Method and device for determining internal leakage coefficient of hydraulic pump, hydraulic system and medium

Abstract

The invention discloses a method and device for determining the internal leakage coefficient of a hydraulic pump, a hydraulic system and a medium, and relates to the technical field of hydraulic pumps. The method comprises the steps that the oil inlet pressure, the oil outlet pressure, the rotating speed and the actual output flow of the hydraulic pump under different working conditions are obtained, and the different working conditions indicate that the rotating speed and / or the oil outlet pressure of the hydraulic pump are / is different; according to the rotating speed and the actual output flow under each working condition, the corresponding internal leakage amount is determined; corresponding pressure differences are determined according to the oil inlet pressure and the oil outlet pressure under all the working conditions; and under at least one rotating speed, the internal leakage coefficient is obtained according to the internal leakage amount under different pressure differences. According to the embodiment of the invention, the internal leakage coefficient is determined by adopting the internal leakage amount under different pressure differences at at least one rotating speed, so that the influence of interference factors such as test temperature on a test result of an individual working condition point can be effectively eliminated, the experiment interference resistance is high, and the accuracy of the internal leakage coefficient is improved.

Description

Technical Field

[0001] The present application relates to the technical field of hydraulic pumps, and in particular to a method, device, hydraulic system and medium for determining an internal leakage coefficient of a hydraulic pump. Background Art

[0002] The hydraulic pump is the power element of the hydraulic system. It is driven by an engine or an electric motor to suck oil from the hydraulic tank, and then discharge the pressure oil to the actuator. As one of the most core components in the hydraulic system, the performance of the hydraulic pump affects the stability, safety and efficiency of the entire hydraulic system.

[0003] The internal leakage coefficient of a hydraulic pump can be used as a direct basis for judging the manufacturing level and energy consumption level of the hydraulic pump. Therefore, it is necessary to provide a more scientific and reasonable solution to test and obtain a more accurate internal leakage coefficient of the hydraulic pump. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a method, device, hydraulic system and medium for determining the internal leakage coefficient of a hydraulic pump, so as to solve the technical problem that the internal leakage coefficient of the hydraulic pump obtained by testing in the prior art is not accurate enough.

[0005] In order to achieve the above-mentioned object, the first aspect of the present application provides a method for determining an internal leakage coefficient of a hydraulic pump, comprising:

[0006] Obtaining the oil inlet pressure, oil outlet pressure, speed, and actual output flow rate of the hydraulic pump under different working conditions, wherein different working conditions indicate that the speed and / or oil outlet pressure of the hydraulic pump are different;

[0007] Determine the corresponding internal leakage according to the rotation speed and actual output flow rate under various working conditions;

[0008] Determine the corresponding pressure difference according to the oil inlet pressure and oil outlet pressure under various working conditions;

[0009] At at least one rotation speed, an internal leakage coefficient is obtained according to the internal leakage amounts under different pressure differences.

[0010] In the embodiment of the present application, the corresponding internal leakage amount is determined according to the rotation speed and the actual output flow rate under various working conditions, including:

[0011] Determine the theoretical flow rate under no-leakage conditions based on the speed and displacement of the hydraulic pump under various working conditions;

[0012] According to the theoretical flow rate and the actual output flow rate, determine the corresponding internal leakage under each working condition.

[0013] In the embodiment of the present application, at at least one rotation speed, the internal leakage coefficient is obtained according to the internal leakage under different pressure differences, including:

[0014] According to the internal leakage and pressure difference, determine the pressure difference-internal leakage curve corresponding to each speed;

[0015] The internal leakage coefficient is determined according to at least one pressure difference-internal leakage curve.

[0016] In the embodiment of the present application, the internal leakage coefficient is determined according to at least one pressure difference-internal leakage curve, including:

[0017] Performing linear regression fitting on points in at least one pressure difference-internal leakage curve to obtain a corresponding fitting regression line;

[0018] The slope of any fitted regression line is taken as the internal leakage coefficient.

[0019] In the embodiment of the present application, the internal leakage coefficient is determined according to at least one pressure difference-internal leakage curve, including:

[0020] Performing linear regression fitting on points in at least one pressure difference-internal leakage curve to obtain a corresponding fitting regression line;

[0021] The internal leakage coefficient was determined from the average of the slopes of each fitted regression line.

[0022] In the embodiment of the present application, the internal leakage coefficient is determined according to at least one pressure difference-internal leakage curve, including:

[0023] Determine the slope of each point in at least one pressure difference-internal leakage curve;

[0024] Based on the slope of each point and the number of points, the internal leakage coefficient is determined.

[0025] In the embodiment of the present application, the oil inlet pressure, oil outlet pressure, speed and actual output flow of the hydraulic pump under different working conditions are obtained, including:

[0026] When the target difference values ​​of the hydraulic pump under different working conditions are less than the preset difference threshold value within the first preset time period, the initial oil inlet pressure, the initial oil outlet pressure, the initial speed and the initial actual output flow rate within the second preset time period after the first preset time period are obtained in real time, wherein the target difference value includes the difference between the oil outlet pressure of the hydraulic pump and the corresponding target oil outlet pressure, and the difference between the speed and the corresponding target speed;

[0027] According to the average value of the initial oil inlet pressure, the average value of the oil outlet pressure, the average value of the initial rotational speed and the average value of the initial actual output flow, the oil inlet pressure, the oil outlet pressure, the rotational speed and the actual output flow are obtained.

[0028] A second aspect of the present application provides a device for determining an internal leakage coefficient of a hydraulic pump, comprising:

[0029] a memory configured to store instructions; and

[0030] The processor is configured to call instructions from the memory and implement the method for determining the internal leakage coefficient of the hydraulic pump according to the first aspect when executing the instructions.

[0031] A third aspect of the present application provides a hydraulic system for determining an internal leakage coefficient of a hydraulic pump, comprising:

[0032] The first pressure sensor is used to collect the oil inlet pressure of the hydraulic pump;

[0033] The second pressure sensor is used to collect the oil outlet pressure of the hydraulic pump;

[0034] Speed ​​sensor, used to collect the speed of the hydraulic pump;

[0035] Flow sensor, used to collect the actual output flow of the hydraulic pump;

[0036] Loading relief valve, used to adjust the pressure difference of the hydraulic pump;

[0037] Prime mover, used to adjust the speed of the hydraulic pump;

[0038] A device for determining the internal leakage coefficient of a hydraulic pump according to the second aspect.

[0039] A fourth aspect of the present application provides a machine-readable storage medium having instructions stored thereon, the instructions being used to enable a machine to execute the method for determining the internal leakage coefficient of a hydraulic pump according to the first aspect.

[0040] Through the above technical scheme, the method provided in the embodiment of the present application uses the internal leakage amount under different pressure differences at at least one speed to determine the internal leakage coefficient, which can effectively eliminate the influence of interfering factors such as test temperature on the test results of individual operating points, and has strong resistance to experimental interference, thereby improving the accuracy of the internal leakage coefficient.

[0041] Other features and advantages of the embodiments of the present application will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. In the accompanying drawings:

[0043] Figure 1A schematic diagram of a flow chart of a method for determining an internal leakage coefficient of a hydraulic pump according to an embodiment of the present application is schematically shown;

[0044] Figure 2 A schematic diagram of the structure of a hydraulic system for determining the internal leakage coefficient of a hydraulic pump according to an embodiment of the present application is shown;

[0045] Figure 3 A hydraulic principle diagram for calculating internal leakage according to an embodiment of the present application is schematically shown;

[0046] Figure 4 A schematic diagram of a pressure difference-internal leakage curve according to an embodiment of the present application is schematically shown;

[0047] Figure 5 Schematically shows a first pressure difference-internal leakage curve and a corresponding fitting regression line according to an embodiment of the present application;

[0048] Figure 6 Schematically shows a second pressure difference-internal leakage curve and a corresponding fitting regression line according to an embodiment of the present application;

[0049] Figure 7 The third pressure difference-internal leakage curve and the corresponding fitting regression line according to the embodiment of the present application are schematically shown;

[0050] Figure 8 A schematic diagram schematically shows another pressure difference-internal leakage curve according to an embodiment of the present application;

[0051] Fig. 9 The schematic diagram shows the structure of a device for determining an internal leakage coefficient of a hydraulic pump according to an embodiment of the present application. DETAILED DESCRIPTION

[0052] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the specific implementation methods described herein are only used to illustrate and explain the embodiments of the present application, and are not used to limit the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0053] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back...), the directional indications are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0054] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0055] Figure 1 The flowchart of a method for determining the internal leakage coefficient of a hydraulic pump according to an embodiment of the present application is schematically shown. Figure 1 As shown, an embodiment of the present application provides a method for determining the internal leakage coefficient of a hydraulic pump, and the method may include the following steps.

[0056] Step 110: Obtain the oil inlet pressure, oil outlet pressure, rotation speed and actual output flow rate of the hydraulic pump under different working conditions, wherein different working conditions indicate that the rotation speed and / or oil outlet pressure of the hydraulic pump are different.

[0057] Please also read Figure 2 , Figure 2 The structure diagram of a hydraulic system for determining the internal leakage coefficient of a hydraulic pump according to an embodiment of the present application is schematically shown. Figure 2 As shown, the first pressure sensor 3-1 is connected to the oil inlet of the hydraulic pump 1 and is used to collect the oil inlet pressure of the hydraulic pump 1; the oil outlet of the hydraulic pump 1 is connected to the second pressure sensor 3-2, the flow sensor 5 and the loading relief valve 6. The second pressure sensor 3-2 is used to collect the oil outlet pressure of the hydraulic pump 1, the flow sensor 5 is used to collect the actual output flow of the hydraulic pump 1, and the loading relief valve 6 is used to adjust the pressure difference of the hydraulic pump 1. A speed sensor 10 is also provided between the hydraulic pump 1 and the prime mover 9 to collect the speed of the hydraulic pump 1. The prime mover 9 can be an electric motor or an engine. In addition, Figure 2 The oil suction filter 8 also includes a first stop valve 4-1, a second stop valve 4-2, a safety relief valve 7, a temperature sensor 2, and an oil suction filter 8. The functions of each component will not be described in detail.

[0058] In the embodiment of the present application, it is necessary to obtain various operating parameters of the hydraulic pump under different working conditions, including oil inlet pressure, oil outlet pressure, speed and actual output flow. Schematically, the loading relief valve 6 can be adjusted first, so that the pressure difference of the hydraulic pump is adjusted to any one of 5% rated pressure difference, 10% rated pressure difference, 20% rated pressure difference, 30% rated pressure difference, 40% rated pressure difference, 50% rated pressure difference, 60% rated pressure difference, 70% rated pressure difference, 80% rated pressure difference, 90% rated pressure difference and 100% rated pressure difference, and then the speed of the hydraulic pump is adjusted to 50% rated speed, 75% rated speed and 100% rated speed under each pressure difference, so that the embodiment of the present application has a total of 33 working conditions. In this way, under various pressure difference conditions, the operating parameters at different speeds are collected, so as to obtain various operating parameters of the hydraulic pump under different working conditions.

[0059] In an optional implementation, step 110 includes:

[0060] When the target difference values ​​of the hydraulic pump under different working conditions are less than the preset difference threshold value within the first preset time period, the initial oil inlet pressure, the initial oil outlet pressure, the initial speed and the initial actual output flow rate within the second preset time period after the first preset time period are obtained in real time, wherein the target difference value includes the difference between the oil outlet pressure of the hydraulic pump and the corresponding target oil outlet pressure, and the difference between the speed and the corresponding target speed;

[0061] According to the average value of the initial oil inlet pressure, the average value of the oil outlet pressure, the average value of the initial rotational speed and the average value of the initial actual output flow, the oil inlet pressure, the oil outlet pressure, the rotational speed and the actual output flow are obtained.

[0062] Specifically, the target oil outlet pressure and the target speed can be understood as the set values ​​of the oil outlet pressure and the speed. Under any working condition, the target difference of the hydraulic pump is less than the preset difference threshold within the first preset time, indicating that the target operating parameters (oil outlet pressure and speed) are stable at the set values. At this time, the various operating parameters within the second preset time after the first preset time are obtained, and the average value of each operating parameter within the second preset time is obtained as the collected operating parameters.

[0063] When conducting tests, there are certain fluctuations in test signals such as speed, pressure, and flow, which are mainly caused by factors such as sensors or electromagnetic interference. Therefore, the embodiment of the present application uses the average value of the oil outlet pressure and speed over a period of time after stabilization, which can effectively eliminate these interferences and thus improve the accuracy of the collected operating parameters.

[0064] It can be understood that the first preset time length and the second preset time length can be set according to actual needs. Schematically, the first preset time length can be 30 seconds and the second preset time length can be 90 seconds. This embodiment of the present application does not limit this.

[0065] Step 120: Determine the corresponding internal leakage amount according to the rotation speed and actual output flow rate under various working conditions.

[0066] In the embodiment of the present application, the corresponding internal leakage amount under any working condition can be calculated through the rotational speed and actual output flow under such working condition.

[0067] In an optional implementation, step 120 includes:

[0068] Determine the theoretical flow rate under no-leakage conditions based on the speed and displacement of the hydraulic pump under various working conditions;

[0069] According to the theoretical flow rate and the actual output flow rate, determine the corresponding internal leakage under each working condition.

[0070] For details, please refer to Figure 3 , Figure 3 A schematic diagram of a hydraulic principle for calculating internal leakage according to an embodiment of the present application is shown. Figure 3 As shown, the theoretical flow rate of the hydraulic pump in a non-leakage state can be obtained by multiplying the speed by the displacement of the hydraulic pump. The following formula (1) can be used as a reference:

[0071] q n =D p ×n p (1)

[0072] In the formula, Q n Indicates the theoretical flow rate of the hydraulic pump in the non-leakage state, D p Indicates the displacement of the hydraulic pump, n p Indicates the speed of the hydraulic pump.

[0073] The internal leakage of the hydraulic pump can be obtained by using the difference between the theoretical flow rate and the actual output flow rate. The following formula (2) can be used for reference:

[0074] d q =Q n -Q (2)

[0075] Where, d q Indicates the internal leakage of the hydraulic pump, Q n It represents the theoretical flow of the hydraulic pump under the non-leakage state, and Q represents the actual output flow.

[0076] Step 130: Determine the corresponding pressure difference according to the oil inlet pressure and the oil outlet pressure under various working conditions.

[0077] In the embodiment of the present application, the pressure difference of the hydraulic pump is obtained by using the difference between the oil inlet pressure and the oil outlet pressure, which can be referred to the following formula (3):

[0078] dP=P p -P t (3)

[0079] Where dP represents the pressure difference of the hydraulic pump, P p Indicates the oil inlet pressure of the hydraulic pump, P t Indicates the outlet pressure of the hydraulic pump.

[0080] Therefore, after step 130 is completed, the internal leakage and pressure difference corresponding to the hydraulic pump under various working conditions can be obtained.

[0081] Step 140: Under at least one rotation speed, an internal leakage coefficient is obtained according to the internal leakage amounts under different pressure differences.

[0082] In the embodiment of the present application, the internal leakage amount under different pressure differences at at least one rotation speed is used to determine the internal leakage coefficient, which can effectively eliminate the influence of interfering factors such as test temperature on the test results of individual operating points and has strong resistance to experimental interference.

[0083] In an optional implementation, step 140 includes:

[0084] Step 141: determining a pressure difference-internal leakage curve corresponding to each rotation speed according to the internal leakage and the pressure difference;

[0085] Step 142: Determine the internal leakage coefficient according to at least one pressure difference-internal leakage curve.

[0086] Specifically, at different speeds, the corresponding relationship between internal leakage and pressure difference can be obtained, that is, the pressure difference-internal leakage curve corresponding to each speed. Figure 4 , Figure 4 A schematic diagram of a pressure difference-internal leakage curve according to an embodiment of the present application is schematically shown. Figure 4 As shown, Figure 4 The internal leakage coefficient can be determined based on at least one of the pressure difference-internal leakage curves.

[0087] The embodiment of the present application provides three implementation methods of step 142, which will be introduced one by one below.

[0088] In an optional implementation, step 142 includes:

[0089] Performing linear regression fitting on at least one point in the pressure difference-internal leakage curve to obtain a corresponding fitting regression line;

[0090] The slope of any fitted regression line is taken as the internal leakage coefficient.

[0091] Specifically, in theory, the internal leakage coefficient Cp of the hydraulic pump is a constant, which is only related to the geometric structure of the hydraulic pump. The specific value is equal to the internal leakage amount dq divided by the inlet and outlet pressure difference dP. Therefore, it should be equal to the internal leakage coefficient obtained under various working conditions.

[0092] However, due to the errors caused by accidental factors such as sensor error and oil temperature, in the embodiment of the present application, Figure 4 Perform linear regression fitting on each point in any pressure difference-internal leakage curve to obtain the corresponding fitting regression line. Figure 5-7 , Figure 5-7 The diagram schematically shows three pressure difference-internal leakage curves and corresponding fitted regression lines according to an embodiment of the present application, which respectively represent the pressure difference-internal leakage curves and corresponding fitted regression lines when the speed of the hydraulic pump is 50% of the rated speed, 75% of the rated speed, and 100% of the rated speed, wherein the dotted curve represents the pressure difference-internal leakage curve, and the dotted line represents the fitted regression line.

[0093] Indicatively, one can use Figure 4 When the speed of the hydraulic pump is 50% of the rated speed, 75% of the rated speed, and 100% of the rated speed, a pressure difference-internal leakage curve is selected, and a linear regression fitting is performed to obtain a fitting regression line, and then the slope of the fitting regression line is used as the internal leakage coefficient.

[0094] The embodiment of the present application can quickly calculate the internal leakage coefficient, thereby improving the efficiency of the method.

[0095] In an optional implementation, step 142 includes:

[0096] Performing linear regression fitting on points in at least one pressure difference-internal leakage curve to obtain a corresponding fitting regression line;

[0097] The internal leakage coefficient was determined from the average of the slopes of each fitted regression line.

[0098] Specifically, similar to the above embodiment, a linear regression fitting is first performed on the points in the pressure difference-internal leakage curve. It is understandable that using the slope of a fitted regression line as the internal leakage coefficient may be inaccurate. Therefore, the embodiment of the present application also provides an implementation method, that is, using the average value of the slopes of multiple fitted regression lines as the internal leakage coefficient to improve the accuracy of the internal leakage coefficient.

[0099] Indicatively, one can use Figure 4The speed of the hydraulic pump is 50% of the rated speed, 75% of the rated speed, and 100% of the rated speed. A total of three pressure difference-internal leakage curves are linearly regressed to obtain three fitting regression lines, and the average value of the slopes of the three fitting regression lines is used as the internal leakage coefficient.

[0100] The embodiments of the present application can improve the accuracy of the internal leakage coefficient.

[0101] In an optional implementation, step 142 includes:

[0102] Determine the slope of each point in at least one pressure difference-internal leakage curve;

[0103] Based on the slope of each point and the number of points, the internal leakage coefficient is determined.

[0104] Specifically, in the embodiment of the present application, the average slope of each point in the pressure difference-internal leakage curve is used as the internal leakage coefficient. Figure 8 , Figure 8 Another schematic diagram of a pressure difference-internal leakage curve according to an embodiment of the present application is shown schematically. Figure 8 As shown, the slope of each point in the pressure difference-internal leakage curve can be expressed as Among them, k1, k2, ..., k n-1 , k n Indicates the slope of the nth point on the pressure difference-internal leakage curve, dq1, dq2, ..., dq n-1 、dq n Indicates the internal leakage of the nth point on the pressure difference-internal leakage curve, dP1, dP2, ..., dP n-1 , dP n It represents the pressure difference of the nth point on the pressure difference-internal leakage curve. The internal leakage coefficient cp can refer to the following formula (4):

[0105]

[0106] Where cp represents the internal leakage coefficient, k1, k2, ..., k n It represents the slope of the nth point on the pressure difference-internal leakage curve, and n represents the number of points on the pressure difference-internal leakage curve.

[0107] It can be understood that the embodiment of the present application uses the pressure difference-internal leakage curve when the hydraulic pump speed is 75% of the rated speed as an example for description, and the pressure difference-internal leakage curve when the hydraulic pump speed is 50% of the rated speed and 100% of the rated speed can also be used. Similarly, the average value of the internal leakage coefficients obtained from the three pressure difference-internal leakage curves can also be used as the final internal leakage coefficient.

[0108] The embodiment of the present application uses the internal leakage amount under different pressure differences at at least one rotation speed to determine the internal leakage coefficient, which can effectively eliminate the influence of interfering factors such as test temperature on the test results of individual operating points, has strong resistance to experimental interference, and thus improves the accuracy of the internal leakage coefficient.

[0109] Corresponding to the above method embodiment, Fig. 9 The structure diagram of a device for determining the internal leakage coefficient of a hydraulic pump according to an embodiment of the present application is schematically shown. Fig. 9 As shown, an embodiment of the present application provides a device for determining an internal leakage coefficient of a hydraulic pump, which may include:

[0110] Memory 910, configured to store instructions; and

[0111] The processor 920 is configured to call instructions from the memory 910 and implement the above-mentioned method for determining the internal leakage coefficient of the hydraulic pump when executing the instructions.

[0112] Specifically, in the embodiment of the present application, the processor 920 may be configured to:

[0113] Obtaining the oil inlet pressure, oil outlet pressure, speed, and actual output flow rate of the hydraulic pump under different working conditions, wherein different working conditions indicate that the speed and / or oil outlet pressure of the hydraulic pump are different;

[0114] Determine the corresponding internal leakage according to the rotation speed and actual output flow rate under various working conditions;

[0115] Determine the corresponding pressure difference according to the oil inlet pressure and oil outlet pressure under various working conditions;

[0116] At at least one rotation speed, an internal leakage coefficient is obtained according to the internal leakage amounts under different pressure differences.

[0117] The device for determining the internal leakage coefficient of a hydraulic pump provided in the embodiment of the present application can implement each process of the method for determining the internal leakage coefficient of a hydraulic pump in the method embodiment, and can achieve the same technical effect. To avoid repetition, it will not be described here.

[0118] The embodiment of the present application further provides a hydraulic system for determining the internal leakage coefficient of a hydraulic pump, which may include:

[0119] The first pressure sensor is used to collect the oil inlet pressure of the hydraulic pump;

[0120] The second pressure sensor is used to collect the oil outlet pressure of the hydraulic pump;

[0121] Speed ​​sensor, used to collect the speed of the hydraulic pump;

[0122] Flow sensor, used to collect the actual output flow of the hydraulic pump;

[0123] Loading relief valve, used to adjust the pressure difference of the hydraulic pump;

[0124] Prime mover, used to adjust the speed of the hydraulic pump;

[0125] Device for determining the internal leakage coefficient of the above hydraulic pump.

[0126] The present application also provides a working machine, which may include:

[0127] Hydraulic pumps;

[0128] The above-mentioned hydraulic system is used to determine the internal leakage coefficient of the hydraulic pump.

[0129] An embodiment of the present application also provides a machine-readable storage medium, on which instructions are stored, and the instructions are used to enable a machine to execute the above-mentioned method for determining the internal leakage coefficient of the hydraulic pump.

[0130] 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 on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0131] 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.

[0132] 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.

[0133] 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.

[0134] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0135] The memory may include non-permanent memory 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.

[0136] 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 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 temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0137] 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.

[0138] The above are only embodiments of the present application and are 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 within the scope of the claims of the present application.

Claims

1. A method for determining the internal leakage coefficient of a hydraulic pump, characterized in that: include: Obtaining the oil inlet pressure, oil outlet pressure, speed, and actual output flow rate of the hydraulic pump under different working conditions, wherein the different working conditions indicate that the speed and / or oil outlet pressure of the hydraulic pump are different; Determine the corresponding internal leakage according to the rotation speed and the actual output flow rate under various working conditions; Determine the corresponding pressure difference according to the oil inlet pressure and the oil outlet pressure under various working conditions; At at least one rotation speed, an internal leakage coefficient is obtained according to the internal leakage amounts under different pressure differences.

2. The method according to claim 1, characterized in that Determining the corresponding internal leakage amount according to the rotation speed and the actual output flow rate under various working conditions includes: Determine the theoretical flow rate under a no-leakage state according to the rotation speed and the displacement of the hydraulic pump under various working conditions; According to the theoretical flow rate and the actual output flow rate, the corresponding internal leakage amount under each working condition is determined.

3. The method according to claim 1, characterized in that The internal leakage coefficient is obtained according to the internal leakage amount under different pressure differences at at least one rotation speed, including: According to the internal leakage and pressure difference, determine the pressure difference-internal leakage curve corresponding to each speed; The internal leakage coefficient is determined according to at least one of the pressure difference-internal leakage curves.

4. The method according to claim 3, characterized in that Determining the internal leakage coefficient according to at least one of the pressure difference-internal leakage curves includes: Performing linear regression fitting on at least one point in the pressure difference-internal leakage curve to obtain a corresponding fitting regression line; The slope of any one of the fitted regression lines is taken as the internal leakage coefficient.

5. The method according to claim 3, characterized in that: Determining the internal leakage coefficient according to at least one of the pressure difference-internal leakage curves includes: Performing linear regression fitting on at least one point in the pressure difference-internal leakage curve to obtain a corresponding fitting regression line; The internal leakage coefficient is determined based on the average value of the slope of each of the fitted regression lines.

6. The method according to claim 3, characterized in that: Determining the internal leakage coefficient according to at least one of the pressure difference-internal leakage curves includes: Determine the slope of each point in at least one of the pressure difference-internal leakage curves; Based on the slope of each point and the number of points, the internal leakage coefficient is determined.

7. The method according to claim 1, characterized in that The obtaining of the oil inlet pressure, oil outlet pressure, speed and actual output flow rate of the hydraulic pump under different working conditions includes: When the target difference values ​​of the hydraulic pump under different working conditions are less than the preset difference threshold value within the first preset time period, the initial oil inlet pressure, the initial oil outlet pressure, the initial speed and the initial actual output flow rate within the second preset time period after the first preset time period are acquired in real time, wherein the target difference value includes the difference between the oil outlet pressure of the hydraulic pump and the corresponding target oil outlet pressure, and the difference between the speed and the corresponding target speed; The oil inlet pressure, the oil outlet pressure, the rotation speed and the actual output flow are obtained according to the average value of the initial oil inlet pressure, the average value of the oil outlet pressure, the average value of the initial rotation speed and the average value of the initial actual output flow.

8. A device for determining the internal leakage coefficient of a hydraulic pump, characterized in that: include: a memory configured to store instructions; as well as A processor is configured to call the instructions from the memory and implement the method for determining the internal leakage coefficient of the hydraulic pump according to any one of claims 1 to 7 when executing the instructions.

9. A hydraulic system for determining the internal leakage coefficient of a hydraulic pump, characterized in that: include: A first pressure sensor, used to collect the oil inlet pressure of the hydraulic pump; A second pressure sensor, used to collect the oil outlet pressure of the hydraulic pump; A rotation speed sensor, used for collecting the rotation speed of the hydraulic pump; A flow sensor, used to collect the actual output flow of the hydraulic pump; A loading relief valve, used to adjust the pressure difference of the hydraulic pump; A prime mover, used to adjust the rotation speed of the hydraulic pump; The device for determining the internal leakage coefficient of a hydraulic pump according to claim 8.

10. A machine-readable storage medium, characterized in that: The machine-readable storage medium stores instructions for causing a machine to execute the method for determining the internal leakage coefficient of a hydraulic pump according to any one of claims 1 to 7.

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