Pump valve matching control method, pump valve matching control system and controller

Abstract

This application discloses a pump-valve matching control method, a pump-valve matching control system, and a controller. The method includes: acquiring the handle command flow rate, the outlet pressure of the variable pump, and the inlet and outlet pressures of the hydraulic cylinder; when the handle command flow rate is greater than a preset value, determining the load type of the hydraulic cylinder and the pump port control pressure based on the handle command flow rate and the inlet and outlet pressures; determining the differential pressure margin of the pump-valve matching control system based on the load type; correcting the pump port control pressure based on the differential pressure margin; and controlling the pump displacement of the variable pump based on the corrected pump port control pressure and the outlet pressure of the variable pump. This application can perform real-time operating condition identification and establish pump-valve matching modes according to different operating conditions, thereby achieving matching of different modes of pump port control pressure and load pressure, which can effectively reduce system energy consumption and improve response time. Furthermore, the variable pump mechanism does not need to be changed between different devices; only the corresponding control parameters need to be adjusted to achieve application in different devices, demonstrating a high degree of versatility.

Description

Technical Field

[0001] This application relates to the field of pump and valve matching control technology, specifically to a pump and valve matching control method, a pump and valve matching control system, and a controller. Background Technology

[0002] Existing pump-valve matching methods mainly include load-sensitive systems. These systems use a shuttle valve to detect the load pressure in real time and transmit it to the control terminal of the load-sensitive valve (LS). The load-sensitive valve then adjusts the pump displacement to maintain a relatively stable state. In other words, the pump inlet pressure and load pressure are controlled by the load-sensitive valve to achieve pressure margin control, thereby balancing the pump and valve flow rates. This method achieves pump-valve matching to a certain extent and reduces system energy consumption. However, traditional load-sensitive systems use a mechanical-hydraulic feedback control principle, which has drawbacks such as low stability and susceptibility to oscillation. Summary of the Invention

[0003] The purpose of this application is to provide a pump-valve matching control method, a pump-valve matching control system, and a controller to solve the problems of low stability and easy oscillation in the traditional load-sensitive system for pump-valve matching in the prior art, which adopts the mechanical-hydraulic feedback control principle.

[0004] To achieve the above objectives, the first aspect of this application provides a pump-valve matching control method, applied to a pump-valve matching control system, the pump-valve matching control system including a variable pump and a hydraulic cylinder, the method comprising:

[0005] Obtain the flow rate from the handle command, the outlet pressure of the variable pump, and the inlet and outlet pressures of the hydraulic cylinder;

[0006] When the flow rate commanded by the handle is greater than the preset value, the load type of the hydraulic cylinder and the control pressure of the pump port are determined based on the flow rate commanded by the handle and the inlet and outlet pressures.

[0007] Determine the differential pressure margin of the pump-valve matching control system based on the load type;

[0008] Adjust the pump inlet control pressure based on the pressure differential margin;

[0009] The pump displacement of the variable pump is controlled based on the modified pump inlet control pressure and the outlet pressure of the variable pump.

[0010] In this embodiment, the hydraulic cylinder includes an oil inlet and an oil outlet. When the handle command flow rate is greater than a preset value, determining the load type of the hydraulic cylinder based on the handle command flow rate and the inlet and outlet pressures includes:

[0011] The oil inlet and outlet of the hydraulic cylinder are determined based on the flow rate commanded by the handle.

[0012] Determine the load type based on the pressure at the inlet and outlet of the oil.

[0013] Among them, the inlet and outlet pressures of the oil cylinder include the pressure at the oil inlet and the pressure at the oil outlet.

[0014] In the embodiment of the present application, according to the pressure at the oil inlet and the pressure at the oil outlet, the load type is determined, including:

[0015] When P

[0020] , mar , I , , T , I ,

[0024] ,

[0019] , I ,

[0023] , ,

[0018] ,

[0022] ,

[0021] , , , O , T ,

[0025] , mar ,

[0026] , , mar , , O , , , *A O / A I -PI < t, the load type is determined as a positive load;

[0016] When P O *A O / A I -P I ≥t, the load type is determined as a negative load;

[0017] Among them, P I is the pressure at the oil inlet, P O is the pressure at the oil outlet, A I is the area of the oil inlet chamber of the oil cylinder, A O is the area of the oil outlet chamber of the oil cylinder; t is the set threshold for working condition identification.

[0018] In the embodiment of the present application, according to the handle command flow rate and the inlet and outlet pressures, the pump port control pressure is determined, including:

[0019] When the load type is a positive load, the pump port control pressure satisfies formula (1):

[0020] P = P I + PV mar ; (1)

[0021] When the load type is a negative load, the pump port control pressure satisfies formula (2):

[0022] P = P T + PV mar + P_S; (2)

[0023] Among them, P is the pump port control pressure; P I is the pressure at the oil inlet of the oil cylinder; P T is the oil tank return oil pressure; P_S is the set value of the back pressure of the pressure control chamber; PV mar is the control pressure difference margin.

[0024] In the embodiment of the present application, according to the load type, the pressure difference margin of the pump valve matching control system is determined, including:

[0025] When the load type is a negative load, the pressure difference margin is determined as the preset margin value. <http: / / www.wipo.int / standards / XMLSchema / ST36 / XMLSchema.xsd>

[0026] In this embodiment of the application, determining the differential pressure margin of the pump-valve matching control system based on the load type includes:

[0027] When the load type is positive load, the differential pressure margin is determined based on the flow rate commanded by the handle.

[0028] In this embodiment of the application, determining the differential pressure margin based on the handle command flow rate includes:

[0029] Get the flow change, which is the change in flow of the controller command over a set time period;

[0030] The pressure margin is determined based on the change in flow rate. When the change in flow rate is greater than a first threshold, the change in flow rate is positively correlated with the pressure margin.

[0031] In this embodiment of the application, determining the differential pressure margin based on the change in flow rate includes:

[0032] When the change in flow rate is less than or equal to a first threshold, the differential pressure margin is determined based on the flow rate commanded by the handle, wherein the flow rate commanded by the handle is positively correlated with the differential pressure margin.

[0033] In this embodiment of the application, controlling the pump displacement of the variable pump based on the modified pump inlet control pressure and the outlet pressure of the variable pump includes:

[0034] Determine the difference between the corrected pump inlet control pressure and the outlet pressure of the variable pump;

[0035] Based on the difference, the pump displacement of the variable pump is adjusted by the PID control system.

[0036] A second aspect of this application provides a controller, comprising:

[0037] The memory is configured to store instructions; and

[0038] The processor is configured to retrieve instructions from memory and, when executing instructions, to implement the aforementioned pump-valve matching control method.

[0039] A third aspect of this application provides a pump-valve matching control system, comprising:

[0040] Variable displacement pump;

[0041] Hydraulic cylinder;

[0042] The controller mentioned above.

[0043] A fourth aspect of this application provides a machine-readable storage medium storing instructions for causing a machine to perform the pump-valve matching control method described above.

[0044] The above technical solution acquires the handle command flow rate, the outlet pressure of the variable pump, and the inlet and outlet pressures of the hydraulic cylinder. When the handle command flow rate exceeds a preset value, the load type of the hydraulic cylinder and the pump port control pressure are determined based on the handle command flow rate and the inlet and outlet pressures. The differential pressure margin of the pump-valve matching control system is determined based on the load type. The pump port control pressure is corrected based on the differential pressure margin. The pump displacement of the variable pump is controlled based on the corrected pump port control pressure and the outlet pressure of the variable pump. This application can identify operating conditions in real time and establish pump-valve matching modes according to different operating conditions, thereby achieving matching between the pump port control pressure and the load type, which can effectively reduce system energy consumption and improve response time.

[0045] Other features and advantages of the embodiments of this application will be described in detail in the following detailed description section. Attached Figure Description

[0046] The accompanying drawings are provided to further illustrate the embodiments of this application and form part of the specification. They are used together with the following detailed description to explain the embodiments of this application, but do not constitute a limitation on the embodiments of this application. In the drawings:

[0047] Figure 1 This schematic diagram illustrates a hydraulic principle diagram of a pump-valve matching control system according to an embodiment of this application;

[0048] Figure 2 A schematic diagram of a pump-valve matching control system according to another embodiment of this application is shown.

[0049] Figure 3 A flowchart illustrating a pump-valve matching control method according to an embodiment of this application is shown schematically.

[0050] Figure 4 This schematically illustrates a flowchart of determining a differential pressure margin according to a specific embodiment of the present application;

[0051] Figure 5 A flowchart illustrating a pump-valve matching control method according to a specific embodiment of this application is shown schematically.

[0052] Figure 6 A schematic block diagram of a controller according to an embodiment of this application is shown.

[0053] Explanation of reference numerals in the attached figures

[0054] 1. Variable pump; 21. Pilot oil filter valve

[0055] 22 Pilot oil pressure reducing valve 31 First pilot solenoid valve

[0056] 32 Second pilot solenoid valve 33 Third pilot solenoid valve

[0057] 34 Fourth pilot solenoid valve 41 First main valve core

[0058] 42 Second main valve core 43 Third main valve core

[0059] 44 Fourth main valve core; 51 First safety valve

[0060] 52 Second safety valve 61 First pressure sensor

[0061] 62 Second pressure sensor 63 Third pressure sensor

[0062] 64 Fourth pressure sensor 7 Hydraulic cylinder

[0063] 8 controllers Detailed Implementation

[0064] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only for illustration and explanation of the embodiments of this application and are not intended to limit the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0065] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of the components in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0066] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0067] Figure 1 A schematic diagram of a pump-valve matching control system according to an embodiment of this application is shown. Figure 1As shown, the pump-valve matching control system of this application embodiment mainly consists of a pump control module, a valve control module, and a controller 8. The pump control module includes a variable pump 1, an oil tank (not shown in the figure), a first pressure sensor 61, and a second pressure sensor 62. The valve control module includes a pilot oil filter 21, a pilot oil pressure reducing valve 22, a first pilot solenoid valve 31, a second pilot solenoid valve 32, a third pilot solenoid valve 33, a fourth pilot solenoid valve 34, a first main valve core 41, a second main valve core 42, a third main valve core 43, a fourth main valve core 44, a first safety valve 51, a second safety valve 52, a third pressure sensor 63, a fourth pressure sensor 64, and a hydraulic cylinder 7.

[0068] Figure 2 A schematic diagram of a pump-valve matching control system according to another embodiment of this application is shown. Figure 2 As shown, the pump-valve matching control system of this application embodiment mainly consists of a pump control module, a valve control module, and a controller 8. The pump control module includes a variable pump 1, an oil tank (not shown in the figure), a first pressure sensor 61, and a second pressure sensor 62. The valve control module includes a pilot oil filter 21, a pilot oil pressure reducing valve 22, a first pilot solenoid valve 31, a second pilot solenoid valve 32, a first main valve core 41, a second main valve core 42, a first safety valve 51, a second safety valve 52, a third pressure sensor 63, a fourth pressure sensor 64, and a hydraulic cylinder 7.

[0069] The valve control module adopts independent control of the load port, and achieves stable control of the cylinder speed by adjusting the valve core displacement of the main valve core; the pump control module adjusts the variable pump displacement in real time by collecting the load pressure from the valve control module, so as to achieve flow matching and balance between the pump control module and the valve control module.

[0070] Figure 3 A flowchart illustrating a pump-valve matching control method according to an embodiment of this application is shown schematically. This pump-valve matching control method can be applied to a pump-valve matching control system including a variable displacement pump and a hydraulic cylinder. To facilitate understanding of the specific implementation of the pump-valve matching control method according to the embodiments of this application, the following embodiments will mainly focus on… Figure 1 or Figure 2 The pump and valve matching control system shown illustrates the method. It is worth emphasizing that... Figure 1 or Figure 2 The pump and valve matching control system shown does not constitute a specific limitation on the application scenarios of the method provided in the embodiments of this application.

[0071] like Figure 3 As shown, the method may include the following steps.

[0072] Step 101: Obtain the handle command flow rate, the outlet pressure of the variable pump, and the inlet and outlet pressures of the hydraulic cylinder.

[0073] In this embodiment, the controller can be considered the execution subject of the method. The controller can acquire signals of handle command flow rate, variable pump outlet pressure, and cylinder inlet and outlet pressures in real time. The handle command flow rate is the flow rate supplied by the operator to the pump-valve matching system via the handle. The controller can identify the operating condition in real time based on the acquired pressure signals and calculate the pump outlet control pressure according to different operating conditions. In one example, the controller can use the calculated pump outlet control pressure as the control variable, and continuously adjust the variable pump's displacement through PID closed-loop control, so that the variable pump's outlet pressure continuously approaches the pump outlet control pressure, thereby achieving pump-valve matching based on differential pressure margin closed-loop control.

[0074] Step 102: When the handle command flow rate is greater than the preset value, determine the load type of the hydraulic cylinder and the pump port control pressure based on the handle command flow rate and the inlet and outlet pressures.

[0075] In this embodiment, the handle command flow rate is the flow rate given by the operator to the pump-valve matching system via the handle. The handle command flow rate can be positive or negative, representing different oil flow directions in the pump-valve matching system. In one example, the cylinder 7 has two ports... Figure 1 For example, the two oil ports can be port A and port B. When the handle command flow rate is positive, the oil flows from port A to port B; when the handle command flow rate is negative, the oil flows from port B to port A. Therefore, when the handle command flow rate is greater than a preset value, the load type of the hydraulic cylinder and the pump port control pressure can be determined based on the handle command flow rate and the inlet and outlet pressures. In one example, the method provided in this application embodiment can be applied to engineering machinery including a boom, and the hydraulic cylinder can be a boom cylinder, etc. Accordingly, the controller can judge the boom movement based on the collected handle command flow rate signal. When the handle command flow rate is 0, it is determined that the boom has no movement, and at this time the pump port control pressure is the static pump port setting pressure. It should be noted that the static pump port setting pressure is a pre-set value.

[0076] Step 103: Determine the differential pressure margin of the pump-valve matching control system according to the load type.

[0077] Existing pump-valve matching control systems employ mechanical load sensitivity and mechanical-hydraulic feedback, resulting in slow system response during rapid startup. Since the differential pressure margin of the feedback valve is determined by an adjusting spring, it cannot be adjusted during rapid startup, leading to slow system response, significant pressure loss, and high energy consumption. On one hand, once the differential pressure margin spring is adjusted, it cannot be changed during control, resulting in significant pressure loss during stable operation and high energy consumption. Furthermore, mechanical adjustment cannot adaptively adjust according to operating conditions, resulting in low intelligence in the pump-valve matching control system. On the other hand, different types of machinery have different load sensitivity margin settings, making adjustment difficult and reducing versatility. Therefore, in this embodiment, operating conditions are identified based on the detected load pressure (i.e., the inlet and outlet pressures of the cylinder), and pressure margin matching is automatically performed according to the specific operating condition (load type). The differential pressure margin of the pump-valve matching control system is also automatically set according to the load type, resulting in a higher level of intelligence.

[0078] Step 104: Adjust the pump inlet control pressure based on the differential pressure margin.

[0079] In this embodiment, the differential pressure margin setting is crucial. If set too high, the pump-valve matching control system responds quickly, but the pressure drop across the throttling orifice is significant, leading to unnecessary energy loss. Conversely, if set too low, energy loss is reduced, but the pump-valve matching control system responds slowly and has a longer pressure build-up time. Therefore, the differential pressure margin needs to be adjusted in real-time according to operating conditions to correct the pump inlet control pressure.

[0080] Step 105: Control the pump displacement of the variable pump according to the corrected pump inlet control pressure and the outlet pressure of the variable pump.

[0081] Based on the PID closed-loop control example above, the corrected pump inlet control pressure obtained in this step can be used as the control pressure for the variable pump. Based on the collected outlet pressure of the variable pump, the difference between the corrected pump inlet control pressure and the variable pump outlet pressure is calculated. This difference is then used as the input for the PID closed-loop control. According to the corrected pump inlet control pressure, the pump displacement is continuously adjusted through PID control until the outlet pressure of the variable pump continuously approaches the corrected pump inlet control pressure, i.e., the difference between the corrected pump inlet control pressure and the variable pump outlet pressure continuously approaches 0. This achieves pressure margin control matching between the pump and the valve.

[0082] Through the above technical solution, first obtain the handle command flow rate, the outlet pressure of the variable pump, and the inlet and outlet pressures of the oil cylinder; when the handle command flow rate is greater than the preset value, determine the load type of the oil cylinder and the pump port control pressure according to the handle command flow rate and the inlet and outlet pressures; then determine the differential pressure margin of the pump valve matching control system according to the load type, and correct the pump port control pressure based on the differential pressure margin; finally, control the pump displacement of the variable pump according to the corrected pump port control pressure and the outlet pressure of the variable pump. This application can perform working condition identification in real time, establish a pump valve matching mode according to different working conditions, so as to achieve the matching of different modes of pump port control pressure and load pressure, effectively reduce system energy consumption, and improve response time. And between different devices, the variable pump mechanism does not need to be changed, and only the corresponding control parameters need to be adjusted to realize the application of different devices, with a high degree of generalization.

[0083] In the embodiment of the present application, the oil cylinder may include an oil inlet and an oil outlet. When the handle command flow rate is greater than the preset value, determining the load type of the oil cylinder according to the handle command flow rate and the inlet and outlet pressures may include:

[0084] Determine the oil inlet and oil outlet of the oil cylinder according to the handle command flow rate;

[0085] Determine the load type according to the pressure at the oil inlet and the pressure at the oil outlet;

[0086] Among them, the inlet and outlet pressures of the oil cylinder may include the pressure at the oil inlet and the pressure at the oil outlet.

[0087] Specifically, the oil cylinder of the pump valve matching control system includes an oil inlet and an oil outlet, and the handle command flow rate is the flow rate given by the operator to the pump valve matching control system through the handle. In the embodiment of the present application, the handle command flow rate may be a positive value or a negative value, respectively representing different oil flow directions of the pump valve matching control system. As Figure 1 shown, the oil cylinder may have two oil ports, namely port A and port B. When the handle command flow rate is a positive value, the oil flows from port A to port B, then the oil inlet is port A and the oil outlet is port B; when the handle command flow rate is a negative value, the oil flows from port B to port A, then the oil inlet is port B and the oil outlet is port A. According to the direction of oil flow and the pressures at the oil inlet and oil outlet of the oil cylinder, the load type of the oil cylinder can be determined.

[0088] In the embodiment of the present application, determining the load type according to the pressure at the oil inlet and the pressure at the oil outlet may include:

[0089] In P O *A O A / I -P I <t, the load type is determined as a positive load;

[0090] In P O*A O / A I When -PI ≥ t, the load type is determined as a negative load;

[0091] where, P I is the pressure at the oil inlet, P O is the pressure at the oil outlet, A I is the area of the oil inlet chamber of the oil cylinder, A O is the area of the oil outlet chamber of the oil cylinder; t is the set threshold for working condition identification.

[0092] Specifically, when the flow direction of the oil fluid and the pressures at the oil inlet and outlet of the oil cylinder are determined, the load type of the pump - valve matching control system can be determined according to the flow direction of the oil fluid and the pressures at the oil inlet and outlet of the oil cylinder. In one example, if the oil fluid in the oil cylinder flows from port A to port B, then the oil inlet is port A, the oil outlet is port B, and the pressure P I is the pressure at port A, P A , and the pressure at the oil outlet, P O is the pressure at port B, P B . Identify the load. When P O *A O / A I -P I < t, it can be determined that the load type of the oil cylinder is a positive load; when P O *A O / A I -P I ≥ t, it can be determined that the load type of the oil cylinder is a negative load. In another example, if the oil fluid in the oil cylinder flows from port B to port A, then the oil inlet is port B, the oil outlet is port A, and the pressure at the oil inlet, P I is the pressure at port B, P B , and the pressure at the oil outlet, P O is the pressure at port A, P A . Identify the load. When P O *A O / A I [[ID=​​​​​​​​​​​​​​​​In this embodiment of the application, determining the pump port control pressure based on the handle command flow rate and the inlet and outlet pressures may include:

[0094] When the load type is positive load, the pump inlet control pressure satisfies formula (1):

[0095] P = P I +PV mar (1)

[0096] When the load type is negative load, the pump inlet control pressure satisfies formula (2):

[0097] P = P T +PV mar +P_S; (2)

[0098] Where P is the pump inlet control pressure; P I P is the pressure at the oil inlet of the hydraulic cylinder. T P_S is the return oil pressure from the oil tank; P_S is the set pressure of the back pressure in the pressure control chamber; PV mar To control the differential pressure margin.

[0099] Specifically, the pump port control pressure can be determined based on the handle command flow rate and the inlet and outlet pressures of the hydraulic cylinder. When the load type is determined to be a positive load, the pump port control pressure is the hydraulic cylinder inlet pressure plus the control pressure differential margin. When the load type is determined to be a negative load, the pump port control pressure is the sum of the oil tank return pressure, the pressure control chamber back pressure setting, and the control pressure differential margin. The pressure control chamber back pressure setting is a pre-set value.

[0100] In this embodiment of the application, determining the differential pressure margin of the pump-valve matching control system based on the load type may include:

[0101] When the load type is negative load, the differential pressure margin is set to the preset margin value.

[0102] Specifically, to avoid unnecessary energy loss, a minimum differential pressure margin, or preset margin value, can first be set for the pump-valve matching control system according to control requirements. For construction machinery, the preset margin value can be set within the range of 5-8 bar. After determining the cylinder load type based on the handle command flow rate and inlet / outlet pressure, the differential pressure margin of the pump-valve matching control system can be determined based on the load type. In this embodiment, when the load type of the pump-valve matching control system is a negative load, a smaller differential pressure margin is sufficient to meet the pump-valve matching requirements. Therefore, when the load type of the pump-valve matching control system is determined to be a negative load, the minimum differential pressure margin, or preset differential pressure margin, can be set as the differential pressure margin of the pump-valve matching control system.

[0103] In this embodiment of the application, determining the differential pressure margin of the pump-valve matching control system based on the load type includes:

[0104] When the load type is positive load, the differential pressure margin is determined based on the flow rate commanded by the handle.

[0105] Specifically, when the load type of the pump-valve matching control system is determined to be a positive load, setting the minimum differential pressure margin to the differential pressure margin of the pump-valve matching system will result in a slow system start-up response and an excessively long pressure build-up time. Therefore, when the load type is a positive load, the differential pressure margin can be determined based on the flow rate commanded by the handle.

[0106] In this embodiment of the application, determining the differential pressure margin based on the handle command flow rate includes:

[0107] Get the flow change, which is the change in flow of the controller command over a set time period;

[0108] The pressure margin is determined based on the change in flow rate. When the change in flow rate is greater than a first threshold, the change in flow rate is positively correlated with the pressure margin.

[0109] Specifically, when the pump-valve matching control system is identified as operating under positive load, the flow rate change within a single cycle can be collected based on the change in flow rate commanded by the handle. Then, the flow rate change is segmented. Based on the different ranges of flow rate change, an appropriate differential pressure margin can be set. In one example, the flow rate change within a single cycle of the handle-command flow rate is ΔQ. * , in ΔQ * If the pressure difference is less than or equal to the first threshold, it indicates that the change in the handle command flow rate is small and the pump displacement is relatively stable, therefore the differential pressure margin PV is high. mar A smaller setting is sufficient to meet the requirements of the pump and valve matching control system; at this point, the differential pressure margin PV can be adjusted. mar Set as the first differential pressure margin t1; in ΔQ * If the flow rate is greater than the first threshold and less than or equal to the second threshold, it indicates that the flow rate of the handle command is changing rapidly. In this case, the differential pressure margin PV can be adjusted. mar Set to 2*t1; in ΔQ * If the flow rate is greater than the second threshold but less than or equal to the third threshold, it indicates that the flow rate of the handle command is changing rapidly. Therefore, the differential pressure margin PV can be adjusted. mar Set to 3*t1; in ΔQ * If the flow rate is greater than the third threshold but less than or equal to the fourth threshold, it indicates that the flow rate changes very rapidly under the handle command, and the pump-valve matching control system is in a rapid start-up state. Therefore, the differential pressure margin PV can be adjusted accordingly. mar It is set to 4*t1 to meet the requirement of rapid increase in valve orifice flow.

[0110] It should be noted that the method for adjusting the differential pressure margin in this application is not limited to the method described above of segmenting the flow rate change to determine the differential pressure margin. Other methods capable of adjusting the differential pressure margin may also be included. For example, in another embodiment of this application, the differential pressure margin can be adjusted based on the linear relationship between the differential pressure margin and the flow rate change, where the differential pressure margin is positively correlated with the flow rate change. In yet another embodiment of this application, the differential pressure margin can be adjusted based on the load change rate, where the differential pressure margin is positively correlated with the load change rate.

[0111] In this embodiment of the application, determining the pressure differential margin based on the change in flow rate may include:

[0112] When the change in flow rate is less than or equal to a first threshold, the differential pressure margin is determined based on the flow rate commanded by the handle, wherein the flow rate commanded by the handle is positively correlated with the differential pressure margin.

[0113] In this embodiment of the application, when the flow rate change is less than or equal to the first threshold, the valve orifice flow rate satisfies formula (3):

[0114]

[0115] Where Q is the valve orifice flow rate, and C d ρ is the flow area coefficient, A is the flow area, ΔP is the valve port pressure difference, and ρ is the oil density.

[0116] Specifically, when the flow rate change is less than or equal to the first threshold, since the valve orifice flow rate is related to the flow area, valve orifice pressure difference, and pressure difference margin, when the handle-command flow rate is large, if the pressure difference margin is set to the first pressure difference margin t1, even if the valve core is fully open (i.e., the flow area reaches its maximum), the flow rate through the valve orifice cannot reach the handle-command flow rate because the valve orifice pressure difference and pressure difference margin are set too small. Therefore, the pressure difference margin needs to be increased. The valve orifice flow rates Q1, Q2, Q3, and Q4 are calculated respectively when the pressure difference margin is t1, 2*t1, 3*t1, and 4*t1 and the valve orifice is fully open. The range of the handle command flow rate is determined. If the handle command flow rate is less than Q1, the differential pressure margin t1 meets the handle command flow rate requirement, so the differential pressure margin can be set to t1. If the handle command flow rate is greater than or equal to Q1 and less than Q2, the differential pressure margin 2*t1 meets the handle command flow rate requirement, so the differential pressure margin can be set to 2*t1. If the handle command flow rate is greater than or equal to Q2 and less than Q3, the differential pressure margin 3*t1 meets the handle command flow rate requirement, so the differential pressure margin can be set to 2*t1. If the handle command flow rate is greater than or equal to Q3 and less than Q4, the differential pressure margin 4*t1 meets the handle command flow rate requirement, so the differential pressure margin can be set to 4*t1. It should be noted that the handle command flow rate is relatively stable when the flow rate change is less than or equal to the first threshold. Furthermore, to avoid setting the differential pressure margin too large, which would lead to excessive pressure loss in the pump-valve matching system, the maximum differential pressure margin of the pump-valve matching system is set to 4*t1.

[0117] Figure 4 A flowchart illustrating a method for determining differential pressure margin according to a specific embodiment of this application is shown schematically. Figure 4 As shown, methods for determining differential pressure margin may include:

[0118] S301, Set minimum PV mar =t1; where PV mar This is the pressure differential margin;

[0119] S302. Determine whether the load type of the pump valve matching control system is a positive load; if yes, proceed to step S303; if no, proceed to step S314.

[0120] S303, Determine the change in handle command flow rate ΔQ * The range of ΔQ; if ΔQ * If the first threshold is less than or equal to the first threshold, proceed to step S304; if the first threshold is less than ΔQ... * If the threshold is less than or equal to the second threshold, proceed to step S305; if the threshold is less than ΔQ... * If the threshold is less than or equal to the third threshold, proceed to step S306; if the threshold is less than ΔQ... * If the value is less than or equal to the fourth threshold, proceed to step S307.

[0121] S304, Set PV mar =t1 and proceed to step S308; where PV mar This is the pressure differential margin;

[0122] S305, Set PV mar = 2*t1; where PV mar This is the pressure differential margin;

[0123] S306, Set PV mar =3*t1; where PV mar This is the pressure differential margin;

[0124] S307, Setting PV mar = 4*t1; where PV mar This is the pressure differential margin;

[0125] S308, Calculate PV respectively mar = t1, 2*t1, 3*t1, 4*t1 and the valve orifice is fully open, the valve orifice flow rates Q1, Q2, Q3, Q4; where PV mar This is the pressure differential margin;

[0126] S309. Determine the change in handle command flow Q * The range of ΔQ; if ΔQ * If Q1 ≤ Q1, proceed to step S310; if Q1 < ΔQ * If Q2 ≤ Q2, proceed to step S311; if Q2 < ΔQ * If Q3 ≤ Q3, proceed to step S312; if Q3 < ΔQ * If ≤Q4, proceed to step S313;

[0127] S310, Setting PV mar =t1; where PV mar This is the pressure differential margin;

[0128] S311, Setting PV mar = 2*t1; where PV mar This is the pressure differential margin;

[0129] S312, Set PV mar =3*t1; where PV mar This is the pressure differential margin;

[0130] S313, Let PV mar = 4*t1; where PV mar This is the pressure differential margin;

[0131] S314, Setting PV mar =t1; where PV mar This represents the pressure differential margin.

[0132] In this embodiment of the application, controlling the pump displacement of the variable pump based on the modified pump inlet control pressure and the outlet pressure of the variable pump includes:

[0133] Determine the difference between the corrected pump inlet control pressure and the outlet pressure of the variable pump;

[0134] Based on the difference, the pump displacement of the variable pump is adjusted by the PID control system.

[0135] Specifically, the corrected pump inlet control pressure is used as the control pressure of the variable pump. Based on the collected outlet pressure of the variable pump, the difference between the corrected pump inlet control pressure and the outlet pressure of the variable pump is calculated. This difference is used as the input for PID closed-loop control. Based on the corrected pump inlet control pressure, the pump displacement is continuously adjusted through PID control until the outlet pressure of the variable pump continuously approaches the corrected pump inlet control pressure, i.e., the difference between the corrected pump inlet control pressure and the outlet pressure of the variable pump continuously approaches 0. This achieves pressure margin control matching between the pump and the valve.

[0136] Figure 5 A flowchart illustrating a pump-valve matching control method according to a specific embodiment of this application is shown schematically. Figure 5 As shown, the control method for pump-valve matching may include:

[0137] S401, Acquisition Handle Command Flow Q * The outlet pressure P of the variable pump P Oil tank return pressure P T The pressure P at the two oil ports of the hydraulic cylinder A P B ;

[0138] S402, Determine the controller command flow Q * Is it greater than 0? If it is greater than 0, proceed to step S403; if it is not greater than 0, proceed to step S407.

[0139] S403. Determine whether the direction of oil flow is from port A to port B; if yes, proceed to step S404; if no, proceed to step S408.

[0140] S404. Identify the load type and determine whether the load type is a positive load; if yes, proceed to step S406; if no, proceed to step S405.

[0141] S405, Set P = P T +PV mar +P_S; where P is the pump inlet control pressure, P T For oil tank return pressure, PVmar P_S represents the differential pressure margin and the back pressure setting of the pressure control chamber.

[0142] S406, Set P = P A +PV mar Where P is the pump inlet control pressure, P A For the oil inlet pressure of the hydraulic cylinder, PV mar This is the pressure differential margin;

[0143] S407. Set P = P_stanby; where P is the pump inlet control pressure and P_stanby is the static pump inlet control pressure.

[0144] S408. Identify the load type and determine whether the load type is a positive load; if yes, proceed to step S409; if no, proceed to step S410.

[0145] S409, Set P = P B +PV mar Where P is the pump inlet control pressure, PB is the cylinder inlet pressure, and PV is the hydraulic cylinder inlet pressure. mar Pressure margin;

[0146] S410, Set P = P T +PV mar +P_S; where P is the pump inlet control pressure, P T For oil tank return pressure, PV mar P_S represents the differential pressure margin and the back pressure setting of the pressure control chamber.

[0147] S411, Calculate the pump inlet control pressure difference ΔP1 = PP P Where P is the pump inlet control pressure, P P The outlet pressure of the variable pump;

[0148] S412. Perform PID closed-loop control based on the pump inlet control pressure difference;

[0149] S413, Adjust the pump displacement so that P P =P; where P P The outlet pressure of the variable pump, P is the pump inlet control pressure.

[0150] Figure 6 A schematic block diagram of a controller according to an embodiment of this application is shown. Figure 6 As shown in the figure, this application provides a controller that may include:

[0151] Memory 610 is configured to store instructions; and

[0152] A processor 620, configured to call instructions from a memory 610 and capable of implementing the above-mentioned method for pump-valve matching control when executing the instructions.

[0153] Specifically, in an embodiment of the present application, the processor 620 may be configured to:

[0154] Obtain the handle command flow rate, the outlet pressure of the variable pump, and the inlet and outlet pressures of the oil cylinder;

[0155] When the handle command flow rate is greater than a preset value, determine the load type of the oil cylinder and the pump port control pressure based on the handle command flow rate and the inlet and outlet pressures;

[0156] Determine the differential pressure margin of the pump-valve matching control system according to the load type;

[0157] Correct the pump port control pressure based on the differential pressure margin;

[0158] Control the pump displacement of the variable pump according to the corrected pump port control pressure and the outlet pressure of the variable pump.

[0159] Further, the processor 620 may also be configured to:

[0160] Determine the inlet and outlet ports of the oil cylinder according to the handle command flow rate;

[0161] Determine the load type according to the pressure of the inlet port and the pressure of the outlet port;

[0162] Wherein, the inlet and outlet pressures of the oil cylinder include the pressure of the inlet port and the pressure of the outlet port.

[0163] Further, the processor 620 may also be configured to:

[0164] In P O *A O / A I -P I <t, the load type is determined as a positive load;

[0165] In P O *A O / A I -A I ≥t, the load type is determined as a negative load;

[0166] Wherein, P I is the pressure of the inlet port, P O is the pressure of the outlet port, A I is the area of the oil cylinder inlet chamber, A O is the area of the oil cylinder outlet chamber; t is the working condition identification setting threshold.

[0167] Further, the processor 620 may also be configured to:

[0168] When the load type is positive load, the pump inlet control pressure satisfies formula (1):

[0169] P = P I +PV mar (1)

[0170] When the load type is negative load, the pump inlet control pressure satisfies formula (2):

[0171] P = P T +PV mar +P_S; (2)

[0172] Where P is the pump inlet control pressure; P I P is the pressure at the oil inlet of the hydraulic cylinder. T P_S is the return oil pressure from the oil tank; P_S is the set pressure of the back pressure in the pressure control chamber; PV mar To control the differential pressure margin.

[0173] Furthermore, the processor 620 can also be configured as follows:

[0174] When the load type is negative load, the differential pressure margin is set to the preset margin value.

[0175] In this embodiment of the application, determining the differential pressure margin of the pump-valve matching control system based on the load type includes:

[0176] When the load type is positive load, the differential pressure margin is determined based on the flow rate commanded by the handle.

[0177] Furthermore, the processor 620 can also be configured as follows:

[0178] Get the flow change, which is the change in flow of the controller command over a set time period;

[0179] The pressure margin is determined based on the change in flow rate. When the change in flow rate is greater than a first threshold, the change in flow rate is positively correlated with the pressure margin.

[0180] Furthermore, the processor 620 can also be configured as follows:

[0181] Determine the difference between the corrected pump inlet control pressure and the outlet pressure of the variable pump;

[0182] Based on the difference, the pump displacement of the variable pump is adjusted by the PID control system.

[0183] The above technical solution first obtains the handle command flow rate, the outlet pressure of the variable pump, and the inlet and outlet pressures of the hydraulic cylinder. When the handle command flow rate exceeds a preset value, the load type of the hydraulic cylinder and the pump port control pressure are determined based on the handle command flow rate and the inlet and outlet pressures. Then, the differential pressure margin of the pump-valve matching control system is determined based on the load type, and the pump port control pressure is corrected based on the differential pressure margin. Finally, the pump displacement of the variable pump is controlled based on the corrected pump port control pressure and the outlet pressure of the variable pump. This application can identify the working condition in real time and establish pump-valve matching modes according to different working conditions, thereby achieving matching of different modes of pump port control pressure and load pressure, which can effectively reduce system energy consumption and improve response time. Furthermore, the variable pump mechanism does not need to be changed between different devices; only the corresponding control parameters need to be adjusted to achieve application in different devices, resulting in a high degree of versatility.

[0184] like Figure 1 As shown in the embodiments of this application, a pump-valve matching control system is also provided, which may include:

[0185] Variable pump 1;

[0186] Hydraulic cylinder 7;

[0187] The aforementioned controller 8.

[0188] Specifically, the controller 8 can collect the operator's handle command flow rate and the inlet and outlet pressures of the hydraulic cylinder 7. Based on the collected signals of the operator's handle command flow rate and the inlet and outlet pressures of the hydraulic cylinder 7, the controller 8 can determine the operating conditions of the pump-valve matching system. For different operating conditions, the valve control module can execute different flow-pressure composite control strategies. According to the identified operating conditions, the controller 8 controls the first pilot solenoid valve 31, the second pilot solenoid valve 32, the third pilot solenoid valve 33, and the fourth pilot solenoid valve 34 respectively, thereby controlling the valve core displacement of the first main valve core 41, the second main valve core 42, the third main valve core 43, and the fourth main valve core 44, thus controlling the flow rate of the hydraulic cylinder 7 to be equal to the handle command flow rate. Based on different operating conditions and the collected inlet and outlet pressures of the hydraulic cylinder 7, by increasing a certain pressure margin, the pump port control pressure can be obtained. The pump port control pressure is input to the pump control module, and the outlet pressure of the variable pump 1 is detected in real time for PID closed-loop control. The outlet pressure of the variable pump 1 is detected by the first pressure sensor 61.

[0189] This application also provides a machine-readable storage medium storing instructions for causing a machine to perform the pump-valve matching control method described above.

[0190] Those skilled in the art will understand that embodiments of this application can be provided as methods, systems, or computer program products. Therefore, this application can take the form of a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, this application can take the form of a computer program product embodied on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0191] This application is described with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of this application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, special-purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, generate instructions for implementing the flowchart... Figure 1 One or more processes and / or boxes Figure 1 A device that provides the functions specified in one or more boxes.

[0192] These computer program instructions may also be stored in a computer-readable storage medium that can direct a computer or other programmable data processing device to function in a particular manner, such that the instructions stored in the computer-readable storage medium produce an article of manufacture including instruction means, which are implemented in a process Figure 1 One or more processes and / or boxes Figure 1 The function specified in one or more boxes.

[0193] These computer program instructions may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps of the function specified in one or more boxes.

[0194] In a typical configuration, a computing device includes one or more processors (CPU), input / output interfaces, network interfaces, and memory.

[0195] Memory may include non-persistent memory in computer-readable media, such as random access memory (RAM) and / or non-volatile memory, such as read-only memory (ROM) or flash RAM. Memory is an example of computer-readable media.

[0196] Computer-readable media includes both permanent and non-permanent, removable and non-removable media that can store information using any method or technology. Information can be computer-readable instructions, data structures, modules of programs, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transferable medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include transient computer-readable media, such as modulated data signals and carrier waves.

[0197] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element.

[0198] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A pump-valve matching control method, characterized in that, Applied to a pump-valve matching control system, the pump-valve matching control system including a variable pump and a hydraulic cylinder, the method includes: The flow rate of the handle command, the outlet pressure of the variable pump, and the inlet and outlet pressures of the hydraulic cylinder are obtained. If the handle command flow rate is greater than a preset value, the load type of the hydraulic cylinder and the pump port control pressure are determined based on the handle command flow rate and the inlet and outlet pressures. The differential pressure margin of the pump-valve matching control system is determined based on the load type. The pump inlet control pressure is adjusted based on the pressure differential margin. The pump displacement of the variable pump is controlled according to the modified pump inlet control pressure and the outlet pressure of the variable pump. The step of determining the differential pressure margin of the pump-valve matching control system based on the load type includes: When the load type is a negative load, the differential pressure margin is determined to be a preset margin value; and / or When the load type is a positive load, the differential pressure margin is determined based on the handle command flow rate.

2. The pump-valve matching control method according to claim 1, characterized in that, The hydraulic cylinder includes an oil inlet and an oil outlet. Determining the load type of the hydraulic cylinder based on the handle command flow rate and the inlet / outlet pressure when the handle command flow rate is greater than a preset value includes: The oil inlet and outlet of the hydraulic cylinder are determined based on the flow rate commanded by the handle. The load type is determined based on the pressure at the oil inlet and the pressure at the oil outlet; The inlet and outlet pressures of the hydraulic cylinder include the pressure at the inlet and the pressure at the outlet.

3. The pump-valve matching control method according to claim 2, characterized in that, The step of determining the load type based on the pressure at the inlet and the pressure at the outlet includes: exist In this case, the load type is determined to be a positive load; exist ≥ t In this case, the load type is determined to be a negative load; in, It is the pressure at the oil inlet. It is the pressure at the oil outlet. Let be the area of ​​the oil inlet chamber of the hydraulic cylinder. The area of ​​the oil outlet chamber of the oil cylinder; Set thresholds for operating condition identification.

4. The pump-valve matching control method according to claim 1, characterized in that, Determining the pump inlet control pressure based on the handle command flow rate and the inlet and outlet pressures includes: When the load type is positive load, the pump inlet control pressure satisfies formula (1): ；（1） When the load type is a negative load, the pump inlet control pressure satisfies formula (2): ；（2） in, Control the pressure at the pump inlet; The pressure at the oil inlet of the cylinder; This refers to the return oil pressure from the oil tank. Set the magnitude of the back pressure of the pressure control chamber; This represents the pressure differential margin.

5. The pump-valve matching control method according to claim 1, characterized in that, Determining the differential pressure margin based on the handle command flow rate includes: The flow rate change is the change in the flow rate of the handle command within a set time period; The pressure margin is determined based on the change in flow rate, wherein the change in flow rate is positively correlated with the pressure margin when the change in flow rate is greater than a first threshold.

6. The pump-valve matching control method according to claim 5, characterized in that, Determining the pressure margin based on the flow rate change includes: If the change in flow rate is less than or equal to a first threshold, the differential pressure margin is determined based on the handle command flow rate, wherein the handle command flow rate is positively correlated with the differential pressure margin.

7. The pump-valve matching control method according to claim 1, characterized in that, The step of controlling the pump displacement of the variable pump based on the modified pump inlet control pressure and the outlet pressure of the variable pump includes: Determine the difference between the corrected pump inlet control pressure and the outlet pressure of the variable pump; Based on the difference, the pump displacement of the variable pump is adjusted by a PID control system.

8. A controller, characterized in that, include: The memory is configured to store instructions; as well as The processor is configured to retrieve the instructions from the memory and, when executing the instructions, to implement the pump-valve matching control method according to any one of claims 1 to 7.

9. A pump-valve matching control system, characterized in that, include: Variable displacement pump; Hydraulic cylinder; The controller according to claim 8.

10. A machine-readable storage medium, characterized in that, The machine-readable storage medium stores instructions for causing the machine to perform the pump-valve matching control method according to any one of claims 1 to 7.

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