Hydraulic system leakage detection method, system, electronic device and readable storage medium

Abstract

The application discloses a hydraulic system leakage detection method and system, electronic equipment and a readable storage medium, and relates to the technical field of industrial automation. The hydraulic system leakage detection method comprises the following steps: determining a current leakage coefficient of a hydraulic system according to a current hydraulic pump flow and a current hydraulic pressure of the hydraulic system; judging whether a difference between the current leakage coefficient and a preset leakage coefficient is greater than a safety threshold value; and outputting leakage fault information if the difference is greater than the safety threshold value. The application can realize automatic detection of hydraulic system leakage, effectively improve the reliability of hydraulic system control, and reduce the loss caused by oil leakage to production and life.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of industrial automation, and particularly relates to a hydraulic system leakage detection method and system, an electronic device and a computer readable storage medium. BACKGROUND

[0002] Various industrial equipment in the current industrial control field, such as injection molding machines, oil presses, die casting machines, bending machines, etc., usually use hydraulic pumps as power sources to provide constant pressure to industrial equipment to drive the equipment to work. However, in the hydraulic oil supply system, oil leakage often occurs due to internal damage of the hydraulic pump, resulting in a decrease in the efficiency of the oil circuit system. If the oil leakage fault cannot be discovered in time, it will cause great economic losses.

[0003] Currently, the pressure closed-loop control of the hydraulic system is usually completed by a frequency converter or a servo driver + motor (including an asynchronous motor and a synchronous motor) + hydraulic pump. In the process of hydraulic pressure closed-loop control, if oil leakage occurs, the driver will automatically increase the motor speed to increase the hydraulic oil flow to compensate for the insufficient pressure caused by leakage. In this way, the pressure in the hydraulic system can be maintained constant in the case that the motor speed can compensate for the pressure reduction caused by oil leakage. Therefore, the current hydraulic system is difficult to determine whether oil leakage has occurred by the pressure change in the hydraulic system, and the oil leakage of the hydraulic system is not easy to be discovered. SUMMARY

[0004] The main purpose of the present application is to provide a hydraulic system leakage detection method, system, electronic device and computer readable storage medium, which aims to solve the technical problem that the oil leakage of the current hydraulic system is not easy to be discovered.

[0005] To achieve the above purpose, the present application provides a hydraulic system leakage detection method, which comprises:

[0006] determining a current leakage coefficient of the hydraulic system according to a current hydraulic pump flow and a current oil circuit pressure of the hydraulic system;

[0007] judging whether a difference between the current leakage coefficient and a preset leakage coefficient is greater than a safety threshold value;

[0008] if yes, outputting leakage fault information.

[0009] Optionally, the step of determining the current leakage coefficient of the hydraulic system according to the current hydraulic pump flow and the current oil circuit pressure of the hydraulic system comprises:

[0010] obtaining a current hydraulic pump speed and a current hydraulic pump displacement of the hydraulic system;

[0011] calculating a product of the current hydraulic pump rotation speed and the current hydraulic pump displacement to obtain the current hydraulic pump flow rate;

[0012] obtaining the current hydraulic line pressure and a differential of the current hydraulic line pressure;

[0013] inputting the current hydraulic pump flow rate, the current hydraulic line pressure and the differential of the current hydraulic line pressure into a preset leakage coefficient function to obtain the current leakage coefficient.

[0014] Optionally, before the step of judging whether the difference between the current leakage coefficient and the preset leakage coefficient is greater than a safety threshold, the method further comprises:

[0015] determining a current phase of the hydraulic pump corresponding to the current leakage coefficient;

[0016] determining a preset leakage coefficient corresponding to the current phase and calculating a difference between the current leakage coefficient and the preset leakage coefficient.

[0017] Optionally, the step of determining the preset leakage coefficient corresponding to the current phase comprises:

[0018] determining a phase leakage coefficient table of the hydraulic system, wherein the phase leakage coefficient table is used to represent the preset leakage coefficients corresponding to respective phases of the hydraulic pump;

[0019] querying the phase leakage coefficient table to determine the preset leakage coefficient corresponding to the current phase.

[0020] Optionally, before the step of determining the phase leakage coefficient table of the hydraulic system, the method further comprises:

[0021] obtaining at least one parameter of a hydraulic pump displacement of the hydraulic system, an elastic constant of hydraulic medium and a total volume of a hydraulic line, and making the hydraulic system operate under a preset pressure value and a no-leakage working condition;

[0022] collecting hydraulic pump rotation speeds of the hydraulic pump at respective phases during operation of the hydraulic system, and calculating the preset leakage coefficients corresponding to respective phases based on a preset leakage coefficient function;

[0023] storing the preset leakage coefficients corresponding to respective phases in a preset table to obtain the phase leakage coefficient table.

[0024] Optionally, after the step of judging whether the difference between the current leakage coefficient and the preset leakage coefficient is greater than a safety threshold, the method further comprises:

[0025] If not, the preset leakage coefficient in the phase leakage coefficient table is updated as the current leakage coefficient.

[0026] The application further provides a hydraulic system leakage detection system, comprising:

[0027] A variable frequency control system, the hydraulic system, and a pressure data acquisition module are connected in sequence, wherein the pressure data acquisition module is configured to acquire the pressure of the hydraulic system and feed back to the variable frequency control system.

[0028] The variable frequency control system is configured to determine the current leakage coefficient of the hydraulic system according to the current hydraulic pump flow and the current hydraulic pressure of the hydraulic system, determine whether the difference between the current leakage coefficient and a preset leakage coefficient is greater than a safety threshold, and output a leakage fault information if yes.

[0029] Optionally, the variable frequency control system comprises a host computer, a frequency converter, and a motor connected in sequence, and the hydraulic system comprises a hydraulic pump and a hydraulic circuit connected in sequence, wherein the motor is connected with the hydraulic pump.

[0030] The host computer is configured to acquire at least one parameter of the displacement of the hydraulic pump, the total volume of the hydraulic circuit, and the elastic constant coefficient of the hydraulic medium, and send the parameter to the frequency converter; the frequency converter is configured to drive the hydraulic pump by controlling the motor, determine the rotation speed of the hydraulic pump according to the rotation speed of the motor, and output the leakage fault information when the difference between the current leakage coefficient and the preset leakage coefficient is greater than the safety threshold.

[0031] The application further provides an electronic device, which is a physical device, comprising at least one processor, and a memory in communication connection with the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the steps of the hydraulic system leakage detection method.

[0032] The application further provides a computer readable storage medium, which stores a program for implementing a hydraulic system leakage detection method, and the program is executed by a processor to implement the steps of the hydraulic system leakage detection method.

[0033] The application further provides a computer program product, which comprises a computer program, and the computer program is executed by a processor to implement the steps of the hydraulic system leakage detection method.

[0034] The application provides a hydraulic system leakage detection method, a hydraulic system leakage detection system, an electronic device and a computer readable storage medium.

[0035] The technical scheme of the application determines the leakage coefficient of the hydraulic system according to the rotating speed, displacement, pressure, volume and elastic constant coefficient in the hydraulic system, compares the leakage coefficient with a preset leakage coefficient, and judges whether the leakage exists in the liquid path by calculating the difference, so that the change of the leakage coefficient can be sensitively obtained in the early stage of the leakage of the liquid path of the hydraulic system, the technical defect of poor sensitivity of the scheme for judging the oil leakage according to the liquid path pressure is overcome, the accurate detection of the oil leakage in the hydraulic system is realized, and the technical problem that the oil leakage in the hydraulic system is not easy to be found is solved. BRIEF DESCRIPTION OF DRAWINGS

[0036] The accompanying drawings, which are incorporated into and form part of the specification, illustrate embodiments consistent with the application and, together with the specification, serve to explain the principles of the application.

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, for those skilled in the art, other drawings can also be obtained based on these drawings without creative labor.

[0038] Figure 1 The hydraulic system leakage detection method flowchart of the first embodiment of the application;

[0039] Figure 2 The pressure closed loop control flowchart based on the frequency converter in the embodiment of the application;

[0040] Figure 3 The internal structure diagram of the internal gear pump involved in the embodiment of the application;

[0041] Figure 4 The corresponding relationship diagram between the gear rotation angle and the leakage coefficient in the embodiment of the application;

[0042] Figure 5 The feasible hydraulic system leakage early warning flowchart in the embodiment of the application;

[0043] Figure 6 The composition structure diagram of the hydraulic system leakage detection system in the embodiment of the application;

[0044] Figure 7 Schematic diagram of the equipment structure of the hardware operating environment involved in the hydraulic system leakage detection method in the embodiment of the present application.

[0045] Description of the accompanying drawings of the embodiment:

[0046] 1 Meniscus 2 Inner ring 3 Driving impeller 4 Front floating side plate 5 Rear floating side plate 6 Pump body

[0047] The realization of the objectives, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0048] In the following description, specific details such as specific system structures and technologies are provided for illustration rather than limitation to facilitate a thorough understanding of the embodiments of the present application. However, it should be clear to those skilled in the art that the embodiments of the present application can also be implemented in other embodiments without these specific details. In other cases, detailed descriptions of well-known systems, devices, circuits, and methods are omitted to prevent unnecessary details from obstructing the description of the embodiments of the present application.

[0049] It should be noted that although a logical order is shown in the flowcharts, in some cases, the steps shown or described may be performed in a different order than that shown in the flowcharts. The terms "first," "second," and the like in the specification, claims, and drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0050] It should also be understood that references to "one embodiment" or "some embodiments" described in the description of the embodiments of the present application mean that one or more embodiments of the embodiments of the present application include specific features, structures or characteristics described in conjunction with the embodiment. Thus, the phrases "in one embodiment," "in some embodiments," "in some other embodiments," "in some other embodiments," etc. that appear in different places in this specification do not necessarily refer to the same embodiment, but rather mean "one or more but not all embodiments," unless otherwise specifically emphasized. The terms "including," "comprising," "having," and their variations all mean "including but not limited to," unless otherwise specifically emphasized.

[0051] In the embodiments of the present application, it should be noted that the pressure closed-loop control of the hydraulic system is usually completed by a frequency converter or a servo driver + motor (including asynchronous motor and synchronous motor) + hydraulic pump. The frequency converter internally adjusts the output flow of the hydraulic pump by a PID (proportional-integral-derivative controller) closed loop to maintain the constant pressure. Therefore, the oil leakage cannot be accurately determined by the pressure, and therefore the current frequency converter usually does not have an oil leakage warning function. During the hydraulic pressure closed-loop control process, once the oil leakage occurs, in order to maintain the constant pressure, the driver will automatically increase the motor speed to increase the hydraulic oil flow to compensate for the pressure drop caused by the leakage. Therefore, when the amount of oil leakage is not large, the system pressure can still be maintained constant, and the user cannot easily detect the occurrence of leakage in the hydraulic system. At present, the commonly used hydraulic pump in the industry is an internal gear pump. This type of hydraulic pump transmits oil from the oil suction port to the oil outlet through gear engagement. During the gear engagement process, a small amount of oil leaks internally, and the amount of oil leakage is different at different engagement positions. Therefore, it is also impossible to determine whether there is leakage in the oil circuit by using a fixed leakage monitoring value.

[0052] The hydraulic system leakage detection method, system, electronic device and computer readable storage medium provided by the embodiments of the present application are specifically described by the following embodiments. First, the hydraulic system leakage detection method in the embodiments of the present application is described.

[0053] Reference Figure 1 In the first embodiment of the hydraulic system leakage detection method of the present application, the hydraulic system leakage detection method is applied to a hydraulic system leakage detection system, and the hydraulic system leakage detection method comprises:

[0054] Step S10, determining the current leakage coefficient of the hydraulic system according to the current hydraulic pump flow and the current oil circuit pressure of the hydraulic system;

[0055] In the embodiments of the present application, the current leakage coefficient can be calculated by using the hydraulic pump flow and the oil circuit pressure and other parameters in the hydraulic system. It should be noted that the hydraulic system can drive the motor to rotate by a frequency converter (or a servo driver), and then the motor provides power for the hydraulic pump to maintain the constant pressure in the hydraulic system.

[0056] Exemplarily, a pressure closed-loop control process based on a frequency converter is as follows Figure 2As shown, the control system is composed of a frequency converter, a motor (including a motor speed regulator) and a hydraulic pump. The final output pressure can be fed back to the frequency converter through a pressure sensor for closed-loop regulation. The frequency converter can be a pressure PID (Proportion Integration Differentiation) controller. The flow output by the hydraulic pump minus the leakage flow enters the hydraulic system cavity and forms pressure in the cavity. Specifically, the control process includes the following steps. First, the frequency converter obtains the pressure setting, generates a corresponding speed command based on the pressure setting, controls the motor to operate through the speed command, and the motor provides speed output to the hydraulic pump. The flow output by the hydraulic pump minus the leakage flow is equal to the pressure output of the hydraulic pump, which provides real-time pressure feedback to the frequency converter for adaptive adjustment of the speed command output by the frequency converter.

[0057] In addition, the hydraulic pump can be an internal gear pump, which is a positive displacement hydraulic element that completes the oil suction and discharge process through mutually meshing internal gear wheels. Figure 3 As shown, in order to prevent the high and low pressure areas inside the pump from being connected, the high and low pressure cavities of the wedge-shaped internal gear wheel have a meniscus structure, which functions to isolate the high and low pressure areas. When the gear pump is working, high-pressure oil enters the gap between the two menisci 1, pressing the two menisci towards the tooth top of the driving gear 3 and the inner ring gear 2, respectively, to achieve radial sealing and play a role in automatic compensation of the radial gap. When the driving gear 3 rotates clockwise, the inner ring gear 2 also rotates in the same direction around the center, and the oil suction cavity forms a vacuum due to the disengagement of the gear teeth, so that the oil enters the oil suction cavity under atmospheric pressure, completing the oil suction process. With the rotation of the gear, the oil in the volume between the teeth is carried to the oil discharge cavity, and the oil discharge cavity volume gradually decreases due to the engagement of the gear pair, so that the oil is squeezed, completing the oil discharge process. In addition, the internal gear pump also includes a front floating side plate 4, a rear floating side plate 5 and a pump body 6.

[0058] It should be noted that the main factor affecting the flow of the gear pump is the axial gap leakage, and the leakage coefficient corresponds to the curve of the rotation position of the gear Figure 4 The leakage coefficient is different at different gear rotation angles (which can also be understood as phase or gear position), and the leakage coefficient changes periodically. Moreover, the curve profile will differ for different hydraulic pumps.

[0059] In step S10, after obtaining the current hydraulic pump flow and current hydraulic pressure of the hydraulic system and other parameters, the corresponding current leakage coefficient can be calculated according to the flow continuity equation, which reflects the oil leakage of the meshing gear at different rotation angles under the current condition.

[0060] Step S20, determining whether the difference between the current leakage coefficient and the preset leakage coefficient is greater than a safety threshold value;

[0061] Step S30, if yes, outputting a leakage fault information.

[0062] After obtaining the current leakage coefficient of the hydraulic system, the current leakage coefficient is compared with the preset leakage coefficient learned in advance. It can be understood that when the hydraulic system is in a no-leakage working condition, the current leakage coefficient is consistent with the preset leakage coefficient, and when the hydraulic system has a leakage, the current leakage coefficient is higher than the preset leakage coefficient. In order to avoid the influence of errors and false reports, the user can set a safety threshold value, and when the difference between the current leakage coefficient and the preset leakage coefficient is greater than the safety threshold value, it is determined that the hydraulic system has a leakage fault, and a leakage fault information is output in real time (such as pushing a visual pop-up window on the display screen).

[0063] In addition, it should be noted that the values of the current leakage coefficient and the preset leakage coefficient fluctuate within a certain range, because the corresponding leakage coefficient is different under different rotation angles of the meshing gear, and the difference between the current leakage coefficient and the preset leakage coefficient is calculated under the same rotation angle.

[0064] In addition, it can be understood that in step S20, if it is determined that the difference between the current leakage coefficient and the preset leakage coefficient is not greater than the safety threshold value, it means that there is no oil leakage, and no prompt information is output. The leakage fault information output can be a digital IO (in-out) information of the frequency converter, or an error display reminder on the upper computer such as a human-machine interface or a PLC (Programmable Logic Controller), and the specific form is not limited.

[0065] Further, in a feasible embodiment, the rotation speed of the hydraulic pump of the hydraulic system is indirectly controlled by the frequency converter through controlling the rotation speed of the motor, and the step of determining the current leakage coefficient of the hydraulic system according to the current hydraulic pump flow and the current hydraulic pressure of the hydraulic system can include:

[0066] Step S11, obtaining the current hydraulic pump rotation speed and the current hydraulic pump displacement of the hydraulic system;

[0067] Firstly, in the process of controlling the hydraulic system by the frequency converter, the hydraulic pump and the motor are directly connected through a shaft coupling, so the rotation speed of the motor is the rotation speed of the hydraulic pump, and therefore the hydraulic pump rotation speed can be directly fed back by the motor encoder.

[0068] Step S12, calculating the product of the current hydraulic pump rotation speed and the current hydraulic pump displacement to obtain the current hydraulic pump flow rate;

[0069] It can be understood that the hydraulic pump flow rate is related to the hydraulic pump rotation speed (r / min) and the hydraulic pump displacement (L / r), and the unit is L / min.

[0070] Step S13, obtaining the current hydraulic line pressure and the differential of the current hydraulic line pressure;

[0071] The pressure sensor is installed in the cylinder and oil pipe of the hydraulic line, and can collect the pressure value inside the hydraulic line and further obtain the differential corresponding to the pressure value.

[0072] Step S14, inputting the current hydraulic pump flow rate, the current hydraulic line pressure and the differential of the current hydraulic line pressure into a preset leakage coefficient function to obtain the current leakage coefficient of the hydraulic line.

[0073] In the constant pressure control mode, the volume from the hydraulic pump outlet to the hydraulic cylinder cavity is constant, so according to the flow continuity equation, the relationship between the hydraulic pump flow rate and the pressure can be expressed by the leakage coefficient function:

[0074]

[0075] Wherein, Q is the hydraulic pump flow rate (i.e. the product of the hydraulic pump displacement and the rotation speed) output by the hydraulic pump, C tp is the current leakage coefficient of the hydraulic line, P is the hydraulic line pressure, is the differential of the hydraulic line pressure, V is the total volume of the hydraulic line, and β is the elastic constant of the hydraulic medium (such as hydraulic oil).

[0076] It should be noted that the size of C tp reflects the size of the leakage of the hydraulic line, and when the hydraulic system has a leakage change, C tp will also change accordingly. In the hydraulic system controlled by the frequency converter, the hydraulic pump and the motor are directly connected through the shaft coupling, and the rotation speed of the motor is the rotation speed of the hydraulic pump, so the rotation speed of the hydraulic pump can be fed back by the motor encoder. In addition, the hydraulic line pressure and the differential of the hydraulic line pressure can be fed back by the pressure sensor, and the volume of the hydraulic line can be calculated by the cylinder and oil pipe specifications. According to the above parameters, the value of C tp can be calculated in real time.

[0077] Exemplarily, the quotient of the total volume of the hydraulic line and the elastic constant can be calculated first, then the product of the quotient and the differential of the current hydraulic line pressure is calculated, the difference between the current hydraulic pump flow rate and the product is calculated, and the quotient of the difference and the current hydraulic line pressure is calculated, so as to obtain the current leakage coefficient of the hydraulic line.

[0078] Further, in a possible implementation, before the step of judging whether the difference between the current leakage coefficient and the preset leakage coefficient is greater than the safety threshold, the method can further include:

[0079] Step S15, determining a current phase of the hydraulic pump corresponding to the current leakage coefficient;

[0080] Step S16, determining a preset leakage coefficient corresponding to the current phase, and calculating a difference between the current leakage coefficient and the preset leakage coefficient.

[0081] It can be understood that, since the frequency converter controls the motor to drive the hydraulic pump to rotate, the internal gear in the hydraulic pump rotates to different positions, and the corresponding current leakage coefficient is also different, so the current leakage coefficient fluctuates in a range varying with the rotation angle (phase) of the internal gear, and correspondingly, the preset leakage coefficient obtained through the self-learning process fluctuates in a range varying with the rotation angle of the internal gear.

[0082] In addition, when calculating the difference between the current leakage coefficient and the corresponding preset leakage coefficient, the difference at each rotation angle is calculated respectively, so as to obtain a difference variation range varying with the rotation angle. It should be noted that, when judging whether the difference is greater than the safety threshold, the maximum difference in the difference variation range can be taken for judgment, so as to improve the detection accuracy of the hydraulic leakage.

[0083] Further, in a possible implementation, the preset leakage coefficient is a phase leakage coefficient table, and the step of determining the preset leakage coefficient corresponding to the current phase can include:

[0084] Step S161, determining a phase leakage coefficient table of the hydraulic system, wherein the phase leakage coefficient table is used to represent the preset leakage coefficient corresponding to each phase of the hydraulic pump;

[0085] Step S162, querying the phase leakage coefficient table to determine the preset leakage coefficient corresponding to the current phase.

[0086] Exemplarily, the preset leakage coefficient can be obtained from the phase leakage coefficient table, the phase leakage coefficient table is stored in the chip of the frequency converter, and the phase leakage coefficient table includes a plurality of rotation angles and a plurality of preset leakage coefficients corresponding to the rotation angles respectively. The table form is conducive to clearly obtaining the preset leakage coefficients at different phases when detecting the hydraulic system, and facilitates the rapid calculation of the difference between the current leakage coefficient and the preset leakage coefficient. In the process of querying the phase leakage coefficient table, the preset leakage coefficient corresponding to each current phase can be queried based on the phase (rotation angle).

[0087] In an embodiment, before the step of determining the phase leakage coefficient table of the hydraulic system, the method can further comprise:

[0088] In step A10, at least one parameter of hydraulic pump displacement, elastic constant of hydraulic medium, and total volume of hydraulic circuit of the hydraulic system is acquired, and the hydraulic system is operated at a preset pressure value and in a no-leakage condition.

[0089] In step A20, the rotational speed of the hydraulic pump at each phase during operation of the hydraulic system is collected, and the preset leakage coefficient corresponding to each phase is calculated based on a preset leakage coefficient function.

[0090] In step A30, the preset leakage coefficient corresponding to each phase is stored in a preset table to obtain the phase leakage coefficient table.

[0091] It should be noted that the embodiment of the present application further provides a method for automatically learning, by software of a frequency converter, the leakage coefficient of a hydraulic pump corresponding to each position (i.e., rotation angle) of a motor encoder before detecting leakage of the hydraulic system, so as to obtain a preset leakage coefficient as a main reference for subsequent leakage detection.

[0092] In the technical solution of the embodiment of the present application, the frequency converter (or driver) is first operated in a normal pressure maintaining condition, and the specific steps include: after confirming that the hydraulic system is operated in a no-leakage condition, a set preset pressure value is input by a host computer connected with the frequency converter, so that the hydraulic control system is operated in a closed loop to maintain constant pressure, and then the user inputs fixed parameters such as hydraulic pump displacement, elastic constant of hydraulic medium, and total volume of hydraulic circuit through the host computer, which are used for real-time calculation of the leakage coefficient of the internal gear at each rotation angle.

[0093] Exemplarily, in the process of self-learning of the leakage coefficient in the embodiment of the present application, the preset leakage coefficient can be obtained by operating for several seconds (for example, 5 seconds) under the condition of ensuring no leakage, and finally the value (which can be rotation angle) of each phase and the corresponding leakage coefficient are stored in a pre-designed two-dimensional table to obtain the phase leakage coefficient table.

[0094] Further, the embodiment of the present application further provides a method for calculating the leakage coefficient and generating the phase leakage coefficient table, and the phase leakage coefficient table is in the form of a two-dimensional table, so that the preset leakage coefficient is stored in the chip of the frequency converter in the form of a two-dimensional table, which facilitates faster query in the subsequent detection process.

[0095] The calculation formula of the leakage coefficient is transformed from the flow continuity equation, and exemplarily, the formula is transformed by equivalent transformation to obtain the preset leakage coefficient function Among them, Q is the pump flow output by the hydraulic pump (that is, the product of the hydraulic pump displacement and the hydraulic pump speed), C tp is the leakage coefficient of the liquid circuit, P is the liquid circuit pressure, is the differential of the hydraulic pressure, V is the total volume of the hydraulic circuit, and β is the constant elastic coefficient of the hydraulic medium (such as hydraulic oil).

[0096] It should be noted that in the hydraulic system of the embodiment of the present application, the main body used to calculate the leakage coefficient is the frequency converter (or servo drive). The built-in processor of the frequency converter can calculate according to the parameters such as pump displacement, elastic constant and total volume of the liquid circuit input by the user, as well as the real-time feedback speed and real-time collected pressure value to obtain the leakage coefficient when the internal meshing gear is in different phases (rotation angles).

[0097] On the other hand, in a feasible embodiment, after the step of determining whether the difference between the current leakage coefficient and the preset leakage coefficient is greater than a safety threshold, the method may further include:

[0098] Step S40: If not, then update the preset leakage coefficient in the phase leakage coefficient table to the current leakage coefficient.

[0099] It can be understood that when it is detected that the difference between the current leakage coefficient and the preset leakage coefficient is less than the safety threshold, it means that there is no leakage in the hydraulic system. At this time, the preset leakage coefficient in the preset phase leakage coefficient table can be updated, thereby realizing adaptive optimization and adjustment of the data in the phase leakage coefficient table.

[0100] For example, in combination with the content of the above embodiment, refer to Figure 5 The hydraulic system leakage detection scheme in the embodiment of the present application may include: first, self-learning the leakage coefficient; under the non-leakage working condition, setting a certain pressure value to perform pressure closed-loop operation; inputting at least one parameter of the hydraulic pump displacement, the elastic constant coefficient β of the hydraulic medium, and the total volume V of the fluid circuit; automatically learning the leakage coefficient of each current motor encoder position; creating a table, and storing it in the chip storage area of ​​the inverter; in the process of detecting hydraulic system leakage, the inverter calculates and updates the leakage coefficient C in real time. tp , determine the current leakage coefficient C tp With the pre-stored leakage coefficient C tp Whether the difference between exceeds the set safety threshold, if so, output leakage fault information, if not, update the leakage coefficient C tp is the current leakage coefficient C tp .

[0101] The embodiment of the present application provides a hydraulic system leakage detection method, in which a current leakage coefficient of the hydraulic system is determined according to a current hydraulic pump flow and a current hydraulic pressure of the hydraulic system, and then it is judged whether a difference between the current leakage coefficient and a preset leakage coefficient is greater than a safety threshold, and if yes, leakage fault information is output. The technical scheme of the embodiment of the present application can determine the leakage coefficient of the hydraulic system according to the rotation speed, displacement, pressure, volume and elastic constant coefficient in the hydraulic system, compare the leakage coefficient with the preset leakage coefficient and calculate the difference to judge whether the oil circuit leaks, can sensitively know the change of the leakage coefficient at the early stage of the oil circuit leakage, overcome the technical defect of poor sensitivity of the scheme for judging the oil leakage according to the hydraulic pressure, realize the accurate detection of the oil leakage in the hydraulic system, and solve the technical problem that the oil leakage in the hydraulic system is not easy to be found.

[0102] In addition, the embodiment of the present application further provides a hydraulic system leakage detection system, which can apply the hydraulic system leakage detection system method in the above-mentioned embodiment to realize sensitive detection of the oil leakage in the hydraulic system, and refer to Figure 6 , the hydraulic system leakage detection system comprises:

[0103] a frequency conversion control system, the hydraulic system and a pressure data acquisition module connected in sequence, wherein the pressure data acquisition module is used to acquire the hydraulic pressure of the hydraulic system and feed back to the frequency conversion control system.

[0104] The frequency conversion control system is used to determine the current leakage coefficient of the hydraulic system according to the current hydraulic pump flow and the current hydraulic pressure of the hydraulic system, judge whether the difference between the current leakage coefficient and the preset leakage coefficient is greater than the safety threshold, and if yes, output the leakage fault information.

[0105] Specifically, the frequency conversion control system comprises a host computer, a frequency converter and a motor connected in sequence, the hydraulic system comprises a hydraulic pump and a hydraulic circuit connected in sequence, and the motor is connected with the hydraulic pump.

[0106] The host computer is used to acquire at least one parameter of the hydraulic pump displacement, the total volume of the hydraulic circuit and the elastic constant coefficient of the hydraulic medium, and send to the frequency converter; the frequency converter is used to drive the hydraulic pump by controlling the motor, determine the rotation speed of the hydraulic pump according to the rotation speed of the motor, and output the leakage fault information when the difference between the current leakage coefficient and the preset leakage coefficient is greater than the safety threshold.

[0107] The hydraulic system leakage detection system provided by the present application adopts the hydraulic system leakage detection method in the above embodiment, and solves the technical problem that the oil leakage of the current hydraulic system is not easy to be found. Compared with the prior art, the hydraulic system leakage detection system provided by the present application has the same beneficial effects as the hydraulic system leakage detection method provided by the above embodiment, and other technical features in the hydraulic system leakage detection system are the same as the features disclosed in the previous embodiment method, which will not be repeated here.

[0108] In addition, the present application also provides an electronic device, which comprises: at least one processor; and a memory communicatively linked with the at least one processor; wherein the memory stores instructions executable by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to execute the hydraulic system leakage detection method in the above embodiment one.

[0109] Reference will be made to the following description of the embodiments of the present application Figure 7 , which shows a structural schematic diagram of an electronic device suitable for implementing the embodiments of the present application. The electronic device in the embodiments of the present application can include but is not limited to mobile terminals such as mobile phones, notebook computers, digital broadcast receivers, PDAs (personal digital assistants), PADs (tablets), PMPs (portable media players), vehicle-mounted terminals (such as vehicle-mounted navigation terminals), and the like, and fixed terminals such as digital TVs, desktop computers, and the like. Figure 7 The electronic device shown is only an example, and should not bring any limitation to the functions and use range of the embodiments of the present application.

[0110] As shown in Figure 7 , the electronic device can include a processing device 1001 (such as a central processor, a graphics processor, etc.), which can perform various appropriate actions and processes according to programs stored in a read-only memory 1002 (ROM) or loaded from a storage device 1003 to a random access memory 1004 (RAM). In the RAM 1004, various programs and data required for the operation of the electronic device are also stored. The processing device 1004, the ROM 1002, and the RAM 1004 are connected to each other through a bus 1005. An input / output (I / O) interface 1006 is also linked to the bus 1005.

[0111] Generally, the following systems can be linked to the I / O interface 1006: input devices 1007 including, for example, a touch screen, a touch pad, a keyboard, a mouse, an image sensor, a microphone, an accelerometer, a gyroscope, etc.; output devices 1008 including, for example, a liquid crystal display (LCD), a speaker, a vibrator, etc.; storage devices 1003 including, for example, a magnetic tape, a hard disk, etc.; and communication devices 1009. The communication devices 1009 can allow the electronic device to communicate wirelessly or wiredly with other devices to exchange data. Although the electronic device is shown as having various systems, it is understood that all of the shown systems are not required to be implemented or possessed. More or fewer systems can be alternatively implemented or possessed.

[0112] In particular, the processes described above with reference to the flowcharts can be implemented as a computer software program according to embodiments of the present disclosure. For example, embodiments of the present disclosure include a computer program product comprising a computer program carried on a computer readable medium, the computer program containing program code for executing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network by a communication device, or installed from a storage device, or installed from a ROM. When the computer program is executed by a processing device, the above-mentioned functions defined in the methods of embodiments of the present disclosure are performed.

[0113] The electronic device provided in the present application adopts the hydraulic system leakage detection method in the above-mentioned embodiments, and solves the technical problem that the oil leakage of the current hydraulic system is not easy to be found. Compared with the prior art, the electronic device provided in the embodiments of the present application has the same beneficial effects as the hydraulic system leakage detection method provided in the above-mentioned embodiments, and other technical features in the electronic device are the same as the features disclosed in the previous embodiment method, which will not be repeated here.

[0114] In addition, the present application also provides a computer readable storage medium, which can be a non-volatile computer readable storage medium, and a computer program is stored on the computer readable storage medium. The computer program is executed by a processor to implement the hydraulic system leakage detection method provided in any of the above-mentioned embodiments.

[0115] As will be appreciated by one of ordinary skill in the art, all or some steps, systems of the above-disclosed methods can be implemented as software, firmware, hardware, or any suitable combination thereof. Some or all of the physical components can be implemented as software executed by a processor, such as a central processing unit, a digital signal processor, or a microprocessor, or as hardware, or as an integrated circuit, such as an application- specific integrated circuit. Such software can be distributed on computer readable media, which can comprise computer storage media (or non-transitory media), and communication media (or transitory media). As is well known to those of ordinary skill in the art, the term computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media include, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by a computer. Further, as is well known to those of ordinary skill in the art, communication media typically embodies computer readable instructions, data structures, program modules, or other data in a modulated data signal, such as a carrier wave or other transport mechanism, and includes any information delivery media.

[0116] The above is the specific description of the preferred implementation of the embodiments of the present application, but the embodiments of the present application are not limited to the above implementation, and those skilled in the art can make various equivalent modifications or replacements without departing from the spirit of the embodiments of the present application, and these equivalent modifications or replacements are all included in the scope defined by the claims of the embodiments of the present application.

Claims

1. A method for detecting leakage in a hydraulic system, characterized in that: The hydraulic system leakage detection method comprises: determining a current leakage coefficient of the hydraulic system according to a current hydraulic pump flow rate and a current hydraulic circuit pressure of the hydraulic system; Determining whether the difference between the current leakage coefficient and the preset leakage coefficient is greater than a safety threshold; If so, output leakage fault information; The step of determining the current leakage coefficient of the hydraulic system according to the current hydraulic pump flow and the current hydraulic circuit pressure of the hydraulic system includes: Obtaining a current hydraulic pump speed and a current hydraulic pump displacement of the hydraulic system; Calculating the product of the current hydraulic pump speed and the current hydraulic pump displacement to obtain the current hydraulic pump flow; obtaining the current fluid circuit pressure and the differential of the current fluid circuit pressure; The current hydraulic pump flow, the current hydraulic circuit pressure, and the differential of the current hydraulic circuit pressure are input into a preset leakage coefficient function to obtain the current leakage coefficient.

2. The hydraulic system leakage detection method according to claim 1, characterized in that: Before the step of determining whether the difference between the current leakage coefficient and the preset leakage coefficient is greater than a safety threshold, the method further includes: determining a current phase of the hydraulic pump corresponding to the current leakage coefficient; A preset leakage coefficient corresponding to the current phase is determined, and a difference between the current leakage coefficient and the preset leakage coefficient is calculated.

3. The hydraulic system leakage detection method according to claim 2, characterized in that: The step of determining the preset leakage coefficient corresponding to the current phase includes: Determining a phase leakage coefficient table of the hydraulic system, wherein the phase leakage coefficient table is used to represent the preset leakage coefficients corresponding to each phase of the hydraulic pump; The phase leakage coefficient table is queried to determine the preset leakage coefficient corresponding to the current phase.

4. The hydraulic system leakage detection method according to claim 3, characterized in that: Before the step of determining the phase leakage coefficient table of the hydraulic system, the method further includes: Obtaining at least one parameter of the hydraulic system including a hydraulic pump displacement, a constant elastic coefficient of a hydraulic medium, and a total volume of a hydraulic circuit, and operating the hydraulic system at a preset pressure value and under a no-leakage condition; collecting the hydraulic pump speed of the hydraulic pump at each phase during the operation of the hydraulic system, and calculating the preset leakage coefficient corresponding to each phase based on a preset leakage coefficient function; The preset leakage coefficient corresponding to each phase is stored in a preset table to obtain the phase leakage coefficient table.

5. The hydraulic system leakage detection method according to claim 3, characterized in that: After the step of determining whether the difference between the current leakage coefficient and the preset leakage coefficient is greater than a safety threshold, the method further includes: If not, the preset leakage coefficient in the phase leakage coefficient table is updated to the current leakage coefficient.

6. A hydraulic system leakage detection system, characterized in that: The hydraulic system leakage detection system comprises: A frequency conversion control system, the hydraulic system and a pressure data acquisition module are sequentially connected, wherein the pressure data acquisition module is used to collect the hydraulic pressure of the hydraulic system and feed it back to the frequency conversion control system; The variable frequency control system is used to determine a current leakage coefficient of the hydraulic system based on a current hydraulic pump flow rate and a current hydraulic circuit pressure of the hydraulic system; determine whether a difference between the current leakage coefficient and a preset leakage coefficient is greater than a safety threshold; and if so, output leakage fault information; Among them, the step of determining the current leakage coefficient of the hydraulic system based on the current hydraulic pump flow and the current hydraulic circuit pressure of the hydraulic system includes: obtaining the current hydraulic pump speed and the current hydraulic pump displacement of the hydraulic system; calculating the product of the current hydraulic pump speed and the current hydraulic pump displacement to obtain the current hydraulic pump flow; obtaining the current hydraulic circuit pressure and the differential of the current hydraulic circuit pressure; inputting the current hydraulic pump flow, the current hydraulic circuit pressure and the differential of the current hydraulic circuit pressure into a preset leakage coefficient function to obtain the current leakage coefficient.

7. The hydraulic system leakage detection system according to claim 6, characterized in that: The frequency conversion control system includes a host computer, a frequency converter and a motor connected in sequence, the hydraulic system includes a hydraulic pump and a hydraulic circuit connected in sequence, and the motor is connected to the hydraulic pump; Among them, the host computer is used to obtain at least one parameter of the hydraulic pump displacement, the total volume of the liquid circuit and the elastic constant coefficient of the hydraulic medium, and send it to the frequency converter; the frequency converter is used to drive the hydraulic pump by controlling the motor, and determine the hydraulic pump speed according to the motor speed, and output the leakage fault information when the difference between the current leakage coefficient and the preset leakage coefficient is greater than the safety threshold.

8. An electronic device, characterized in that: The electronic device comprises: at least one processor; and, a memory communicatively connected to the at least one processor; wherein, The memory stores instructions that can be executed by the at least one processor, and the instructions are executed by the at least one processor to enable the at least one processor to perform the steps of the hydraulic system leakage detection method according to any one of claims 1 to 5.

9. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a program for implementing a hydraulic system leakage detection method, and the program for implementing a hydraulic system leakage detection method is executed by a processor to implement the steps of the hydraulic system leakage detection method according to any one of claims 1 to 5.

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