An electro-hydrostatic drive work system energy efficiency optimization method and system

Abstract

The application provides an electro-hydrostatic drive operation system energy efficiency optimization method and system, and the core scheme comprises receiving and processing the expected displacement length of a hydraulic cylinder piston, performing grid division; the initial displacement is reversely calculated from the terminal displacement, the optimal hydraulic pump motor output flow and displacement of the system energy consumption per unit displacement are determined; based on these optimal parameters, the corresponding optimal motor speed and hydraulic cylinder speed are calculated; according to the calculation result, the control signal is output, and the system is ensured to run according to the optimal trajectory. The method optimizes the energy efficiency by comprehensively considering the system parameters and load conditions, and adopts a dynamic programming algorithm to realize the optimization of energy efficiency, thereby significantly reducing the energy consumption. At the same time, the solving speed is improved through algorithm reduction, and the response ability of the system is enhanced. In addition, the optimal control curve is drawn and the control signal is output, so that the system is ensured to run in an optimized manner in each stage, and the energy efficiency is further improved.

Description

Technical Field

[0001] This application relates to the field of engineering machinery technology, and in particular to a method and system for optimizing the energy efficiency of an electro-hydraulic drive system. Background Technology

[0002] Energy efficiency of hydraulic operating systems is a crucial factor influencing the electrification of construction machinery. Currently, the hydraulic operating systems of electrified construction machinery are largely consistent with diesel-powered models, typically driven by an independent motor and mechanically decoupled from the travel system. The hydraulic control circuit employs centralized throttling control technology. Compared to diesel-powered models, the energy efficiency advantage of electrified wheel loaders primarily stems from the high-efficiency output of the electric motor. However, the hydraulic operating system still suffers from significant throttling losses and difficulties in energy recovery, limiting the machine's overall energy efficiency and operating time.

[0003] Distributed electro-hydraulic driven hydraulic operating systems eliminate the throttle control valve, enabling independent variable speed control of the motor and energy recovery, thus improving energy efficiency. Furthermore, some studies have explored further improvements in energy efficiency by optimizing motor speed and hydraulic pump displacement. However, existing operating parameter optimizations only address standard or typical operating conditions. In actual use, operating conditions are influenced by terrain, usage habits, and scenarios, and cannot fully represent real-world usage, leading to discrepancies between optimized parameters and actual performance. Therefore, a combined optimization approach integrating operating parameters and operating conditions is needed to achieve optimal energy efficiency. Summary of the Invention

[0004] The purpose of this application is to provide a method and system for optimizing the energy efficiency of an electrostatic hydraulic drive system, which can improve the above-mentioned problems.

[0005] The embodiments of this application are implemented as follows:

[0006] Firstly, this application provides a method for optimizing the energy efficiency of an electro-hydraulic driven operating system. The method optimizes the energy efficiency of the electro-hydraulic driven operating system, which includes a motor controller, a servo motor, a hydraulic pump motor, a hydraulic cylinder, a first solenoid valve, and a second solenoid valve. The motor controller controls the output speed of the servo motor, which drives the hydraulic pump motor. The first port of the hydraulic pump motor is connected to the rod chamber of the hydraulic cylinder via the first solenoid valve, and the second port of the hydraulic pump motor is connected to the rodless chamber of the hydraulic cylinder via the second solenoid valve. The method includes steps S1 to S4, where S1, S2, etc., are merely step identifiers. The execution order of the method does not necessarily follow an ascending numerical order; for example, step S2 may be executed first, followed by step S1. This application does not impose any restrictions.

[0007] S1, Receive the desired displacement length for the piston in the hydraulic cylinder, calculate the end displacement of the piston based on the desired displacement length, divide the desired displacement length into a grid to obtain each unit displacement;

[0008] S2, starting from the terminal displacement until the initial displacement of the piston, calculate the optimal hydraulic pump motor output flow rate and optimal hydraulic pump motor displacement with the lowest system energy consumption under different load requirements for each unit displacement.

[0009] S3, calculate the optimal motor speed and optimal hydraulic cylinder speed corresponding to each unit displacement based on the optimal hydraulic pump motor output flow rate and the optimal hydraulic pump motor displacement;

[0010] S4, output a control signal to the hydraulic pump motor according to the optimal hydraulic pump motor output flow and the optimal hydraulic pump motor displacement, and output a control signal to the motor controller according to the optimal motor speed, so that the hydraulic cylinder runs at the optimal hydraulic cylinder speed in each of the unit displacement stages.

[0011] This application provides an energy efficiency optimization method for an electro-hydraulic driven operating system, specifically a method for optimizing the combination of operating parameters and working conditions of the system. First, starting from the overall system operating parameters and load conditions, this method uses a dynamic programming algorithm to accurately calculate the optimal motor speed, hydraulic pump motor displacement, and hydraulic cylinder speed trajectory, maximizing the energy efficiency of the operating system, effectively reducing energy waste, and improving the system's economy and environmental friendliness. Second, this method innovatively uses the mapping relationship between hydraulic pump motor flow rate, pressure difference, and optimal displacement as an optimization reference, reducing the order of the multi-state variable dynamic programming algorithm. This not only simplifies the complexity of the optimization algorithm but also significantly improves the algorithm's solution speed, enabling the system to adapt to different working condition changes more quickly, thus improving the system's response speed and flexibility. Furthermore, by plotting the optimal control curve and outputting the corresponding control signal, this method ensures that the hydraulic cylinder operates at the optimal speed in each unit displacement stage, avoiding unnecessary energy loss and further improving the system's energy efficiency.

[0012] In an optional embodiment of this application, step S2 includes steps S21 to S22.

[0013] S21, Based on the efficiency spectrum of the electric motor pump, determine the mapping relationship between the hydraulic pump motor output flow, the pressure difference before and after the pump, and the hydraulic pump motor displacement to minimize the energy consumption of the electric motor pump.

[0014] S22, using the mapping relationship, starting from the terminal displacement to the initial displacement of the piston, determine the optimal hydraulic pump motor output flow rate and the optimal hydraulic pump motor displacement when the system energy consumption is lowest for each unit displacement.

[0015] It is understandable that by precisely determining the optimal parameter combination of the motor pump under various operating conditions (hydraulic pump motor output flow, pressure difference, and displacement), the system energy consumption is significantly reduced. This step, which calculates backward from the terminal displacement to the initial displacement, ensures that the system operates with the lowest energy consumption throughout the entire working process. This not only improves energy efficiency but also enhances the system's economy and environmental friendliness, providing important support for the optimized operation of electro-hydraulic drive systems.

[0016] In an optional embodiment of this application, step S21 includes steps S211 to S214.

[0017] S211, divide the hydraulic pump motor output flow grid, front and rear pressure difference grid and hydraulic pump motor displacement grid corresponding to each unit displacement.

[0018] S212, traverse the hydraulic pump motor output flow grid, the front and rear pressure difference grid, and the hydraulic pump motor displacement grid, and calculate the possible values ​​of motor pump energy consumption corresponding to each unit displacement based on the motor pump efficiency spectrum.

[0019] S213, select the lowest possible value of motor pump energy consumption corresponding to each unit displacement as the optimal motor pump energy consumption value.

[0020] S214, determine the mapping relationship between the hydraulic pump motor output flow rate, the pressure difference before and after, and the hydraulic pump motor displacement corresponding to the optimal motor pump energy consumption value.

[0021] In an optional embodiment of this application, step S22 includes the following steps S221 to S223:

[0022] S221, determine the system energy consumption corresponding to each unit displacement according to the following formula: ; Representing the The motor input power of the servo motor at each unit displacement is calculated as follows: ; Representing the The rotational speed of the servo motor at each unit displacement is calculated as follows: ,in, This represents the effective area of ​​the rodless chamber in the hydraulic cylinder. Representing the The displacement velocity of the piston in the hydraulic cylinder at the unit displacement is calculated as follows: , Representing the The hydraulic pump motor output flow rate at the unit displacement is described. Representing the The displacement of the hydraulic pump motor at the unit displacement mentioned above. This represents the volumetric efficiency of the hydraulic pump motor. Representing the The torque of the servo motor at each unit displacement is calculated as follows: ,in, Representing the The pressure difference before and after at the unit displacement mentioned above This represents the mechanical efficiency of the hydraulic pump motor. This represents the motor efficiency of the servo motor. Representing the The unit displacement mentioned above Representing the The displacement velocity of the piston in the hydraulic cylinder at the unit displacement is calculated as follows: , Representing the The hydraulic pump motor output flow rate at the unit displacement;

[0023] S222, utilizing the mapping relationship between the hydraulic pump motor output flow rate and the pressure difference before and after, starting from the terminal displacement until the initial displacement of the piston, the optimal hydraulic pump motor output flow rate at which the system energy consumption is lowest for each unit displacement is determined according to the following formula: ;

[0024] S223, using the mapping relationship between the output flow rate of the hydraulic pump motor and the displacement of the hydraulic pump motor, calculate the optimal hydraulic pump motor displacement when the system energy consumption is lowest for each unit displacement.

[0025] In an optional embodiment of this application, step S3 includes steps S31 to S32.

[0026] S31, Calculate the optimal hydraulic cylinder speed corresponding to each unit displacement based on the output flow rate of the optimal hydraulic pump motor.

[0027] S32, Calculate the optimal motor speed corresponding to each unit displacement based on the optimal hydraulic pump motor output flow rate and the optimal hydraulic pump motor displacement.

[0028] In an optional embodiment of this application, step S31 includes: calculating the optimal hydraulic cylinder speed corresponding to each unit displacement according to the following formula: ; Representing the The optimal hydraulic cylinder speed at the unit displacement. Representing the The optimal hydraulic pump motor output flow rate at the unit displacement is given. This represents the effective area of ​​the rodless chamber in the hydraulic cylinder.

[0029] In an optional embodiment of this application, step S32 includes: calculating the optimal motor speed corresponding to each unit displacement according to the following formula: ,

[0030] in, No. The optimal motor speed at each unit displacement; Representing the The optimal hydraulic pump motor displacement at the unit displacement is given. This represents the volumetric efficiency of the hydraulic pump motor.

[0031] In an optional embodiment of this application, step S4 includes steps S41 to S42.

[0032] S41, plot the optimal hydraulic pump motor displacement curve and the optimal hydraulic pump motor output flow curve along the piston displacement, plot the optimal motor speed curve along the piston displacement, and plot the optimal hydraulic cylinder speed curve along the piston displacement.

[0033] S42, output control signals to the hydraulic pump motor according to the optimal hydraulic pump motor displacement curve and the optimal hydraulic pump motor output flow curve, and output control signals to the motor controller according to the optimal motor speed curve, so that the hydraulic cylinder runs according to the optimal hydraulic cylinder speed curve.

[0034] In a second aspect, this application discloses an energy efficiency optimization system for an electro-hydraulic driven operating system, comprising an electro-hydraulic driven operating system and an optimization system, wherein the optimization system is used to perform the method as described in any of the first aspects;

[0035] The electro-hydraulic drive system includes a motor controller, a servo motor, a hydraulic pump motor, a hydraulic cylinder, a first solenoid valve, and a second solenoid valve. The motor controller controls the output speed of the servo motor, the servo motor drives the hydraulic pump motor, the first port of the hydraulic pump motor is connected to the rod chamber of the hydraulic cylinder through the first solenoid valve, and the second port of the hydraulic pump motor is connected to the rodless chamber of the hydraulic cylinder through the second solenoid valve.

[0036] The optimization system includes a combined optimization unit and a motion controller. The combined optimization unit is used to execute steps S1-S3 and output a control signal to the hydraulic pump motor according to the optimal hydraulic pump motor output flow rate and the optimal hydraulic pump motor displacement. The motion controller is used to output a control signal to the motor controller according to the optimal motor speed.

[0037] It is understood that the energy efficiency optimization system for electro-hydraulic driven operating systems provided in this application has significant beneficial effects. First, the system accurately calculates the optimal motor speed, hydraulic pump motor displacement, and hydraulic cylinder speed trajectory using a dynamic programming algorithm, maximizing the energy efficiency of the operating system, effectively reducing energy waste, and improving the system's economy and environmental friendliness. Second, it innovatively uses the mapping relationship between hydraulic pump motor flow rate, pressure difference, and optimal displacement as an optimization reference, simplifying the complexity of the optimization algorithm, increasing the solution speed, and enabling the system to adapt to changes in operating conditions more quickly, thus improving response speed and flexibility. Furthermore, by plotting the optimal control curve and outputting control signals, it ensures that the hydraulic cylinder operates at the optimal speed in each stage, avoiding unnecessary energy loss and further improving the system's energy efficiency.

[0038] In an optional embodiment of this application, the electro-hydraulic drive system further includes a first safety valve, a second safety valve, a low-pressure accumulator, a first hydraulically controlled check valve, a second hydraulically controlled check valve, a third safety valve, and a fourth safety valve. The inlet of the first hydraulically controlled check valve is connected to the port where the first solenoid valve communicates with the rod chamber, the outlet of the first hydraulically controlled check valve is connected to the outlet of the second hydraulically controlled check valve, the inlet of the second hydraulically controlled check valve is connected to the port where the second solenoid valve communicates with the rodless chamber, the low-pressure accumulator is connected between the first hydraulically controlled check valve and the second hydraulically controlled check valve, and the low-pressure accumulator replenishes hydraulic oil to the first port through the first hydraulically controlled check valve. The first safety valve is used to limit the maximum pressure between the first port and the first solenoid valve, the second safety valve is used to limit the maximum pressure between the second port and the second solenoid valve, the third safety valve is used to limit the maximum pressure between the first solenoid valve and the rod chamber, and the fourth safety valve is used to limit the maximum pressure between the second solenoid valve and the rodless chamber.

[0039] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, optional embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description

[0040] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0041] Figure 1 This is a flowchart illustrating an electro-hydraulic driven operating system and its energy efficiency optimization method provided in this application;

[0042] Figure 2 This is a schematic diagram of the structure of an electro-hydraulic driven operating system and its energy efficiency optimization system provided in this application. Detailed Implementation

[0043] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0044] Firstly, this application provides a method for optimizing the energy efficiency of an electrostatic hydraulic drive system, used to optimize the energy efficiency of the electrostatic hydraulic drive system. For example... Figure 2 As shown, the electro-hydraulic drive system includes a motor controller 3, a servo motor 4, a hydraulic pump motor 5, a hydraulic cylinder 15, a first solenoid valve 8, and a second solenoid valve 9. The motor controller 3 is used to control the output speed of the servo motor 4, and the servo motor 4 is used to drive the hydraulic pump motor 5. The first oil port of the hydraulic pump motor 5 is connected to the rod chamber of the hydraulic cylinder 15 through the first solenoid valve 8, and the second oil port of the hydraulic pump motor 5 is connected to the rodless chamber of the hydraulic cylinder 15 through the second solenoid valve 9.

[0045] like Figure 1 As shown, the method includes steps S1 to S4, where S1, S2, etc. are only step identifiers. The execution order of the method does not necessarily follow the numerical order from smallest to largest. For example, step S2 can be executed first and then step S1 can be executed. This application does not impose any restrictions.

[0046] S1 receives the desired displacement length of the piston in the hydraulic cylinder, calculates the end displacement of the piston based on the desired displacement length, divides the desired displacement length into a grid, and obtains the individual unit displacements.

[0047] S2, starting from the terminal displacement until the initial displacement of the piston, calculates the optimal hydraulic pump motor output flow rate and optimal hydraulic pump motor displacement with the lowest system energy consumption under different load requirements for each unit displacement.

[0048] S3, based on the optimal hydraulic pump motor output flow rate and the optimal hydraulic pump motor displacement, calculate the optimal motor speed and the optimal hydraulic cylinder speed corresponding to each unit displacement.

[0049] S4 outputs a control signal to the hydraulic pump motor 5 based on the optimal hydraulic pump motor output flow and the optimal hydraulic pump motor displacement, and outputs a control signal to the motor controller 3 based on the optimal motor speed, so that the hydraulic cylinder 15 runs at the optimal hydraulic cylinder speed in each unit displacement stage.

[0050] This application provides an energy efficiency optimization method for an electro-hydraulic driven operating system, specifically a method for optimizing the combination of operating parameters and working conditions of the system. First, starting from the overall system operating parameters and load conditions, this method uses a dynamic programming algorithm to accurately calculate the optimal motor speed, hydraulic pump motor displacement, and hydraulic cylinder 15 speed trajectory, maximizing the energy efficiency of the operating system, effectively reducing energy waste, and improving the system's economy and environmental friendliness. Second, this method innovatively uses the mapping relationship between the hydraulic pump motor 5's flow rate, pressure difference, and optimal displacement as an optimization reference, reducing the order of the multi-state variable dynamic programming algorithm. This not only simplifies the complexity of the optimization algorithm but also significantly improves the algorithm's solution speed, enabling the system to adapt to different working condition changes more quickly, thus improving the system's response speed and flexibility. Furthermore, by plotting the optimal control curve and outputting the corresponding control signal, this method ensures that the hydraulic cylinder 15 operates at the optimal speed in each unit displacement stage, avoiding unnecessary energy loss and further improving the system's energy efficiency.

[0051] In an optional embodiment of this application, S2 includes the steps S21 to S22.

[0052] S21, Based on the efficiency spectrum of the electric motor pump, determine the mapping relationship between the hydraulic pump motor output flow, the pressure difference before and after the pump, and the hydraulic pump motor displacement to minimize the energy consumption of the electric motor pump.

[0053] In step S21, "motor-pump" refers to the combination of an electric motor and a hydraulic pump motor, which work together to convert electrical energy into hydraulic energy. The "motor-pump efficiency graph" is a chart showing the energy conversion efficiency of the motor-pump combination under different operating conditions (such as different output flow rates, pressure differentials, and displacements). By analyzing this graph, it is possible to determine under what operating parameters the energy consumption of the motor-pump is minimized, i.e., to find the optimal mapping relationship between the hydraulic pump motor output flow rate, pressure differential, and displacement. "Pressure differential" refers to the pressure difference between the first and second ports of the hydraulic pump motor, i.e., the pressure difference between the inlet and outlet of the hydraulic pump motor due to the flow of hydraulic oil during operation. This parameter has a significant impact on system energy consumption and efficiency. This step is crucial for optimizing the energy efficiency of the electro-hydraulic drive system because it provides the basic data for subsequent calculations, ensuring that the system operates with the lowest energy consumption at each unit displacement.

[0054] S22, using the mapping relationship, starting from the terminal displacement to the initial displacement of the piston, determine the optimal hydraulic pump motor output flow rate and the optimal hydraulic pump motor displacement when the system energy consumption is lowest for each unit displacement.

[0055] In step S22, using the mapping relationship obtained in step S21, the optimal hydraulic pump motor output flow rate and displacement are calculated backward from the terminal displacement to the initial displacement, determining the minimum system energy consumption for each unit displacement. This step, by applying the optimal mapping relationship to each displacement stage of the system, ensures that the system operates with the lowest energy consumption throughout the entire operation, thereby maximizing energy efficiency.

[0056] It is understandable that by precisely determining the optimal parameter combination of the motor pump under various operating conditions (hydraulic pump motor output flow, pressure difference, and displacement), the system energy consumption is significantly reduced. This step, which calculates backward from the terminal displacement to the initial displacement, ensures that the system operates with the lowest energy consumption throughout the entire working process. This not only improves energy efficiency but also enhances the system's economy and environmental friendliness, providing important support for the optimized operation of electro-hydraulic drive systems.

[0057] In an optional embodiment of this application, S21 includes the steps S211 to S214.

[0058] S211, divide the hydraulic pump motor output flow grid, front and rear pressure difference grid, and hydraulic pump motor displacement grid corresponding to each unit displacement.

[0059] S212, traverse the hydraulic pump motor output flow grid, the front and rear pressure difference grid, and the hydraulic pump motor displacement grid, and calculate the possible values ​​of motor pump energy consumption corresponding to each unit displacement based on the motor pump efficiency spectrum.

[0060] S213, select the lowest possible value of motor pump energy consumption corresponding to each unit displacement, as the optimal motor pump energy consumption value.

[0061] S214, determine the mapping relationship between the hydraulic pump motor output flow, the pressure difference before and after, and the hydraulic pump motor displacement corresponding to the optimal motor pump energy consumption value.

[0062] In an optional embodiment of this application, S22 includes the following steps S221 to S223:

[0063] S221, determine the system energy consumption corresponding to each unit displacement according to the following formula: ; Representing the The motor input power of servo motor 4 at a unit displacement is calculated as follows: ; Representing the The speed of servo motor 4 at a unit displacement is calculated as follows: ,in, This represents the effective area of ​​the rodless chamber in hydraulic cylinder 15. Representing the The displacement velocity of the piston in hydraulic cylinder 15 at a unit displacement is calculated as follows: , Representing the The hydraulic pump motor output flow rate at a unit displacement is [missing information]. Representing the Hydraulic pump motor displacement per unit displacement This represents the volumetric efficiency of hydraulic pump motor 5; Representing the The torque of servo motor 4 at a unit displacement is calculated as follows: ,in, Representing the Pressure difference at a unit displacement Table 5 shows the mechanical efficiency of the hydraulic pump motor 5; This represents the motor efficiency of servo motor 4. Representing the Unit displacement, Representing the The displacement velocity of the piston in hydraulic cylinder 15 at a unit displacement is calculated as follows: , Representing the The hydraulic pump motor output flow rate at a unit displacement;

[0064] S222, utilizing the mapping relationship between the hydraulic pump motor output flow and the pressure difference across the system, starting from the final displacement to the initial displacement of the piston, the optimal hydraulic pump motor output flow that minimizes system energy consumption for each unit displacement is determined according to the following formula: ;

[0065] S223 utilizes the mapping relationship between the hydraulic pump motor output flow rate and the hydraulic pump motor displacement to calculate the optimal hydraulic pump motor displacement at which the system energy consumption is lowest for each unit displacement.

[0066] In an optional embodiment of this application, S3 includes steps S31 to S32.

[0067] S31, calculate the optimal hydraulic cylinder speed corresponding to each unit displacement based on the optimal hydraulic pump motor output flow rate.

[0068] S31 includes: calculating the optimal hydraulic cylinder speed corresponding to each unit displacement according to the following formula: ; Representing the The optimal hydraulic cylinder speed at a unit displacement. Representing the The optimal hydraulic pump motor output flow rate at a unit displacement. This represents the effective area of ​​the rodless chamber in hydraulic cylinder 15.

[0069] S32, calculate the optimal motor speed corresponding to each unit displacement based on the optimal hydraulic pump motor output flow rate and the optimal hydraulic pump motor displacement.

[0070] S32 includes: calculating the optimal motor speed corresponding to each unit displacement according to the following formula: ,

[0071] in, No. The optimal motor speed at a unit displacement; Representing the The optimal hydraulic pump motor displacement at a unit displacement. This represents the volumetric efficiency of hydraulic pump motor 5.

[0072] In an optional embodiment of this application, S4 includes the steps S41 to S42.

[0073] S41, plot the optimal hydraulic pump motor displacement curve and the optimal hydraulic pump motor output flow curve along the piston displacement, plot the optimal motor speed curve along the piston displacement, and plot the optimal hydraulic cylinder speed curve along the piston displacement.

[0074] S42 outputs control signals to the hydraulic pump motor 5 according to the optimal hydraulic pump motor displacement curve and the optimal hydraulic pump motor output flow curve, and outputs control signals to the motor controller 3 according to the optimal motor speed curve, so that the hydraulic cylinder 15 runs according to the optimal hydraulic cylinder speed curve.

[0075] Secondly, such as Figure 2 As shown, this application discloses an energy efficiency optimization system for an electro-hydraulic driven operating system, including an electro-hydraulic driven operating system 100 and an optimization system 200, wherein the optimization system is used to perform the method as described in any of the first aspects.

[0076] The electro-hydraulic drive system includes a motor controller 3, a servo motor 4, a hydraulic pump motor 5, a hydraulic cylinder 15, a first solenoid valve 8, and a second solenoid valve 9. The motor controller 3 is used to control the output speed of the servo motor 4, and the servo motor 4 is used to drive the hydraulic pump motor 5. The first oil port of the hydraulic pump motor 5 is connected to the rod chamber of the hydraulic cylinder 15 through the first solenoid valve 8, and the second oil port of the hydraulic pump motor 5 is connected to the rodless chamber of the hydraulic cylinder 15 through the second solenoid valve 9.

[0077] like Figure 2 As shown, the optimization system 200 includes a combined optimization unit 1 and a motion controller 2. The combined optimization unit 1 is used to execute steps S1-S3 and output control signals to the hydraulic pump motor 5 according to the optimal hydraulic pump motor output flow and the optimal hydraulic pump motor displacement. The motion controller 2 is used to execute the output control signal to the motor controller 3 according to the optimal motor speed.

[0078] It is understood that the energy efficiency optimization system for the electro-hydraulic drive operating system provided in this application has significant beneficial effects. First, the system accurately calculates the optimal motor speed, hydraulic pump motor displacement, and hydraulic cylinder 15 speed trajectory using a dynamic programming algorithm, maximizing the energy efficiency of the operating system, effectively reducing energy waste, and improving the system's economy and environmental friendliness. Second, it innovatively uses the mapping relationship between the hydraulic pump motor 5's flow rate, pressure difference, and optimal displacement as an optimization reference, simplifying the complexity of the optimization algorithm, increasing the solution speed, enabling the system to adapt to changes in operating conditions more quickly, and improving response speed and flexibility. Furthermore, by plotting the optimal control curve and outputting control signals, it ensures that the hydraulic cylinder 15 operates at the optimal speed in each stage, avoiding unnecessary energy loss and further improving the system's energy efficiency.

[0079] In optional embodiments of this application, reference continues to be made to... Figure 2The electro-hydraulic drive system also includes a first safety valve 6, a second safety valve 7, a low-pressure accumulator 10, a first hydraulically controlled check valve 11, a second hydraulically controlled check valve 12, a third safety valve 13, and a fourth safety valve 14. The inlet of the first hydraulically controlled check valve 11 is connected to the port of the first solenoid valve 8 that connects to the rod chamber. The outlet of the first hydraulically controlled check valve 11 is connected to the outlet of the second hydraulically controlled check valve 12. The inlet of the second hydraulically controlled check valve 12 is connected to the port of the second solenoid valve 9 that connects to the rodless chamber. The low-pressure accumulator 10 is connected between the first hydraulically controlled check valve 11 and the second hydraulically controlled check valve 12. The low-pressure accumulator 10 replenishes hydraulic oil to the first port through the first hydraulically controlled check valve 11. The first safety valve 6 is used to limit the maximum pressure between the first port and the first solenoid valve 8. The second safety valve 7 is used to limit the maximum pressure between the second port and the second solenoid valve 9. The third safety valve 13 is used to limit the maximum pressure between the first solenoid valve 8 and the rod chamber. The fourth safety valve 14 is used to limit the maximum pressure between the second solenoid valve 9 and the rodless chamber.

[0080] The terms "first," "second," "first," or "second" as used in the various embodiments of this disclosure may modify various components regardless of their order and / or importance, but these terms do not limit the corresponding components. The above terms are configured only for the purpose of distinguishing an element from other elements. For example, "first user equipment" and "second user equipment" refer to different user equipments, although both are user equipment. For example, without departing from the scope of this disclosure, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.

[0081] When a component (e.g., a first component) is referred to as being "(operably or communicatively) coupled" or "(operably or communicatively) coupled to" or "connected to" another component (e.g., a second component), it should be understood that the first component is directly connected to the second component or that the first component is indirectly connected to the second component via yet another component (e.g., a third component). Conversely, it can be understood that when a component (e.g., a first component) is referred to as being "directly connected" or "directly coupled" to another component (the second component), no component (e.g., a third component) is inserted between the two.

[0082] It should be noted that, in this document, 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 a process, method, article, or apparatus. Without further limitations, 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. Furthermore, components, features, and elements with the same names in different embodiments of this application may have the same meaning or different meanings, the specific meaning of which must be determined by its interpretation in that specific embodiment or further in conjunction with the context of that specific embodiment.

[0083] The above description is merely an optional embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in this application.

[0084] Depending on the context, the words “if” or “suppose” as used here can be interpreted as “when” or “in response to determination” or “in response to detection.” Similarly, depending on the context, the phrases “if determination” or “if detection (of the stated condition or event)” can be interpreted as “when determination” or “in response to determination” or “when detection (of the stated condition or event)” or “in response to detection (of the stated condition or event).”

[0085] The above description is merely an optional embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in this application.

[0086] The above description is merely an optional embodiment of this application and is not intended to limit 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 protection scope of this application.

Claims

1. A method for optimizing the energy efficiency of an electro-hydraulic driven operating system, the electro-hydraulic driven operating system comprising a motor controller, a servo motor, a hydraulic pump motor, a hydraulic cylinder, a first solenoid valve, and a second solenoid valve; the motor controller is used to control the output speed of the servo motor, the servo motor is used to drive the hydraulic pump motor, the first oil port of the hydraulic pump motor is connected to the rod chamber of the hydraulic cylinder through the first solenoid valve, and the second oil port of the hydraulic pump motor is connected to the rodless chamber of the hydraulic cylinder through the second solenoid valve, characterized in that... Includes the following steps: S1, Receive the desired displacement length for the piston in the hydraulic cylinder, calculate the end displacement of the piston based on the desired displacement length, divide the desired displacement length into a grid to obtain each unit displacement; S2, starting from the terminal displacement until the initial displacement of the piston, calculate the optimal hydraulic pump motor output flow rate and optimal hydraulic pump motor displacement with the lowest system energy consumption under different load requirements for each unit displacement. S3, calculate the optimal motor speed and optimal hydraulic cylinder speed corresponding to each unit displacement based on the optimal hydraulic pump motor output flow rate and the optimal hydraulic pump motor displacement; S4, output a control signal to the hydraulic pump motor according to the optimal hydraulic pump motor output flow and the optimal hydraulic pump motor displacement, and output a control signal to the motor controller according to the optimal motor speed, so that the hydraulic cylinder runs at the optimal hydraulic cylinder speed in each of the unit displacement stages; S2 includes the following steps: S21, Based on the efficiency spectrum of the electric motor pump, determine the mapping relationship between the output flow rate of the hydraulic pump motor, the pressure difference before and after the motor pump and the displacement of the hydraulic pump motor when the energy consumption of the electric motor pump is minimized. S22, using the mapping relationship, starting from the terminal displacement to the initial displacement of the piston, determine the optimal hydraulic pump motor output flow rate and the optimal hydraulic pump motor displacement when the system energy consumption is lowest for each unit displacement. S21 includes the following steps: S211, divide the hydraulic pump motor output flow grid, front and rear pressure difference grid and hydraulic pump motor displacement grid corresponding to each unit displacement; S212, traverse the hydraulic pump motor output flow grid, the front and rear pressure difference grid and the hydraulic pump motor displacement grid, and calculate the possible values ​​of motor pump energy consumption corresponding to each unit displacement based on the motor pump efficiency spectrum; S213, Select the lowest possible value of motor pump energy consumption corresponding to each unit displacement as the optimal value of motor pump energy consumption; S214, determine the mapping relationship between the hydraulic pump motor output flow rate, the pressure difference before and after, and the hydraulic pump motor displacement corresponding to the optimal motor pump energy consumption value; S22 includes the following steps: S221, determine the system energy consumption corresponding to each unit displacement according to the following formula: ; Representing the The motor input power of the servo motor at each unit displacement is calculated as follows: ; Representing the The rotational speed of the servo motor at each unit displacement is calculated as follows: ,in, This represents the effective area of ​​the rodless chamber in the hydraulic cylinder. Representing the The displacement velocity of the piston in the hydraulic cylinder at the unit displacement is calculated as follows: , Representing the The hydraulic pump motor output flow rate at the unit displacement is described. Representing the The displacement of the hydraulic pump motor at the unit displacement mentioned above. This represents the volumetric efficiency of the hydraulic pump motor. Representing the The torque of the servo motor at each unit displacement is calculated as follows: ,in, Representing the The pressure difference before and after at the unit displacement mentioned above This represents the mechanical efficiency of the hydraulic pump motor. This represents the motor efficiency of the servo motor. Representing the The unit displacement mentioned above Representing the The displacement velocity of the piston in the hydraulic cylinder at the unit displacement is calculated as follows: , Representing the The hydraulic pump motor output flow rate at the unit displacement; S222, utilizing the mapping relationship between the hydraulic pump motor output flow rate and the pressure difference before and after, starting from the terminal displacement until the initial displacement of the piston, the optimal hydraulic pump motor output flow rate at which the system energy consumption is lowest for each unit displacement is determined according to the following formula: ; S223, using the mapping relationship between the output flow rate of the hydraulic pump motor and the displacement of the hydraulic pump motor, calculate the optimal hydraulic pump motor displacement when the system energy consumption is lowest for each unit displacement.

2. The energy efficiency optimization method for an electro-hydraulic driven operating system according to claim 1, characterized in that, S3 includes: S31, Calculate the optimal hydraulic cylinder speed corresponding to each unit displacement based on the output flow rate of the optimal hydraulic pump motor; S32, Calculate the optimal motor speed corresponding to each unit displacement based on the optimal hydraulic pump motor output flow rate and the optimal hydraulic pump motor displacement.

3. The energy efficiency optimization method for an electro-hydraulic driven operating system according to claim 2, characterized in that, S31 includes: calculating the optimal hydraulic cylinder speed corresponding to each unit displacement according to the following formula: ; Representing the The optimal hydraulic cylinder speed at the unit displacement. Representing the The optimal hydraulic pump motor output flow rate at the unit displacement is given. This represents the effective area of ​​the rodless chamber in the hydraulic cylinder.

4. The energy efficiency optimization method for the electro-hydraulic drive system according to claim 3, characterized in that, S32 includes: calculating the optimal motor speed corresponding to each unit displacement according to the following formula: , in, No. The optimal motor speed at each unit displacement; Representing the The optimal hydraulic pump motor displacement at the unit displacement is given. This represents the volumetric efficiency of the hydraulic pump motor.

5. The energy efficiency optimization method for an electro-hydraulic driven operating system according to claim 1, characterized in that, S4 includes the following steps: S41, plot the optimal hydraulic pump motor displacement curve and the optimal hydraulic pump motor output flow curve along the piston displacement, plot the optimal motor speed curve along the piston displacement, and plot the optimal hydraulic cylinder speed curve along the piston displacement. S42, output control signals to the hydraulic pump motor according to the optimal hydraulic pump motor displacement curve and the optimal hydraulic pump motor output flow curve, and output control signals to the motor controller according to the optimal motor speed curve, so that the hydraulic cylinder runs according to the optimal hydraulic cylinder speed curve.

6. An energy efficiency optimization system for an electro-hydraulic driven operating system, characterized in that, It includes an electro-hydraulic drive system and an optimization system, the optimization system being used to perform the method as described in any one of claims 1 to 5; The electro-hydraulic drive system includes a motor controller, a servo motor, a hydraulic pump motor, a hydraulic cylinder, a first solenoid valve, and a second solenoid valve. The motor controller controls the output speed of the servo motor, the servo motor drives the hydraulic pump motor, the first port of the hydraulic pump motor is connected to the rod chamber of the hydraulic cylinder through the first solenoid valve, and the second port of the hydraulic pump motor is connected to the rodless chamber of the hydraulic cylinder through the second solenoid valve. The optimization system includes a combined optimization unit and a motion controller. The combined optimization unit is used to execute steps S1-S3 and output a control signal to the hydraulic pump motor according to the optimal hydraulic pump motor output flow rate and the optimal hydraulic pump motor displacement. The motion controller is used to output a control signal to the motor controller according to the optimal motor speed.

7. The energy efficiency optimization system for the electro-hydraulic drive operation system according to claim 6, characterized in that, The electro-hydraulic drive system also includes a first safety valve, a second safety valve, a low-pressure accumulator, a first hydraulically controlled check valve, a second hydraulically controlled check valve, a third safety valve, and a fourth safety valve. The inlet of the first hydraulically controlled check valve is connected to the port where the first solenoid switch valve is connected to the rod chamber. The outlet of the first hydraulically controlled check valve is connected to the outlet of the second hydraulically controlled check valve. The inlet of the second hydraulically controlled check valve is connected to the port where the second solenoid switch valve is connected to the rodless chamber. The low-pressure accumulator is connected between the first hydraulically controlled check valve and the second hydraulically controlled check valve. The low-pressure accumulator replenishes hydraulic oil to the first port through the first hydraulically controlled check valve. The first safety valve is used to limit the maximum pressure between the first port and the first solenoid valve; the second safety valve is used to limit the maximum pressure between the second port and the second solenoid valve; the third safety valve is used to limit the maximum pressure between the first solenoid valve and the rod chamber; and the fourth safety valve is used to limit the maximum pressure between the second solenoid valve and the rodless chamber.

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