pump such as flow rate and pressure at different temperatures can be obtained, including but not limited to the following aspects:

[0072] Flow rate: The amount of oil that an oil pump can provide per unit time.

[0073] Pressure: The maximum output pressure that the oil pump can produce.

[0074] Efficiency: includes volumetric efficiency, which is the ratio of the actual amount of oil delivered to the theoretical value; and mechanical efficiency, which is the ratio of the oil pump output power to the input power.

[0075] Noise level: The intensity of the sound produced by the oil pump when it is working.

[0076] Vibration characteristics: the vibration generated when the oil pump is working.

[0077] Temperature effect: The effect of different temperatures on oil pump performance, such as the effect of viscosity changes on flow and pressure.

[0078] Response speed: the time it takes for the oil pump to start and reach a stable state.

[0079] Durability: The service life of the oil pump under specific conditions.

[0080] Reliability: The ability of an oil pump to maintain normal operation within a predetermined period of time.

[0081] Flow demand refers to the flow rate required by the system under different working conditions.

[0082] The overflow capacity of a mechanical pump refers to the ability of the mechanical pump to release excess flow through the overflow valve when the flow generated by the mechanical pump at high speed exceeds the actual demand of the system. The function of the overflow valve is to protect the system from excessive pressure and ensure that the pressure in the system does not exceed the safe range.

[0083] The pumping capacity of an electric pump refers to the maximum flow and pressure that the pump can provide under different operating conditions. This is usually determined by the design parameters of the pump, including displacement, speed range, and volumetric efficiency. The output of an electric pump can usually be adjusted by changing the drive signal to adapt to different flow requirements.

[0084] Through the above analysis, we can comprehensively consider factors such as the performance of the oil pump, flow requirements, overflow capacity of the mechanical pump, and oil pumping capacity of the electric pump. Based on this information, we can calculate a set of optimal working modes or target working condition test tables.

[0085] like Figure 3 As shown, Figure 3 The figure shows an initial working condition test diagram provided in the embodiment of the present application. The figure shows the possible value ranges of the engine speed parameter (i.e., the engine speed in the figure) and the electric pump speed parameter (i.e., the electric pump speed in the figure) under the same temperature parameter. Of course, the value ranges of the engine speed and the electric pump speed can be set according to actual test requirements and are not limited to Figure 3The table shown in the figure is not equivalent to the initial operating condition test table, but only a part of the initial operating condition test table. Assuming that the temperature parameters include -40 degrees, -30 degrees, -20 degrees, -10 degrees, 0 degrees, 24 degrees, 60 degrees, and 90 degrees, the table shown in the figure is the possible value range of the engine speed parameter and the electric pump speed parameter when the temperature is 0 degrees. Then the complete initial operating condition test table should also include the possible value range of the engine speed parameter and the electric pump speed parameter when the temperature parameters are -40 degrees, -30 degrees, -20 degrees, -10 degrees, 24 degrees, 60 degrees, and 90 degrees respectively.

[0086] like Figure 4 As shown, Figure 4 A target operating condition test table diagram provided for an embodiment of the present application. The figure shows the target operating condition test table screened out when the engine does not participate in vehicle driving in pure electric mode and the engine speed is constant at 0. The table is divided into invalid test points to be eliminated (i.e., the part marked with a short horizontal line) and retained test points (i.e., the part marked with numbers, such as 1.56, 2.86, and 5.54).

[0087] like Figure 5 As shown, Figure 5 Another target operating condition test table provided for the embodiment of the present application is shown in the figure. The target operating condition test table selected when the engine participates in vehicle driving in series mode and the electric pump speed is constant at 0. The table is divided into invalid test points to be eliminated (i.e., the part marked with a short dash) and retained test points (i.e., the part marked with numbers, such as 10.45, 11.52, and 12.21).

[0088] like Figure 6 As shown, Figure 6 Another target operating condition test table provided in the embodiment of the present application is shown in the figure. The figure shows the target operating condition test table selected when the engine and the drive motor are simultaneously involved in the vehicle driving in the parallel mode.

[0089] In addition, multiple target operating condition test tables under different driving modes can be combined into one table. Figure 4 , Figure 5 , Figure 6 The table data shown is combined.

[0090] In this embodiment, by obtaining the initial operating condition test table, determining the flow demand of the hybrid transmission and the actual flow output of the oil pump, and determining the target operating condition test table based on the gap between the flow demand and the actual flow output, a large number of invalid test points can be eliminated, reducing unnecessary testing and debugging time, thereby reducing testing costs.

[0091] Based on any of the above embodiments, the engine speed is positively correlated with the speed of the mechanical pump; determining the actual flow output of the oil pump includes:

[0092] The actual flow output is determined according to the electric pump speed parameter, the displacement of the electric pump, the volumetric efficiency of the electric pump, the engine speed parameter, the displacement of the mechanical pump, and the volumetric efficiency of the mechanical pump.

[0093] It should be noted that there is a speed ratio (ie, transmission ratio) between the engine speed and the mechanical pump speed. When the motor speed increases, the mechanical pump speed also increases accordingly. The mechanical pump speed can be determined according to the engine speed.

[0094] The electric pump speed parameter may be the electric pump required speed, which refers to the target speed that the electric pump needs to reach at a certain moment, and is calculated by the vehicle's electronic control system or computing module according to different vehicle operating conditions (such as engine speed, load, temperature, etc.). This calculation process is usually based on pre-set algorithms that are intended to ensure that the electric pump can provide appropriate oil pressure and flow to the hybrid transmission or other components that require lubrication.

[0095] The rotation speed of the mechanical pump generally does not need to be calculated.

[0096] The displacement and volumetric efficiency of electric and mechanical pumps are key performance parameters, usually provided by the manufacturer. Displacement and volumetric efficiency are measured under specific conditions, such as certain temperature, pressure, and viscosity. Therefore, when applying these data, ensure the consistency of conditions. Specifically, obtain the speed, displacement, and volumetric efficiency of the electric pump and the speed, displacement, and volumetric efficiency of the mechanical pump at the same temperature.

[0097] In the specific implementation, the speed, displacement and volumetric efficiency of the mechanical pump are obtained to determine the required speed, displacement and volumetric efficiency of the electric pump. The actual flow output = required speed of the electric pump × displacement of the electric pump × volumetric efficiency of the electric pump + speed of the mechanical pump × displacement of the mechanical pump × volumetric efficiency of the mechanical pump.

[0098] In this embodiment, the actual flow output of the pump is calculated based on the speed parameters, displacement and volumetric efficiency of the electric pump and the mechanical pump.

[0099] On the basis of any of the above embodiments, the step of obtaining the pressure data collected by the pressure collection device under the operating parameters includes:

[0100] After the operating condition parameter is maintained for a preset time period, the pressure data is acquired.

[0101] It should be noted that this embodiment does not limit the preset time. Each operating condition parameter simulates a corresponding operating condition, and tests are performed according to the temperature parameters, engine speed parameters, and electric pump speed parameters included in the operating condition parameters, and the system is ensured to operate under the operating condition for a period of time, so that the system reaches a stable state, and then the pressure data is obtained through the pressure acquisition device.

[0102] In the specific implementation, start the test bench input motor and run the transmission according to the selected operating parameters. Record the time when the test starts so that the preset duration can be calculated later. Run the transmission under the specified operating parameters for a period of time to allow the system to reach thermal equilibrium. This period of time is called the preset duration, which is usually at least a few minutes to ensure that the system fully responds and reaches a stable operating state. After the preset duration is over, start the pressure acquisition device and start recording pressure data. Repeat the above steps for different operating parameters to obtain complete and comprehensive pressure data.

[0103] In this embodiment, the system operates in a stable state, which can eliminate fluctuations caused by rapid changes and improve the accuracy of pressure data.

[0104] Based on any of the above embodiments, the pressure borne by the hybrid transmission pipeline includes a transient maximum pressure and a stable working pressure; and determining the pressure borne by the hybrid transmission pipeline under the operating parameters based on the pressure data includes:

[0105] Calculate the peak value and average value of the pressure data within the acquisition time window;

[0106] It is understandable that for each set of pressure data, the peak value and average value within the acquisition time window are calculated. The peak value represents the maximum value of pressure in a short period of time, which may occur when the system is suddenly loaded or unloaded. The average value reflects the average pressure level of the system over a longer period of time.

[0107] The peak value is determined as the transient maximum pressure, and the average value is determined as the stable working pressure.

[0108] Specifically, the calculated peak value is determined as the transient maximum pressure, which is the maximum pressure that the hybrid transmission lubrication pipeline can withstand in a short period of time. The transient maximum pressure is crucial for evaluating the durability and safety of the system under extreme working conditions. The calculated average value is determined as the stable working pressure of the hybrid transmission lubrication pipeline, which refers to the pressure level of the hybrid transmission lubrication pipeline during normal operation.

[0109] In this embodiment, the transient maximum pressure and the stable working pressure are important reference points for evaluating the pressure that the pipeline can withstand. By measuring the transient maximum pressure, it is possible to ensure that the lubrication pipeline can remain intact in an emergency and prevent rupture or leakage. Determining the stable working pressure helps to optimize the design of the lubrication pipeline, ensuring that it can provide sufficient lubrication under normal working conditions while avoiding the cost increase caused by overdesign. By analyzing the transient maximum pressure and the stable working pressure, the design of the lubrication pipeline can be improved and the reliability and durability of the system can be improved.

[0110] On the basis of any of the above embodiments, after obtaining the pressure data under each of the operating parameters, the method further includes:

[0111] The electric pump is controlled to change the rotational speed direction.

[0112] It should be noted that the factors affecting pressure building are significantly different under normal temperature and low temperature conditions, such as liquid viscosity and pipe wall flow resistance under low temperature. Therefore, a reversal strategy is adopted to control the electric pump to change the speed direction, effectively simulating the state of cold start after a long period of low temperature static parking under low temperature conditions, simulating the long-term self-return and dripping of oil, and avoiding the continuous operation of the oil pump, which causes oil to accumulate in the pipeline, resulting in inconsistent pressure building process and inaccurate measurement results.

[0113] In a specific implementation, after each working condition test is completed, the electric pump is controlled to reverse at an appropriate speed for more than a certain period of time to allow the oil in the pipeline to fall back into the oil tank or oil pan before the next working condition test is carried out.

[0114] In this embodiment, a reversal strategy is used to improve the test efficiency at low temperatures, and the test efficiency is improved by simulating a state after long-term parking at low temperatures.

[0115] Based on any of the above embodiments, the input end of the hybrid transmission is connected to a simulated input motor, and the simulated input motor is used to simulate the engine and / or the drive motor to input power to the hybrid transmission.

[0116] It should be noted that the actual driving condition is simulated by adjusting the speed and torque of the simulated input motor and simulating the engine and / or drive motor inputting power to the hybrid transmission.

[0117] As an example, the hybrid transmission pipeline pressure test is completed by the following steps:

[0118] 1. Test preparation:

[0119] 101 Modify the valve body of the hybrid transmission to be used, open a hole at the pump outlet and equip it with a pressure sensor;

[0120] 102 Check the status of the samples to be tested before assembly, and the samples after assembly should be qualified;

[0121] 103 After the transmission is prepared, it is installed on the test bench, and the test bench input motor (i.e., the simulated input motor) is connected to the input end of the hybrid transmission;

[0122] 104 The pressure sensor is connected to the data acquisition, and the sampling frequency is not less than 10Hz;

[0123] 2. Perform pressure test on the hybrid transmission lubrication and cooling lines:

[0124] 201: Carry out the test according to the test conditions in the target working condition test table. After the temperature reaches the target value, control the speed of the electric pump or engine to increase from 0r / min to the target speed value, stabilize for more than a certain period of time, and then control the speed of the electric pump or engine to drop to 0r / min;

[0125] 202: Conduct a separate test for each speed condition, and record the lubrication cooling pipeline pressure, electric pump voltage, electric pump current, and electric pump feedback speed during the test;

[0126] 203: After each working condition is completed, control the electric pump to reverse at an appropriate speed for a certain period of time before proceeding to the next working condition test.

[0127] 3. Repeat the test of multiple samples under the same working conditions, obtain relevant data, process and analyze the data.

[0128] In this embodiment, a variety of actual driving conditions can be reproduced by simulating the input motor, and the simulated input motor can accurately control the speed and torque, making the test environment more controllable and improving the accuracy of the test data.

[0129] Based on the method described in any of the above embodiments, the present application also provides a computer program product, which includes one or more computer programs or instructions. The computer program or instructions can be stored in a computer-readable storage medium, or transmitted from one computer-readable storage medium to another computer-readable storage medium. When the computer program is executed by a processor, the method described in any of the above embodiments is implemented.

[0130] Based on the method described in any of the above embodiments, the present application also provides a vehicle, which uses the method described in any of the above embodiments to test the hybrid transmission pipeline pressure.

[0131] The present application also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, it can be used to execute the method described in any of the above embodiments.

[0132] In several embodiments provided in the present application, it should be understood that the disclosed devices and methods can also be implemented in other ways. The device embodiments described above are merely schematic. For example, the flowcharts and block diagrams in the accompanying drawings show the possible architecture, functions and operations of the devices, methods and computer program products according to multiple embodiments of the present application. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of a code, and the module, a program segment or a part of a code contains one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, depending on the functions involved. It should also be noted that each box in the block diagram and / or flowchart, and the combination of boxes in the block diagram and / or flowchart can be implemented with a dedicated hardware-based system that performs a specified function or action, or can be implemented with a combination of dedicated hardware and computer instructions.

[0133] In addition, the functional modules in the various embodiments of the present application may be integrated together to form an independent part, or each module may exist separately, or two or more modules may be integrated to form an independent part.

[0134] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present application can be essentially or partly embodied in the form of a software product that contributes to the prior art. The computer software product is stored in a storage medium, including several instructions to enable a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the methods described in each embodiment of the present application. The aforementioned storage medium includes: various media that can store program codes, such as a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk.

[0135] The above description is only an embodiment of the present application and is not intended to limit the scope of protection of the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present application should be included in the scope of protection of the present application. It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings.

[0136] The above is only a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

[0137] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article 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, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

Claims

1. A method for testing the pipeline pressure of a hybrid transmission, characterized in that: The oil pump provides lubricating oil to the hybrid transmission through the pipeline; the oil outlet of the oil pump is equipped with a pressure collection device; The oil pump includes a mechanical pump and an electric pump; the method includes: Obtain a target operating condition test table; the target operating condition test table includes a target operating condition test table in a series mode and a target operating condition test table in a parallel mode; each of the target operating condition test tables includes operating condition parameters, and the operating condition parameters include temperature parameters, engine speed parameters, and electric pump speed parameters; For each of the operating parameters, obtaining pressure data collected by the pressure collection device under the operating parameter; Based on the pressure data, the pressure borne by the hybrid transmission pipeline under the operating parameters is determined.

2. The method according to claim 1, characterized in that The step of obtaining the target operating condition test table includes: Obtaining an initial operating condition test table; the initial operating condition test table includes an initial operating condition test table in a series mode and an initial operating condition test table in a parallel mode; each of the initial operating condition test tables includes the operating condition parameters; For each of the operating parameters, determining the flow demand of the hybrid transmission under the operating parameter and the actual flow output of the oil pump under the operating parameter; Based on the difference between the flow demand and the actual flow output, the target operating condition test table is determined from the initial operating condition test table.

3. The method according to claim 2, characterized in that The engine speed is positively correlated with the speed of the mechanical pump; Determining the actual flow output of the oil pump includes: The actual flow output is determined according to the electric pump speed parameter, the displacement of the electric pump, the volumetric efficiency of the electric pump, the engine speed parameter, the displacement of the mechanical pump, and the volumetric efficiency of the mechanical pump.

4. The method according to claim 1, characterized in that The step of acquiring the pressure data collected by the pressure collection device under the operating parameters comprises: After the operating condition parameter is maintained for a preset time period, the pressure data is acquired.

5. The method according to claim 1, characterized in that The pressure borne by the hybrid transmission pipeline includes a transient maximum pressure and a stable working pressure; and determining the pressure borne by the hybrid transmission pipeline under the operating parameters based on the pressure data includes: Calculate the peak value and average value of the pressure data within the acquisition time window; The peak value is determined as the transient maximum pressure, and the average value is determined as the stable working pressure.

6. The method according to claim 1, characterized in that After obtaining the pressure data under each of the operating parameters, the method further includes: The electric pump is controlled to change the rotational speed direction.

7. The method according to claim 1, characterized in that The input end of the hybrid transmission is connected to a simulated input motor, and the simulated input motor is used to simulate an engine and / or a drive motor to input power to the hybrid transmission.

8. A computer program product, characterized in that The computer program product comprises a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

9. A vehicle, characterized in that: The vehicle uses the method described in any one of claims 1-7 to test the hybrid transmission pipeline pressure.

10. A computer-readable storage medium, characterized in that: Computer instructions are stored thereon, and when the computer instructions are executed by a processor, the steps of any method described in claims 1-7 are implemented.

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