A smart control box and control method for a dual-pressure solenoid directional valve

Abstract

This application relates to the field of electromagnetic directional valve technology, specifically to an intelligent control box and control method for a dual-pressure electromagnetic directional valve. The method includes: within the working cycle of the hydraulic system, recording the time period between each mode switch and the next mode switch as the output time period; collecting the output pressure and hydraulic oil flow rate of each valve port on each electromagnetic directional valve at each moment during the output time period after each mode switch, as well as the displacement of the valve core after each mode switch; calculating the displacement deviation of each electromagnetic directional valve to identify abnormal electromagnetic directional valves; calculating the trend deviation to determine the first evaluation value, second evaluation value, and discrimination coefficient of each valve port on the abnormal electromagnetic directional valve after each mode switch; evaluating the valve port fault of the electromagnetic directional valve; and monitoring and controlling the electromagnetic directional valve in real time. This application improves the accuracy of valve port fault detection for dual-pressure electromagnetic directional valves, ensuring the operational stability and reliability of the entire hydraulic system.

Description

Technical Field

[0001] This application relates to the field of electromagnetic directional valve technology, specifically to an intelligent control box and control method for a dual-pressure electromagnetic directional valve. Background Technology

[0002] Hydraulic systems, as crucial power transmission and control mechanisms in industrial equipment, rely heavily on the performance of their core component, the solenoid directional valve, which directly impacts system stability and reliability. The solenoid directional valve switches oil circuits via valve spool displacement, enabling the hydraulic system to transition between high-pressure and low-pressure modes. During operation, the output pressure and flow rate at the valve port change with mode switching. However, factors such as valve port wear, seal failure, or blockage by foreign objects can cause abnormal output characteristics, such as pressure fluctuations, unstable flow, or response delays, thus affecting the overall reliability of the hydraulic system.

[0003] Traditional methods for detecting valve port faults in dual-pressure solenoid directional valves primarily rely on deviations in output pressure to identify faults. This ignores the dynamic changes in output pressure during mode switching. Furthermore, the output pressure and flow rate at the valve port are coupled, and when the hydraulic system maintains pressure stability through pressure compensation mechanisms, it cannot effectively identify abnormal flow rates at the valve port. Therefore, relying on a single parameter cannot comprehensively and accurately reflect the true working state of the valve port, resulting in inaccurate valve port fault detection for dual-pressure solenoid directional valves and affecting the stability and reliability of the entire hydraulic system. Summary of the Invention

[0004] To address the aforementioned technical problems, a dual-pressure solenoid directional valve intelligent control box and control method are provided to solve the existing issues.

[0005] The solution to the technical problem addressed in this application is to provide an intelligent control box and control method for a dual-pressure solenoid directional valve, including the following steps:

[0006] In a first aspect, embodiments of this application provide an intelligent control method for a dual-pressure solenoid directional valve, the method comprising the following steps:

[0007] Within the working cycle of the hydraulic system, the time period between each mode switch and the next mode switch is recorded as the output time period. The output pressure and hydraulic oil flow of each valve port on each solenoid directional valve are collected at each moment during the output time period after each mode switch, as well as the displacement of the valve core after each mode switch. The mode switch is divided into two cases: switching from low pressure to high pressure mode and switching from high pressure to low pressure mode.

[0008] Analyze the differences in displacement of each solenoid directional valve when switching to low-pressure and high-pressure modes in all mode switching cycles, as well as the deviation of displacement after mode switching. Calculate the displacement deviation of each solenoid directional valve, judge the working status of the solenoid directional valve, and identify abnormal solenoid directional valves.

[0009] When the solenoid directional valve is working normally, record the output pressure of each valve port at different flow rates to construct a standard curve; for each valve port of the abnormal solenoid directional valve, calculate the trend deviation by observing the trend changes of the output pressure and flow rate of each valve port before and after each mode switch, and combine the output pressure and flow rate deviation of each valve port from the standard curve after the mode switch to determine the first evaluation value of each valve port of the abnormal solenoid directional valve after each mode switch.

[0010] The system analyzes the deviation of the output pressure and flow rate from the standard curve at different times during the output period, as well as the fluctuation of the output pressure, to determine the second evaluation value of each valve port on the abnormal solenoid directional valve after each mode switch. Combined with the first evaluation value, the system obtains the discrimination coefficient of each valve port on the abnormal solenoid directional valve after each mode switch, evaluates the valve port failure of the solenoid directional valve, and monitors and controls the solenoid directional valve in real time.

[0011] Preferably, the calculation of the displacement deviation of each solenoid directional valve includes:

[0012] The absolute values ​​of all displacements after switching to high-pressure mode and all displacements after switching to low-pressure mode in all sub-mode switching are respectively used to form high-pressure displacement sequence and low-pressure displacement sequence;

[0013] The difference between each element in the high-pressure displacement sequence and the corresponding element in the low-pressure displacement sequence is denoted as the relative difference; the sum of the relative differences of all elements in the high-pressure displacement sequence is calculated.

[0014] Calculate the average difference between the mean of the high-pressure displacement sequence and the mean of the low-pressure displacement sequence and the preset theoretical displacement.

[0015] The displacement deviation is the product of the sum and the average value.

[0016] Preferably, the process of obtaining the abnormal electromagnetic directional valve is as follows: electromagnetic directional valves with displacement deviation greater than or equal to a preset threshold are recorded as abnormal electromagnetic directional valves.

[0017] Preferably, the method for constructing the standard curve is as follows: when the dual-pressure solenoid directional valve is in normal working condition, the output pressure of the hydraulic oil at each valve port at different flow rates is continuously recorded, and each output pressure and its corresponding flow rate are combined into a two-dimensional array, and a standard curve is plotted in a plane coordinate system.

[0018] Preferably, the calculation of trend deviation includes:

[0019] The moment before each mode switch begins is recorded as the switch start time, and the moment after the switch ends is recorded as the switch completion time.

[0020] For each mode switch, the output pressure and flow rate of each valve port on the abnormal electromagnetic reversing valve at the start of the switch and the output pressure and flow rate at the end of the switch are respectively formed into a two-dimensional array; the data points represented by the two-dimensional array are mapped to the plane coordinate system where the standard curve is located, and the slope between the data points corresponding to the start of the switch and the data points corresponding to the end of the switch in the plane coordinate system is calculated and recorded as the actual slope.

[0021] When the dual-pressure solenoid directional valve is in normal working condition, the standard output pressure of each valve port in high-pressure mode and low-pressure mode is obtained respectively. The data points corresponding to the standard output pressure in high-pressure mode and low-pressure mode on the standard curve are recorded as standard data points. The slope between the standard data points in high-pressure mode and the standard data points in low-pressure mode on the standard curve is calculated and recorded as the standard slope.

[0022] The trend deviation is the difference between the actual slope and the standard slope.

[0023] Preferably, the first evaluation value of each valve port on the electromagnetic directional valve that determines the abnormality after each mode switch includes:

[0024] For the electromagnetic directional valve with abnormality, the distance between the data point corresponding to each valve port at the time of completion of each mode switch and the standard data point corresponding to the pressure mode after the mode switch in the planar coordinate system is recorded as the first distance.

[0025] The first evaluation value is the product of the first distance and the trend deviation.

[0026] Preferably, the second evaluation value of each valve port on the electromagnetic directional valve that determines the abnormality after each mode switch includes:

[0027] For each valve port on an abnormal electromagnetic directional valve, the sum of the differences between the output pressure at all times during the corresponding output period after each mode switch and the standard output pressure under the pressure mode after the mode switch is recorded as the pressure fluctuation degree.

[0028] The output pressure and flow rate of each valve port at each time during the corresponding output period after each mode switch are formed into a two-dimensional array. The data points represented by the two-dimensional array at all times during the output period are mapped to the plane coordinate system where the standard curve is located. The distance between the data points corresponding to each time during the output period and the standard data points corresponding to the pressure mode after the mode switch is calculated and recorded as the second distance.

[0029] The second evaluation value is the product of the sum of the second distances at all times within the output period and the pressure fluctuation.

[0030] Preferably, the discrimination coefficient is the product of the first evaluation value and the second evaluation value of each valve port on the abnormal electromagnetic directional valve after each mode switch.

[0031] Preferably, the assessment of valve port faults of the electromagnetic directional valve includes: normalizing the discrimination coefficients of all valve ports on all electromagnetic directional valves in the control box after each mode switch; if the normalized discrimination coefficients of each valve port on an abnormal electromagnetic directional valve after each mode switch are less than a preset first value, the valve port is not faulty; if the normalized discrimination coefficients are greater than or equal to the preset first value and less than a preset second value, the valve port has a minor fault; if the normalized discrimination coefficients are greater than or equal to the preset second value, the valve port has a serious fault, wherein the preset first value is less than the preset second value.

[0032] Secondly, this application also provides an intelligent control box for a dual-pressure solenoid directional valve, wherein multiple dual-pressure solenoid directional valves are integrated in the control box, and the fault detection process of the dual-pressure solenoid directional valve is realized by adopting the steps of the intelligent control method for a dual-pressure solenoid directional valve described in any one of the above-mentioned methods.

[0033] This application has at least the following beneficial effects:

[0034] This application analyzes the differences in displacement and deviations between low-pressure and high-pressure modes during multiple mode switching processes to calculate the displacement deviation of each solenoid directional valve. Its advantage lies in considering the degree of deviation in the valve core movement to assess abnormal operating conditions and identify anomalous solenoid directional valves. The application also calculates the trend deviation, which considers the instantaneous output pressure and flow trends of each port on the anomalous solenoid directional valve before and after mode switching, reflecting the deviation of the port's output characteristics before and after mode switching and assessing the anomalous condition of that port. Finally, the application determines the first evaluation value for each port on the anomalous solenoid directional valve after each mode switch. Its beneficial effects include: initially assessing the instantaneous abnormal changes of the valve port during a single mode switch, reflecting the possibility of a valve port malfunction; determining the second evaluation value of each valve port on the abnormal solenoid directional valve after each mode switch, which takes into account the unstable pressure output of the valve port after the mode switch, further assessing the possibility of a valve port malfunction; obtaining the discrimination coefficient of each valve port on the abnormal solenoid directional valve after each mode switch, evaluating the valve port malfunction of the solenoid directional valve, and monitoring and controlling the solenoid directional valve in real time, which comprehensively and accurately reflects the valve port malfunction through the coordinated change characteristics of multiple parameters such as output pressure and flow, improving the accuracy of valve port malfunction detection for dual-pressure solenoid directional valves, and ensuring the operational stability and reliability of the entire hydraulic system. Attached Figure Description

[0035] The following detailed description, in conjunction with the accompanying drawings, provides a further explanation of an intelligent control method for a dual-pressure electromagnetic directional valve according to this application.

[0036] Figure 1 A flowchart illustrating the steps of an intelligent control method for a dual-pressure solenoid directional valve provided in this application embodiment;

[0037] Figure 2 A schematic diagram of the standard curves provided for embodiments of this application;

[0038] Figure 3 A flowchart illustrating the steps of the method for obtaining the discrimination coefficient provided in this application embodiment. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this application clearer, the following detailed description, in conjunction with the accompanying drawings and embodiments, provides a further detailed explanation of the intelligent control box and control method for a dual-pressure electromagnetic directional valve proposed in this application. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the scope of this application.

[0040] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0041] Please see Figure 1 The diagram illustrates a flowchart of a smart control method for a dual-pressure solenoid directional valve according to an embodiment of this application. The method includes the following steps:

[0042] Step 1: During the working cycle of the hydraulic system, the time period between each mode switch and the next mode switch is recorded as the output time period. The output pressure and hydraulic oil flow rate of each valve port on each solenoid directional valve at each moment during the output time period after each mode switch, as well as the displacement of the valve core after each mode switch, are collected.

[0043] A dual-pressure solenoid directional valve is a solenoid directional valve capable of simultaneously controlling two different pressures. It provides two different operating pressures by adjusting and switching the flow direction of hydraulic or pneumatic fluids. It typically has two pressure regulating channels, one for low-pressure and one for high-pressure fluid control.

[0044] The dual-pressure solenoid directional valve consists of a valve core, solenoid coils, and a hydraulic control port. It switches pressure modes by controlling the on / off state of the solenoid coils, which drive the valve core. When the hydraulic system needs to switch to high-pressure mode, the left solenoid coil is switched on and the right is switched off. The current generates a magnetic field, pushing the valve core to the right, changing the flow direction of the hydraulic oil, thus switching to high-pressure mode. When high-pressure output is not needed, the right solenoid coil is switched on and the left is switched off, pushing the valve core to the left, returning the hydraulic oil to its original flow direction, thus switching to low-pressure mode. Multiple solenoid directional valves can be integrated into the control box to simultaneously control multiple hydraulic circuits.

[0045] In this embodiment, 12 electromagnetic reversing valves are integrated in the control box. As for other implementation methods, the implementer can determine the appropriate method based on the actual situation.

[0046] Because the dual-pressure solenoid directional valve switches output pressure through the coordinated movement of the valve core and hydraulic oil, the output pressure is closely related to the flow rate of the hydraulic oil under different pressure modes. Secondly, the valve core moves left and right under the action of the solenoid coil, and its displacement determines the opening of the valve port. Therefore, the oil inlet and oil outlet of the dual-pressure solenoid directional valve are denoted as each valve port. During the working cycle of the hydraulic system, the time period between each mode switch and the next mode switch is denoted as the corresponding output time period after each mode switch. The output pressure and hydraulic oil flow rate of each valve port of each directional valve in the control box at each moment during the output time period, as well as the displacement of the valve core of each directional valve after each mode switch, are collected. The mode switch includes switching from low pressure to high pressure mode and switching from high pressure to low pressure mode.

[0047] In this embodiment, the data acquisition time interval is 0.5s. As for other implementation methods, the implementer can set it according to the actual situation.

[0048] Thus, the output pressure and hydraulic oil flow rate of each valve port on each solenoid directional valve at each moment during the output period after each mode switch, as well as the displacement of the valve core after each mode switch, are obtained.

[0049] Step 2: Analyze the differences in displacement of each solenoid directional valve when switching to low-pressure and high-pressure modes in all mode switching cycles, as well as the deviation of displacement after mode switching. Calculate the displacement deviation of each solenoid directional valve, judge the working status of the solenoid directional valve, and identify abnormal solenoid directional valves.

[0050] Since the dual-pressure solenoid directional valve switches the output pressure mode by driving the valve core to move left and right with electromagnetic force, the movement of the valve core is the core of the solenoid valve's directional control. If the valve core fails to reach the predetermined position, the hydraulic system's working mode cannot be switched correctly, indicating that the dual-pressure solenoid directional valve has malfunctioned.

[0051] When a dual-pressure solenoid directional valve is in operation, magnetic force drives the valve core to displace the valve port to the corresponding position. This ensures the connection between the inlet and outlet ports under different pressure modes, guaranteeing the flow of hydraulic oil and generating pressure output. Abnormal valve core movement is generally reflected in its displacement. When the dual-pressure solenoid directional valve adjusts the output pressure mode through high-low pressure mode switching, the same power current is applied to one end of the electromagnet to drive the valve core displacement. Since the applied power is the same during high-low pressure mode switching, ideally, the valve core displacement should be the same after multiple mode switches. Therefore, by analyzing the differences in valve core displacement after different mode switches, it is possible to determine whether abnormal movement exists.

[0052] It should be noted that since the valve core displacement is referenced to its center position, when switching to high-pressure mode, the valve core moves to the right, resulting in a positive displacement. When switching to low-pressure mode, the valve core moves to the left, resulting in a negative displacement. Therefore, by analyzing the differences in valve core displacement after switching between different modes, and the deviation between the valve core displacement and the theoretical displacement, the displacement difference is calculated to assess the fault condition of the dual-pressure solenoid directional valve. Specifically:

[0053] All displacements after switching to high-pressure mode in all sub-mode switching are combined to form a high-pressure displacement sequence;

[0054] The absolute values ​​of all displacements after switching to low-pressure mode in all sub-mode switching are used to form a low-pressure displacement sequence.

[0055] Align the high-pressure displacement sequence with the low-pressure displacement sequence, calculate the difference between each element in the high-pressure displacement sequence and the corresponding element in the low-pressure displacement sequence, and record it as the relative difference.

[0056] It should be noted that by aligning the sequences, the sequence lengths of the high-pressure displacement sequence and the low-pressure displacement sequence are made consistent. The sequence alignment method is a well-known technique and will not be described in detail here. In this embodiment, the padding method is used to make the lengths of the two sequences consistent.

[0057] In this embodiment, the absolute value of the difference between each element in the high-pressure displacement sequence and the corresponding element in the low-pressure displacement sequence is calculated and denoted as the relative difference.

[0058] Calculate the sum of the relative differences of all elements within the high-pressure displacement sequence;

[0059] The mean values ​​of the high-pressure displacement sequence and the low-pressure displacement sequence are calculated respectively and denoted as high-pressure displacement and low-pressure displacement, respectively.

[0060] The difference between the high-pressure displacement and the preset theoretical displacement is calculated and denoted as the first difference;

[0061] The difference between the low-pressure displacement and the preset theoretical displacement is calculated and denoted as the second difference;

[0062] In this embodiment, the absolute value of the difference between the high-pressure displacement and the preset theoretical displacement is calculated and denoted as the first difference; the absolute value of the difference between the low-pressure displacement and the preset theoretical displacement is calculated and denoted as the second difference; secondly, according to the design parameters of the dual-pressure solenoid directional valve, when fully switched to the high-pressure mode, the theoretical displacement of the valve core should be 5mm, and when fully switched to the low-pressure mode, the theoretical displacement of the valve core should be -5mm. Since all elements in the low-pressure displacement sequence are the result of taking the absolute value of the displacement, the preset theoretical displacement is set to 5mm. As for other implementation methods, the implementer can set it according to the production specifications and design parameters of the dual-pressure solenoid directional valve.

[0063] Calculate the average of the first difference and the second difference;

[0064] The normalized result of the product of the sum and the average value is used as the displacement deviation of each electromagnetic directional valve.

[0065] In this embodiment, the sigmoid function is used for normalization. The sigmoid function is a well-known technique and will not be described in detail here. As other implementation methods, implementers may use other methods of the prior art, such as the softmax function, tanh function, etc. This embodiment does not impose any special restrictions on this.

[0066] It should be noted that the larger the sum, the less consistent the displacement change is when the dual-pressure solenoid directional valve switches pressure modes multiple times, and the higher the possibility of abnormal situations. The larger the average value, the greater the difference between the valve core displacement and the theoretical displacement, and the greater the displacement deviation, indicating that the dual-pressure solenoid directional valve is more likely to malfunction.

[0067] Furthermore, based on the aforementioned displacement deviation, the abnormal movement of the valve core of the electromagnetic directional valve is evaluated, specifically as follows:

[0068] Electromagnetic directional valves whose displacement deviation is greater than or equal to a preset threshold are classified as abnormal electromagnetic directional valves.

[0069] In this embodiment, the preset threshold value is 0.88. As for other implementation methods, the implementer can set it according to the actual situation.

[0070] At this point, the abnormal electromagnetic directional valve was discovered.

[0071] Step 3: When the solenoid directional valve is working normally, record the output pressure of each valve port at different flow rates to construct a standard curve; for each valve port of the abnormal solenoid directional valve, calculate the trend deviation by observing the deviation of the instantaneous output pressure and flow rate of each valve port from the standard curve before and after each mode switch, and combine the instantaneous output pressure and flow rate deviation from the standard curve after the mode switch to determine the first evaluation value of each valve port of the abnormal solenoid directional valve after each mode switch.

[0072] Furthermore, because the dual-pressure solenoid directional valve switches output pressure through the coordinated movement of the valve core and hydraulic oil, the valve core changes the direction of hydraulic oil flow through displacement, simultaneously connecting the inlet and outlet ports of the hydraulic oil to the corresponding hydraulic source for switching. Generally, when the hydraulic source is at high pressure, the hydraulic oil flow rate increases to maintain high pressure output; when the hydraulic source is at low pressure, the hydraulic oil flow rate decreases to save energy and improve efficiency. That is, as the hydraulic oil flow rate increases, its output pressure is positively correlated with the flow rate.

[0073] If the valve core displacement of the dual-pressure solenoid directional valve is abnormal, the valve core will not move to the predetermined position when the pressure mode is switched, resulting in incomplete valve opening. This will cause abnormal hydraulic oil flow and abnormal output pressure at the valve port. Specifically, the abnormal output pressure is manifested in the following ways: (1) At the moment of mode switching, the abnormal valve port will cause the instantaneous change of flow and output pressure at the moment of pressure switching to not reach the ideal result; (2) During the pressure mode output period, after the pressure mode is switched, the real-time output pressure and flow will remain stable before the next mode switch. If the valve port is abnormal, this stable state may be destroyed, resulting in abnormal fluctuations in output pressure and flow.

[0074] Based on the above analysis, when the dual-pressure solenoid directional valve is under normal operating conditions, by continuously recording the output pressure of the hydraulic oil at different flow rates at each valve port, the output pressure and its corresponding flow rate are combined into a two-dimensional array, and a standard curve is plotted in the plane coordinate system.

[0075] It should be noted that, under normal operating conditions, by continuously adjusting the output of the hydraulic source, the output pressure of each valve port is measured at multiple different flow rates. The flow rates corresponding to each output pressure are formed into a two-dimensional array, and curves are plotted on all two-dimensional arrays to obtain a standard curve. In this embodiment, the horizontal axis of the standard curve represents the output pressure, and the vertical axis represents the flow rate.

[0076] Secondly, for dual-pressure solenoid directional valves with abnormal valve core movement, since the relationship between the output pressure and hydraulic oil flow rate at the valve port deviates from the standard curve at the moment of pressure mode switching, the changes in output pressure and flow rate at each valve port before and after each mode switch are analyzed on the abnormal solenoid directional valve, and the first evaluation value is calculated, specifically:

[0077] The moment before each mode switch begins is recorded as the switch start time, and the moment after the switch ends is recorded as the switch completion time.

[0078] For each mode switch, the output pressure and flow rate of each valve port on the abnormal electromagnetic directional valve at the start and end of the switch are respectively formed into two-dimensional arrays; the data points represented by the two-dimensional arrays are mapped to the plane coordinate system where the standard curve is located; the slope between the data points corresponding to the start and end of the switch in the plane coordinate system where the standard curve is located is calculated and recorded as the actual slope.

[0079] When the dual-pressure solenoid directional valve is in normal working condition, the standard output pressure of each valve port in high pressure mode and low pressure mode is obtained respectively. The data points corresponding to the standard output pressure in high pressure mode and low pressure mode on the standard curve are recorded as standard data points.

[0080] Calculate the slope between the standard data points corresponding to the high-pressure mode and the standard data points corresponding to the low-pressure mode on the standard curve, and denot it as the standard slope.

[0081] It should be noted that the calculation of the slope is a well-known technique and will not be elaborated here. The standard output pressure is set according to the specific application scenario and design requirements of the hydraulic system. In this embodiment, the standard output pressure in high pressure mode is set to 200 bar, and the standard output pressure in low pressure mode is set to 20 bar. As for other implementation methods, implementers can set it according to the actual situation.

[0082] It should be noted that, for ease of understanding, the standard curve diagram provided in this embodiment is as follows: Figure 2 As shown, Figure 2 Midpoints a and b are the data points corresponding to the start and completion times of the switching, respectively. Point c is the standard output pressure in low-pressure mode and point d is the standard output pressure in high-pressure mode. Therefore, points e and f are the standard data points corresponding to low-pressure and high-pressure modes, respectively. Thus, the slope between points a and b is calculated and recorded as the actual slope, and the slope between points e and f is recorded as the standard slope.

[0083] The distance between the data point corresponding to the completion time of each mode switch on each valve port of the abnormal electromagnetic directional valve and the standard data point corresponding to the pressure mode after the mode switch is recorded as the first distance.

[0084] In this embodiment, the distance is measured by calculating the Euclidean distance between the data points corresponding to the completion time of each mode switch on each valve port of the abnormal electromagnetic reversing valve and the standard data points corresponding to the pressure mode after the mode switch. The calculation of Euclidean distance is a well-known technique and will not be described in detail here. As other implementation methods, implementers can use other methods of the prior art, such as Manhattan distance, etc. This embodiment does not impose any special restrictions on this.

[0085] It should be noted that if the i-th mode switch is from low voltage to high voltage mode, the Euclidean distance between the standard data point corresponding to the high voltage mode after the i-th mode switch and the data point corresponding to the time of switch completion is calculated; if the i-th mode switch is from high voltage to low voltage mode, the Euclidean distance between the standard data point corresponding to the low voltage mode after the i-th mode switch and the data point corresponding to the time of switch completion is calculated.

[0086] The difference between the actual slope and the standard slope is denoted as the trend deviation.

[0087] In this embodiment, the absolute value of the difference between the actual slope and the standard slope is denoted as the trend deviation.

[0088] The product of the first distance and the trend deviation is used as the first evaluation value of each valve port after each mode switch;

[0089] It should be noted that the greater the trend deviation, the greater the deviation between the actual output pressure and flow rate changes of the valve port before and after mode switching and the trend of the standard curve, indicating a greater degree of abnormality of the valve port and a higher probability of failure. The greater the first distance, the greater the deviation between the actual output pressure and flow rate after mode switching and the standard output pressure and flow rate on the standard curve. The greater the first evaluation value, the more significant the abnormality of the valve port during this mode switching process, reflecting a higher probability of failure of the valve port.

[0090] Thus, the first evaluation value of each valve port on the abnormal electromagnetic directional valve is obtained after each mode switch.

[0091] Step 4: Analyze the deviation of the output pressure and flow rate from the standard curve at different times during the output period of each valve port, as well as the fluctuation of the output pressure. Determine the second evaluation value of each valve port on the abnormal solenoid directional valve after each mode switch. Combine the first evaluation value to obtain the discrimination coefficient of each valve port on the abnormal solenoid directional valve after each mode switch. Evaluate the valve port failure of the solenoid directional valve and monitor and control the solenoid directional valve in real time.

[0092] When the valve port of the dual-pressure solenoid directional valve is under normal operating conditions, it will maintain a stable and continuous output pressure after switching to the corresponding pressure mode. However, if an abnormality occurs at the valve port, the output pressure may become unstable. Therefore, the changes in output pressure and flow rate at each valve port of the abnormal solenoid directional valve at different times after each mode switch and before the next mode switch are analyzed to calculate the second evaluation value, specifically:

[0093] The sum of the differences between the output pressure of each valve port on the abnormal solenoid directional valve at all times during the corresponding output period after each mode switch and the standard output pressure under the pressure mode after the mode switch is denoted as the pressure fluctuation degree.

[0094] In this embodiment, if the i-th mode switch is from low pressure to high pressure, then the system is in high pressure mode after the i-th mode switch. The absolute value of the difference between the output pressure of each valve port on the abnormal solenoid directional valve at each moment during the output period after the i-th mode switch and the standard output pressure in high pressure mode is calculated. If the i-th mode switch is from high pressure to low pressure, then the system is in low pressure mode after the i-th mode switch. The absolute value of the difference between the output pressure of each valve port on the abnormal solenoid directional valve at each moment during the output period after the i-th mode switch and the standard output pressure in low pressure mode is calculated.

[0095] It should be noted that the greater the pressure fluctuation, the lower the real-time stability of the pressure output, and the higher the impact of the valve port failure after this mode switch.

[0096] The output pressure and flow rate of each valve port on the abnormal electromagnetic reversing valve at each time during the corresponding output period after each mode switch are formed into a two-dimensional array. The data points represented by the two-dimensional array at all times during the output period are mapped to the plane coordinate system where the standard curve is located. The distance between the data points corresponding to each time during the output period and the standard data points corresponding to the pressure mode after the mode switch is calculated and recorded as the second distance.

[0097] In this embodiment, the Euclidean distance between the data points corresponding to each moment within the output period and the standard data points corresponding to the pressure mode after the mode switch is calculated, and denoted as the second distance.

[0098] The product of the sum of the second distances at all times within the output period and the pressure fluctuation is used as the second evaluation value of each valve port on the abnormal electromagnetic directional valve after each mode switch.

[0099] It should be noted that the larger the second distance, the greater the difference between the data points mapped at different times and the standard data points on the standard curve, reflecting a worse coordination between the output pressure and flow rate of this valve port. The larger the obtained second evaluation value, the lower the stability of the output pressure of this valve port after this mode switch, reflecting a greater possibility of an anomaly in this valve port.

[0100] Furthermore, based on the first and second evaluation values, a discrimination coefficient is determined to evaluate the fault conditions of different valve ports on the abnormal solenoid directional valve, specifically as follows:

[0101] The product of the first evaluation value and the second evaluation value of each valve port on the abnormal solenoid directional valve after each mode switch is used as the discrimination coefficient of each valve port on the abnormal solenoid directional valve after each mode switch.

[0102] It should be noted that the larger the discrimination coefficient, the more severe the fault at that valve port of the dual-pressure solenoid directional valve. The flowchart of the method for obtaining the discrimination coefficient provided in this application embodiment is shown below. Figure 3 As shown.

[0103] After each mode switch, the discrimination coefficients of all valve ports on all solenoid directional valves in the control box are normalized. If the normalized discrimination coefficients of each valve port on an abnormal solenoid directional valve are less than a preset first value after each mode switch, the valve port is not faulty. If the normalized discrimination coefficients are greater than or equal to the preset first value and less than the preset second value, the valve port has a minor fault. If the normalized discrimination coefficients are greater than or equal to the preset second value, the valve port has a serious fault. The preset first value is less than the preset second value.

[0104] In this embodiment, maximum and minimum value normalization is used for normalization processing. Maximum and minimum value normalization is a well-known technique and will not be described in detail here. As other implementation methods, implementers can use other methods of existing technology, such as the tanh function, etc. This embodiment does not impose any special restrictions on this. Secondly, the first preset value is 0.3 and the second preset value is 0.6. As other implementation methods, implementers can set them according to the actual situation.

[0105] It should be noted that for solenoid directional valves with minor valve port malfunctions, they should be inspected after the hydraulic system's working cycle ends. For solenoid directional valves with serious valve port malfunctions, a control command should be sent to the solenoid directional valve to automatically trigger the emergency stop circuit, cut off the power supply to the solenoid directional valve, and immediately and automatically switch to the standby valve for inspection.

[0106] Based on the same inventive concept as the above method, this application embodiment also provides a dual-pressure solenoid directional valve intelligent control box, which integrates multiple dual-pressure solenoid directional valves. The fault detection process of the dual-pressure solenoid directional valve is implemented by adopting any of the steps of the above-mentioned dual-pressure solenoid directional valve intelligent control method.

[0107] In this embodiment, 12 electromagnetic reversing valves are integrated in the control box. As for other implementation methods, the implementer can determine the appropriate method based on the actual situation.

[0108] 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 completed 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.

[0109] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0110] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application. Therefore, any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application, without departing from the content of the technical solution of this application, shall fall within the protection scope of the technical solution of this application.

Claims

1. A method for intelligent control of a dual-pressure solenoid directional valve, characterized in that, The method includes the following steps: Within the working cycle of the hydraulic system, the time period between each mode switch and the next mode switch is recorded as the output time period. The output pressure and hydraulic oil flow of each valve port on each solenoid directional valve are collected in real time during the output time period after each mode switch, as well as the displacement of the valve core after each mode switch. The mode switch is divided into two cases: switching from low pressure to high pressure mode and switching from high pressure to low pressure mode. Based on the differences in displacement of each solenoid directional valve when switching to low-pressure and high-pressure modes in all mode switching cycles, as well as the deviation of displacement after mode switching, the displacement deviation of each solenoid directional valve is calculated to determine the working status of the solenoid directional valve and identify abnormal solenoid directional valves. When the solenoid directional valve is working normally, record the output pressure of each valve port at different flow rates to construct a standard curve; for each valve port of the abnormal solenoid directional valve, calculate the trend deviation by observing the trend changes of the output pressure and flow rate of each valve port before and after each mode switch, and combine the output pressure and flow rate deviation of each valve port from the standard curve after the mode switch to determine the first evaluation value of each valve port of the abnormal solenoid directional valve after each mode switch. Analyze the deviation of the standard curve of output pressure and flow at different times during the output period of each valve port, as well as the fluctuation of output pressure, determine the second evaluation value of each valve port on the abnormal solenoid directional valve after each mode switch, and combine it with the first evaluation value to obtain the discrimination coefficient of each valve port on the abnormal solenoid directional valve after each mode switch, evaluate the valve port failure of the solenoid directional valve, and monitor and control the solenoid directional valve in real time. The second evaluation value of each valve port on the electromagnetic directional valve that is determined to be abnormal after each mode switch includes: For each valve port on an abnormal electromagnetic directional valve, the sum of the differences between the output pressure at all times during the corresponding output period after each mode switch and the standard output pressure under the pressure mode after the mode switch is recorded as the pressure fluctuation degree. The output pressure and flow rate of each valve port at each time during the corresponding output period after each mode switch are formed into a two-dimensional array. The data points represented by the two-dimensional array at all times during the output period are mapped to the plane coordinate system where the standard curve is located. The distance between the data points corresponding to each time during the output period and the standard data points corresponding to the pressure mode after the mode switch is calculated and recorded as the second distance. The second evaluation value is the product of the sum of the second distances at all times within the output period and the pressure fluctuation.

2. The intelligent control method for a dual-pressure solenoid directional valve as described in claim 1, characterized in that, The calculation of the displacement deviation of each solenoid directional valve includes: The absolute values ​​of all displacements after switching to high-pressure mode and all displacements after switching to low-pressure mode in all sub-mode switching are respectively used to form high-pressure displacement sequence and low-pressure displacement sequence; The difference between each element in the high-pressure displacement sequence and the corresponding element in the low-pressure displacement sequence is denoted as the relative difference; the sum of the relative differences of all elements in the high-pressure displacement sequence is calculated. Calculate the average difference between the mean of the high-pressure displacement sequence and the mean of the low-pressure displacement sequence and the preset theoretical displacement. The displacement deviation is the product of the sum and the average value.

3. The intelligent control method for a dual-pressure solenoid directional valve as described in claim 1, characterized in that, The process for identifying abnormal electromagnetic directional valves is as follows: electromagnetic directional valves with displacement deviations greater than or equal to a preset threshold are recorded as abnormal electromagnetic directional valves.

4. The intelligent control method for a dual-pressure solenoid directional valve as described in claim 1, characterized in that, The method for constructing the standard curve is as follows: when the dual-pressure solenoid directional valve is in normal working condition, continuously record the output pressure of the hydraulic oil at each valve port at different flow rates, and form a two-dimensional array of each output pressure and its corresponding flow rate, and plot the standard curve in the plane coordinate system.

5. The intelligent control method for a dual-pressure solenoid directional valve as described in claim 1, characterized in that, The calculation of trend deviation includes: The moment before each mode switch begins is recorded as the switch start time, and the moment after the switch ends is recorded as the switch completion time. For each mode switch, the output pressure and flow rate of each valve port on the abnormal electromagnetic reversing valve at the start of the switch and the output pressure and flow rate at the end of the switch are respectively formed into a two-dimensional array; the data points represented by the two-dimensional array are mapped to the plane coordinate system where the standard curve is located, and the slope between the data points corresponding to the start of the switch and the data points corresponding to the end of the switch in the plane coordinate system is calculated and recorded as the actual slope. When the dual-pressure solenoid directional valve is in normal working condition, the standard output pressure of each valve port in high-pressure mode and low-pressure mode is obtained respectively. The data points corresponding to the standard output pressure in high-pressure mode and low-pressure mode on the standard curve are recorded as standard data points. The slope between the standard data points in high-pressure mode and the standard data points in low-pressure mode on the standard curve is calculated and recorded as the standard slope. The trend deviation is the difference between the actual slope and the standard slope.

6. The intelligent control method for a dual-pressure solenoid directional valve as described in claim 5, characterized in that, The first evaluation value of each valve port on the electromagnetic directional valve that is determined to be abnormal after each mode switch includes: For the electromagnetic directional valve with abnormality, the distance between the data point corresponding to each valve port at the time of completion of each mode switch and the standard data point corresponding to the pressure mode after the mode switch in the planar coordinate system is recorded as the first distance. The first evaluation value is the product of the first distance and the trend deviation.

7. The intelligent control method for a dual-pressure solenoid directional valve as described in claim 1, characterized in that, The discrimination coefficient is the product of the first evaluation value and the second evaluation value of each valve port on the abnormal electromagnetic directional valve after each mode switch.

8. The intelligent control method for a dual-pressure solenoid directional valve as described in claim 1, characterized in that, The assessment of valve port faults of the solenoid directional valves includes: normalizing the discrimination coefficients of all valve ports on all solenoid directional valves in the control box after each mode switch; if the normalized discrimination coefficients of each valve port on an abnormal solenoid directional valve after each mode switch are less than a preset first value, the valve port is not faulty; if the normalized discrimination coefficients are greater than or equal to the preset first value and less than a preset second value, the valve port has a minor fault; if the normalized discrimination coefficients are greater than or equal to the preset second value, the valve port has a serious fault, wherein the preset first value is less than the preset second value.

9. A smart control box for a dual-pressure solenoid directional valve, characterized in that, The control box integrates multiple dual-pressure solenoid directional valves, and the fault detection process of the dual-pressure solenoid directional valves is achieved by adopting the steps of the intelligent control method for dual-pressure solenoid directional valves as described in any one of claims 1-8.

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