Power matching method, device, equipment and readable storage medium for electronically controlled hydraulic system

Abstract

The present invention discloses a power matching method, device, equipment and readable storage medium for an electronically controlled hydraulic system, including: determining a first constant power curve of a current working mode of a variable pump; controlling the displacement of the variable pump to increase according to a positive flow curve until the actual power of the variable pump is the power of the first constant power curve; the intersection of the positive flow curve and the first constant power curve is a constant power starting point; constant power control of the variable pump; when the load pressure increases, the displacement of the variable pump is adjusted along the first constant power curve; when the load pressure decreases, the displacement of the variable pump is adjusted with a delay, the pressure drops to a first pressure value, and the variable pump is controlled to be adjusted to a displacement value corresponding to the first pressure value according to the first constant power curve; when the pressure drops to a second pressure value, the variable pump is controlled to be adjusted to a displacement corresponding to the constant power starting point on the first constant power curve; the first pressure value is greater than or equal to the pressure value of the constant power starting point on the first constant power curve, and the second pressure value is less than the pressure value, and the variable pump has strong anti-interference performance.

Description

Technical Field

[0001] The present invention relates to the technical field of variable displacement pump and variable displacement motor control, and more specifically, to a power matching method for an electronically controlled hydraulic system. In addition, the present invention also relates to a power matching device for an electronically controlled hydraulic system, a power matching equipment for an electronically controlled hydraulic system, and a computer-readable storage medium. Background Art

[0002] At present, in engineering machinery, there are solutions using electronically controlled variable pumps and electronically controlled variable motor systems. For electronically controlled variable pumps and electronically controlled variable motor systems, power matching has always been a hot topic and difficulty in research.

[0003] In the related art, the variable pump is controlled at constant power. When the load pressure starts to decrease, the displacement of the variable pump is adjusted along the constant power curve, that is, the swash plate opening of the variable pump is increased, the pump flow output of the variable pump is increased, and the displacement of the variable pump changes along the constant power curve as the load pressure decreases. This pump flow regulation method can track the load pressure changes in real time. However, when the load pressure fluctuates, the variable pump is in a frequent adjustment state, which is prone to hydraulic self-excited vibration, making the variable pump control unstable and poorly resistant to interference.

[0004] In summary, how to ensure the stability of variable pump control and improve the variable pump's resistance to interference is an urgent problem to be solved by technical personnel in this field. Summary of the invention

[0005] In view of this, an object of the present invention is to provide a power matching method for an electronically controlled hydraulic system, which can improve the stability of the control of a variable pump, and the variable pump has strong resistance to interference.

[0006] Another object of the present invention is to provide an electronically controlled hydraulic system power matching device, an electronically controlled hydraulic system power matching equipment and a computer-readable storage medium, wherein the variable pump has good pump control stability and strong resistance to interference.

[0007] In order to achieve the above object, the present invention provides the following technical solutions:

[0008] A power matching method for an electronically controlled hydraulic system is applied to the electronically controlled hydraulic system, wherein the electronically controlled hydraulic system includes a variable displacement pump. The power matching method for the electronically controlled hydraulic system includes:

[0009] Determining a first constant power curve of the variable displacement pump in a current working mode;

[0010] When the actual power of the variable pump is less than the power of the first constant power curve, the displacement of the variable pump is controlled to increase according to the positive flow control method until the actual power of the variable pump reaches the power of the first constant power curve; the intersection point of the positive flow curve of the positive flow control method and the first constant power curve is used as the constant power starting point;

[0011] When the actual power of the variable pump reaches the power of the first constant power curve, performing constant power control on the variable pump;

[0012] When the load pressure increases, the displacement of the variable pump is adjusted along the first constant power curve;

[0013] When the load pressure drops, the displacement of the variable pump is delayed to be adjusted, and when the load pressure drops to a first stable pressure value, the displacement of the variable pump is controlled to be adjusted to a displacement value corresponding to the first pressure value according to the first constant power curve; when the load pressure drops to a second stable pressure value, the displacement of the variable pump is controlled to be adjusted to a displacement corresponding to the constant power starting point on the first constant power curve; the first pressure value is greater than or equal to the pressure value corresponding to the constant power starting point on the first constant power curve, and the second pressure value is less than the pressure value.

[0014] Optionally, it also includes:

[0015] When the actual power of the variable pump is greater than the power of the first constant power curve, switching to a second constant power curve in another working mode, the power of the second constant power curve is greater than the power of the first constant power curve;

[0016] performing constant power control on the variable pump according to the second constant power curve;

[0017] When the actual power of the variable pump is greater than the maximum power of the constant power curve under all working modes, or when the load pressure reaches a preset maximum pressure value, the variable pump is controlled to unload so that the displacement of the variable pump is the minimum displacement.

[0018] Optionally, before determining the first constant power curve of the variable displacement pump in the current working mode, the method further includes:

[0019] Determine the maximum absorbed power of the variable displacement pump under the current working mode;

[0020] The first constant power curve of the variable displacement pump in the current working mode is determined according to the maximum absorbed power.

[0021] Optionally, determining the maximum absorbed power of the variable displacement pump in the current working mode includes:

[0022] Determine a target torque and a target speed of the engine for driving the variable displacement pump under the current working mode;

[0023] determining an overall efficiency of the engine to the variable displacement pump;

[0024] The maximum absorbed power is determined according to the target torque, the target rotation speed, and the overall efficiency.

[0025] Optionally, the electronically controlled hydraulic system further includes a variable motor, and the electronically controlled hydraulic system power matching method further includes:

[0026] Determining a minimum pressure and a minimum displacement of the variable displacement motor, and determining a minimum torque of the variable displacement motor according to the minimum pressure and the minimum displacement;

[0027] Determine the maximum pressure of the variable motor in each working mode, and determine the maximum torque of the variable motor in each working mode according to the maximum pressure corresponding to each working mode and the maximum displacement of the variable motor;

[0028] Determining a working torque straight line segment of the variable motor corresponding to each working mode according to the minimum torque and the maximum torque of the variable motor in each working mode;

[0029] Determining the lowest pressure of the variable motor corresponding to each of the working modes;

[0030] According to the slope of the working torque straight line segment of the variable motor corresponding to each working mode, when the load pressure changes between the minimum pressure and the maximum pressure corresponding to each working mode, the displacement of the variable motor is controlled to be adjusted to the displacement value corresponding to the load pressure.

[0031] Optionally, after determining the lowest pressure of the variable motor corresponding to each of the working modes, the method further includes:

[0032] Determining the minimum displacement of the variable motor corresponding to each of the working modes according to the minimum pressure of the variable motor corresponding to each of the working modes and the slope of the corresponding working torque straight line segment;

[0033] According to the minimum displacement of the variable displacement motor corresponding to each of the working modes, the maximum stroke of the handle for controlling the displacement of the variable displacement pump and the variable displacement motor corresponding to each of the working modes is determined.

[0034] A power matching device for an electronically controlled hydraulic system is applied to an electronically controlled hydraulic system, wherein the electronically controlled hydraulic system includes a variable displacement pump, and the power matching device for the electronically controlled hydraulic system includes:

[0035] A first constant power curve determining module, used to determine a first constant power curve of the variable displacement pump in a current working mode;

[0036] A positive flow control module, used for controlling the displacement of the variable pump to increase according to a positive flow control method when the actual power of the variable pump is less than the power of the first constant power curve, until the actual power of the variable pump reaches the power of the first constant power curve; taking the intersection of the positive flow curve of the positive flow control method and the first constant power curve as the constant power starting point; a constant power control module, used for performing constant power control on the variable pump when the actual power of the variable pump reaches the power of the first constant power curve;

[0037] a first displacement regulating module, configured to regulate the displacement of the variable pump along the first constant power curve when the load pressure increases;

[0038] A second displacement regulating module is used for delaying the adjustment of the displacement of the variable pump when the load pressure drops, and when the load pressure drops to a first pressure value after stabilization, controlling the displacement of the variable pump to be adjusted to a displacement value corresponding to the first pressure value according to the first constant power curve; when the load pressure drops to a second pressure value after stabilization, controlling the displacement of the variable pump to be adjusted to a displacement corresponding to the constant power starting point on the first constant power curve; the first pressure value is greater than or equal to the pressure value corresponding to the constant power starting point on the first constant power curve, and the second pressure value is less than the pressure value.

[0039] A power matching device for an electronically controlled hydraulic system, comprising:

[0040] Memory for storing computer programs;

[0041] A processor is used to implement the steps of any one of the above-mentioned methods for power matching of an electronically controlled hydraulic system when executing the computer program.

[0042] A computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of any one of the above-mentioned methods for power matching of an electronically controlled hydraulic system are implemented.

[0043] The beneficial effects of the power matching method of the electronically controlled hydraulic system provided by the present invention are as follows:

[0044] Before the actual power of the variable pump reaches the power of the first constant power curve, the variable pump is subjected to positive flow control. During this process, the handle opening for controlling the displacement of the variable pump and the variable motor gradually increases, and the opening of the variable pump electronically controlled proportional valve is proportional to the handle opening. As the handle opening increases, the displacement of the variable pump increases, and the system flow is "what is needed", and positive flow control is performed. At the same time, as the handle opening increases, the load pressure increases, and the load pressure is proportional to the displacement of the variable pump, and a positive flow curve is formed between the two. When the actual power value of the variable pump reaches the power of the first constant power curve, that is, when the positive flow curve formed by the load pressure and the displacement of the variable pump intersects with the first constant power curve, the variable pump begins to be subjected to constant power control, and the intersection of the positive flow curve and the first constant power curve is used as the constant power starting point. During this process, the displacement of the variable pump is controlled by controlling the opening of the electronically controlled proportional valve of the variable pump. During the process of constant power control of the variable pump, when the load pressure increases, the displacement of the variable pump is adjusted along the first constant power curve, and the flow output of the variable pump is reduced by reducing the swash plate angle of the variable pump, so that the displacement of the variable pump decreases with the increase of the load pressure, and the power is maintained constant. This method enables the variable pump to respond in time when the load pressure increases, reduce the pump displacement, and prevent the system from being overloaded. When the load pressure decreases, the displacement of the variable pump is not adjusted according to the first constant power curve, but the current displacement of the variable pump is maintained for a period of time, so that the load pressure drops to a stable pressure value, and then the displacement of the variable pump is adjusted according to the stable pressure value after the load pressure drops. For example, when the load pressure drops to the first pressure value after stabilization, since the first pressure value is greater than or equal to the pressure value corresponding to the constant power starting point on the first constant power curve, the displacement value on the first constant power curve corresponding to the first pressure value is less than or equal to the displacement value on the first constant power curve corresponding to the constant power starting point. At this time, the displacement of the variable pump can be controlled to be adjusted to the displacement value corresponding to the first pressure value according to the first constant power curve, so that the variable pump meets the constant power control. When the load pressure drops to the second pressure value after stabilization, since the second pressure value is less than the pressure value corresponding to the constant power starting point on the first constant power curve, if the displacement of the variable pump is adjusted to the displacement value corresponding to the constant power starting point on the first constant power curve, since the product of the load pressure multiplied by the displacement value corresponding to the constant power starting point on the first constant power curve is lower than the first constant power curve, it is obviously feasible. Therefore, at this time, the displacement of the variable pump is adjusted to the displacement value corresponding to the constant power starting point on the first constant power curve to keep the opening of the variable pump electronically controlled proportional valve consistent with the handle opening ratio.

[0045] It can be seen that the power matching method of the electronically controlled hydraulic system immediately reduces the displacement of the variable pump when the load pressure rises, and adjusts the displacement of the variable pump in real time according to the first constant power curve; when the load pressure drops, the displacement of the variable pump is not strictly adjusted in real time according to the first constant power curve, but the response is delayed, and the displacement of the variable pump is adjusted according to the first constant power curve after the load pressure drops to a stable pressure value. In this way, frequent adjustment of the variable pump due to pressure fluctuations can be avoided, thereby improving the stability of the variable pump control and making the variable pump have strong anti-interference ability. At the same time, when the load pressure drops to a stable pressure that is less than the load pressure value corresponding to the constant power starting point on the first constant power curve, the displacement of the variable pump is controlled to be adjusted to the displacement value corresponding to the constant power starting point on the first constant power curve, and the opening of the electronically controlled proportional valve of the variable pump is kept consistent with the opening ratio of the handle.

[0046] The power matching device for an electronically controlled hydraulic system provided by the present invention corresponds to the power matching method for an electronically controlled hydraulic system and has the above-mentioned beneficial effects.

[0047] The electronically controlled hydraulic system power matching device and the computer-readable storage medium provided by the present invention are used to implement the electronically controlled hydraulic system power matching method and have the above-mentioned beneficial effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0049] Figure 1 A flow chart of a power matching method for an electronically controlled hydraulic system provided in a specific embodiment of the present invention;

[0050] Figure 2 It is the principle diagram of electronically controlled positive flow and constant power regulation;

[0051] Figure 3 It is a curve diagram of electronically controlled positive flow and constant power;

[0052] Figure 4 A flow chart of a power matching method for an electronically controlled hydraulic system provided by another embodiment;

[0053] Figure 5 A flow chart for variable control of a variable motor;

[0054] Figure 6 It is the working characteristic curve principle diagram of the variable motor in different working modes;

[0055] Figure 7 A structural block diagram of a power matching device for a Qing electric-controlled hydraulic system provided in a specific embodiment of the present invention;

[0056] Figure 8 This is a structural block diagram of a power matching device for an electronically controlled hydraulic system provided in a specific embodiment of the present invention.

[0057] Reference numerals:

[0058] 1- Constant power curve of heavy load power mode; 2- Constant power curve of heavy load energy saving mode; 3- Constant power curve of economic power mode; 4- Constant power curve of economic energy saving mode; 5- Constant power curve of light load power mode; 6- Constant power curve of light load energy saving mode; 7- Electronically controlled positive flow curve; 8- Pressure cut-off line; 9- Maximum flow line of variable pump; 10- Straight line segment of working torque in heavy load mode; 11- Straight line segment of working torque in economic mode; 12- Straight line segment of working torque in light load mode. DETAILED DESCRIPTION

[0059] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0060] The core of the present invention is to provide a power matching method for an electronically controlled hydraulic system, which can improve the stability of the variable pump control, and the variable pump has strong resistance to interference. Another core of the present invention is to provide an electronically controlled hydraulic system power matching device, an electronically controlled hydraulic system power matching equipment and a computer-readable storage medium, which have the same beneficial effects as the aforementioned electronically controlled hydraulic system power matching method.

[0061] Please refer to Figure 1 The embodiment of the present invention provides a power matching method for an electronically controlled hydraulic system, which is applied to the electronically controlled hydraulic system. The electronically controlled hydraulic system includes a variable displacement pump. The power matching method for the electronically controlled hydraulic system includes steps S1 to S5:

[0062] Step S1: Determine a first constant power curve of the variable displacement pump in the current working mode.

[0063] Step S2: When the actual power of the variable pump is less than the power of the first constant power curve, the displacement of the variable pump is controlled to increase according to the positive flow control method until the actual power of the variable pump reaches the power of the first constant power curve; the intersection point of the positive flow curve of the positive flow control method and the first constant power curve is used as the constant power starting point.

[0064] Step S3: When the actual power of the variable pump reaches the power of the first constant power curve, the variable pump is subjected to constant power control.

[0065] Step S4: When the load pressure increases, the displacement of the variable displacement pump is adjusted along the first constant power curve.

[0066] Step S5: When the load pressure drops, the displacement of the variable pump is delayed and adjusted, and when the load pressure drops to a first pressure value after stabilization, the displacement of the variable pump is controlled to be adjusted to the displacement value corresponding to the first pressure value according to the first constant power curve; when the load pressure drops to a second pressure value after stabilization, the displacement of the variable pump is controlled to be adjusted to the displacement corresponding to the constant power starting point on the first constant power curve; the first pressure value is greater than or equal to the pressure value corresponding to the constant power starting point on the first constant power curve, and the second pressure value is less than the pressure value corresponding to the constant power starting point on the first constant power curve.

[0067] That is to say, before the actual power of the variable pump reaches the power of the first constant power curve, the variable pump is subjected to positive flow control. In this process, the handle opening for controlling the displacement of the variable pump and the variable motor gradually increases, and the opening of the variable pump electronically controlled proportional valve is proportional to the handle opening. As the handle opening increases, the displacement of the variable pump increases, and the system flow is "what is needed", and positive flow control is performed. At the same time, as the handle opening increases, the load pressure increases, and the load pressure is proportional to the displacement of the variable pump, and a positive flow curve is formed between the two. The positive flow curve is a positive proportional function. When the actual power value of the variable pump reaches the power of the first constant power curve, that is, when the positive flow curve formed by the load pressure and the displacement of the variable pump intersects with the first constant power curve, the variable pump begins to perform constant power control, and the intersection of the positive flow curve and the first constant power curve is used as the constant power starting point. In this process, the displacement of the variable pump is controlled by controlling the opening of the electronically controlled proportional valve of the variable pump.

[0068] During the process of constant power control of the variable pump, when the load pressure increases, the displacement of the variable pump is adjusted along the first constant power curve, and the flow output of the variable pump is reduced by reducing the swash plate angle of the variable pump, so that the displacement of the variable pump decreases with the increase of the load pressure, and the power is maintained constant. This method enables the variable pump to respond in time when the load pressure increases, reduce the pump displacement, and prevent the system from being overloaded. When the load pressure decreases, the displacement of the variable pump is not adjusted according to the first constant power curve, but the current displacement of the variable pump is maintained for a period of time, so that the load pressure drops to a stable pressure value, and then the displacement of the variable pump is adjusted according to the stable pressure value after the load pressure drops.

[0069] For example, Figure 2As shown in FIG. 1 , when the load pressure drops from the pressure value corresponding to point D to the first pressure value after stabilization (such as the pressure value corresponding to point E or point G), since the first pressure value is greater than or equal to the pressure value corresponding to the constant power starting point on the first constant power curve (such as the pressure value corresponding to point J), the displacement value on the first constant power curve corresponding to the first pressure value is less than or equal to the displacement value on the first constant power curve corresponding to the constant power starting point. At this time, the displacement of the variable displacement pump can be controlled according to the first constant power curve to be adjusted to the displacement value corresponding to the first pressure value (such as the load pressure drops from the pressure value corresponding to point D to the pressure value corresponding to point E). When the load pressure drops from the pressure value corresponding to point F to the pressure value corresponding to point G and stabilizes for a preset time, the displacement of the variable pump is controlled to be adjusted to the displacement value corresponding to point H on the first constant power curve; when the load pressure drops from the pressure value corresponding to point H to the pressure value corresponding to point I and stabilizes for a preset time, the displacement of the variable pump is controlled to be adjusted to the displacement value corresponding to point J on the first constant power curve, that is, the displacement value corresponding to the constant power starting point), so that the variable pump meets the constant power control. When the load pressure drops from the pressure value corresponding to point D to the second pressure value after stabilization (such as the pressure value corresponding to point K), since the second pressure value is less than the pressure value corresponding to the constant power starting point on the first constant power curve (such as the pressure value corresponding to point J), if the displacement of the variable pump is adjusted to the displacement value corresponding to the constant power starting point on the first constant power curve, since the product of the load pressure and the displacement value corresponding to the constant power starting point on the first constant power curve is point L, and point L is lower than the first constant power curve, it is obviously feasible. Therefore, at this time, the displacement of the variable pump is adjusted to the displacement value corresponding to the constant power starting point on the first constant power curve to keep the opening of the variable pump consistent with the handle opening ratio.

[0070] It can be seen that the power matching method of the electronically controlled hydraulic system immediately reduces the displacement of the variable pump when the load pressure rises, and adjusts the displacement of the variable pump in real time according to the first constant power curve; when the load pressure drops, the displacement of the variable pump is not strictly adjusted in real time according to the first constant power curve, but the response is delayed, and the displacement of the variable pump is adjusted according to the first constant power curve after the load pressure drops to a stable pressure value. In this way, frequent adjustment of the variable pump due to pressure fluctuations can be avoided, thereby improving the stability of the variable pump control and making the variable pump have strong anti-interference ability. At the same time, when the load pressure drops to a stable pressure that is less than the load pressure value corresponding to the constant power starting point on the first constant power curve, the displacement of the variable pump is controlled to be adjusted to the displacement value corresponding to the constant power starting point on the first constant power curve, and the opening of the electronically controlled proportional valve of the variable pump is kept consistent with the opening ratio of the handle.

[0071] It should be noted that the judgment criteria for the load pressure to drop to the first pressure value or the second pressure value after stabilization in this embodiment can be: when the load pressure drops to the first pressure value or the second pressure value and remains unchanged for a preset period of time, it means that the load pressure is constant, so as to determine that the load pressure drops to the first pressure value or the second pressure value after stabilization, and the displacement of the variable pump can be adjusted at this time. It can be understood that the first pressure value can be any pressure value located below the first constant power curve and greater than or equal to the load pressure value corresponding to the constant power starting point on the first constant power curve, and the second pressure value can be any pressure value located below the first constant power curve and less than the load pressure value corresponding to the constant power starting point on the first constant power curve.

[0072] In addition, it should be noted that when the displacement of the variable pump is adjusted, the displacement of the variable pump is adjusted by controlling the current value of the variable pump electronically controlled proportional valve. That is, there is a preset corresponding relationship between the current value of the variable pump electronically controlled proportional valve and the displacement of the variable pump. According to the displacement that the variable pump needs to adjust and the preset corresponding relationship, the current value of the variable pump electronically controlled proportional valve is controlled to change to achieve the displacement adjustment of the variable pump.

[0073] It should be noted that the pressure at the constant power starting point is a pressure range, not a specific pressure value.

[0074] In addition, please continue to refer to Figure 4 In some embodiments, the power matching method of the electronically controlled hydraulic system further includes the following step S6:

[0075] When the actual power of the variable pump is greater than the power of the first constant power curve, it switches to a second constant power curve in another working mode, and the power of the second constant power curve is greater than the power of the first constant power curve;

[0076] Performing constant power control on the variable pump according to the second constant power curve;

[0077] When the actual power of the variable pump is greater than the maximum power of the constant power curve in all working modes, or when the load pressure reaches the preset maximum pressure value, the variable pump is controlled to unload so that the displacement of the variable pump is the minimum displacement.

[0078] That is, when the actual power of the variable pump exceeds the power range of the first constant power curve of the current working mode, the power curve transition or pressure cut-off function is executed, that is, Figure 3As shown, in different working modes of the variable pump, the corresponding constant power curves are different. For example, the variable pump has a heavy load mode, an economic mode and a light load mode. The power of the constant power curve of the variable pump corresponding to the heavy load mode is greater than the power of the constant power curve of the economic mode, and the power of the constant power curve of the variable pump corresponding to the economic mode is greater than the power of the constant power curve of the light load mode. Therefore, when the current working mode of the variable pump is the light load mode, when the actual power of the variable pump is greater than the power of the constant power curve of the light load mode, the variable pump is transitioned from the light load mode to the economic mode, and the constant power curve of the economic mode is used to control the variable pump to work at constant power; when the current working mode of the variable pump is the economic mode, when the actual power of the variable pump is greater than the power of the constant power curve of the economic mode, the variable pump is transitioned from the economic mode to the heavy load mode, and the constant power curve of the heavy load mode is used to control the variable pump to work at constant power; and when the current working mode of the variable pump is the heavy load mode, when the actual power of the variable pump is greater than the power of the constant power curve of the heavy load mode, the variable pump is controlled to unload, so that the displacement of the variable pump is the minimum displacement.

[0079] It can be seen that the current working mode and another working mode in this embodiment are relative concepts. Similarly, the first constant power curve and the second constant power curve are relative concepts. That is, when the current working mode of the variable pump is the light load mode, the constant power curve of the light load mode is the first constant power curve, and the other working mode is the economic mode, and the constant power curve of the economic mode is the second constant power curve; when the current working mode of the variable pump is the economic mode, the constant power curve of the economic mode is the first constant power curve, and the other working mode is the heavy load mode, and the constant power curve of the heavy load mode is the second constant power curve. When the variable pump has other working modes, and so on, when the actual power of the variable pump exceeds the power range of the first constant power curve of the current working mode, the power curve transition or pressure cut-off function is executed. The pressure cut-off function refers to controlling the variable pump to unload so that the displacement of the variable pump is closed to the minimum. In addition, when the load pressure reaches the preset maximum pressure value (such as Figure 3 When the pressure is 30MPa in the figure, the variable pump is controlled to unload, so that the displacement of the variable pump is the minimum displacement. That is to say, this embodiment protects the system, and the preset maximum pressure is the maximum pressure of the system. When the load pressure reaches the preset maximum pressure value, the variable pump is controlled to unload. In this way, the power of the engine driving the variable pump, the variable pump and the load are matched, so that the power of the engine is absorbed by the variable pump and the load as much as possible, reducing power loss.

[0080] In addition, please continue to refer to Figure 4 In some embodiments, before determining the first constant power curve of the variable pump in the current working mode, the method further includes:

[0081] S7: Determine the maximum absorbed power of the variable pump in the current working mode;

[0082] S8: Determine a first constant power curve of the variable pump in the current working mode according to the maximum absorbed power.

[0083] It should be noted that the maximum absorbed power refers to the power matched by the variable displacement pump from the engine used to drive the variable displacement pump, and this power is used as the power of the first constant power curve of the variable displacement pump in the current working mode.

[0084] For further information, please refer to Figure 4 In some embodiments, determining the maximum absorbed power of the variable displacement pump in the current working mode includes:

[0085] S9: determining a target torque and a target speed of an engine for driving the variable displacement pump in a current working mode;

[0086] S10: determining the total efficiency of the transmission from the engine to the variable displacement pump;

[0087] S71: Determine the maximum absorbed power of the variable displacement pump according to the target torque and target speed and the total efficiency of the engine in the current working mode.

[0088] It should be noted that in different working modes, the target torque M of the engine e0 and target speed n e0 When the engine operating mode is selected, the target torque M of the engine is determined. e0 and target speed n e0 In some embodiments, the working mode includes three power modes, namely: heavy load mode, economic mode and light load mode. Since there are two power points corresponding to the speed at each throttle position when the engine is working: the maximum power point and the fuel economy point, each power mode has two output modes, namely the power output mode and the energy-saving output mode. That is, the power mode and the output mode constitute six working modes, namely: heavy load power mode, heavy load energy-saving mode, economic power mode, economic energy-saving mode, light load power mode and light load energy-saving mode.

[0089] In addition, the overall efficiency of the engine to the variable pump It is related to system pressure, pump speed and displacement. There are many factors that affect efficiency. Constant power regulation generally works in the high-pressure range of 20Mp-30Mp. At this time, the efficiency is high and does not change much. In the medium and high speed range, the efficiency can generally reach above 0.85. When the displacement ratio of the variable pump is less than 0.5, the efficiency is low, and the total efficiency is not higher than 0.6-0.7. As the displacement ratio of the variable pump increases, the total efficiency increases. When the displacement ratio of the variable pump is greater than 0.5, the total efficiency reaches above 0.75. Based on this, in some embodiments, when the displacement ratio of the variable pump is set to be less than 0.5, the total efficiency =0.4, when the displacement ratio of the variable pump is greater than 0.5, =0.7.

[0090] Furthermore, the target torque M of the engine is e0 and target speed n e0 According to the following formula (1), the engine power can be obtained , by engine power and the total efficiency of the engine to the variable pump According to the following formula (2), the variable pump power can be obtained , that is, the maximum absorption power of the variable pump, according to the maximum absorption power of the variable pump (that is, the variable pump power ) Determine the first constant power curve of the variable pump in the current working mode, and calculate the different load pressures according to the following formula (2): The displacement value of the variable pump is , in order to achieve constant power control of the variable pump.

[0091] , (1)

[0092] , (2)

[0093] In the above formulas (1) and (2), M e0 is the target torque of the engine, n e0 is the target speed of the engine, is the engine power, is the variable pump power, is the total efficiency of the transmission from the engine to the variable pump, is the load pressure, is the displacement of the variable pump, is the variable pump torque.

[0094] Also, please refer to Figure 5 In some embodiments, the electronically controlled hydraulic system further includes a variable motor, and the electronically controlled hydraulic system power matching method further includes:

[0095] S21: determining a minimum pressure and a minimum displacement of the variable motor, and determining a minimum torque of the variable motor according to the minimum pressure and the minimum displacement;

[0096] S22: determining the maximum pressure of the variable motor in each working mode, and determining the maximum torque of the variable motor in each working mode according to the maximum pressure corresponding to each working mode and the maximum displacement of the variable motor;

[0097] S23: determining a working torque straight line segment of the variable motor corresponding to each working mode according to the minimum torque and the maximum torque of the variable motor in each working mode;

[0098] S24: Determine the minimum pressure of the variable motor corresponding to each working mode;

[0099] S25: According to the slope of the working torque straight line segment of the variable motor corresponding to each working mode, when the load pressure changes between the minimum pressure and the maximum pressure corresponding to each working mode, the displacement of the variable motor is controlled to be adjusted to the displacement value corresponding to the load pressure.

[0100] That is to say, this embodiment is mainly used to match the load pressure value with the displacement of the variable displacement motor. According to the following formula (3), the motor torque is equivalent to the product of the load pressure and the motor displacement.

[0101] , (3)

[0102] In formula (3), is the motor torque, Absorbs power for the motor, is the motor speed, is the motor displacement, is the load pressure.

[0103] In addition, it should be noted that the embodiment of the present invention utilizes a handle to control the displacement of a variable pump and a variable motor, and defines that when the handle opening is less than an inflection point, the variable pump is subjected to variable control, at which time the opening of the variable motor's electronically controlled proportional valve is at a minimum, and the displacement of the variable motor is at a maximum value; when the handle opening is greater than the inflection point, the variable pump operates at a maximum displacement, and as the handle opening increases, the opening of the variable motor's electronically controlled proportional valve increases, the displacement of the variable motor becomes smaller, and the motor speed increases, at which time the variable motor is subjected to variable control, so that the displacement of the variable motor matches the load pressure variation range, so that the torque output by the variable motor is absorbed by the load as much as possible, thereby achieving the purpose of effective energy utilization, while taking into account the system's working capacity and work efficiency.

[0104] It should be noted that the variable control of the variable pump and the variable control of the variable motor in the embodiment of the present invention refers to the control of the opening of the variable pump electronically controlled proportional valve that controls the displacement of the variable pump and the control of the opening of the variable motor electronically controlled proportional valve that controls the displacement of the variable motor as the load changes during the process of pushing the handle.

[0105] like Figure 6 As shown, it is the working characteristic curve of the variable motor in different working modes. Figure 6 The vertical axis represents the load pressure value, and the horizontal axis represents the displacement ratio value of the variable motor, the speed of the variable motor and the handle opening.

[0106] It can be understood that the minimum displacement of the variable motor corresponding to each working mode can be determined based on the minimum pressure of the variable motor corresponding to each working mode and the slope of the corresponding working torque straight line segment; the maximum stroke of the handle corresponding to each working mode can be determined based on the minimum displacement of the variable motor corresponding to each working mode.

[0107] Initially, the displacement of the variable motor is the largest, the displacement ratio of the variable motor is 1, and the speed of the variable motor is the speed n corresponding to the turning point of the handle. g When the heavy load mode is selected, the handle travel end point is X H ; When the economic mode is selected, the end point of the handle stroke is X E ; When the light load mode is selected, the handle travel end point is X L ; After releasing the mode selection, the handle travel end point is the default travel end point X f .

[0108] Figure 6 In the figure, point C is the minimum torque point of the variable motor determined by the minimum pressure and minimum displacement of the variable motor; M H Point is the maximum torque point corresponding to the highest load pressure and the largest displacement of the variable motor, which is also the maximum torque corresponding to the heavy load mode; M E Point is the maximum torque corresponding to the economic mode; M L Point C is the maximum torque corresponding to the light load mode. H Line connecting points CM H is the working torque straight line segment of the variable motor in heavy load mode, point C and M E Line connecting points CM E is the working torque straight line segment of the variable motor in economic mode, point C and M L Line connecting points CM L It is the working torque straight line segment of the variable motor in light load mode.

[0109] Furthermore, according to the minimum pressure of the variable motor corresponding to each working mode, for example, the minimum pressure of the variable motor in the heavy load mode is the load pressure value corresponding to point A, the minimum pressure of the variable motor in the economic mode is the load pressure value corresponding to point B, and the minimum pressure of the variable motor in the light load mode is the load pressure value corresponding to point C. Therefore, the working torque straight line segment of the variable motor in the load pressure range corresponding to each working mode can be further determined, that is, the working torque straight line segment of the variable motor in the heavy load mode according to its corresponding load pressure range is AM H In the economic mode, the variable motor has a working torque straight line segment of BM according to its corresponding load pressure range. E In light load mode, the variable motor has a working torque linear segment of CM according to its corresponding load pressure range. LAt the same time, according to the slope of the working torque straight line segment of the variable motor corresponding to each working mode and the minimum pressure of the variable motor corresponding to each working mode, the displacement ratio value corresponding to the minimum pressure of each working mode can be determined, that is, the displacement ratio value of the variable motor corresponding to the minimum pressure point A of the heavy load mode is q H The displacement ratio of the variable motor corresponding to the lowest pressure point B in the economic mode is q E , the displacement ratio of the variable motor corresponding to the lowest pressure point C in light load mode is q L .

[0110] It can be seen that the working area of ​​the variable motor in heavy load mode is M H AHr H 1. The load pressure range is from the pressure corresponding to point A to M H The pressure corresponding to the point is, for example, 22~30MPa, and the displacement ratio value range of the variable motor is q H ~1, the handle travel range is X H ~X g ; The working area of ​​the variable motor in economic mode is M E Bq E 1. The load pressure range is from the pressure corresponding to point B to M E The pressure corresponding to the point is, for example, 12~25MPa, and the displacement ratio value range of the variable motor is q E ~1, the handle travel range is X E ~X g ; The working area of ​​the variable motor in light load mode is M L C L 1. The load pressure range is from the pressure corresponding to point C to M L The pressure corresponding to the point is, for example, 3~15MPa, and the displacement ratio value range of the variable motor is q L ~1, the handle travel range is X L ~X g It can be seen that, in practice, the load pressure value changes of the variable motor when working in three different working modes are not strictly stable. Therefore, when partitioned by load pressure, the load pressure ranges under different working modes overlap to adapt to pressure fluctuations.

[0111] Furthermore, according to the working area of ​​the variable motor in each working mode, when the handle opening is constant, the displacement of the variable motor is determined, the speed of the variable motor is determined, and the load pressure is allowed to change below the working straight line segment corresponding to the current mode and within the load pressure range corresponding to the current handle opening. When the load pressure changes, the displacement value of the variable motor corresponding to the load pressure can be determined according to the slope of the working torque straight line segment of the variable motor corresponding to each working mode. Therefore, the displacement value of the variable motor can be adjusted by controlling the opening of the variable motor electronically controlled proportional valve. Selecting different working modes allows different load pressure variation ranges, so that the displacement of the variable motor adapts to the load pressure changes, and the torque output by the variable motor is absorbed by the load as much as possible. The selection of different torque straight line segments in different working modes meets the different requirements of working capacity and work efficiency.

[0112] Please refer to Figure 7 In addition to the above-mentioned power matching method for an electronically controlled hydraulic system, the present invention further provides a power matching device for an electronically controlled hydraulic system, which is applied to an electronically controlled hydraulic system, wherein the electronically controlled hydraulic system includes a variable displacement pump, and the power matching device for the electronically controlled hydraulic system includes:

[0113] A first constant power curve determining module 31, used to determine a first constant power curve of the variable displacement pump in a current working mode;

[0114] The positive flow control module 32 is used to control the displacement of the variable pump to increase according to the positive flow control method when the actual power of the variable pump is less than the power of the first constant power curve, until the actual power of the variable pump reaches the power of the first constant power curve; the intersection point of the positive flow curve of the positive flow control method and the first constant power curve is used as the constant power starting point;

[0115] The constant power control module 33 is used to perform constant power control on the variable pump when the actual power of the variable pump reaches the power of the first constant power curve;

[0116] A first displacement regulating module 34, used for regulating the displacement of the variable displacement pump along a first constant power curve when the load pressure increases;

[0117] The second displacement regulating module 35 is used for delaying the adjustment of the displacement of the variable pump when the load pressure drops, and when the load pressure drops to a first pressure value after stabilization, controlling the displacement of the variable pump to be adjusted to a displacement value corresponding to the first pressure value according to the first constant power curve; when the load pressure drops to a second pressure value after stabilization, controlling the displacement of the variable pump to be adjusted to a displacement corresponding to a constant power starting point on the first constant power curve; the first pressure value is greater than or equal to the pressure value corresponding to the constant power starting point on the first constant power curve, and the second pressure value is less than the pressure value corresponding to the constant power starting point on the first constant power curve.

[0118] It can be seen that the power matching device of the electronically controlled hydraulic system corresponds to the power matching method of the electronically controlled hydraulic system described above, and therefore has the same beneficial effects as the power matching method of the electronically controlled hydraulic system described above, which will not be described in detail here.

[0119] Please refer to Figure 8 In addition to the above-mentioned power matching method and control device for an electronically controlled hydraulic system, the present invention also provides a power matching device for an electronically controlled hydraulic system, which includes a memory 41 and a processor 42, wherein the memory 41 is used to store computer programs; the processor 42 is used to implement the steps of the power matching method for an electronically controlled hydraulic system disclosed in any one of the above embodiments when executing the computer program.

[0120] It can be seen that the electronically controlled hydraulic system power matching device corresponds to the electronically controlled hydraulic system power matching method described above. For the introduction of the electronically controlled hydraulic system power matching device provided in the embodiment of the present invention, please refer to the above-mentioned electronically controlled hydraulic system power matching method embodiment, which will not be repeated here.

[0121] In addition to the above-mentioned power matching method, control device and control equipment of the electronically controlled hydraulic system, the present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the power matching method of the electronically controlled hydraulic system disclosed in any one of the above embodiments are implemented.

[0122] It can be seen that the computer-readable storage medium corresponds to the power matching method of the electronically controlled hydraulic system described above, and has the same beneficial effects as the power matching method of the electronically controlled hydraulic system described above, which will not be described in detail here.

[0123] The computer-readable storage medium may include: a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and other media that can store program codes.

[0124] It should also be noted that, in this specification, relational terms such as first and second, etc. are merely used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations.

[0125] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0126] The above is a detailed introduction to the power matching method, device, equipment and computer-readable storage medium of the electronically controlled hydraulic system provided by the present invention. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method and core ideas of the present invention. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present invention, the present invention can also be improved and modified in a number of ways, and these improvements and modifications also fall within the scope of protection of the present invention.

Claims

1. A power matching method for an electronically controlled hydraulic system, characterized in that: Applied to an electronically controlled hydraulic system, the electronically controlled hydraulic system includes a variable displacement pump, and the power matching method of the electronically controlled hydraulic system includes: Determining a first constant power curve of the variable displacement pump in a current working mode; When the actual power of the variable pump is less than the power of the first constant power curve, the displacement of the variable pump is controlled to increase according to the positive flow control method until the actual power of the variable pump reaches the power of the first constant power curve; the intersection point of the positive flow curve of the positive flow control method and the first constant power curve is used as the constant power starting point; When the actual power of the variable pump reaches the power of the first constant power curve, performing constant power control on the variable pump; When the load pressure increases, the displacement of the variable pump is adjusted along the first constant power curve; When the load pressure drops, the displacement of the variable pump is adjusted with a delay, and when the load pressure drops to a first stable pressure value, the displacement of the variable pump is controlled to be adjusted to a displacement value corresponding to the first pressure value according to the first constant power curve; when the load pressure drops to a second stable pressure value, the displacement of the variable pump is controlled to be adjusted to a displacement corresponding to the constant power starting point on the first constant power curve; the first pressure value is greater than or equal to the pressure value corresponding to the constant power starting point on the first constant power curve, and the second pressure value is less than the pressure value corresponding to the constant power starting point on the first constant power curve.

2. The power matching method of the electronically controlled hydraulic system according to claim 1, characterized in that: Also includes: When the actual power of the variable pump is greater than the power of the first constant power curve, switching to a second constant power curve in another working mode, the power of the second constant power curve is greater than the power of the first constant power curve; performing constant power control on the variable pump according to the second constant power curve; When the actual power of the variable pump is greater than the maximum power of the constant power curve under all working modes, or when the load pressure reaches a preset maximum pressure value, the variable pump is controlled to unload so that the displacement of the variable pump is the minimum displacement.

3. The power matching method of the electronically controlled hydraulic system according to claim 1, characterized in that: Before determining the first constant power curve of the variable displacement pump in the current working mode, the method further includes: Determine the maximum absorbed power of the variable displacement pump under the current working mode; The first constant power curve of the variable displacement pump in the current working mode is determined according to the maximum absorbed power.

4. The power matching method of the electronically controlled hydraulic system according to claim 3, characterized in that: The determining of the maximum absorbed power of the variable displacement pump in the current working mode comprises: Determine a target torque and a target speed of the engine for driving the variable displacement pump under the current working mode; determining an overall efficiency of the engine to the variable displacement pump; The maximum absorbed power is determined according to the target torque, the target rotation speed, and the overall efficiency.

5. The power matching method of an electronically controlled hydraulic system according to any one of claims 1 to 4, characterized in that: The electronically controlled hydraulic system further includes a variable motor, and the electronically controlled hydraulic system power matching method further includes: Determining a minimum pressure and a minimum displacement of the variable displacement motor, and determining a minimum torque of the variable displacement motor according to the minimum pressure and the minimum displacement; Determine the maximum pressure of the variable motor in each working mode, and determine the maximum torque of the variable motor in each working mode according to the maximum pressure corresponding to each working mode and the maximum displacement of the variable motor; Determining a working torque straight line segment of the variable motor corresponding to each working mode according to the minimum torque and the maximum torque of the variable motor in each working mode; Determining the lowest pressure of the variable motor corresponding to each of the working modes; According to the slope of the working torque straight line segment of the variable motor corresponding to each working mode, when the load pressure changes between the minimum pressure and the maximum pressure corresponding to each working mode, the displacement of the variable motor is controlled to be adjusted to the displacement value corresponding to the load pressure.

6. The power matching method of the electronically controlled hydraulic system according to claim 5, characterized in that: After determining the lowest pressure of the variable motor corresponding to each of the working modes, the method further includes: Determining the minimum displacement of the variable motor corresponding to each of the working modes according to the minimum pressure of the variable motor corresponding to each of the working modes and the slope of the corresponding working torque straight line segment; According to the minimum displacement of the variable displacement motor corresponding to each of the working modes, the maximum stroke of the handle for controlling the displacement of the variable displacement pump and the variable displacement motor corresponding to each of the working modes is determined.

7. A power matching device for an electronically controlled hydraulic system, characterized in that: Applied to an electronically controlled hydraulic system, the electronically controlled hydraulic system includes a variable displacement pump, and the electronically controlled hydraulic system power matching device includes: A first constant power curve determining module, used to determine a first constant power curve of the variable displacement pump in a current working mode; A positive flow control module, configured to control the displacement of the variable pump to increase according to a positive flow control method when the actual power of the variable pump is less than the power of the first constant power curve, until the actual power of the variable pump reaches the power of the first constant power curve; and use the intersection of the positive flow curve of the positive flow control method and the first constant power curve as a constant power starting point; A constant power control module, configured to perform constant power control on the variable pump when the actual power of the variable pump reaches the power of the first constant power curve; a first displacement regulating module, configured to regulate the displacement of the variable pump along the first constant power curve when the load pressure increases; A second displacement regulating module is used for delaying the adjustment of the displacement of the variable pump when the load pressure drops, and when the load pressure drops to a first pressure value after stabilization, controlling the displacement of the variable pump to be adjusted to a displacement value corresponding to the first pressure value according to the first constant power curve; when the load pressure drops to a second pressure value after stabilization, controlling the displacement of the variable pump to be adjusted to a displacement corresponding to the constant power starting point on the first constant power curve; the first pressure value is greater than or equal to the pressure value corresponding to the constant power starting point on the first constant power curve, and the second pressure value is less than the pressure value corresponding to the constant power starting point on the first constant power curve.

8. A power matching device for an electronically controlled hydraulic system, characterized in that: include: Memory for storing computer programs; A processor, configured to implement the steps of the power matching method for an electronically controlled hydraulic system as claimed in any one of claims 1 to 6 when executing the computer program.

9. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the power matching method for an electronically controlled hydraulic system as claimed in any one of claims 1 to 6 are implemented.

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