Method and device for determining flow of hydraulic unit in hydraulic system

Abstract

The invention discloses a flow determination method and device for a hydraulic unit in a hydraulic system, and relates to the technical field of hydraulic pressure. The method for determining the flow of the hydraulic unit in the hydraulic system comprises the steps that the oil temperature, the inlet oil pressure and the inlet and outlet oil hydraulic pressure difference of the hydraulic unit are obtained; based on the inlet oil pressure and the oil temperature, the actual oil density of the hydraulic system is determined; and the flow of the hydraulic unit is determined based on the inlet and outlet oil hydraulic pressure difference of the hydraulic unit and the actual oil liquid density. The actual oil density fully considers the influence of the temperature and the pressure, so that the actual oil density is more accurate, the flow which better conforms to the actual working condition can be determined based on the hydraulic difference of the inlet oil and the outlet oil and the actual oil density, the determined flow of the hydraulic unit is more accurate, and the efficiency and the reliability of a hydraulic system are improved.

Description

Technical Field

[0001] This application relates to the field of hydraulic technology, specifically to a method for determining the flow rate of a hydraulic unit in a hydraulic system, a device for a hydraulic unit in a hydraulic system, a machine-readable storage medium, and an electronic device. Background Technology

[0002] In hydraulic systems, hydraulic units can be mainly classified into fluid resistance units (such as throttle valves and hydraulic pipelines) and fluid capacity units (such as hydraulic cylinders and accumulators) based on their functional characteristics. Currently, flow rate calculations for various hydraulic units are typically based on fluid dynamics theory for modeling and analysis, with oil density being one of the important physical properties.

[0003] However, in existing calculation models, oil density is often set as a fixed constant. In reality, oil density changes with varying operating conditions during operation. This simplistic approach of treating density as a constant leads to discrepancies between flow rate calculations and actual operating conditions, affecting the accuracy and dynamic performance of system control. This is especially problematic in hydraulic applications with high precision requirements or frequent changes in operating conditions, where such discrepancies can further limit the overall system efficiency and reliability. Summary of the Invention

[0004] The purpose of this application is to provide a method and apparatus for determining the flow rate of a hydraulic unit in a hydraulic system, so as to solve the problem that the flow rate calculation in the prior art deviates from the actual working conditions, affecting the accuracy and dynamic performance of system control.

[0005] To achieve the above objectives, the first aspect of this application provides a method for determining the flow rate of a hydraulic unit in a hydraulic system, comprising: Obtain the hydraulic unit's oil temperature, inlet oil pressure, and inlet / outlet hydraulic pressure difference; The actual oil density of the hydraulic system is determined based on the inlet oil pressure and oil temperature. The flow rate of the hydraulic unit is determined based on the pressure difference between the inlet and outlet oil of the hydraulic unit and the actual oil density.

[0006] In this embodiment of the application, determining the actual oil density of the hydraulic system based on the inlet oil pressure and oil temperature includes: The inlet oil pressure and oil temperature of the hydraulic unit are substituted into a preset oil density correction model to obtain the actual oil density of the hydraulic system. The oil density correction model is used to correct the reference oil density of the hydraulic system based on the inlet oil pressure and oil temperature.

[0007] In this embodiment of the application, the preset oil density correction model is: , in, For reference baseline parameters, The coefficient of hydraulic oil volume expansion. It is a constant. For reference pressure, For reference temperature, For reference oil density, The hydraulic fluid temperature of the hydraulic unit. These are parameters related to oil quality. The inlet oil pressure of the hydraulic unit. This represents the actual oil density of the hydraulic unit.

[0008] In this embodiment of the application, there are multiple hydraulic units; Determining the flow rate of the hydraulic unit based on the inlet and outlet hydraulic pressure difference and the actual oil density includes: Based on the connection relationship of each hydraulic unit, the flow rate relationship and the inlet and outlet oil pressure relationship of each hydraulic unit are determined. Based on the inlet and outlet hydraulic pressure difference of each hydraulic unit, the actual oil density, the inlet and outlet oil pressure relationship, and the flow rate relationship, the flow rate of each hydraulic unit is calculated.

[0009] In the embodiments of this application, the inlet oil pressure and the inlet / outlet oil pressure difference of any hydraulic unit among the plurality of hydraulic units are obtained by at least one of the following methods: Measured by a pressure sensor; It is determined by the relationship between the inlet and outlet oil pressures of other hydraulic units.

[0010] In this embodiment of the application, determining the flow rate of the hydraulic unit based on the inlet and outlet hydraulic pressure difference and the actual oil density includes: Obtain the actual flow coefficient of the hydraulic unit; The flow rate of the hydraulic unit is calculated based on the inlet and outlet hydraulic pressure difference of the hydraulic unit, the actual oil density, and the actual flow coefficient.

[0011] In this embodiment of the application, obtaining the actual flow coefficient of the hydraulic unit includes: Based on the oil temperature of the hydraulic unit, the actual kinematic viscosity of the hydraulic oil in the hydraulic unit is obtained; The actual flow coefficient of the hydraulic unit is obtained based on the actual kinematic viscosity of the hydraulic fluid.

[0012] A second aspect of this application provides a flow rate determination device for a hydraulic unit in a hydraulic system, comprising: The acquisition module is used to acquire the hydraulic unit's oil temperature, inlet oil pressure, and inlet / outlet hydraulic pressure difference; The first determining module is used to determine the actual oil density of the hydraulic system based on the inlet oil pressure and oil temperature. The second determining module is used to determine the flow rate of the hydraulic unit based on the pressure difference between the inlet and outlet oil of the hydraulic unit and the actual oil density.

[0013] A third aspect of this application provides an electronic device, the electronic device comprising: At least one processor; A memory connected to the at least one processor; The memory stores instructions that can be executed by the at least one processor, and the at least one processor implements the above-described method for determining the flow rate of the hydraulic unit in the hydraulic system by executing the instructions stored in the memory.

[0014] A fourth aspect of this application provides a machine-readable storage medium storing instructions that, when executed by a processor, configure the processor to perform the flow determination method for a hydraulic unit in a hydraulic system as described above.

[0015] The above technical solution obtains the hydraulic unit's oil temperature, inlet oil pressure, and inlet / outlet oil pressure difference. Based on the inlet oil pressure and oil temperature, the actual oil density of the hydraulic system is determined. Based on the inlet / outlet oil pressure difference and the actual oil density, the flow rate of the hydraulic unit is determined. The actual oil density fully considers the influence of temperature and pressure, making it more accurate. The flow rate, which more closely matches actual operating conditions, can be determined based on the inlet / outlet oil pressure difference and the actual oil density, resulting in a more precise flow rate for the hydraulic unit and improving the efficiency and reliability of the hydraulic system. When modeling a hydraulic system, this method can quickly obtain accurate flow rates for hydraulic units, thus facilitating the rapid establishment of a more accurate hydraulic system model.

[0016] Other features and advantages of the embodiments of this application will be described in detail in the following detailed description section. Attached Figure Description

[0017] The accompanying drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the following detailed description to explain the embodiments of this application, but do not constitute a limitation on the embodiments of this application. In the drawings: Figure 1 The illustration shows a flowchart of a method for determining the flow rate of a hydraulic unit in a hydraulic system according to an embodiment of this application; Figure 2 A schematic diagram of a flow control module according to an embodiment of this application is shown. Figure 3 A schematic diagram of the hydraulic unit hardware according to an embodiment of this application is shown; Figure 4 A schematic diagram illustrating a simple example of a hydraulic unit according to an embodiment of this application is shown. Figure 5 This schematically illustrates a system diagram of two flow control modules connected in series according to an embodiment of this application. Figure 6 This schematic diagram illustrates a system formed by connecting three flow control modules in series and in parallel according to an embodiment of this application. Figure 7 This illustration schematically shows a software framework diagram of a traffic accuracy calculation unit according to an embodiment of this application; Figure 8 This illustration schematically shows a structural diagram of a flow rate determination device for a hydraulic unit in a hydraulic system according to an embodiment of this application; Figure 9 The diagram illustrates the internal structure of a computer device according to an embodiment of this application.

[0018] Explanation of reference numerals in the attached figures 410 - Acquisition module; 420 - First determination module; 430 - Second determination module; A01 - Processor; A02 - Network interface; A03 - Internal memory; A04 - Display screen; A05 - Input device; A06 - Non-volatile storage medium; B01 - Operating system; B02 - Computer program. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for illustration and explanation of the embodiments of this application and are not intended to limit the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0020] It should be noted that the acquisition, transmission, storage, use, and processing of data in the technical solution of this application all comply with relevant laws and regulations. In the embodiments of this application, certain existing industry solutions such as software, components, and models may be mentioned. These should be considered exemplary, intended only to illustrate the feasibility of implementing the technical solution of this application, and do not imply that the applicant has already used or necessarily used such solutions.

[0021] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0022] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0023] Figure 1 The illustration schematically shows a flow chart of a method for determining the flow rate of a hydraulic unit in a hydraulic system according to an embodiment of this application. Figure 1 As shown in the figure, this application provides a method for determining the flow rate of a hydraulic unit in a hydraulic system, which may include the following steps: Step 210: Obtain the hydraulic unit's oil temperature, inlet oil pressure, and inlet / outlet hydraulic pressure difference; Step 220: Determine the actual oil density of the hydraulic system based on the inlet oil pressure and oil temperature; Step 230: Determine the flow rate of the hydraulic unit based on the inlet and outlet hydraulic pressure difference of the hydraulic unit and the actual oil density.

[0024] The above technical solution acquires the hydraulic unit's oil temperature, inlet oil pressure, and inlet / outlet oil pressure difference. Based on the inlet oil pressure and oil temperature, the actual oil density of the hydraulic system is determined. Based on the inlet / outlet oil pressure difference and the actual oil density, the flow rate of the hydraulic unit is determined. The actual oil density fully considers the influence of temperature and pressure, making it more accurate. The flow rate, which better reflects actual operating conditions, can be determined based on the inlet / outlet oil pressure difference and the actual oil density, resulting in a more precise flow rate for the hydraulic unit and contributing to improved efficiency and reliability of the hydraulic system.

[0025] When modeling hydraulic systems, this method can quickly and accurately obtain the flow rate of hydraulic units, thereby helping to rapidly build a more accurate hydraulic system model.

[0026] In this embodiment, the hydraulic unit can be either a resistance type (such as a throttle valve, hydraulic pipeline, etc.) or a capacitive type (such as a hydraulic cylinder). The oil temperature of the hydraulic unit can be obtained by collecting the oil temperature at the inlet. In specific implementations, a temperature sensor can be installed at the inlet of the hydraulic unit to collect the temperature in real time. Please refer to... Figure 3 , Figure 3 A schematic diagram of the hydraulic unit hardware according to an embodiment of this application is shown. In the case of a hydraulic system with multiple hydraulic units, to save costs, multiple temperature sensors are not installed throughout the entire hydraulic system; temperature sensors can be installed only at the key control valves. The aforementioned inlet oil pressure refers to the pressure at the inlet of the hydraulic unit, which can be obtained by collecting the pressure at the hydraulic unit's inlet, specifically by installing a pressure sensor at the hydraulic unit's inlet to collect the pressure in real time; or it can be calculated. The aforementioned inlet and outlet hydraulic pressure difference can be measured by a differential pressure sensor, or it can be calculated by the difference between the inlet oil pressure and the outlet oil pressure.

[0027] In some feasible implementations, when modeling or calculating the flow rate of a hydraulic system, only the pressure loss of the hydraulic unit can be considered, while the pressure loss of the pipeline can be ignored, and the pipeline can be treated as an ideal body, thereby reducing the difficulty of modeling or calculation.

[0028] Please refer to Figure 2 , Figure 2 The schematic diagram illustrates a flow control module according to an embodiment of this application. In a specific implementation, each hydraulic unit corresponds to a flow accuracy calculation unit. The hydraulic unit and the flow accuracy calculation unit together form the flow control module. The hydraulic unit mainly provides the hydraulic hardware (such as throttle valves, hydraulic lines, etc.), while the flow accuracy calculation unit mainly provides the software for accurate flow calculation.

[0029] The above-mentioned determination of the actual oil density of the hydraulic system based on the inlet oil pressure and oil temperature can be achieved by pre-establishing a correspondence table between inlet oil pressure, oil temperature, and oil density, and then looking up the actual oil density in the table based on the inlet oil pressure and oil temperature. Alternatively, the reference oil density can be corrected based on the inlet oil pressure and oil temperature to obtain the actual oil density.

[0030] In some embodiments, determining the actual oil density of the hydraulic system based on the inlet oil pressure and oil temperature includes: The inlet oil pressure and oil temperature of the hydraulic unit are substituted into a preset oil density correction model to obtain the actual oil density of the hydraulic system. The oil density correction model is used to correct the reference oil density of the hydraulic system based on the inlet oil pressure and oil temperature.

[0031] In this embodiment, the aforementioned preset oil density correction model can be a pre-established mathematical model related to the inlet oil pressure and oil temperature. The reference oil density is a known parameter, and the actual oil density is calculated by substituting the inlet oil pressure and oil temperature into the model.

[0032] The preset oil density correction model is as follows: , in, As a reference parameter, it can be set as a constant value or calculated through other relationships, for example, , The volumetric expansion coefficient of hydraulic oil represents the relative rate of change of the volume of a unit volume of hydraulic oil as the temperature increases under constant pressure. Typical or approximate values ​​can be taken. It is a constant, an empirical value. For reference pressure, atmospheric pressure (used for gauge pressure) or standard atmospheric pressure (used for absolute pressure) can be used. For reference temperature, 20°C can be used. The reference oil density refers to the mass per unit volume of hydraulic oil under reference temperature and pressure, and can be determined in advance. The hydraulic fluid temperature of the hydraulic unit. These are parameters related to oil quality. The inlet oil pressure of the hydraulic unit. This represents the actual oil density of the hydraulic unit.

[0033] In this embodiment, the hydraulic oil volume expansion coefficient, parameters related to oil quality, reference pressure, reference temperature, and reference oil density are all known quantities. By substituting the inlet oil pressure and oil temperature into the above model, the actual oil density can be obtained.

[0034] By setting an oil density correction model to correct the reference oil density of the hydraulic system based on the inlet oil pressure and oil temperature, the actual oil density can be obtained quickly and accurately.

[0035] The flow rate of the hydraulic unit is determined based on the inlet and outlet hydraulic pressure difference and the actual oil density. This can be achieved using a mathematical model, such as a state-space model, employing differential equations and transfer functions. The bond graph approach is the most commonly used method. By using a signal flow graph, higher-order differential equations are transformed into state equations. The differential equations describing the system are then transformed into algebraic equations using a Laplace transform, resulting in a mathematical model.

[0036] To simplify the calculation, the flow rate of the hydraulic unit can also be calculated using flow rate calculation formulas from fluid mechanics. Taking a hydraulic resistance type throttle valve (hydraulic unit) as an example, the flow rate satisfies the thin-walled orifice flow formula, i.e., the flow rate calculation formula is: , in, The flow coefficient can be taken as an empirical value; The throttling area under a certain opening of the valve core depends on the actual hardware of the hydraulic unit. Used to represent different hydraulic units This refers to the pressure drop across the valve core, i.e., the pressure difference between the inlet and outlet oil. The density of the oil can be a constant. (The above...) , It can be obtained by inputting the hardware characteristic parameters of the hydraulic components into the controller based on the actual hardware of the hydraulic unit, by substituting the inlet and outlet oil pressure difference. Substitute the actual oil density into The flow rate of the hydraulic unit is calculated.

[0037] The following explanation uses the simplest hydraulic system as an example. Please refer to [link / reference]. Figure 4 , Figure 4 The diagram schematically illustrates a simple example of a hydraulic unit according to an embodiment of this application. The hydraulic unit is a hydraulic resistance type throttle valve that satisfies the thin-walled orifice flow formula.

[0038] For ease of analysis, the output pressure of hydraulic unit P2 can be taken as atmospheric pressure, i.e., zero. Equivalent to the inlet oil pressure of the hydraulic unit Substituting the pre-set oil density correction model into the thin-walled orifice flow formula, we can obtain: ; By substituting the hydraulic unit's oil temperature and inlet oil pressure into the above formula, the real-time flow rate during temperature changes can be calculated. .

[0039] In some embodiments, there may be multiple hydraulic units. For each hydraulic unit, the oil temperature, inlet oil pressure, and inlet-outlet oil pressure difference of the hydraulic unit can be obtained first according to the above steps. Then, based on the inlet oil pressure and oil temperature, the actual oil density of the hydraulic system is determined. Based on the inlet-outlet oil pressure difference and the actual oil density of the hydraulic unit, the flow rate of the hydraulic unit is determined.

[0040] In some embodiments, when the hydraulic system is complex, multiple hydraulic units are connected in series, parallel, or a combination of series and parallel. The flow rate of each hydraulic unit can be further calculated based on the flow rate relationship and the inlet / outlet oil pressure relationship of each hydraulic unit. Specifically, there are multiple hydraulic units; correspondingly, determining the flow rate of each hydraulic unit based on the inlet / outlet oil pressure difference and the actual oil density includes: First, based on the connection relationship of each hydraulic unit, the flow rate relationship and the inlet and outlet oil pressure relationship of each hydraulic unit are determined. In this embodiment, both the flow rate relationship and the inlet / outlet oil pressure relationship can be expressed by expressions. The flow rate relationship and the inlet / outlet oil pressure relationship of each hydraulic unit are determined according to the specific connection relationship, which includes series and parallel connections. For example, in series, the outlet oil pressure of the previous hydraulic unit is equal to the inlet oil pressure of the next hydraulic unit, and the flow rates of the hydraulic units are the same; in parallel, the inlet oil pressures of the parallel hydraulic units are the same, and the sum of the flow rates of the parallel hydraulic units equals the total flow rate.

[0041] Then, based on the inlet and outlet hydraulic pressure difference of each hydraulic unit, the actual oil density, the inlet and outlet oil pressure relationship, and the flow rate relationship, the flow rate of each hydraulic unit is calculated.

[0042] In this embodiment, based on the inlet and outlet hydraulic pressure difference of each hydraulic unit, the actual oil density, the inlet and outlet oil pressure relationship, and the flow rate relationship, multiple equations can be established, and then the flow rate of each hydraulic unit can be calculated by solving the equation set.

[0043] This method eliminates the need for complex transformations of high-order differential equations into state equations and cumbersome Laplace transforms. Engineers can quickly build hydraulic systems using tools like MATLAB and Simulink to obtain precise flow rates. It can be applied to arbitrarily complex hydraulic systems constructed in series, parallel, or a combination of series and parallel configurations, demonstrating strong versatility.

[0044] To facilitate the explanation of the plan, the following is a specific example: For example, please see Figure 5 , Figure 5This diagram schematically illustrates a system formed by two flow control modules connected in series according to an embodiment of this application. Taking a hydraulic unit as a hydraulic resistance type throttle valve that satisfies the thin-walled orifice flow formula as an example, the system is assembled from two flow control modules. Each flow control module includes a hydraulic unit and a flow precision calculation unit. The hydraulic unit mainly provides the hydraulic hardware (such as throttle valves, hydraulic lines, etc.), while the flow precision calculation unit mainly provides the software for accurate flow calculation. The two flow control modules are connected in series, and the flow rate through both hydraulic units is equal to Q because of the constant pressure source supplying oil. Let the inlet oil pressure of hydraulic unit 1 be the inlet oil pressure, and the outlet oil pressure of hydraulic unit 1 be equal to the inlet oil pressure of hydraulic unit 2. Let the outlet oil pressure of hydraulic unit 2 be atmospheric pressure. Then, the flow calculation equations for the two hydraulic units can be obtained as follows: , , in, Let be the throttling area under a certain opening of the valve core of hydraulic unit 1. The throttling area under a certain opening of the valve core of hydraulic unit 2. The outlet oil pressure of hydraulic unit 1; The oil temperature of hydraulic unit 1. Let Q be the oil temperature of hydraulic unit 2. By solving the above system of equations, we can obtain two variables (flow rate Q, pressure). This means obtaining the flow rate of each hydraulic unit.

[0045] For example: Please see Figure 6 , Figure 6 This diagram schematically illustrates a system formed by three flow control modules connected in series and parallel according to an embodiment of this application. Taking a hydraulic unit as a hydraulic resistance-type throttle valve that satisfies the thin-walled orifice flow formula as an example, the hydraulic system formed by the three flow control modules in series and parallel comprises a hydraulic unit and a flow accuracy calculation unit. The hydraulic unit mainly provides the hydraulic hardware (such as throttle valves, hydraulic lines, etc.), while the flow accuracy calculation unit mainly provides the software for accurate flow calculation. The flow rate through hydraulic unit 1 is denoted as Q1, the flow rate through hydraulic unit 2 as Q2, and the flow rate through hydraulic unit 3 as Q3. The flow rate of hydraulic unit 1 is equal to the sum of the flow rates of hydraulic units 2 and 3. The inlet oil pressure of hydraulic unit 1 is supplied by a constant pressure source. It is known that the outlet oil pressure of hydraulic unit 1 is equal to the inlet oil pressure of hydraulic units 2 and 3. If the outlet oil pressure of hydraulic unit 2 and hydraulic unit 3 is taken as atmospheric pressure, then the flow calculation equations for the four hydraulic units can be obtained as follows: , , , , in, The throttling area is the area under a certain opening of the valve core of hydraulic unit 3. Let this be the oil temperature of hydraulic unit 3. By solving the above system of equations, we can obtain four variables (flow rate, etc.). , , and This means obtaining the flow rate of each hydraulic unit.

[0046] It should be noted that the above examples are just illustrations. In practical applications, they can also be combined to form infinitely complex hydraulic systems. The solution to the system can be obtained by constructing a system of n equations with n unknowns. The analogy is as above, and will not be repeated here.

[0047] The inlet oil pressure and inlet / outlet oil pressure difference of any one of the multiple hydraulic units are obtained through at least one of the following methods: Measured by a pressure sensor; It is determined by the relationship between the inlet and outlet oil pressures of other hydraulic units.

[0048] In this embodiment, when there are multiple hydraulic units, the inlet oil pressure of a hydraulic unit can be obtained by measuring it with a pressure sensor, or it can be determined based on the relationship between the inlet and outlet oil pressures of other hydraulic units. Correspondingly, the inlet and outlet oil pressure difference can also be obtained by directly measuring it with a pressure sensor, or it can be determined based on the relationship between the inlet and outlet oil pressures of other hydraulic units. This makes it applicable to more scenarios.

[0049] For example, in Figure 5 In this process, the inlet oil pressure of hydraulic unit 1 can be measured by a pressure sensor. Based on the connection relationship between hydraulic unit 1 and hydraulic unit 2, it can be known that the inlet oil pressure of hydraulic unit 2 is equal to the outlet oil pressure of hydraulic unit 1. Therefore, the inlet oil pressure of hydraulic unit 2 can be expressed as the outlet oil pressure of hydraulic unit 1. Since the outlet oil pressure of hydraulic unit 2 is 0, the pressure difference between the inlet and outlet oil pressures of hydraulic unit 2 is... .

[0050] In some embodiments, to further improve the accuracy of flow rate calculation, the calculation can also be performed in conjunction with the actual flow rate coefficient. That is, determining the flow rate of the hydraulic unit based on the inlet and outlet hydraulic pressure difference of the hydraulic unit and the actual oil density includes: First, obtain the actual flow coefficient of the hydraulic unit; In this embodiment, the actual flow coefficient can be the actual flow coefficient at the current oil temperature. Since temperature changes cause changes in fluid viscosity, which in turn changes the flow state and ultimately leads to changes in the flow coefficient, the fluid viscosity at the current oil temperature can be calculated first, and then the actual flow coefficient can be obtained. That is, obtaining the actual flow coefficient of the hydraulic unit includes: The first step is to obtain the actual kinematic viscosity of the hydraulic fluid in the hydraulic unit based on the fluid temperature. In this embodiment, the actual kinematic viscosity of the hydraulic oil can be calculated based on the real-time collected oil temperature using the relationship between hydraulic oil viscosity and temperature. The relationship between hydraulic oil viscosity and temperature is as follows: , in, , , These are hydraulic oil parameters, and are only related to oil quality. To obtain the actual kinematic viscosity of the hydraulic fluid, the oil temperature of the hydraulic unit is substituted into the formula. The actual kinematic viscosity of the oil can be calculated. In practice, the actual kinematic viscosity of the oil can also be obtained by referring to an oil viscosity-temperature table.

[0051] The second step is to obtain the actual flow coefficient of the hydraulic unit based on the actual kinematic viscosity of the hydraulic fluid.

[0052] In this embodiment, the viscosity of the hydraulic oil affects the flow coefficient, i.e., the flow rate coefficient. =f(v oil viscosity, valve core displacement x), based on the actual kinematic viscosity of the hydraulic unit, the actual flow coefficient can be calculated.

[0053] First, determine the actual kinematic viscosity of the hydraulic fluid based on the oil temperature of the hydraulic unit. Then, based on the actual kinematic viscosity of the hydraulic fluid in the hydraulic unit, the actual flow coefficient of the hydraulic unit can be accurately obtained.

[0054] Then, based on the inlet and outlet hydraulic pressure difference of the hydraulic unit, the actual oil density, and the actual flow coefficient, the flow rate of the hydraulic unit is calculated.

[0055] In this embodiment, the aforementioned inlet and outlet hydraulic pressure difference, actual oil density, and actual flow coefficient are all actual values, thus allowing for a more accurate calculation of the flow rate. Taking a hydraulic resistance type throttle valve (hydraulic unit) as an example, where the flow rate satisfies the thin-walled orifice flow formula, substituting the actual flow coefficient into the flow parameters in the formula allows for a more accurate calculation of the flow rate value.

[0056] When changes in oil temperature cause changes in oil viscosity, the flow coefficient is corrected to automatically compensate for the resulting changes in flow gain. This ensures that the flow calculation fully considers the influence of hydraulic temperature, making the flow more accurate and helping to improve the reliability of the hydraulic system in all weather and all seasons.

[0057] For specific implementation details, please refer to [link / reference]. Figure 7 , Figure 7 The schematic diagram illustrates the software framework of the flow rate precision calculation unit according to an embodiment of this application. The flow rate precision calculation unit can collect the inlet pressure (inlet oil pressure) P1, the outlet pressure (outlet oil pressure) P2, and the inlet temperature (hydraulic temperature) T in real time, and output the current Ix of the electro-hydraulic valve (or the pressure Px of the hydraulic valve) in real time.

[0058] Figure 1 This is a flowchart illustrating the method for determining the flow rate of a hydraulic unit in a hydraulic system, as illustrated in this embodiment. It should be understood that, although... Figure 1 The steps in the flowchart are shown sequentially as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Figure 1 At least some of the steps in the process may include multiple sub-steps or multiple stages. These sub-steps or stages are not necessarily executed at the same time, but can be executed at different times. The execution order of these sub-steps or stages is not necessarily sequential, but can be executed in turn or alternately with other steps or at least some of the sub-steps or stages of other steps.

[0059] Please refer to Figure 8 , Figure 8 This illustration schematically shows a structural diagram of a flow rate determination device for a hydraulic unit in a hydraulic system according to an embodiment of this application. This embodiment provides a flow rate determination device for a hydraulic unit in a hydraulic system, including an acquisition module 410, a first determination module 420, and a second determination module 430, wherein: The acquisition module 410 is used to acquire the oil temperature, inlet oil pressure, and inlet / outlet oil pressure difference of the hydraulic unit; The first determining module 420 is used to determine the actual oil density of the hydraulic system based on the inlet oil pressure and oil temperature. The second determining module 430 is used to determine the flow rate of the hydraulic unit based on the inlet and outlet hydraulic pressure difference of the hydraulic unit and the actual oil density.

[0060] The flow determination device of the hydraulic unit in the hydraulic system includes a processor and a memory. The aforementioned acquisition module 410, the first determination module 420, and the second determination module 430 are all stored in the memory as program units. The processor executes the aforementioned program modules stored in the memory to implement the corresponding functions.

[0061] The processor contains a kernel, which retrieves the corresponding program unit from memory. One or more kernels can be configured, and the flow rate of the hydraulic units in the hydraulic system is determined by adjusting the kernel parameters.

[0062] The memory may include non-permanent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM, and the memory includes at least one memory chip.

[0063] This invention provides a processor for running a program, wherein the program executes a method for determining the flow rate of a hydraulic unit in a hydraulic system.

[0064] This application provides a machine-readable storage medium storing a program that, when executed by a processor, implements the above-described method for determining the flow rate of a hydraulic unit in a hydraulic system.

[0065] In one embodiment, a computer device is provided, which may be a terminal, and its internal structure diagram may be as follows: Figure 9 As shown. The computer device includes a processor A01, a network interface A02, a display screen A04, an input device A05, and a memory (not shown) connected via a system bus. The processor A01 provides computing and control capabilities. The memory includes internal memory A03 and a non-volatile storage medium A06. The non-volatile storage medium A06 stores an operating system B01 and a computer program B02. The internal memory A03 provides an environment for the operation of the operating system B01 and the computer program B02 stored in the non-volatile storage medium A06. The network interface A02 is used for communication with external terminals via a network connection. When the computer program is executed by the processor A01, it implements a method for determining the flow rate of a hydraulic unit in a hydraulic system. The display screen A04 can be a liquid crystal display (LCD) or an e-ink display. The input device A05 can be a touch layer covering the display screen, buttons, a trackball, or a touchpad mounted on the computer device casing, or an external keyboard, touchpad, or mouse.

[0066] Those skilled in the art will understand that Figure 9The structure shown is merely a block diagram of a portion of the structure related to the present application and does not constitute a limitation on the computer device to which the present application is applied. Specific computer devices may include more or fewer components than those shown in the figure, or combine certain components, or have different component arrangements.

[0067] In one embodiment, the flow determination device for the hydraulic unit in the hydraulic system provided in this application can be implemented as a computer program, which can be implemented in, for example... Figure 9 The computer device shown runs on this system. The computer device's memory can store the various program modules of the flow determination device that makes up the hydraulic unit in this hydraulic system, for example... Figure 8 The acquisition module 410, the first determination module 420, and the second determination module 430 are shown. The computer program, comprised of these modules, causes the processor to execute the steps in the flow determination method for the hydraulic unit in the hydraulic system of the various embodiments of this application described in this specification.

[0068] Figure 9 The computer equipment shown can be used as follows Figure 8 In the hydraulic system shown, the acquisition module 410 in the flow determination device of the hydraulic unit executes step 210. The computer device can execute step 220 via the first determination module 420. The computer device can execute step 230 via the second determination module 430.

[0069] This application provides an electronic device comprising: at least one processor; and a memory connected to the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the at least one processor implements the above-described method for determining the flow rate of a hydraulic unit in a hydraulic system by executing the instructions stored in the memory. When the processor executes the instructions, it performs the following steps: Obtain the hydraulic unit's oil temperature, inlet oil pressure, and inlet / outlet hydraulic pressure difference; The actual oil density of the hydraulic system is determined based on the inlet oil pressure and oil temperature. The flow rate of the hydraulic unit is determined based on the pressure difference between the inlet and outlet oil of the hydraulic unit and the actual oil density.

[0070] In one embodiment, determining the actual oil density of the hydraulic system based on the inlet oil pressure and oil temperature includes: The inlet oil pressure and oil temperature of the hydraulic unit are substituted into a preset oil density correction model to obtain the actual oil density of the hydraulic system. The oil density correction model is used to correct the reference oil density of the hydraulic system based on the inlet oil pressure and oil temperature.

[0071] In one embodiment, the preset oil density correction model is: , in, For reference baseline parameters, The coefficient of hydraulic oil volume expansion. It is a constant. For reference pressure, For reference temperature, For reference oil density, The hydraulic fluid temperature of the hydraulic unit. These are parameters related to oil quality. The inlet oil pressure of the hydraulic unit. This represents the actual oil density of the hydraulic unit.

[0072] In one embodiment, there are multiple hydraulic units; Determining the flow rate of the hydraulic unit based on the inlet and outlet hydraulic pressure difference and the actual oil density includes: Based on the connection relationship of each hydraulic unit, the flow rate relationship and the inlet and outlet oil pressure relationship of each hydraulic unit are determined. Based on the inlet and outlet hydraulic pressure difference of each hydraulic unit, the actual oil density, the inlet and outlet oil pressure relationship, and the flow rate relationship, the flow rate of each hydraulic unit is calculated.

[0073] In one embodiment, the inlet oil pressure and the inlet / outlet oil pressure difference of any one of the plurality of hydraulic units are obtained by at least one of the following methods: Measured by a pressure sensor; It is determined by the relationship between the inlet and outlet oil pressures of other hydraulic units.

[0074] In one embodiment, determining the flow rate of the hydraulic unit based on the inlet and outlet hydraulic pressure difference and the actual oil density includes: Obtain the actual flow coefficient of the hydraulic unit; The flow rate of the hydraulic unit is calculated based on the inlet and outlet hydraulic pressure difference of the hydraulic unit, the actual oil density, and the actual flow coefficient.

[0075] In one embodiment, obtaining the actual flow coefficient of the hydraulic unit includes: Based on the oil temperature of the hydraulic unit, the actual kinematic viscosity of the hydraulic oil in the hydraulic unit is obtained; The actual flow coefficient of the hydraulic unit is obtained based on the actual kinematic viscosity of the hydraulic fluid.

[0076] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0077] This application is described with reference to flowchart illustrations and block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and block diagrams, as well as combinations of blocks in the flowchart illustrations and block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create a machine for implementing the flowchart illustrations. Figure 1 One or more processes and boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0078] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and boxes Figure 1 The function specified in one or more boxes.

[0079] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and boxes Figure 1 The steps of the function specified in one or more boxes.

[0080] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0081] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0082] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, 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 technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0083] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0084] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A method for determining the flow rate of a hydraulic unit in a hydraulic system, characterized in that, include: Obtain the hydraulic unit's oil temperature, inlet oil pressure, and inlet / outlet hydraulic pressure difference; The actual oil density of the hydraulic system is determined based on the inlet oil pressure and oil temperature. The flow rate of the hydraulic unit is determined based on the pressure difference between the inlet and outlet oil of the hydraulic unit and the actual oil density.

2. The method according to claim 1, characterized in that, Determining the actual oil density of the hydraulic system based on the inlet oil pressure and oil temperature includes: The inlet oil pressure and oil temperature of the hydraulic unit are substituted into a preset oil density correction model to obtain the actual oil density of the hydraulic system. The oil density correction model is used to correct the reference oil density of the hydraulic system based on the inlet oil pressure and oil temperature.

3. The method according to claim 2, characterized in that, The preset oil density correction model is as follows: ， in, For reference baseline parameters, The coefficient of hydraulic oil volume expansion. It is a constant. For reference pressure, For reference temperature, For reference oil density, The hydraulic fluid temperature of the hydraulic unit. These are parameters related to oil quality. The inlet oil pressure of the hydraulic unit. This represents the actual oil density of the hydraulic unit.

4. The method according to claim 1, characterized in that, The hydraulic units are multiple; Determining the flow rate of the hydraulic unit based on the inlet and outlet hydraulic pressure difference and the actual oil density includes: Based on the connection relationship of each hydraulic unit, the flow rate relationship and the inlet and outlet oil pressure relationship of each hydraulic unit are determined. Based on the inlet and outlet hydraulic pressure difference of each hydraulic unit, the actual oil density, the inlet and outlet oil pressure relationship, and the flow rate relationship, the flow rate of each hydraulic unit is calculated.

5. The method according to claim 4, characterized in that, The inlet oil pressure and inlet / outlet oil pressure difference of any one of the multiple hydraulic units are obtained through at least one of the following methods: Measured by a pressure sensor; It is determined by the relationship between the inlet and outlet oil pressures of other hydraulic units.

6. The method according to claim 1, characterized in that, Determining the flow rate of the hydraulic unit based on the inlet and outlet hydraulic pressure difference and the actual oil density includes: Obtain the actual flow coefficient of the hydraulic unit; The flow rate of the hydraulic unit is calculated based on the inlet and outlet hydraulic pressure difference of the hydraulic unit, the actual oil density, and the actual flow coefficient.

7. The method according to claim 6, characterized in that, Obtaining the actual flow coefficient of the hydraulic unit includes: Based on the oil temperature of the hydraulic unit, the actual kinematic viscosity of the hydraulic oil in the hydraulic unit is obtained; The actual flow coefficient of the hydraulic unit is obtained based on the actual kinematic viscosity of the hydraulic fluid.

8. A flow rate determination device for a hydraulic unit in a hydraulic system, characterized in that, include: The acquisition module is used to acquire the hydraulic unit's oil temperature, inlet oil pressure, and inlet / outlet hydraulic pressure difference; The first determining module is used to determine the actual oil density of the hydraulic system based on the inlet oil pressure and oil temperature. The second determining module is used to determine the flow rate of the hydraulic unit based on the pressure difference between the inlet and outlet oil of the hydraulic unit and the actual oil density.

9. A machine-readable storage medium storing instructions thereon, characterized in that, This instruction is used to cause the machine to perform the method according to any one of claims 1 to 7.

10. An electronic device, characterized in that, The electronic device includes: At least one processor; A memory connected to the at least one processor; The memory stores instructions executable by the at least one processor, which implements the method of any one of claims 1 to 7 by executing the instructions stored in the memory.

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