Control method, device and equipment based on distributed boom valve hydraulic system

Abstract

The application discloses a control method, device and equipment of a hydraulic system based on a distributed boom valve. The hydraulic system comprises an actuator, a hydraulic pump and a boom valve installed on a boom. The control method comprises the following steps: obtaining an instruction signal for the actuator; determining an initial displacement of the hydraulic pump and a target spool opening of the boom valve according to the instruction signal; obtaining a pre-valve and post-valve pressure difference of the boom valve under the condition that the boom valve is controlled to be at the target spool opening; and correcting the initial displacement of the hydraulic pump according to the pre-valve and post-valve pressure difference and a set pressure difference, so as to control the operation of the actuator. The application can not only greatly shorten the pipeline between the valve and the cylinder and improve the response speed of the actuator, but also control the output displacement of the hydraulic pump based on the control strategy of the pre-valve and post-valve pressure difference of the boom valve, so as to eliminate the pipeline influence, be more adaptable to the environmental temperature and be more accurate in flow control.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of working machines, in particular to a control method, device and equipment of a hydraulic system based on distributed boom valves. BACKGROUND

[0002] The working equipment such as concrete pump trucks, high-altitude spraying fire trucks, overhead working vehicles, boom-type working robots, etc. includes an upper vehicle and a lower vehicle. At present, the hydraulic oil output by a hydraulic pump is distributed to the driving oil cylinders of different booms and the slewing motor of the upper vehicle through the boom valve group installed on the lower vehicle, so as to drive the boom and the slewing ring to act, thereby moving the end of the boom to a specified position for facilitating work.

[0003] In the existing boom hydraulic system, the following problems exist: first, the valve group installed on the lower vehicle is far away from the boom driving oil cylinder, the hydraulic pipeline between the two is long, and the response time is slow; second, the long and thin pipeline causes high pressure loss, and the pressure loss is greatly affected by factors such as temperature, thereby making it difficult to effectively control the flow of the boom valve. SUMMARY

[0004] The purpose of the embodiments of the present application is to provide a control method, device and equipment of a hydraulic system based on distributed boom valves, which can not only greatly shorten the pipeline between the valve and the cylinder, improve the response speed of the actuator, but also control the output displacement of the hydraulic pump based on the control strategy of the pre-valve and post-valve pressure difference of the boom valve, eliminate the influence of the pipeline, have stronger adaptability to environmental temperature, more accurate flow control, and higher energy utilization rate.

[0005] In order to achieve the above-mentioned purpose, the first aspect of the present application provides a control method of a hydraulic system based on distributed boom valves, the hydraulic system including an actuator, a hydraulic pump and a boom valve installed on a boom, the control method comprising: obtaining an instruction signal for the actuator; determining an initial displacement of the hydraulic pump and a target spool opening of the boom valve according to the instruction signal; obtaining a pre-valve and post-valve pressure difference of the boom valve in a case where the boom valve is controlled to be at the target spool opening; and correcting the initial displacement of the hydraulic pump according to the pre-valve and post-valve pressure difference and a set pressure difference, so as to control the operation of the actuator.

[0006] In the embodiments of the present application, the target spool opening of the boom valve is determined according to the instruction signal, which comprises: in a case where the boom valve is configured with a pressure compensation valve, the target spool opening of the boom valve is determined according to the flow corresponding to the instruction signal and the pressure compensation value.

[0007] In the embodiment of the present application, the arm support valve comprises an oil inlet valve and an oil return valve, the oil inlet valve is connected to an oil inlet of the actuator, the oil return valve is connected to an oil return of the actuator, the target valve core opening of the arm support valve is determined according to the instruction signal, which comprises: determining the first target valve core opening of the oil inlet valve and the second target valve core opening of the oil return valve according to the instruction signal, and the control of the arm support valve at the target valve core opening comprises: controlling the oil inlet valve at the first target valve core opening and controlling the oil return valve at the second target valve core opening.

[0008] In the embodiment of the present application, the first target valve core opening of the oil inlet valve and the second target valve core opening of the oil return valve are determined according to the instruction signal, which comprises: determining the corresponding target oil inlet flow of the oil inlet valve according to the instruction signal; obtaining a first flow fluctuation amplitude and a second flow fluctuation amplitude, wherein the first flow fluctuation amplitude is the actual flow fluctuation amplitude of the oil inlet valve, and the second flow fluctuation amplitude is the actual flow fluctuation amplitude of the oil return valve; determining the target oil return flow of the oil return valve according to the target oil inlet flow, the first flow fluctuation amplitude and the second flow fluctuation amplitude; and determining the first target valve core opening of the oil inlet valve according to the target oil inlet flow, and determining the second target valve core opening of the oil return valve according to the target oil return flow.

[0009] In the embodiment of the present application, the pressure difference before and after the valve of the arm support valve is the pressure difference before and after the valve of the oil inlet valve.

[0010] In the embodiment of the present application, in the case that the actuator is a plurality of actuators, the control method further comprises: distributing the flow corresponding to the instruction signal of each actuator according to the flow corresponding to the instruction signal of each actuator, the preset adjustment amount and the maximum displacement of the hydraulic pump.

[0011] In the embodiment of the present application, the distribution of the flow corresponding to the instruction signal of each actuator comprises: determining the required flow of the plurality of actuators according to the flow corresponding to the instruction signal of each actuator and the preset adjustment amount; and in the case that the required flow of the plurality of actuators is greater than the maximum displacement, multiplying the flow corresponding to the instruction signal of each actuator by a preset proportion, wherein the preset proportion is less than 1.

[0012] In the embodiment of the present application, the hydraulic system comprises a plurality of the actuators and a plurality of arm support valves corresponding to the plurality of actuators, and the correcting the initial displacement of the hydraulic pump comprises: determining a difference between a valve front and valve rear pressure difference of an oil inlet valve of each arm support valve and the set pressure difference; according to each difference, performing the following operations: in the case that each difference is greater than 0, determining a minimum difference and correcting the initial displacement of the hydraulic pump according to the minimum difference, or in the case that any difference is less than or equal to 0, updating the difference greater than or equal to 0 to 0 and determining a sum of each updated difference, and correcting the initial displacement of the hydraulic pump according to the determined sum of differences.

[0013] Through the above technical solution, the arm support valve is creatively installed on the arm support, which can greatly shorten the pipeline between the valve and the cylinder, improve the response speed of the actuator, control the variable pump output displacement based on the control strategy of the valve front and valve rear pressure difference of the arm support valve, eliminate the influence of the traditional load-sensitive control system hydraulic pipeline on the flow control accuracy, have stronger adaptability to environmental temperature, more accurate flow control, and higher energy utilization rate.

[0014] The second aspect of the present application provides a control device, comprising: a memory configured to store instructions; and a processor configured to call the instructions from the memory and capable of realizing the control method of the hydraulic system based on the distributed arm support valve when executing the instructions.

[0015] The third aspect of the present application provides a working equipment, comprising: an actuator; a hydraulic pump; an arm support valve installed on an arm support; and the control device.

[0016] The fourth aspect of the present application provides a machine readable storage medium, and the machine readable storage medium stores a computer program, and the computer program is executed by a processor to realize the control method of the hydraulic system based on the distributed arm support valve.

[0017] Other features and advantages of the embodiments of the present application will be described in detail in the following specific implementation part. BRIEF DESCRIPTION OF DRAWINGS

[0018] The accompanying drawings are included to provide a further understanding of the embodiments of the present application, and constitute a part of the specification, and are used together with the following specific implementation to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. In the drawings:

[0019] Figure 1 A flow chart of a control method of a hydraulic system based on a distributed arm support valve according to the embodiments of the present application is schematically shown;

[0020] Figure 2AA structural schematic diagram of an arm support valve according to an embodiment of the present application is shown schematically.

[0021] Figure 2B A structural schematic diagram of an arm support valve according to an embodiment of the present application is shown schematically.

[0022] Figure 3 A flow schematic diagram of single-arm driving control according to an embodiment of the present application is shown schematically.

[0023] Figure 4 A flow schematic diagram of multi-arm driving arm closing control according to an embodiment of the present application is shown schematically.

[0024] Figure 5 A structural schematic diagram of a working device according to an embodiment of the present application is shown schematically. DETAILED DESCRIPTION

[0025] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. It should be understood that the specific embodiments described herein are only used to explain and illustrate the embodiments of the present application, and should not be used to limit the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0026] It should be noted that if the present application has a description of "first", "second", etc., the description of "first", "second", etc. is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person of ordinary skill in the art can realize it, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor within the scope of protection required by the present application.

[0027] In various embodiments of the present application, in order to facilitate the description, the actuator is mainly described as a cylinder, but the actuator is not limited to a cylinder, and can also be a motor or the like.

[0028] Taking the actuator as an oil cylinder as an example, in the actual driving working condition of the working device, there can be a single-arm driving working condition or a multi-arm driving working condition. The single-arm driving working condition refers to that the variable pump only supplies oil to the driving oil cylinder (i.e., the boom cylinder) of a single-section arm on the boom, for example, to realize single-arm arm retraction or extension. The multi-arm driving working condition refers to that the variable pump supplies oil to the driving oil cylinder (i.e., the boom cylinder) of two-section arms or more arms on the boom, to realize multi-arm arm retraction or extension. Taking the actuator as a motor as an example, in the actual driving working condition of the working device, there can be a winch working condition.

[0029] The control method provided by the present application can be applied to any distributed boom valve, which can be an existing boom valve or a boom valve improved based on the existing distributed boom valve in Figure 2A . In order to facilitate the description of the corresponding control strategy, in each embodiment of the present application, the structure of the boom valve shown in Figure 2A can be referred to for understanding, which includes an oil inlet valve 5.1, an oil return valve 6.2, an oil inlet valve 5.2, and an oil return valve 6.1, but the control method is not limited to the specific structure of the boom valve shown in Figure 2A . The number of oil inlet valves and oil return valves is set according to actual needs, for example, only including the oil inlet valve 5.1 and the oil return valve 6.2, which is not limited herein.

[0030] Figure 2A The structure of a boom valve according to an embodiment of the present application is schematically shown. As shown in Figure 2A , the embodiment of the present application provides a boom valve 100 installed on a boom, which can include a multi-way valve assembly 110 with pressure compensation function. The multi-way valve assembly 110 can include at least one working valve group. That is, in actual application, the boom valve 100 can also include one working valve group for control of a single actuator, or a multi-way valve assembly 110 including multiple working valve groups. In order to simplify the description, the multi-way valve assembly 110 is used uniformly in the following description, but this does not constitute a specific limitation on the number of working valve groups.

[0031] The multi-way valve assembly 110 is configured to control the opening and closing of the first oil inlet path S1, the first oil return path S2, the second oil inlet path S3, and the second oil return path S4. The outlet of the first oil inlet path S1 and the inlet of the first oil return path S2 are connected to the rod cavity of the boom cylinder 9. The outlet of the second oil inlet path S3 and the inlet of the second oil return path S4 are connected to the rodless cavity of the boom cylinder 9. The inlet of the first oil inlet path S1 and the inlet of the second oil inlet path S3 (i.e. the oil inlet of the multi-way valve assembly) are connected to the main oil inlet P. The outlet of the first oil return path S2 and the outlet of the second oil return path S4 (i.e. the oil outlet of the multi-way valve assembly) are connected to the main oil return T. In other words, the oil inlet of the multi-way valve assembly is connected to the main oil inlet P in parallel, and the oil outlet of the multi-way valve assembly is connected to the main oil return T in parallel. The boom valve is a distributed boom valve. The main oil inlet P and the main oil return T are connected to the hydraulic system in a bus power supply mode. The number of pipes in the boom hydraulic control system is greatly reduced, the number of leakage points is reduced, the cost of pipe arrangement is reduced, and the response speed of the actuator is improved.

[0032] The boom valve 100 further comprises a pressure regulating assembly 120 connected to the multi-way valve assembly 110. The pressure regulating assembly 120 is configured to adjust the opening degree of the spool of the multi-way valve assembly 110 on the first oil inlet path S1 and the second oil return path S4, or to adjust the opening degree of the spool of the first oil return path S2 and the second oil inlet path S3.

[0033] As some alternative solutions, when the multi-way valve assembly 110 is an electric control valve, the pressure regulating assembly 120 can be omitted.

[0034] In the embodiment, the hydraulic pump 10 (e.g. an electrically controlled variable pump) can change the variable pump swing angle based on a given command signal, output hydraulic oil to the main oil inlet P, and then most of the hydraulic oil flows to the main oil path (represented by the solid line part, e.g. S1-S4), and a small part flows to the pressure regulating assembly 120 on the control oil path (represented by the dashed line). The pressure regulating assembly 120 (e.g. electric proportional pressure reducing valves 2.1, 2.2, 2.3, 2.4) can convert the pressure of the hydraulic oil into different levels of pressure based on the current control signal and apply the hydraulic oil with different levels of pressure to the spools (e.g. oil inlet valves 5.1, 5.2, oil return valves 6.1, 6.2) of the multi-way valve assembly on the first oil inlet path, the first oil return path, the second oil inlet path, and the second oil return path, and control the oil path switching. Due to the pressure compensation function of the multi-way valve assembly, the A port oil inlet / outlet flow and the B port oil inlet / outlet flow can be controlled.

[0035] Since the arm valve 100 is installed on the arm, the distance between the arm valve 100 and the arm cylinder 9 is short, so that the valve and the cylinder are located on the arm of the upper car, and the valve and the cylinder can be connected through a short pipeline. Compared with the traditional load-sensitive pump-based arm hydraulic control system, the embodiment directly cancels the problems of slow response, pressure loss and the like caused by long pipeline connection between the valve and the cylinder, and simultaneously realizes the variable pump P, T port bus type piping scheme. Therefore, the distributed arm valve in the application can greatly reduce the number of pipeline arrangement, facilitate pipeline layout, reduce leakage points and facilitate maintenance, reduce layering loss, and reduce piping cost.

[0036] In an embodiment, the multi-way valve assembly 110 includes an oil inlet pressure compensation valve 4.1, an oil return pressure compensation valve 7.1, an oil inlet pressure compensation valve 4.2 and an oil return pressure compensation valve 7.2, as shown in Figure 2A .

[0037] The oil inlet of the oil inlet pressure compensation valve 4.1, the oil inlet of the oil inlet pressure compensation valve 4.2 and the main oil inlet P are connected, the oil outlet of the oil inlet pressure compensation valve 4.1 is connected with the oil inlet of the oil inlet valve 5.1, the oil outlet of the oil inlet pressure compensation valve 4.2 is connected with the oil inlet of the oil inlet valve 5.2, the oil outlet of the oil inlet valve 5.1 is connected with the rod cavity, and the oil outlet of the oil inlet valve 5.2 is connected with the rodless cavity, as shown in Figure 2A .

[0038] The oil inlet of the oil return pressure compensation valve 7.1 is connected with the rod cavity, the oil inlet of the oil return pressure compensation valve 7.2 is connected with the rodless cavity, the oil outlet of the oil return pressure compensation valve 7.1 is connected with the oil inlet of the oil return valve 6.1, and the oil outlet of the oil return pressure compensation valve 7.2 is connected with the oil inlet of the oil return valve 6.2, the oil outlet of the oil return valve 6.1 and the oil outlet of the oil return valve 6.2 are connected with the main oil return port T, as shown in Figure 2A .

[0039] The oil inlet of the oil return pressure compensation valve 7.1 is connected with the rod cavity, the oil inlet of the oil return pressure compensation valve 7.2 is connected with the rodless cavity, the oil outlet of the oil return pressure compensation valve 7.1 is connected with the oil inlet of the oil return valve 6.1, and the oil outlet of the oil return pressure compensation valve 7.2 is connected with the oil inlet of the oil return valve 6.2, the oil outlet of the oil return valve 6.1 and the oil outlet of the oil return valve 6.2 are connected with the main oil return port T, as shown in Figure 2A .

[0040] Specifically, the hydraulic pump 10 (e.g. an electronically controlled variable pump) can change the variable pump swing angle based on a given command signal, outputting hydraulic oil into the main oil inlet P. The oil inlet valve 5.1 connects the main oil inlet P with the working oil port A, and the oil inlet valve 5.1 can adjust the valve core opening degree based on the pressure regulation assembly 120 (e.g. an electric proportional pressure reducing valve 2.1) controlling the pressure of the hydraulic oil on the first oil path, to cooperate with the oil inlet pressure compensation valve 4.1 to control the A port oil inlet flow; the oil return valve 6.2 connects the main oil return port T with the working oil port B, and the oil return valve 6.2 can adjust the valve core opening degree based on the pressure regulation assembly 120 (e.g. an electric proportional pressure reducing valve 2.4) controlling the pressure of the hydraulic oil on the fourth oil path, to cooperate with the oil return pressure compensation valve 7.2 to control the B port oil return flow, thereby realizing the arm retraction process of the boom.

[0041] The hydraulic pump 10 (e.g. an electronically controlled variable pump) can change the variable pump swing angle based on a given command signal, outputting hydraulic oil into the main oil inlet P. The oil return valve 6.1 connects the main oil return port T with the working oil port A, and the oil return valve 6.1 can adjust the valve core opening degree based on the pressure regulation assembly 120 (e.g. an electric proportional pressure reducing valve 2.2) controlling the pressure of the hydraulic oil on the second oil path, to cooperate with the oil return pressure compensation valve 7.1 to control the A port oil return flow; the oil inlet valve 5.2 connects the main oil inlet P with the working oil port B, and the oil inlet valve 5.2 can adjust the valve core opening degree based on the pressure regulation assembly 120 (e.g. an electric proportional pressure reducing valve 2.3) controlling the pressure of the hydraulic oil on the third oil path, to cooperate with the oil inlet pressure compensation valve 4.2 to control the B port oil inlet flow, thereby realizing the arm extension process of the boom.

[0042] In some possible embodiments, the hydraulic pump 10 described above can also use a combination of a fixed displacement pump and a variable speed motor, by changing the speed of the motor to adjust the output flow of the hydraulic pump 10.

[0043] Since in the arm retraction working condition, the first oil inlet oil path S1 and the second oil return oil path S4 are used to work in cooperation, and the other two oil paths are in a disconnected state, or in the arm extension working condition, the second oil inlet oil path S3 and the first oil return oil path S2 are used to work in cooperation, and the other two oil paths are in a disconnected state, in the next embodiment, a two-position three-way directional valve is used instead of the oil inlet valve and the oil return valve in the previous embodiment. In an embodiment, the multi-way valve assembly 110 includes a three-dimensional four-way directional valve with pressure compensation function, for controlling the main oil path P, the working oil port A, the working oil port B, and the main oil return path.

[0044] In another embodiment, the multi-way valve assembly 110 includes a first two-position three-way directional valve (not shown) with pressure compensation function for controlling the opening and closing of the first oil inlet and the first oil return, and a second two-position three-way directional valve (not shown) with pressure compensation function for controlling the opening and closing of the second oil inlet and the second oil return.

[0045] In another embodiment, the multi-way valve assembly 110 includes a first two-position three-way directional valve (not shown) with pressure compensation function for controlling the opening and closing of the first oil inlet and the first oil return, and a second two-position three-way directional valve (not shown) with pressure compensation function for controlling the opening and closing of the second oil inlet and the second oil return.

[0046] In an embodiment, the pressure regulating assembly 120 can include four two-position three-way electric proportional pressure reducing valves, wherein each two-position three-way electric proportional pressure reducing valve is connected to the spool of the multi-way valve assembly on the corresponding oil line. As shown in Figure 2A , the oil inlet of each two-position three-way electric proportional pressure reducing valve is connected to the output pressure port of the subtraction valve 1, the oil outlet is connected to the corresponding spool (for example, the corresponding oil inlet / return valve), and the drain port is connected to the pilot return port Y. The pilot return port Y also supplies oil in a bus power supply mode, greatly reducing the number of arm hydraulic control system pipelines, reducing system leakage points and pipeline costs, and improving the response speed of the actuator.

[0047] As shown in Figure 2A , the pressure regulating assembly 120 can include electric proportional pressure reducing valves 2.1, 2.2, 2.3, 2.4. For example, the oil outlet of electric proportional pressure reducing valve 2.1 is connected to the oil inlet valve 5.1; the oil outlet of electric proportional pressure reducing valve 2.2 is connected to the oil return valve 6.1; the oil outlet of electric proportional pressure reducing valve 2.3 is connected to the oil inlet valve 6.1; and the oil outlet of electric proportional pressure reducing valve 2.4 is connected to the oil return valve 6.2

[0048] In another embodiment, the pressure regulating assembly 120 can include two three-position four-way electric proportional pressure reducing valves, wherein one three-position four-way electric proportional pressure reducing valve is connected to the spool of the multi-way valve assembly on the first oil inlet and the first oil return, and the other three-position four-way electric proportional pressure reducing valve is connected to the spool of the multi-way valve assembly on the second oil inlet and the second oil return.

[0049] That is, since the first oil inlet oil way and the first oil return oil way are conducted under different working conditions, the same electric proportional pressure reducing valve can be used to control the conduction of the two oil ways, and different current control signals can be received under different working conditions to reduce the hydraulic oil to different degrees.

[0050] Figure 2A The arm valve 100 can further comprise a first locking assembly arranged on the oil way between the intersection of the outlet of the first oil inlet oil way and the inlet of the first oil return oil way and the rod cavity, for locking the hydraulic oil in the rod cavity when the arm valve is powered off; and a second locking assembly arranged on the oil way between the intersection of the outlet of the second oil inlet oil way and the inlet of the second oil return oil way and the rodless cavity, for locking the hydraulic oil in the rodless cavity when the arm valve is powered off.

[0051] The embodiment can lock the action of the actuator when powered off, avoiding the hidden dangers of personal and property safety caused by sudden power failure.

[0052] The first locking assembly can be a first one-way valve 8.1, and the second locking assembly can be a second one-way valve 8.2. The first one-way valve 8.1 is used to one-way conduct the first oil inlet oil way S1 to the rod cavity, and the second one-way valve 8.2 is used to one-way conduct the second oil inlet oil way S3 to the rodless cavity. The first one-way valve 8.1 and the second one-way valve 8.2 have a reverse conduction function, for example, the first one-way valve 8.1 reversely conducts the rod cavity to the second oil return oil way S4 when the hydraulic oil pressure in the rod cavity exceeds a certain pressure, and the first one-way valve 8.2 reversely conducts the rodless cavity to the first oil return oil way S2 when the hydraulic oil pressure in the rodless cavity exceeds a certain pressure.

[0053] The first locking assembly can be a first balance valve, and the second locking assembly can be a second balance valve. The specific connection mode is the same as that of the one-way valve shown in Figure 2A

[0054] As shown in Figure 2A The arm valve 100 can further comprise a first overflow oil supplement valve 3.1 and a second overflow oil supplement valve 3.2, wherein one end of the first overflow oil supplement valve 3.1 is connected with the rod cavity, one end of the second overflow oil supplement valve 3.2 is connected with the rodless cavity, and the other end of the first overflow oil supplement valve 3.1 and the other end of the second overflow oil supplement valve 3.2 are connected with the main oil return port T.

[0055] The first overflow oil supplement valve 3.1 and the second overflow oil supplement valve 3.2 can limit the working pressure of the working oil port A and B, and supplement oil when the working pressure is too low, playing a protection role.​

[0056] As shown in Figure 2A The arm support valve 100 can further comprise a pressure reducing valve 1 for converting the hydraulic oil from the main oil inlet P into hydraulic oil of a preset low pressure and outputting the hydraulic oil of the preset low pressure to the pressure regulating assembly 120.

[0057] Specifically, the pressure reducing valve 1 can convert the high-pressure oil at the main oil inlet P into low-pressure oil of constant pressure and output the low-pressure oil to the oil inlet of the pressure regulating assembly 120 (for example, the electric proportional pressure reducing valves 2.1, 2.2, 2.3, 2.4), and discharge the excess oil to the pilot oil return port Y. The pressure regulating assembly 120 (for example, the electric proportional pressure reducing valves 2.1, 2.2, 2.3, 2.4) can convert the pressure output by the pressure reducing valve 1 into different levels of pressure acting on the oil inlet valve 5.1 and the oil return valve 6.1 (or the oil return valve 6.2 and the oil inlet valve 5.2) based on the current control signal, so as to control the oil path switching.

[0058] In summary, the present application creatively sets the arm support valve on the arm support, and the oil inlet of the multi-way valve assembly is in parallel from the main oil inlet P, and the oil outlet of the multi-way valve assembly is in parallel from the main oil return port T, that is, the arm support valve is set as a distributed arm support valve and installed near the oil cylinder, which can greatly shorten the pipeline between the valve and the cylinder, improve the response speed of the actuator, reduce the number of pipelines of the arm support hydraulic control system, reduce the system leakage points and piping costs, and also reduce the laminated loss and is not affected by low temperature environment.

[0059] The arm support valve can be installed on the corresponding oil cylinder of the arm support, which can greatly shorten the hydraulic pipeline between the valve and the cylinder, thereby greatly improving the response speed of the actuator. If the arm support comprises four arms, one arm support valve is installed on each oil cylinder of each arm.

[0060] Although the pipeline between the above-mentioned arm support valve and the oil cylinder is short (even without pipeline connection), the applicant has found through research that shortening / removing the pipeline connection between the valve and the cylinder means that the pipeline connection between the pump located on the lower vehicle and the arm support valve located on the upper vehicle is increased, and the pipeline pressure loss between the pump and the valve changes with temperature. However, the traditional load sensing pump-based control system mainly compares the difference between the load port pressure (A port / B port) and the pump outlet pressure with the expected difference, and then controls the variable pump output flow according to the comparison result. The inventor believes that the traditional load sensing pump-based control system is easily affected by the hydraulic pipeline connecting the pump and the valve, the pipeline connecting the load feedback port and the pump, and the surrounding environment (such as temperature), and thus it is not suitable for distributed arm support valves. Therefore, the applicant designs a control strategy suitable for distributed arm support valves to effectively solve the above-mentioned problems, which will be described in detail below.

[0061] Figure 1 A flow chart of a control method of a hydraulic system based on a distributed boom valve according to an embodiment of the present application is shown schematically. The hydraulic system comprises actuators, a hydraulic pump and boom valves mounted on a boom. As shown, the control method comprises steps S101-S104. Figure 1

[0062] In step S101, an instruction signal for the actuator is obtained.

[0063] The type of the actuator is set according to actual requirements, which can be a cylinder, a motor, etc., and is not limited herein. In an actual working scenario, a user can send an instruction signal for the actuator by using a handle or other human-computer interaction device according to expected parameters such as expected displacement and expected speed of the actuator.

[0064] The instruction signal can include speed, rotational speed or flow rate. Another two instruction signals (for example, rotational speed and flow rate) can be obtained according to any one of the above instruction signals (for example, speed).

[0065] In an embodiment, whether to redistribute the target control flow of the boom valve on each actuator (or each boom section) involved in a multi-boom driving working condition can be determined based on whether the flow is saturated.

[0066] In the case where the actuator is a plurality of actuators, the control method further comprises: distributing the flow corresponding to the instruction signal for each actuator according to the flow corresponding to the instruction signal for each actuator, a preset adjustment amount and a maximum displacement of the hydraulic pump.

[0067] Specifically, the distributing the flow corresponding to the instruction signal for each actuator comprises: determining the flow required by the plurality of actuators according to the flow corresponding to the instruction signal for each actuator and the preset adjustment amount; and multiplying the flow corresponding to the instruction signal for each actuator by a preset proportion in the case where the flow required by the plurality of actuators is greater than the maximum displacement. The preset proportion is less than 1.

[0068] The preset proportion is directly proportional to the difference between the maximum displacement and the preset adjustment amount.

[0069] Specifically, in a multi-boom driving working condition, taking the case where the boom comprises four boom sections and three of the boom sections (boom section 1, boom section 2 and boom section 3, corresponding actuators are actuator 1, actuator 2 and actuator 3, i = 1, 2, 3) are driven in combination as an example, the flow required by the plurality of actuators Q1+Q2+Q3+ΔQ is determined based on the flow Q1, Q2 and Q3 corresponding to the instruction signal of each actuator and the preset adjustment amount ΔQ p .​p Q1+Q2+Q3+ΔQ p Qmax p Q1+Q2+Q3+ΔQ Figure 4 Qmax p Q1+Q2+Q3+ΔQ p Q1+Q2+Q3+ΔQ p Q1+Q2+Q3+ΔQ p Q1+Q2+Q3+ΔQ For example,

[0070] S102, according to the instruction signal, determine the initial displacement of the hydraulic pump and the target spool opening of the boom valve.

[0071] When the instruction signal is flow, the initial displacement of the hydraulic pump is the flow in the case of the actuator being a motor; and in the case of the actuator being a cylinder: for single-arm driving, the initial displacement of the hydraulic pump is the flow; for multi-arm driving, the initial displacement of the hydraulic pump is the sum of each flow of the plurality of actuators. For the case of the instruction signal being other quantities, the initial displacement of the hydraulic pump can also be determined according to the instruction signal and existing various signal conversion methods, which will not be described here.

[0072] In an embodiment, for S102, according to the instruction signal, determine the target spool opening of the boom valve, comprising: in the case that the boom valve is configured with a pressure compensation valve, according to the flow Q corresponding to the instruction signal and the pressure compensation value ΔP, determine the target spool opening of the boom valve.

[0073] Specifically, in the case that the boom valve is configured with a pressure compensation valve, according to the flow corresponding to the instruction signal, determine the target flow of the oil inlet cavity of the actuator; determine the target oil inlet flow of the spool of the boom valve as the target flow of the oil inlet cavity.

[0074] In an embodiment, the spool of the boom valve can have a pressure compensation function. In another embodiment, as shown in Figure 2A The boom valve further comprises an oil inlet pressure compensation valve 4.1 and an oil return pressure compensation valve 7.2. Of course, the number of pressure compensation valves is also determined according to the data of the oil inlet valve and the oil return valve.

[0075] According to the flow Q corresponding to the instruction signal and the spool pressure compensation value ΔP of the boom valve, the target spool opening x of the boom valve is determined by the following formula:

[0076]

[0077] wherein, p is the density of the hydraulic oil, C d is the flow parameter of the hydraulic oil, and k is the spool flow area coefficient of the arm support valve.

[0078] In another embodiment, the arm support valve comprises an oil inlet valve and an oil return valve, the oil inlet valve is connected to the oil inlet port of the actuator, and the oil return valve is connected to the oil return port of the actuator.

[0079] For step S102, determining the target spool opening of the arm support valve according to the instruction signal comprises: determining the first target spool opening of the oil inlet valve and the second target spool opening of the oil return valve according to the instruction signal.

[0080] Specifically, determining the first target spool opening of the oil inlet valve and the second target spool opening of the oil return valve according to the instruction signal comprises: determining the corresponding target oil inlet flow of the oil inlet valve according to the instruction signal; obtaining a first flow fluctuation amplitude and a second flow fluctuation amplitude, wherein the first flow fluctuation amplitude is the actual flow fluctuation amplitude of the oil inlet valve, and the second flow fluctuation amplitude is the actual flow fluctuation amplitude of the oil return valve; determining the target oil return flow of the oil return valve according to the target oil inlet flow, the first flow fluctuation amplitude and the second flow fluctuation amplitude; and determining the first target spool opening of the oil inlet valve according to the target oil inlet flow, and determining the second target spool opening of the oil return valve according to the target oil return flow.

[0081] For ease of understanding, in the embodiment of the present application, the actuator is an oil cylinder.

[0082] Wherein, the spools of the oil inlet valve and the oil return valve can have pressure compensation function. In another embodiment, as shown in Figure 2A The arm support valve further comprises: oil inlet pressure compensation valves 4.1, 4.2; and oil return pressure compensation valves 7.1, 7.2.

[0083] First, in the case that the oil inlet valve and the oil return valve are both configured with pressure compensation valves, the target flow of the oil inlet cavity of the actuator is determined according to the instruction signal of the actuator; and the target oil inlet flow corresponding to the oil inlet valve is determined as the target flow of the oil inlet cavity.

[0084] Q 进 = Q formula (1)

[0085] Wherein, Q 进 is the target oil inlet flow corresponding to the oil inlet valve, and Q is the target flow of the oil inlet cavity of the actuator.

[0086] Taking the arm closing working condition as an example, the oil inlet cavity of the actuator is a rod cavity, and according to the handle flow instruction Q1, the target flow of the oil inlet cavity of the actuator is determined as Q1, and the target oil inlet flow Q of the oil inlet valve corresponding to the target oil inlet flow 进 .

[0087] Taking the arm opening working condition as an example, the oil inlet cavity of the actuator is a rodless cavity, and according to the handle flow instruction Q1, the target flow of the oil inlet cavity of the actuator is determined as , and the target oil inlet flow Q of the oil inlet valve corresponding to the target oil inlet flow .

[0088] Secondly, in the case of controlling the oil inlet valve and the oil return valve based on the same control parameters, the first flow fluctuation amplitude is the actual flow fluctuation amplitude of the oil inlet valve, and the second flow fluctuation amplitude is the actual flow fluctuation amplitude of the oil return valve. The first flow fluctuation amplitude and the second flow fluctuation amplitude can be directly obtained through bench test of the working equipment, without the need for real-time detection of parameters of the working equipment, thereby reducing the flow control difficulty of the action actuator.

[0089] The first flow fluctuation amplitude and the second flow fluctuation amplitude are both determined by the hysteresis of the working equipment. The actual speed of the actuator is controlled by the oil return valve, and the smaller the hysteresis of the working equipment, the smaller the error between the actual speed of the actuator and the expected speed corresponding to the control instruction.

[0090] Then, the target oil return flow of the oil return valve is determined according to the target oil inlet flow, the first flow fluctuation amplitude and the second flow fluctuation amplitude, including: determining the flow relationship between the oil inlet flow and the oil return flow based on the type of the actuator; and determining the target oil return flow of the oil return valve according to the flow relationship, the target oil inlet flow, the first flow fluctuation amplitude and the second flow fluctuation amplitude.

[0091] The flow relationship between the oil inlet flow and the oil return flow is determined based on the type of the actuator, and the flow relationship corresponding to each type of action actuator is different. The target oil return flow of the oil return valve is determined by substituting the target oil inlet flow, the first flow fluctuation amplitude and the second flow fluctuation amplitude into the flow relationship according to the flow relationship, the target oil inlet flow, the first flow fluctuation amplitude and the second flow fluctuation amplitude, so as to determine the opening degree of the oil return valve.

[0092] In the case that the type of the action actuator is a cylinder, the area ratio A A / A B between the rod cavity area and the rodless cavity area of the actuator is obtained; and based on the area ratio A A / A B , the flow relationship between the target oil inlet flow Q 进 and the target oil return flow Q 回 under the arm closing working condition is determined as:

[0093]

[0094] Based on the area ratio A A / A B , the flow relationship between the target oil inlet flow Q 进 and the target oil return flow Q 回 is determined:

[0095]

[0096] Wherein, ΔQ1 is the first flow fluctuation amplitude, i.e. the actual flow fluctuation amplitude of the oil inlet valve, and ΔQ2 is the second flow fluctuation amplitude, i.e. the actual flow fluctuation amplitude of the oil return valve.

[0097] In the case where the type of the actuator is a motor, the flow relationship between the oil inlet flow and the oil return flow is that the oil inlet flow is equal to the oil return flow.

[0098] Finally, taking the retracted arm working condition as an example, the oil inlet cavity of the actuator is a rod cavity, according to the target oil inlet flow Q 进 of the oil inlet valve corresponding to Q1 and formula (1), the target spool opening x1 and control current I1 of the oil inlet valve 5.1 are obtained:

[0099]

[0100] As shown in Figure 3 , wherein ΔQ1 is 0, and wherein k1 is the spool flow area coefficient of the oil inlet valve 5.1. According to the target oil return flow Q of the oil return valve 6.2 corresponding to Q1 and formula (1), the target spool opening x4 and control current I4 of the oil return valve 6.2 are obtained:

[0101]

[0102] Wherein k4 is the spool flow area coefficient of the oil return valve, Figure 3 x4 shown is a special case of ΔQ1 = 0. Taking the extended arm working condition as an example, the oil inlet cavity of the actuator is a rodless cavity, according to the target oil inlet flow Q of the oil inlet valve corresponding to Q2 and formula (1), the target spool opening x3 and control current I3 of the oil inlet valve 5.2 are obtained:

[0103]

[0104] As shown in Figure 3 , wherein ΔQ1 is 0, and wherein k3 is the spool flow area coefficient of the oil inlet valve 5.2. According to the target oil return flow Q of the oil return valve 6.1 corresponding to Q2 and formula (1), the target spool opening x2 and control current I2 of the oil return valve 6.1 are obtained.

[0105]

[0106] wherein k2 is the spool flow area coefficient of the oil return valve 6.2, Figure 3 x2 shown is a special case of AQ1 = 0. AQ2 can be equal to AQ4.

[0107] Similarly, in the multi-arm retraction mode, the target spool opening x i and the control current I i1 of the oil inlet valve 5.1 of the boom valve on the actuator i (or the boom i) can be determined by the following formula: i1 and the control current I i4 and the control current I i4 :

[0108]

[0109]

[0110] wherein p is the density of the hydraulic oil, C d is the flow parameter of the hydraulic oil, ΔP is the pressure compensation value, k i1 and k i4 are the spring stiffness of the oil inlet valve 5.1 and the oil return valve 6.2 on the actuator i (or the boom i) respectively, A iA and A iB are the areas of the rod cavity and the rodless cavity of the boom cylinder on the actuator i (or the boom i) respectively, AQ i4 is the control flow fluctuation amplitude of the oil return valve 6.2 on the actuator i (or the boom i), and f(x) is the function between the control current and the spool displacement (which is an existing function and will not be described here).

[0111] Specifically, in the multi-arm extension mode, the target spool opening x i and the control current I i2 required by the oil return valve 6.1 of the boom valve on the actuator i (or the boom i) and the target spool opening x i2 and the control current I i3 required by the oil inlet valve 5.2 can be determined by the following formula: i3

[0112]

[0113]

[0114] wherein p is the density of the hydraulic oil, C​d is the flow parameter of the hydraulic oil, ΔP is the pressure compensation value, k i2 , k i3 are the spring stiffness of the oil return valve 6.1 and the oil inlet valve 5.2 on the actuator i (or the arm i) respectively, A iA , A iB are the areas of the rod chamber and the rodless chamber of the boom cylinder on the actuator i (or the arm i) respectively, ΔQ i2 is the control flow fluctuation amplitude of the oil return valve 6.1 of the boom valve on the actuator i (or the arm i), and f(x) is the function between the control current and the spool displacement. ΔQ i4 may be equal to ΔQ i2 .

[0115] For the above formula (8)-(11) in the multi-arm driving working condition, ΔQ i1 is set to 0. Of course, the case where ΔQ i1 is not 0 can refer to the above formula (4)-(7).

[0116] Correspondingly, the control of the boom valve at the target spool opening includes: controlling the oil inlet valve at a first target spool opening, and controlling the oil return valve at a second target spool opening.

[0117] For example, in the case where the oil inlet valve and the oil return valve are electric control valves, the oil inlet valve can be controlled at a first target spool opening by a first control current (or voltage), and the oil return valve can be controlled at a second target spool opening by a second control current (or voltage).

[0118] In addition, in the case where the oil inlet valve and the oil return valve are hydraulic control valves, the oil inlet valve can also be controlled at a first target spool opening by a first control pressure, and the oil return valve can be controlled at a second target spool opening by a second control pressure.

[0119] It is worth noting that the above formula is some examples for the calculation method of the relevant control quantity. In practical application, for the purpose of obtaining the control quantity, the conventional changes made to the formula, such as multiplying some parameters by a correction coefficient, or adding a correction amount, etc., are all within the protection scope of the present application.

[0120] For example, in the case where the oil inlet valve and the oil return valve are electric control valves, the oil inlet valve can be controlled at a first target spool opening by a first control current (or voltage), and the oil return valve can be controlled at a second target spool opening by a second control current (or voltage). Figure 2AAs shown, the arm support valve further comprises a pressure regulating assembly 120, which comprises an electric proportional pressure reducing valve 2.1 and an electric proportional pressure reducing valve 2.4. The electric proportional pressure reducing valve 2.1 is connected to the oil inlet valve 5.1, and the electric proportional pressure reducing valve 2.4 is connected to the oil return valve 6.2. The electric proportional pressure reducing valve 2.1 outputs a corresponding control pressure based on a first control signal (current or voltage), which acts on the oil inlet valve 5.1 to control the opening degree of the oil inlet valve 5.1. The electric proportional pressure reducing valve 2.4 outputs a corresponding control pressure based on a second control signal (current or voltage), which acts on the oil return valve 6.2 to control the opening degree of the oil return valve 6.2.

[0121] Step S103, under the condition that the arm support valve is controlled to be at the target spool opening degree, acquiring a pre-valve and post-valve pressure difference of the arm support valve.

[0122] In the case where the arm support valve comprises an oil inlet valve and an oil return valve, the pre-valve and post-valve pressure difference of the arm support valve is a pre-valve and post-valve pressure difference of the oil inlet valve.

[0123] For example, the pre-valve pressure (i.e. the pressure at the main oil inlet) P Figure 2A of the oil inlet valve (e.g. the first oil inlet valve 5.1 or the second oil inlet valve 5.2) p and the post-valve pressure (i.e. the pressure at the outlet of the first oil inlet oil path) P a of the oil inlet valve p According to the two values, the pre-valve and post-valve pressure difference P a of the oil inlet valve is determined.

[0124] The control strategy proposed in this embodiment controls the output displacement of the variable pump based on the pre-valve and post-valve pressure difference of the arm support valve, which eliminates the influence of the hydraulic pipeline of the traditional load sensing control system on the flow control accuracy, is more adaptable to environmental temperature, has more accurate flow control, and has higher energy utilization rate.

[0125] Step S104, correcting the initial displacement of the hydraulic pump according to the pre-valve and post-valve pressure difference and a set pressure difference, to control the operation of the actuating mechanism.

[0126] For example, taking the oil cylinder as the actuating mechanism, in the actual driving working condition of the working equipment, there may be a single-arm driving working condition or a multi-arm driving working condition.

[0127] In an embodiment, for the single-arm driving working condition, the actuating mechanism is one actuating mechanism and the arm support valve is one arm support valve.

[0128] First, the pre-valve pressure (i.e. the pressure at the main oil inlet) P pand the valve back pressure (i.e. the pressure at the outlet of the first oil inlet oil passage) P of the oil inlet valve a , the valve front valve back pressure difference P of the oil inlet valve is determined according to the two values p -P a , and the difference value Δ = P p -P a -ΔP v , where ΔP v is the set pressure difference, as shown in Figure 3 .

[0129] Then, according to the closed-loop control strategy (for example, PID control) output ΔI according to the difference value Δ, the target control current I is adjusted to I = I - ΔI, and the adjusted I is sent to the hydraulic pump to adjust its output flow, and the adjustment in S13 and S14 is repeated until Δ = 0, that is, the actual difference value is consistent with the expected difference value, at which time the hydraulic pump output flow is the required flow.

[0130] In another embodiment, for multi-arm driving working conditions, the actuator is a plurality of actuators, the boom valve is a plurality of boom valves, and the plurality of actuators correspond to the plurality of boom valves.

[0131] For step S104, the correction of the initial displacement of the hydraulic pump includes: determining the difference between the valve front valve back pressure difference of the oil inlet valve of each boom valve and the set pressure difference; according to each difference value, the following operations are performed: in the case where each difference value is greater than 0, determining the minimum difference value and correcting the initial displacement of the hydraulic pump according to the minimum difference value, or in the case where any difference value is less than or equal to 0, updating the difference value greater than or equal to 0 to 0 and determining the sum of each updated difference value, and correcting the initial displacement of the hydraulic pump according to the determined sum of difference values.

[0132] For single-arm retraction working conditions, the control process of the hydraulic system can include S11-S14. The control current and displacement of the hydraulic pump can be converted according to the current and displacement control curve I = F(Q) determined by the existing method, and in this embodiment, the control current of the hydraulic pump is used instead of the displacement.

[0133] S11, the target spool opening x1 of the oil inlet valve 5.1 and the control current I1 can be determined according to the above formula (4), and the target spool opening x4 of the oil return valve 6.2 and the control current I4 can be determined according to the above formula (5), as shown in Figure 4 .

[0134] S12, the proportional pressure reducing valves 2.1, 2.4 controlled by I1 and I4 output corresponding pressure of hydraulic oil, as shown in Figure 3As shown, the hydraulic oil output from the hydraulic pump is adjusted to a first pressure and a fourth pressure via electro-proportional pressure reducing valves 2.1 and 2.4. Under the action of the first pressure hydraulic oil, the inlet valve 5.1 achieves the target valve core opening degree x1, and under the action of the fourth pressure hydraulic oil, the return valve 6.2 achieves the target valve core opening degree x4. At this time, the single-arm cylinder retracts, performing single-arm arm retraction.

[0135] S13, the inlet pressure P of the oil inlet valve 5.1 is collected by two pressure sensors. p and valve back pressure P a And determine the difference Δ = P p -P a -ΔP v ,like Figure 3 As shown.

[0136] S14, based on the difference Δ, a closed-loop control strategy (e.g., PID control) outputs ΔI to correct the target control current I to I = I - ΔI, and sends the corrected I to the hydraulic pump to adjust its output flow. The adjustments in S13 and S14 are repeated until Δ = 0, meaning the actual difference matches the expected difference. At this point, the hydraulic pump output flow is the required flow. Figure 3 As shown.

[0137] For single-arm extended boom operation, the hydraulic system control process may include S21-S24. The control current and displacement of the hydraulic pump can be converted to each other based on the current and displacement control curve I=F(Q) determined by existing methods. In this embodiment, the control current of the hydraulic pump is used instead of the displacement.

[0138] S21, the target valve core opening x3 and control current I3 of the inlet valve 5.2 can be determined according to the above formula (6), and the target valve core opening x2 and control current I2 of the return valve 6.1 can be determined according to the above formula (7), such as Figure 3 As shown.

[0139] S22, based on I2 and I3, controls the proportional pressure reducing valves 2.2 and 2.3 to output hydraulic oil at corresponding pressures, such as... Figure 3 As shown, the hydraulic oil output from the hydraulic pump is adjusted to a second and a third pressure via electro-proportional pressure reducing valves 2.2 and 2.3. Under the action of the third pressure hydraulic oil, the inlet valve 5.2 achieves the target valve core opening degree x3, and under the action of the second pressure hydraulic oil, the return valve 6.1 achieves the target valve core opening degree x2. At this time, the single-arm cylinder extends, performing the single-arm extension action.

[0140] S23, the inlet pressure P of the oil inlet valve 5.2 is collected by two pressure sensors. p and valve back pressure P b And determine the difference Δ = Pp - P b - ΔP v As shown in Figure 3 .

[0141] S24, according to the difference Δ closed-loop control strategy (for example, PID control) output ΔI, the target control current I is adjusted to I = I-ΔI, and the adjusted I is sent to the hydraulic pump to adjust its output flow, and the adjustment in S23 and S24 is repeated until Δ = 0, that is, the actual difference and the expected difference are consistent, at which time the hydraulic pump output flow is the required flow.

[0142] In single-arm driving working condition, the hydraulic pump only needs to supply oil to the single-arm support driving cylinder, at which time flow distribution is not needed and flow saturation problem does not need to be considered, and its control scheme is as shown in Figure 3 . In multi-arm (composite) driving working condition, the distributed arm support control system based on the hydraulic pump needs to further consider flow distribution and flow saturation problems, and its control scheme is as shown in Figure 4 . The control current of the hydraulic pump and the displacement can be converted according to the current and displacement control curve I = F (Q) determined by the existing method, and in this embodiment, the control current of the hydraulic pump is used instead of the displacement.

[0143] For multi-arm arm-retracting working condition, taking an example of an arm support including 4 arms and 3 arms being driven in combination, the control process of the hydraulic system can include S31-S36.

[0144] S31, based on whether the flow is saturated, it is determined whether to redistribute the flow required by each actuator, as shown in Figure 4 .

[0145] If Q p <Q1+Q2+Q3+ΔQ p , the control current required by the oil inlet valve is determined according to the updated flow required by each actuator; otherwise, the flow required by each actuator is maintained.

[0146] S32, according to the flow required by each actuator, the target valve core opening x i1 and control current I i1 of the oil inlet valve 5.1 corresponding to each actuator can be determined according to the above formula (8), and the target valve core opening x i4 and control current I i4 of the oil return valve 6.2 corresponding to each actuator can be determined according to the above formula (9); and based on the current and displacement control curve I = F (Q) of the hydraulic pump, the target control current I = F (Q1+Q2+Q3) required by the hydraulic pump is determined, as shown in Figure 4 .

[0147] ​S33, for the actuator i (or the arm i) (i = 1, 2, 3), based on I i1 and I i4 , the electric proportional pressure reducing valve 2.1, 2.4 controlling the corresponding actuator i outputs hydraulic oil of corresponding pressure, as shown in Figure 4 , the hydraulic oil output by the hydraulic pump is adjusted to hydraulic oil of first pressure and fourth pressure via the electric proportional pressure reducing valve 2.1, 2.4, under the action of the hydraulic oil of the first pressure, the oil inlet valve 5.1 of the actuator i realizes the target valve core opening x i1 , and under the action of the hydraulic oil of the fourth pressure, the oil return valve 6.2 of the corresponding actuator i realizes the target valve core opening x i4 . At this time, the multi-arm oil cylinder is retracted, and the multi-arm arm retraction action is performed.

[0148] S34, for the actuator i (or the arm i) (i = 1, 2, 3), the pre-valve pressure P ip and the post-valve pressure P ia of the corresponding oil inlet valve 5.1 are collected by the two pressure sensors on the actuator i, and the difference ΔP i = P ip -P ia -ΔP v is determined, as shown in Figure 4 .

[0149] S35, when the pressure differences Δ1, Δ2, Δ3 are all greater than the set pressure difference ΔP v (Δ i = P ip -P ia -ΔP v > 0, i = 1, 2, 3), the minimum difference is taken as the difference Δ = min(Δ1, Δ2, Δ3), the difference Δ is output by the closed-loop control strategy (such as PID control) ΔI, the target control current I is adjusted to I = I-ΔI, and the adjusted I is sent to the hydraulic pump to adjust its output flow, so as to reduce the output flow of the hydraulic pump in real time. Otherwise, the difference is reset: if Δ i ≥ 0, set Δ i to 0; if Δ i < 0, maintain Δ i unchanged and perform the sum calculation Δ = Δ1+Δ2+Δ3, the difference Δ is output by the closed-loop control strategy (such as PID control) ΔI, the target control current I is adjusted to I = I-ΔI, and the adjusted I is sent to the hydraulic pump to adjust its output flow, so as to increase the output flow of the hydraulic pump in real time.

[0150] S36, repeat S34 and S35 until Δ = 0, that is, the actual difference and the expected difference are consistent, at this time the output flow of the hydraulic pump is the required flow.

[0151] For the multi-arm unfolded arm working condition, refer to the multi-arm folded arm and single-arm unfolded arm working conditions, which are not described here.

[0152] The control strategy in the embodiment can be extended to more-arm compound driving working conditions, and only the 3-section arm compound driving working condition is shown here.

[0153] The hydraulic pump in each embodiment of the application can be a variable pump, or a fixed displacement pump and a variable speed motor. The variable pump can be an electrically controlled variable pump, or any variable pump (only needs to have the function of outputting a specified flow signal based on a given signal).

[0154] In summary, the application creatively eliminates the influence of the hydraulic pipeline of the traditional load sensing control system on the flow control accuracy, controls the output displacement of the variable pump based on the control strategy of the pressure difference before and after the arm support valve, eliminates the pipeline influence, is more adaptable to the environmental temperature, is more accurate in flow control, and is higher in energy utilization rate.

[0155] An embodiment of the application provides a control device, which comprises a memory configured to store instructions, and a processor configured to call the instructions from the memory and capable of realizing the control method of the hydraulic system based on the distributed arm support valve when executing the instructions.

[0156] The processor contains a core, and the core calls the corresponding program unit from the memory. The core can be set to one or more, and the problem of difficult effective control of the over-flow of the arm support valve can be solved by adjusting the core parameters.

[0157] The memory can include non-permanent memory in a computer readable medium, random access memory (RAM) and / or non-volatile memory such as read-only memory (ROM) or flash memory (flash RAM), and the memory includes at least one memory chip.

[0158] Figure 5 is a structural schematic diagram of a working equipment provided by an embodiment of the application. As shown in Figure 5 the working equipment comprises an execution mechanism 300, a hydraulic pump 10, an arm support valve 100 mounted on an arm support, and the control device 200.

[0159] The working equipment can be a concrete pump truck, a crane, an aerial work machine, a high-lift jet fire fighting truck, and other engineering machinery, can also be an agricultural machine with an arm support, or a working robot with an arm support, and is not limited here.

[0160] The control device comprises a memory configured to store instructions, and a processor configured to call the instructions from the memory and implement the control method of the distributed boom valve-based hydraulic system when executing the instructions.

[0161] In an embodiment, the working device can further comprise an electric proportional relief valve 11 for controlling the maximum working pressure of the main oil inlet, as shown in the figure. Figure 2A

[0162] The maximum working pressure of the main oil inlet P can be defined based on the current control instruction, and the excess oil is output to the main oil return port T to ensure the safety of the hydraulic system.

[0163] The control strategy of the variable displacement pump output displacement based on the pressure difference control of the inlet and outlet of the multi-way valve assembly adopted by various embodiments of the present application is based on electronic load sensing control, has faster response, stronger system adaptability, and more accurate flow control.

[0164] The embodiment provides a machine readable storage medium, and the machine readable storage medium stores a computer program.

[0165] Those skilled in the art should understand that the embodiments of the present application can be provided as a method, a system or a computer program product. Therefore, the present application can adopt a completely hardware embodiment, a completely software embodiment, or an embodiment combining software and hardware aspects. Moreover, the present application can adopt a computer program product in the form of one or more computer usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer usable program codes.

[0166] The present application is described with reference to flowcharts and / or block diagrams of methods, devices (systems), computer program products according to embodiments of the present application. It should be understood that each flow and / or block in the flowcharts and / or block diagrams, and the combination of the flows and / or blocks in the flowcharts 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, a special-purpose computer, an embedded processor, or other programmable data processing devices to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing devices produce a device that implements the functions specified in the flowcharts and / or block diagrams. Figure 1 The functions specified in one flow or multiple flows and / or blocks Figure 1 The functions specified in one flow or multiple flows and / or blocks

[0167] ​These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the Figure 1 function specified in the flow or flows and / or blocks Figure 1 of the block or blocks.

[0168] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions that are executed on the computer or other programmable apparatus provide steps for implementing the Figure 1 function specified in the flow or flows and / or blocks Figure 1 of the block or blocks.

[0169] In a typical configuration, a computing device includes one or more processors (CPUs), input / output interfaces, network interfaces, and memory.

[0170] The memory can include non-persistent memory and / or volatile memory, e.g., random access memory (RAM) and / or non-volatile memory, e.g., read-only memory (ROM) or flash memory. The memory is an example of computer readable media.

[0171] Computer readable media includes permanent and non-permanent, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile discs (DVDs) or other optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information accessible to a computing device. According to the definition herein, computer readable media does not include transitory media, such as modulated data signals and carrier waves.

[0172] It is also to be noted that the terms "comprising", "including", and any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises a... " does not, without more constraints, exclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0173] The above embodiments are only used to illustrate the present application, but not to limit it. Instead of the above, various modifications and changes can be made to the application by those skilled in the art. Any modification, equivalent replacement, improvement, and the like made within the spirit and principle of the application shall fall into the scope of claims of the application.

Claims

1. A control method for a hydraulic system based on a distributed boom valve, characterized in that, The hydraulic system comprises an actuator, a hydraulic pump and a boom valve mounted on a boom, and the control method comprises: obtaining an instruction signal for the actuator; determining an initial displacement of the hydraulic pump and a target spool opening of the boom valve according to the instruction signal; obtaining a pre-valve pressure difference and a post-valve pressure difference of the boom valve while controlling the boom valve to be at the target spool opening; and correcting the initial displacement of the hydraulic pump according to the pre-valve pressure difference and the post-valve pressure difference and a set pressure difference to control the operation of the actuator, wherein the boom valve comprises an oil inlet valve connected to an oil inlet of the actuator and an oil return valve connected to an oil return of the actuator, determining the target spool opening of the boom valve according to the instruction signal comprises determining a first target spool opening of the oil inlet valve and a second target spool opening of the oil return valve according to the instruction signal, controlling the boom valve to be at the target spool opening comprises controlling the oil inlet valve to be at the first target spool opening and controlling the oil return valve to be at the second target spool opening, wherein determining the first target spool opening of the oil inlet valve and the second target spool opening of the oil return valve according to the instruction signal comprises: determining a target oil inlet flow corresponding to the oil inlet valve according to the instruction signal; obtaining a first flow fluctuation amplitude and a second flow fluctuation amplitude, wherein the first flow fluctuation amplitude is an actual flow fluctuation amplitude of the oil inlet valve and the second flow fluctuation amplitude is an actual flow fluctuation amplitude of the oil return valve; determining a target oil return flow of the oil return valve according to the target oil inlet flow, the first flow fluctuation amplitude and the second flow fluctuation amplitude; and determining the first target spool opening of the oil inlet valve according to the target oil inlet flow and determining the second target spool opening of the oil return valve according to the target oil return flow.

2. The control method according to claim 1, characterized by, determining the target spool opening of the boom valve according to the instruction signal comprises: in a case where the boom valve is provided with a pressure compensation valve, determining the target spool opening of the boom valve according to a flow corresponding to the instruction signal and a pressure compensation value.

3. The control method according to claim 1, characterized by, The pre-valve pressure difference and the post-valve pressure difference of the boom valve are pre-valve pressure differences and post-valve pressure differences of the oil inlet valve.

4. The control method according to claim 1, characterized by, In a case where the actuator is a plurality of actuators, the control method further comprises: allocating a flow corresponding to each of the instruction signals according to the flow corresponding to each of the instruction signals, a preset adjustment amount and a maximum displacement of the hydraulic pump.

5. The control method according to claim 4, characterized by The allocation of the flow corresponding to each of the instruction signals comprises: determining a required flow of the plurality of actuators according to the flow corresponding to each of the instruction signals and the preset adjustment amount; and in a case where the required flow of the plurality of actuators is greater than the maximum displacement, multiplying the flow corresponding to each of the instruction signals by a preset proportion, wherein the preset proportion is less than 1.

6. The control method according to any one of claims 1 to 5, characterized by, The hydraulic system comprises a plurality of the actuators and a plurality of arm frame valves corresponding to the plurality of the actuators, and the correcting the initial displacement of the hydraulic pump comprises: determining a difference between a pre-valve and post-valve pressure difference of an oil inlet valve of each arm frame valve and the set pressure difference; according to each difference, performing the following operations: and in a case where each difference is greater than 0, determining a minimum difference and correcting the initial displacement of the hydraulic pump according to the minimum difference, or in a case where any difference is less than or equal to 0, updating the difference greater than or equal to 0 to 0 and determining a sum of each updated difference, and correcting the initial displacement of the hydraulic pump according to the determined sum of the differences.

7. A control device characterized by comprising: comprise: a memory configured to store instructions; and a processor configured to call the instructions from the memory and capable of implementing the control method of the distributed arm frame valve-based hydraulic system according to any one of claims 1-6 when executing the instructions.

8. A work apparatus characterized by comprising: The working device comprises: an actuator; a hydraulic pump; an arm frame valve installed on an arm frame; and the control device according to claim 7.

9. A machine-readable storage medium, characterized in that, The machine readable storage medium has stored thereon a computer program, and the computer program is executed by the processor to implement the control method of the distributed arm frame valve-based hydraulic system according to any one of claims 1-6.

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