Electro-hydraulic control method, system and engineering machine

Abstract

The application provides an electro-hydraulic control method, system and engineering machinery, and belongs to the technical field of engineering machinery. The control method comprises the following steps: obtaining the displacement of a hydraulic pump and the rotating speed of a motor; obtaining the flow demand of the hydraulic pump based on the displacement and the rotating speed; judging whether the flow demand is less than the maximum flow of the hydraulic pump; if yes, obtaining the motor set rotating speed matched with the flow demand based on a preset corresponding relationship, and controlling the rotating speed of the motor based on the motor set rotating speed. The method is used to solve the defects that the motor advantage cannot be exerted and the power source is wasted in the prior art, in which the motor driving the hydraulic pump is controlled by gear speed in different working conditions, and the rotating speed of the motor is adjusted based on the flow demand of the hydraulic pump, so that the motor is in a reasonable working interval, the energy consumption is reduced, and the energy-saving effect is achieved.

Description

Technical Field

[0001] This invention relates to the field of engineering machinery technology, and in particular to an electro-hydraulic control method, system, and engineering machinery. Background Technology

[0002] Currently, the common practice for pure electric drive construction machinery is simply to replace the diesel engine with a power motor. The speed regulation method of the motor is also basically to simply simulate the engine's different working conditions and adjust the speed according to the gear. This means that the excellent speed regulation and strong overload capacity of the motor cannot be fully utilized.

[0003] Meanwhile, most construction machinery currently driven by electric motors to operate hydraulic pumps adopts a constant speed control strategy. This means that construction machinery cannot take advantage of the electric motor's rapid response during operation, nor can it reduce power by changing the speed. Therefore, it is difficult to achieve global power matching between the power source, hydraulic pump, and load, and it is impossible to improve energy utilization efficiency from the root. Summary of the Invention

[0004] This invention provides an electro-hydraulic control method, system, and engineering machinery to solve the defects in the prior art where the speed of the motor driving the hydraulic pump is adjusted according to different working conditions and gears, which results in the motor's advantages not being fully utilized and the power source being wasted. The invention realizes the adjustment of the motor speed based on the flow demand of the hydraulic pump, so that the motor is in a reasonable working range, reducing energy consumption and achieving the effect of energy saving.

[0005] This invention provides an electro-hydraulic control method, comprising:

[0006] Obtain the displacement of the hydraulic pump and the speed of the motor;

[0007] Based on the displacement and the rotational speed, the flow rate requirement of the hydraulic pump is obtained;

[0008] Determine whether the required flow rate is less than the maximum flow rate of the hydraulic pump;

[0009] If so, based on the preset correspondence, a motor speed setting that matches the flow demand is obtained, and the motor speed is controlled based on the motor speed setting.

[0010] According to the electro-hydraulic control method of the present invention, obtaining a set motor speed matching the flow demand based on a preset correspondence, and controlling the motor speed based on the set motor speed, includes:

[0011] Based on the pump flow range in the corresponding relationship where the flow demand falls, the set speed of the motor corresponding to the pump flow range where the flow demand is located is obtained, and the speed of the motor is controlled based on the set speed of the motor.

[0012] According to the electro-hydraulic control method of the present invention, the pump flow range is divided based on the measured efficiency of the motor at different speeds.

[0013] According to the electro-hydraulic control method of the present invention, the step of obtaining a set motor speed matching the flow demand based on a preset correspondence, and controlling the motor speed based on the set motor speed, further includes:

[0014] Determine whether the motor speed is less than a preset motor speed threshold;

[0015] If so, based on the pump flow range into which the flow demand falls, the motor set speed corresponding to the pump flow range where the flow demand is located is obtained by the correspondence between the motor set speed and the pump flow range.

[0016] The motor speed is controlled based on the obtained motor set speed, while keeping the hydraulic pump displacement constant;

[0017] If not, based on the pump flow range into which the flow demand falls, the motor set speed and pump flow rate corresponding to the pump flow range where the flow demand is located are obtained by the correspondence between the motor set speed, the pump flow range, and the pump displacement.

[0018] Based on the obtained motor set speed and pump displacement, the motor speed and the hydraulic pump displacement are controlled respectively.

[0019] The present invention also provides an electro-hydraulic control system, comprising:

[0020] The acquisition module is used to acquire the displacement of the hydraulic pump and the speed of the motor;

[0021] An analysis module is used to determine the flow rate requirement of the hydraulic pump based on the displacement and the rotational speed.

[0022] The judgment module is used to determine whether the flow demand is less than the maximum flow of the hydraulic pump;

[0023] The processing module is used to obtain a set motor speed that matches the flow demand based on a preset correspondence when the flow demand is less than the maximum flow of the hydraulic pump, and to control the motor speed based on the set motor speed.

[0024] According to the electro-hydraulic control system of the present invention, the judgment module is further configured to determine whether the speed of the motor is less than a preset motor speed threshold.

[0025] The processing module is further configured to, when the motor speed is greater than the motor speed threshold, obtain the motor set speed and pump displacement corresponding to the pump flow range in which the flow demand falls, based on the correspondence between the motor set speed, the pump flow range, and the pump displacement, and control the motor speed and the hydraulic pump displacement respectively based on the obtained motor set speed and pump displacement.

[0026] The electro-hydraulic control system according to the present invention further includes:

[0027] A coordination module is used to coordinate the rate of change of the displacement of the motor and the hydraulic pump.

[0028] The present invention also provides an engineering machine, including a hydraulic pump and an electric motor for driving the hydraulic pump, and further including an electro-hydraulic control system as described in any of the above.

[0029] According to the present invention, the construction machinery is an electric excavator.

[0030] The present invention also provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executed, implements the steps of any of the electro-hydraulic control methods described above.

[0031] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, implements the steps of any of the electro-hydraulic control methods described above.

[0032] The present invention also provides a computer program product, including a computer program that, when executed by a processor, implements the steps of any of the electro-hydraulic control methods described above.

[0033] This invention provides an electro-hydraulic control method, system, and engineering machinery. By acquiring the displacement of the hydraulic pump and the rotational speed of the motor, the flow rate requirement of the hydraulic pump is obtained. Then, when the flow rate requirement of the hydraulic pump is less than the maximum flow rate of the hydraulic pump, based on a preset correspondence between the motor rotational speed and the pump flow rate, a motor rotational speed matching the flow rate requirement of the hydraulic pump can be obtained. By controlling the motor speed based on the motor rotational speed adapted to the flow rate requirement of the hydraulic pump, the motor operates at a reasonable speed, avoiding the power waste caused by the control strategy based on fixed motor speed based on gear position, and achieving the effect of energy saving.

[0034] By adjusting the motor speed based on the flow demand of the hydraulic pump, the motor speed is matched with the actual demand, giving full play to the motor's rapid response advantage. Attached Figure Description

[0035] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0036] Figure 1 This is one of the flowcharts of an electro-hydraulic control method provided by the present invention;

[0037] Figure 2 This is a second schematic flowchart of an electro-hydraulic control method provided by the present invention;

[0038] Figure 3 This is a schematic diagram of the structure of an electro-hydraulic control system provided by the present invention;

[0039] Figure 4 This is a schematic diagram of the structure of the electronic device provided by the present invention. Detailed Implementation

[0040] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0041] The following is combined Figure 1 and Figure 2 The present invention describes an electro-hydraulic control method, which is executed by an electro-hydraulic control device or a combination of software and / or hardware therein, such as... Figure 1 As shown, the electro-hydraulic control method includes the following steps:

[0042] 101. Obtain the displacement of the hydraulic pump and the speed of the motor;

[0043] It should be noted that electro-hydraulic control refers to a control method in hydraulic transmission and control that can accept analog or digital signals to control the output flow or pressure.

[0044] The displacement of a hydraulic pump refers to the volume of oil discharged in one revolution of the pump shaft, commonly represented by V, and measured in ml / r. The displacement of a hydraulic pump depends on the geometry of its sealed chamber; different pumps have different displacements due to varying parameters.

[0045] The motor's speed is also its rated speed. It refers to the motor's speed at its rated power. That is, the motor speed under full load, hence it is also called the full-load speed, and the unit is "revolutions per minute" (rpm). When a hydraulic pump is driven by a motor, the motor's speed determines the hydraulic pump's speed.

[0046] Specifically, in step 101, the hydraulic pump is at a certain displacement and the motor is rotating at a certain speed, which will determine the flow rate output by the hydraulic pump, and this flow rate determines the capacity of the external load.

[0047] More specifically, taking an electric excavator as an example, when the handle is in a certain position, the displacement of the hydraulic pump of the electric excavator will be adjusted to a certain value, and when the throttle knob is turned to a certain gear, the speed of the motor will also be at a certain value.

[0048] 102. Based on the displacement and the rotational speed, the flow rate requirement of the hydraulic pump is obtained;

[0049] It should be noted that the flow rate of a hydraulic pump refers to the volume of hydraulic fluid output by the pump per unit time, commonly represented by qt, with units of L / min (liters per minute). The approximate relationship between the pump's displacement and flow rate is: qt = nV; where n is the pump's rotational speed (r / min); and V is the pump's displacement.

[0050] Specifically, in step 102, the electro-hydraulic control of the motor-driven hydraulic pump is performed, so the speed of the motor determines the speed of the hydraulic pump. Based on this, the flow rate requirement of the hydraulic pump can be obtained based on the displacement and the speed.

[0051] 103. Determine whether the required flow rate is less than the maximum flow rate of the hydraulic pump; if so, proceed to step 104.

[0052] Specifically, when the flow demand has reached the maximum flow of the hydraulic pump, that is, when the obtained displacement of the hydraulic pump has reached the maximum displacement of the hydraulic pump, and the motor speed has reached the maximum speed of the motor, further adjustment of the motor speed can only be to reduce the motor speed. However, when the speed is reduced, the flow required by the hydraulic pump will not be met, thus affecting normal operation. Therefore, in the embodiment of the present invention, a judgment mechanism for the obtained flow demand is added to improve the efficiency of motor speed adjustment.

[0053] It is understood that when the electro-hydraulic control method determines that the flow demand is not less than the maximum flow of the hydraulic pump, it should also include step 105, namely, 105, keeping the displacement of the hydraulic pump and the speed of the motor constant.

[0054] 104. Based on a preset correspondence, obtain a motor speed setting that matches the flow demand, and control the motor speed based on the motor speed setting.

[0055] It should be noted that hydraulic pumps and motors undergo testing and inspection before leaving the factory. For example, the characteristic parameters of the pump or motor are measured. Therefore, based on the test data of the hydraulic pump and motor, the efficient operating range of the hydraulic pump and motor can be obtained. Based on this data, the correspondence between motor speed and pump flow rate can be preset, so that the set motor speed in the correspondence is within the reasonable efficient range of the motor.

[0056] Specifically, in step 104, based on a preset correspondence, such as in the form of a table, after obtaining the flow demand, the set speed of the motor that matches the flow demand is obtained by looking up the table. This can satisfy the motor's operation within a reasonable and efficient range. Therefore, when controlling the motor speed based on the obtained set speed, the flow demand of the hydraulic pump can be met, and energy saving can be achieved by changing the speed.

[0057] More specifically, by utilizing the fast response of the motor, the motor can perform gearless self-adjustment according to changes in load size (flow demand), effectively reducing the complexity of operating engineering machinery based on the electro-hydraulic control method described in the embodiments of the present invention.

[0058] As one embodiment of the present invention, obtaining a motor set speed matching the flow demand based on a preset correspondence, and controlling the motor speed based on the motor set speed, includes:

[0059] Based on the pump flow range in the corresponding relationship where the flow demand falls, the set speed of the motor corresponding to the pump flow range where the flow demand is located is obtained, and the speed of the motor is controlled based on the set speed of the motor.

[0060] It should be noted that the existing control strategy of fixing the motor speed according to the gear cannot fully utilize the motor's fast response speed and is prone to wasting power source. However, the low frequency of motor speed change is conducive to reducing energy consumption.

[0061] Based on this, in the above embodiments of the present invention, the set speed of each motor in the correspondence is set to correspond to different pump flow ranges. That is, the correspondence between the set speed of the motor and the flow rate in the correspondence is divided into multiple interval blocks according to the pump flow range. Then, within a specific interval block, the motor speed is kept at a fixed value. This ensures that as long as the different flow demand falls within a certain interval block, the set speed of the motor is the same. This not only ensures the matching between the motor speed and the pump flow rate, but also effectively prevents the extra energy consumption caused by frequent changes in motor speed and the impact on operability. At the same time, it reduces the computational load of the electro-hydraulic control device, that is, it improves the computational efficiency.

[0062] As one embodiment of the present invention, the pump flow range is divided according to the measured efficiency of the motor at different speeds.

[0063] Specifically, based on the measured efficiency of the motor at different speeds, a range in which the efficiency does not change much is taken as a block. Within this block, the motor speed remains constant, so that the set motor speed corresponding to the pump flow range can meet the flow requirements of the hydraulic pump while avoiding frequent changes in motor speed.

[0064] As an embodiment of the present invention, the step of obtaining a motor set speed matching the flow demand based on a preset correspondence, and controlling the motor speed based on the motor set speed, further includes:

[0065] Determine whether the motor speed is less than a preset motor speed threshold;

[0066] If so, based on the pump flow range into which the flow demand falls, the motor set speed corresponding to the pump flow range where the flow demand is located is obtained by the correspondence between the motor set speed and the pump flow range.

[0067] The motor speed is controlled based on the obtained motor set speed, while keeping the hydraulic pump displacement constant;

[0068] If not, based on the pump flow range into which the flow demand falls, the motor set speed and pump flow rate corresponding to the pump flow range where the flow demand is located are obtained by the correspondence between the motor set speed, the pump flow range, and the pump displacement.

[0069] Based on the obtained motor set speed and pump displacement, the motor speed and the hydraulic pump displacement are controlled respectively.

[0070] It should be noted that the displacement and speed of a hydraulic pump are the two factors that determine its flow rate. Increasing the displacement or speed can increase the flow rate of the hydraulic pump. However, increasing the displacement requires more energy than increasing the speed, which reduces energy efficiency. But when the required flow rate is large, it is difficult to quickly reach or even fail to reach the required flow rate by simply adjusting the motor speed. In this case, it is necessary not only to adjust the motor speed but also to increase the displacement of the hydraulic pump to quickly increase the flow rate of the hydraulic pump, that is, to obtain a faster response speed.

[0071] Specifically, in the above embodiments of the present invention, in order to balance the energy efficiency and response speed of the hydraulic pump, the adjustment strategy for the hydraulic pump and the motor is determined by comparing the motor speed with a preset motor speed threshold, so as to achieve the effect that the engineering machinery using the electro-hydraulic control method described in the embodiments of the present invention can achieve a good working state under different working conditions.

[0072] More specifically, when the motor speed is less than the preset motor speed threshold, it is determined that the construction machinery focuses more on energy efficiency, and the hydraulic pump flow rate can reach the required flow rate at a relatively fast speed simply by adjusting the motor speed. At this time, when the flow demand falls into a range that is different from the previous flow demand, the motor speed is adjusted only according to the motor speed set by the corresponding relationship.

[0073] When the motor speed is greater than the preset motor speed threshold, it is determined that the construction machinery focuses more on response speed. That is, it may be difficult to make the hydraulic pump flow meet the flow demand simply by adjusting the motor speed. At this time, when the flow demand falls into a range that is different from the previous flow demand, the motor speed and pump flow are adjusted respectively according to the motor speed setting and hydraulic pump displacement obtained from the corresponding relationship.

[0074] Furthermore, based on the electro-hydraulic control method described in the embodiments of the present invention, the advantage of the motor's fast speed regulation can also be fully utilized to achieve the energy-saving effect of automatic idling. That is, within the allowable working range of the hydraulic pump, the optimal idling range is sought based on measured data. Then, when the motor speed is less than the motor speed threshold, a lower idling speed is used to reduce energy consumption, while when the motor speed is greater than the motor speed threshold, the idling speed is increased to obtain better response characteristics.

[0075] Based on the above embodiments, the overall flow of the electro-hydraulic control method of the present invention is as follows: Figure 2 As shown, it includes:

[0076] 201. Obtain the displacement of the hydraulic pump and the speed of the motor;

[0077] 202. Based on the displacement and the rotational speed, the flow rate requirement of the hydraulic pump is obtained;

[0078] 203. Determine whether the required flow rate is less than the maximum flow rate of the hydraulic pump; if yes, proceed to step 204; if no, proceed to step 209.

[0079] 204. Determine whether the speed of the motor is less than a preset motor speed threshold; if yes, proceed to step 205; if no, proceed to step 207.

[0080] 205. Based on the pump flow range into which the flow demand falls, the motor set speed corresponding to the pump flow range where the flow demand is located is obtained by the correspondence between the motor set speed and the pump flow range.

[0081] 206. Control the speed of the motor based on the obtained motor set speed, and keep the displacement of the hydraulic pump constant;

[0082] 207. Based on the pump flow range into which the flow demand falls, the motor set speed and pump flow range, and the corresponding relationship between the motor set speed, the pump flow range, and the pump displacement are used to obtain the motor set speed and pump displacement corresponding to the pump flow range where the flow demand is located.

[0083] 208. Based on the obtained motor set speed and pump displacement, control the motor speed and the hydraulic pump displacement respectively;

[0084] 209. Keep the hydraulic pump displacement and motor speed constant.

[0085] Specifically, the electro-hydraulic control method of the present invention, on the one hand, makes full use of the fast response characteristics of the motor, enabling the motor to perform gearless self-adjustment according to the changes in load size, thereby reducing the operational complexity of engineering machinery using motor-driven hydraulic pumps; on the other hand, through zoned speed change and variable displacement control, it matches the high-efficiency working range of the motor and pump displacement, reduces the power consumption of the motor, and improves the energy efficiency of engineering machinery using motor-driven hydraulic pumps.

[0086] The following is combined Figure 3 An electro-hydraulic control system provided by the present invention will be described below. The electro-hydraulic control system described below can be referred to in correspondence with the electro-hydraulic control method described above.

[0087] like Figure 3 As shown, the electro-hydraulic control system provided by the present invention includes: an acquisition module 310, an analysis module 320, a judgment module 330, and a processing module 340; wherein,

[0088] The acquisition module 310 is used to acquire the displacement of the hydraulic pump and the speed of the motor;

[0089] The analysis module 320 is used to obtain the flow rate requirement of the hydraulic pump based on the displacement and the rotational speed;

[0090] The judgment module 330 is used to determine whether the flow demand is less than the maximum flow of the hydraulic pump;

[0091] The processing module 340 is used to obtain a motor set speed that matches the flow demand based on a preset correspondence when the flow demand is less than the maximum flow of the hydraulic pump, and to control the motor speed based on the motor set speed.

[0092] The electro-hydraulic control system of this invention obtains the hydraulic pump's flow demand by acquiring the hydraulic pump's displacement and the motor's rotational speed. Then, when the hydraulic pump's flow demand is less than its maximum flow rate, based on a preset correspondence between the motor's set rotational speed and the pump's flow rate, a motor rotational speed matching the hydraulic pump's flow demand can be determined. By controlling the motor's rotational speed based on the hydraulic pump's flow demand, the motor operates at a reasonable speed, avoiding the power waste caused by control strategies based on fixed motor speeds, thus achieving energy saving. By adjusting the motor's rotational speed based on the hydraulic pump's flow demand, the motor's rotational speed matches the actual demand, fully leveraging the motor's rapid response advantage.

[0093] In a preferred embodiment, the judgment module 330 is further configured to determine whether the speed of the motor is less than a preset motor speed threshold.

[0094] The processing module 340 is further configured to, when the speed of the motor is greater than the motor speed threshold, obtain the motor set speed and pump displacement corresponding to the pump flow range in which the flow demand falls, based on the correspondence between the motor set speed, the pump flow range, and the pump displacement, and control the speed of the motor and the displacement of the hydraulic pump respectively based on the obtained motor set speed and pump displacement.

[0095] Specifically, taking an excavator as an example, determining whether the motor speed is less than the preset motor speed threshold can be converted into determining whether the excavator's throttle gear is in a high or low gear in practical applications. When it is in a low gear, the focus is considered to be on the excavator's energy efficiency, so variable speed control is the main approach when the flow demand changes. When it is in a high gear, the focus is considered to be on response speed, so the pump displacement adjustment response speed advantage is fully utilized when the flow demand changes. Variable speed and variable displacement operate simultaneously. The rapid response of the plunger variable pump compensates for the slower speed response of the variable frequency motor, so that the system can still obtain the required flow response characteristics when the speed changes.

[0096] In a preferred embodiment, the electro-hydraulic control system further includes a coordination module;

[0097] The coordination module is used to coordinate the rate of change of the displacement of the motor and the hydraulic pump.

[0098] Specifically, during the direct conversion between different blocks, the coordination module coordinates the rate of change of motor and pump displacement, which makes the output flow more stable and improves the user experience of the construction machinery.

[0099] The present invention also provides an engineering machine, including a hydraulic pump and an electric motor for driving the hydraulic pump, as well as an electro-hydraulic control system as described in any of the above embodiments.

[0100] Specifically, the engineering machinery described herein applies the electro-hydraulic control system described in this invention, and therefore possesses all the advantages and technical effects of the electro-hydraulic control system, which will not be elaborated here.

[0101] Preferably, the construction machinery is an electric excavator.

[0102] Specifically, the electric excavator described in this embodiment of the invention adopts an electro-hydraulic control method of positive flow variable speed + variable pump. Through an energy efficiency dynamic optimization control strategy, it seeks a reasonable and efficient working range for the motor and pump displacement, thereby achieving the effect of reducing energy consumption and saving energy.

[0103] Figure 4 An example is a schematic diagram of the physical structure of an electronic device, such as... Figure 4 As shown, the electronic device may include a processor 410, a communication interface 420, a memory 430, and a communication bus 440, wherein the processor 410, the communication interface 420, and the memory 430 communicate with each other through the communication bus 440. The processor 410 can call logic instructions in the memory 430 to execute an electro-hydraulic control method, which includes: obtaining the displacement of the hydraulic pump and the speed of the motor; obtaining the flow demand of the hydraulic pump based on the displacement and the speed; determining whether the flow demand is less than the maximum flow of the hydraulic pump; if so, obtaining a set motor speed matching the flow demand based on a preset correspondence, and controlling the speed of the motor based on the set motor speed.

[0104] Furthermore, the logical instructions in the aforementioned memory 430 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, essentially, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0105] On the other hand, the present invention also provides a computer program product, the computer program product including a computer program stored on a non-transitory computer-readable storage medium, the computer program including program instructions, when the program instructions are executed by a computer, the computer is able to execute an electro-hydraulic control method provided by the above methods, the method including: obtaining the displacement of a hydraulic pump and the rotational speed of a motor; obtaining the flow demand of the hydraulic pump based on the displacement and the rotational speed; determining whether the flow demand is less than the maximum flow of the hydraulic pump; if so, obtaining a set rotational speed of the motor matching the flow demand based on a preset correspondence, and controlling the rotational speed of the motor based on the set rotational speed of the motor.

[0106] In another aspect, the present invention also provides a non-transitory computer-readable storage medium storing a computer program thereon, which, when executed by a processor, implements an electro-hydraulic control method provided above. The method includes: obtaining the displacement of a hydraulic pump and the rotational speed of a motor; obtaining a flow rate demand of the hydraulic pump based on the displacement and the rotational speed; determining whether the flow rate demand is less than the maximum flow rate of the hydraulic pump; if so, obtaining a set rotational speed of the motor that matches the flow rate demand based on a preset correspondence, and controlling the rotational speed of the motor based on the set rotational speed.

[0107] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0108] Through the above description of the embodiments, those skilled in the art can clearly understand that each embodiment can be implemented by means of software plus necessary general-purpose hardware platforms, and of course, it can also be implemented by hardware. Based on this understanding, the above technical solutions, in essence or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An electro-hydraulic control method, characterized in that, include: Obtain the displacement of the hydraulic pump and the speed of the motor; Based on the displacement and the rotational speed, the flow rate requirement of the hydraulic pump is obtained; Determine whether the required flow rate is less than the maximum flow rate of the hydraulic pump; If so, then based on the preset correspondence, the set motor speed that matches the flow demand is obtained, and the motor speed is controlled based on the set motor speed; The process of obtaining a set motor speed that matches the flow demand based on a preset correspondence, and controlling the motor speed based on the set motor speed, includes: Based on the pump flow range in the corresponding relationship where the flow demand falls, the set speed of the motor corresponding to the pump flow range where the flow demand is located is obtained, and the speed of the motor is controlled based on the set speed of the motor. The pump flow range is divided according to the measured efficiency of the motor at different speeds; The method of obtaining a motor speed setting that matches the flow demand based on a preset correspondence, and controlling the motor speed based on the motor speed setting, further includes: Determine whether the motor speed is less than a preset motor speed threshold; If so, based on the pump flow range into which the flow demand falls, the motor set speed corresponding to the pump flow range where the flow demand is located is obtained by the correspondence between the motor set speed and the pump flow range. The motor speed is controlled based on the obtained motor set speed, while keeping the hydraulic pump displacement constant; If not, based on the pump flow range into which the flow demand falls, the motor set speed and pump flow rate corresponding to the pump flow range where the flow demand is located are obtained by the correspondence between the motor set speed, the pump flow range, and the pump displacement. Based on the obtained motor set speed and pump displacement, the motor speed and the hydraulic pump displacement are controlled respectively.

2. An electro-hydraulic control system, operating according to the electro-hydraulic control method as described in claim 1, characterized in that, include: The acquisition module is used to acquire the displacement of the hydraulic pump and the speed of the motor; An analysis module is used to determine the flow rate requirement of the hydraulic pump based on the displacement and the rotational speed. The judgment module is used to determine whether the flow demand is less than the maximum flow of the hydraulic pump; The processing module is used to obtain a set motor speed that matches the flow demand based on a preset correspondence when the flow demand is less than the maximum flow of the hydraulic pump, and to control the motor speed based on the set motor speed.

3. The electro-hydraulic control system according to claim 2, characterized in that, The judgment module is also used to determine whether the speed of the motor is less than a preset motor speed threshold. The processing module is further configured to, when the motor speed is greater than the motor speed threshold, obtain the motor set speed and pump displacement corresponding to the pump flow range in which the flow demand falls, based on the correspondence between the motor set speed, the pump flow range, and the pump displacement, and control the motor speed and the hydraulic pump displacement respectively based on the obtained motor set speed and pump displacement.

4. The electro-hydraulic control system according to claim 3, characterized in that, Also includes: A coordination module is used to coordinate the rate of change of the displacement of the motor and the hydraulic pump.

5. An engineering machine, comprising a hydraulic pump and an electric motor for driving the hydraulic pump, characterized in that, It also includes the electro-hydraulic control system as described in any one of claims 2-4.

6. The engineering machinery according to claim 5, characterized in that, The construction machinery in question is an electric excavator.

7. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps of the electro-hydraulic control method as described in claim 1.

8. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the electro-hydraulic control method as described in claim 1.

9. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the electro-hydraulic control method as described in claim 1.

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