Oil pump control method and device of electric loader, electric loader and vehicle control unit

Abstract

The invention discloses an oil pump control method and device of an electric loader, the electric loader and a vehicle control unit, and relates to the field of new energy engineering machinery. The whole vehicle controller firstly determines the working modes of the electric loader according to the whole vehicle state, and the working modes comprise the initial working mode, the rotating speed real-time control mode and the oil pump pressure overshoot mode; when the electric loader is in the initial working mode, the whole vehicle controller controls the oil pump to keep the oil pump running at the designed minimum rotating speed through the oil pump motor controller; when the electric loader is in the rotating speed real-time control mode, the vehicle control unit calculates the optimal oil pump rotating speed according to the oil pump outlet pressure change, and the oil pump motor controller controls the oil pump to operate according to the optimal oil pump rotating speed; when the electric loader is in an oil pump pressure overshoot mode, the whole vehicle controller controls the oil pump to operate according to the designed minimum rotating speed of the oil pump through the oil pump motor controller. The invalid power consumption output of the whole vehicle can be reduced under the three working modes, and better energy-saving and consumption-reducing effects are achieved.

Description

Technical Field

[0001] The present application relates to the technical field of new energy engineering machinery, and in particular to an oil pump control method and device for an electric loader, an electric loader and a vehicle controller. Background Art

[0002] With the continuous maturity of battery, motor and electronic control technologies, the manufacturing cost of electrified products continues to decrease, and pure electric new energy engineering machinery that replaces fuel power has become a development trend. During the operation of traditional powered loaders, the engine, as the power source of the vehicle's hydraulic system, provides power for the hydraulic oil pump. The engine and the oil pump cannot be completely decoupled. Under some working conditions, the power redundancy provided by the engine to the oil pump is large, resulting in power waste and affecting the life of the engine. With the emergence of electric loaders that replace traditional power, there have been certain improvements in environmental protection, energy saving, low noise and high efficiency energy saving. On this basis, this field is in urgent need of an oil pump control solution that can better adapt to electric loaders, in order to further optimize the energy consumption of the entire vehicle and avoid energy waste. Summary of the invention

[0003] The purpose of the present application is to provide an oil pump control method and device for an electric loader, an electric loader and a vehicle controller to reduce the ineffective power output of the vehicle and achieve better energy-saving and consumption-reducing effects.

[0004] To achieve the above objectives, this application provides the following solutions.

[0005] In a first aspect, the present application provides an oil pump control method for an electric loader, comprising:

[0006] The vehicle controller determines the working mode of the electric loader according to the vehicle status, including the initial working mode, the speed real-time control mode and the oil pump pressure overshoot mode;

[0007] When the electric loader is in the initial working mode, the vehicle controller controls the oil pump through the oil pump motor controller to keep the oil pump running at the minimum designed speed;

[0008] When the electric loader is in the speed real-time control mode, the vehicle controller calculates the optimal oil pump speed according to the change of the oil pump outlet pressure, and controls the oil pump to run at the optimal oil pump speed through the oil pump motor controller;

[0009] When the electric loader is in the oil pump pressure overshoot mode, the vehicle controller controls the oil pump to run at the designed minimum speed of the oil pump through the oil pump motor controller.

[0010] Optionally, the vehicle controller determines the working mode of the electric loader according to the vehicle state, specifically including:

[0011] When the vehicle is in neutral and ready state and the boom and bucket are not moving, it is determined that the electric loader is in the initial working mode;

[0012] When the vehicle has a boom or bucket in motion and the boom or bucket has not reached its limit position, it is determined that the electric loader is in real-time speed control mode;

[0013] When the boom or bucket runs to the limit position, the oil pump outlet pressure no longer changes, and the oil pump speed exceeds the speed threshold, it is determined that the electric loader is in the oil pump pressure overshoot mode.

[0014] Optionally, the oil pump outlet pressure no longer changes means that the oil pump outlet pressure change rate r p Less than or equal to the rate of change threshold R.

[0015] Optionally, before the vehicle controller controls the oil pump through the oil pump motor controller to maintain the oil pump running at the designed minimum speed, the vehicle controller further includes:

[0016] Obtain the minimum pressure required by the hydraulic system to maintain the operation of the entire vehicle;

[0017] Determine the minimum design speed v of the oil pump corresponding to the minimum pressure required by the hydraulic system min .

[0018] Optionally, before the vehicle controller calculates the optimal oil pump speed according to the change in the oil pump outlet pressure, the process further includes:

[0019] According to the design of the oil pump or the actual measurement of the whole vehicle, a corresponding relationship table between the oil pump speed and the oil pump outlet pressure is obtained.

[0020] Optionally, the vehicle controller calculates the optimal oil pump speed according to the change of the oil pump outlet pressure, specifically including:

[0021] The vehicle controller obtains the oil pump outlet pressure p detected by the oil pump outlet pressure sensor in real time o ;

[0022] Find p from the corresponding relationship table of oil pump speed and oil pump outlet pressure o Corresponding required oil pump speed v req ;

[0023] Using the formula v e =v req -v o Calculate the speed deviation value v e ; where v o is the actual oil pump speed;

[0024] Using the formula v opt =k p v e +k i ∫ve dt calculates the optimal oil pump speed v opt ; where k p and k i are the proportional coefficient and integral coefficient of the PI controller respectively; t represents time.

[0025] Optionally, controlling the oil pump to operate at an optimal oil pump speed through an oil pump motor controller specifically includes:

[0026] The vehicle controller will calculate the optimal oil pump speed v opt Send to the oil pump motor controller via CAN communication;

[0027] The oil pump motor controller determines v according to the one-dimensional linear relationship between the oil pump motor speed and the oil pump speed. opt Corresponding oil pump motor speed v motor ;

[0028] The oil pump motor controller controls the oil pump motor according to the oil pump motor speed v motor Run, thereby driving the oil pump to run at the optimal oil pump speed v opt run.

[0029] In the second aspect, the present application provides an oil pump control device for an electric loader, comprising: a vehicle controller, an oil pump motor controller, an oil pump motor and an oil pump outlet pressure sensor, wherein the vehicle controller is communicatively connected to the oil pump motor controller and the oil pump outlet pressure sensor respectively; the oil pump outlet pressure sensor is installed at the oil pump outlet for detecting the oil pump outlet pressure; the oil pump motor controller is connected to the oil pump motor for controlling the speed of the oil pump motor; the oil pump motor and the oil pump are connected via a constant ratio gearbox, and there is a one-dimensional linear relationship between the speed of the oil pump motor and the speed of the oil pump; the vehicle controller is used to execute the oil pump control method for the electric loader.

[0030] In a third aspect, the present application provides an electric loader on which the oil pump control device of the electric loader is mounted.

[0031] In a fourth aspect, the present application provides a vehicle controller, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the oil pump control method of the electric loader.

[0032] According to the specific embodiments provided in this application, this application discloses the following technical effects.

[0033] The present application provides an oil pump control method, device, electric loader and vehicle controller for an electric loader, which are developed for pure electric loader vehicles and can meet the oil pump speed requirements of the electric loader in three different working modes. The three modes are: ① the initial working mode of oil pump speed control; ② the real-time speed control mode that calculates the optimal oil pump speed in real time according to the change of the oil pump outlet pressure; and ③ the oil pump pressure overshoot mode after the oil pump pressure is overshot. Compared with the situation in which the engine in the traditional excavator loader frequently changes the working condition, resulting in low engine fuel efficiency and high energy consumption, the oil pump control method and device of the present application are used, and the vehicle controller can automatically match the corresponding oil pump speed according to the working mode and workload of the vehicle, which greatly reduces the ineffective power consumption output and achieves excellent energy-saving effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0035] Figure 1 A schematic flow chart of an oil pump control method for an electric loader according to the present application;

[0036] Figure 2 This is a structural schematic diagram of an oil pump control device of an electric loader in the present application;

[0037] Figure 3 This is a control logic diagram of an oil pump control method for an electric loader in the present application. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0039] The purpose of this application is to propose an oil pump control method and device for an electric loader, an electric loader and a vehicle controller to reduce the ineffective power output of the vehicle and achieve better energy-saving and consumption-reducing effects.

[0040] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0041] In an exemplary embodiment, Figure 1 As shown, a method for controlling an oil pump of an electric loader is provided, comprising steps 1 to 4 below.

[0042] The oil pump control method proposed in this application is based on an oil pump control device for an electric loader. Figure 2 As shown, the oil pump control device includes: a vehicle control unit (VCU), an oil pump motor controller, an oil pump motor and an oil pump outlet pressure sensor. The vehicle control unit is connected to the oil pump motor controller and the oil pump outlet pressure sensor. The oil pump outlet pressure sensor is installed at the oil pump outlet to detect the oil pump outlet pressure p o The oil pump motor controller is connected to the oil pump motor and is used to control the oil pump motor speed v motor The oil pump motor and the oil pump are connected via a constant ratio gearbox, and there is a one-dimensional linear relationship between the speed of the oil pump motor and the speed of the oil pump. The vehicle controller is used to execute the oil pump control method of the electric loader.

[0043] The oil pump described in this application is a hydraulic oil pump of an electric loader. The oil pump motor adopts a variable frequency motor. The hydraulic oil pump is connected to the variable frequency motor, and the variable frequency motor is driven by the oil pump motor controller. The vehicle controller calculates the optimal oil pump speed v according to the required oil pump pressure through the PI control algorithm. opt The oil pump motor controller controls the speed of the oil pump motor, and then completes the speed control of the entire oil pump. This control makes the speed of the oil pump better meet the operation requirements, further optimizes the energy consumption of the whole vehicle, and avoids energy waste.

[0044] Refer to the following Figures 1 to 3 The control logic of the oil pump control method of the electric loader of the present application is introduced in detail.

[0045] Step 1: The vehicle controller determines the working mode of the electric loader according to the vehicle status, including the initial working mode, the speed real-time control mode and the oil pump pressure overshoot mode.

[0046] In the oil pump control scheme adapted for the electric loader in this application, the vehicle controller calculates the corresponding optimal oil pump speed according to the vehicle status and the change of the hydraulic oil pump outlet pressure, and sends the optimal oil pump speed to the oil pump motor controller through the J1939 protocol. The oil pump motor controller controls the oil pump motor to achieve the speed target, and the oil pump motor is connected to the hydraulic oil pump through a mechanical structure, so as to achieve the purpose of controlling the hydraulic oil pump speed and provide suitable power for the hydraulic system of the whole vehicle.

[0047] The working modes of the electric loader determined by the vehicle controller according to the vehicle state include the initial working mode, the speed real-time control mode and the oil pump pressure overshoot mode. The step 1 specifically includes:

[0048] Step 1.1: When the vehicle is in neutral and ready, and the boom and bucket are not moving, make sure the electric loader is in the initial working mode.

[0049] The initial working mode of the oil pump speed control means that after the vehicle is high-pressured, it is in the neutral gear preparation state. In the preparation state, if no other operations (such as controlling the bucket, boom, and forearm) are performed at this time, that is, when the boom and bucket are not moving, the vehicle controller determines that the vehicle is in the initial working state and gives the optimal oil pump speed v for the initial demand of the oil pump motor. opt =v min . Where v min Indicates the minimum design speed of the oil pump. This speed is obtained based on the design parameters of the hydraulic system of the whole vehicle and is an inherent characteristic. This speed value only needs to maintain the minimum pressure required by the hydraulic system when the whole vehicle is working.

[0050] Based on the CAN communication between the vehicle controller and the oil pump motor controller, the oil pump design minimum speed v min The oil pump motor controller is sent to the oil pump motor controller through the J1939 protocol, and the oil pump motor controller controls the oil pump motor according to v min The corresponding initial motor speed v int Running, this speed value v int It is only necessary to maintain the minimum pressure required by the hydraulic system when the vehicle is working. This minimum pressure is determined by the hydraulic system of the vehicle and can be a theoretical design value or an actual measured value of the vehicle. This pressure mainly provides hydraulic steering power for the vehicle. The control logic of this part can be seen in Figure 3 The Swich1 part. Figure 3 Where Swich represents a switch device, AND represents an AND gate, and Add represents an adder. In the embodiment of the present application, the oil pump is designed to have a minimum speed v min =400r / min. When the vehicle is in neutral gear preparation state after high pressure is completed and the boom and bucket are not moving, the AND gate output is 1. The final output oil pump speed v o =v min .

[0051] Step 1.2: When the vehicle has a boom or bucket in motion and the boom or bucket has not reached its limit position, make sure that the electric loader is in real-time speed control mode.

[0052] After the vehicle is powered on with high voltage and the system self-test preparation is completed, if the pilot valve stem is manually controlled at this time, the pilot valve will control the on-off and distribution of the fluid by changing the position of the valve core inside it. When the pressure oil generated by the hydraulic pump enters the pilot valve, the pressure oil will move the valve core, change the channel between the valve core and the valve seat, and thus control the flow path and flow rate of the hydraulic oil. The hydraulic oil enters the hydraulic cylinder of the boom and arm of the bucket to achieve various actions. When the vehicle has a boom or bucket action and the boom or bucket has not run to the limit position, it is determined that the electric loader is in real-time speed control mode. In the real-time speed control mode, the optimal oil pump speed needs to be calculated in real time according to the changes in the oil pump outlet pressure.

[0053] In the speed real-time control mode, firstly, according to the design of the oil pump or the actual measurement of the vehicle, the corresponding relationship table between the oil pump speed and the oil pump outlet pressure is obtained, so that the vehicle controller can check the speed through the pressure according to this relationship table. When the vehicle operates the pilot valve stem, the bucket or the arm has a corresponding action. According to the pilot control principle, the pressure at the hydraulic oil pump outlet will change according to the load of the operation. The control algorithm stored in the vehicle controller checks the required speed v of the oil pump according to the changing oil pump outlet pressure. req , combined with PI control, to achieve the optimal oil pump speed v opt The optimal oil pump speed v calculated by the vehicle controller opt The oil pump motor controller is sent via CAN communication, and the oil pump motor controller controls the oil pump motor to the corresponding speed. The control logic of this part is shown in Figure 3 The upper part of Swich 2 is shown in FIG.

[0054] Step 1.3: When the boom or bucket moves to the limit position, the oil pump outlet pressure does not change and the oil pump speed exceeds the speed threshold, it is determined that the electric loader is in the oil pump pressure overshoot mode.

[0055] According to the characteristics of the hydraulic system, if the bucket or arm reaches the limit position, the accumulator of the hydraulic system will keep the hydraulic system pressure unchanged. At this time, if the oil pump continues to maintain a high speed, the hydraulic oil provided will be completely bypassed and will not be used by the hydraulic system, resulting in energy waste. Therefore, when the oil pump outlet pressure no longer changes (r p ≤R), and the oil pump speed exceeds a certain speed threshold (v o ≥V), the VCU control algorithm believes that the hydraulic system has reached its limit and determines that the electric loader is in the oil pump pressure overshoot mode. According to the characteristics of the hydraulic system, the oil pump does not need to continue to rotate at a high speed to maintain the oil pressure. The VCU control algorithm controls the oil pump motor to return to the initial required oil pump speed (that is, the minimum designed speed of the oil pump v min ), thereby achieving energy saving for the entire vehicle. The control logic of this part is shown in Figure 3The lower part of Swich2.

[0056] The oil pump outlet pressure no longer changes means that the oil pump outlet pressure change rate r p Less than or equal to the change rate threshold R. The speed threshold V is determined by measurement. Due to the characteristics of the hydraulic system, the oil pump speed will only maintain a high speed after the bucket or the boom reaches the limit position. This value is obtained by measurement and used as the speed judgment threshold V. In the embodiment of the present application, the oil pump outlet pressure change rate threshold R = 0.2, and the speed threshold V = 3500r / min.

[0057] Step 2: When the electric loader is in the initial working mode, the vehicle controller controls the oil pump through the oil pump motor controller to keep the oil pump running at the minimum designed speed.

[0058] First, obtain the minimum pressure required by the hydraulic system to maintain the operation of the vehicle, and then determine the minimum design speed v of the oil pump corresponding to the minimum pressure required by the hydraulic system min .like Figure 3 As shown in the Swich 1 part of the diagram, when the vehicle is in neutral and the boom or bucket does not need to work (no action), the oil pump maintains the designed minimum speed v min This state has the best energy-saving effect. At this time, the final output oil pump speed is the actual oil pump speed v o =v min .

[0059] Step 3: When the electric loader is in the real-time speed control mode, the vehicle controller calculates the optimal oil pump speed according to the change of the oil pump outlet pressure, and controls the oil pump to run at the optimal oil pump speed through the oil pump motor controller.

[0060] like Figure 3 As shown in the upper part of Swich2, before the vehicle controller calculates the optimal oil pump speed according to the change of the oil pump outlet pressure, it is first necessary to obtain a corresponding relationship table or relationship curve between the oil pump speed and the oil pump outlet pressure based on the design of the oil pump or the actual measurement of the vehicle, which is recorded as 1-DT(u).

[0061] The oil pump outlet pressure sensor is installed at the hydraulic oil pump outlet, and is connected to the vehicle controller via a hard line. Figure 2 As shown in the figure, the oil pump outlet pressure sensor transmits the analog signal of the oil pump outlet pressure to the vehicle controller, and the vehicle controller converts the analog signal of the oil pump outlet pressure into a digital pressure value. o and the vehicle working status, the corresponding optimal oil pump speed v is calculated by the internal algorithm of the vehicle controller opt, and then sent to the oil pump motor controller through the J1939 protocol, so as to achieve the purpose of controlling the oil pump speed. The oil pump motor speed is sent by the oil pump motor controller to the vehicle controller through the J1939 protocol. Since the oil pump motor and the oil pump are connected through a constant ratio gearbox, there is a one-dimensional linear relationship between the oil pump motor speed and the oil pump speed.

[0062] When the electric loader is in the speed real-time control mode, the vehicle controller obtains the oil pump outlet pressure p detected by the oil pump outlet pressure sensor in real time. o Then find p from the corresponding relationship table or relationship curve between oil pump speed and oil pump outlet pressure o Corresponding required oil pump speed v req This step can be implemented by the 1-D Lookup Table module. At adder Add1, the formula v e =v req -v o Calculate the speed deviation value v e ; where v o is the actual oil pump speed, that is, the final output oil pump speed.

[0063] Furthermore, using the PI control algorithm and adder Add2, according to the formula v opt =k p v e +k i ∫v e dt calculates the optimal oil pump speed v opt . Where k p and k i They are the proportional coefficient and integral coefficient of the PI controller, which are obtained through calibration; t represents time.

[0064] The vehicle controller will calculate the optimal oil pump speed v opt The oil pump motor controller is sent to the oil pump motor controller through CAN communication. The oil pump motor controller determines v according to the one-dimensional linear relationship between the oil pump motor speed and the oil pump speed. opt Corresponding oil pump motor speed v motor The oil pump motor controller controls the oil pump motor according to the oil pump motor speed v motor Run, thereby driving the oil pump to run at the optimal oil pump speed v opt Run. At this time, the final output oil pump speed v o =v opt When the vehicle has a boom or bucket working, the optimal speed is matched at any time according to the vehicle controller algorithm, effectively avoiding energy waste.

[0065] Step 4: When the electric loader is in the oil pump pressure overshoot mode, the vehicle controller controls the oil pump to run at the designed minimum speed of the oil pump through the oil pump motor controller.

[0066] like Figure 3 As shown in the lower part of Swich 2, when the arm or bucket reaches the limit position, if the oil pump outlet pressure does not change (r p ≤R) and the oil pump speed exceeds the speed threshold (v o ≥V), it is determined that the electric loader is in the oil pump pressure overshoot mode. In this mode, the oil pump does not need to maintain a high speed. The vehicle controller controls the oil pump through the oil pump motor controller to reduce the oil pump to the minimum speed v designed for the oil pump. min , effectively avoiding the waste of energy.

[0067] In an oil pump control method for an electric loader of the present application, a vehicle controller calculates a matching oil pump speed through an internal algorithm according to the vehicle state and the hydraulic oil pump outlet pressure, thereby making the oil pump speed control more intelligent and more energy-efficient.

[0068] In an exemplary embodiment, the present application also provides an oil pump control device for an electric loader, comprising: a vehicle controller, an oil pump motor controller, an oil pump motor, and an oil pump outlet pressure sensor. The vehicle controller is respectively connected to the oil pump motor controller and the oil pump outlet pressure sensor for communication. The oil pump outlet pressure sensor is installed at the oil pump outlet for detecting the oil pump outlet pressure. The oil pump motor controller is connected to the oil pump motor for controlling the speed of the oil pump motor. The oil pump motor and the oil pump are connected via a constant ratio gearbox, and there is a one-dimensional linear relationship between the speed of the oil pump motor and the speed of the oil pump. The vehicle controller is used to execute the oil pump control method for the electric loader.

[0069] This oil pump control device is developed for pure electric loaders and meets the oil pump speed requirements of electric loaders in three different working modes. The three modes are: ① the initial working mode of oil pump speed control; ② the real-time speed control mode that calculates the optimal oil pump speed in real time according to the changes in the oil pump outlet pressure; ③ the oil pump pressure overshoot mode after the oil pump pressure is overshoot.

[0070] Compared with the situation in which the engine in traditional excavator loaders frequently changes operating conditions, resulting in low engine fuel efficiency and high energy consumption, the oil pump control method and device of the present application can automatically match the corresponding oil pump speed according to the vehicle's working mode and workload, greatly reducing the ineffective power consumption output and achieving excellent energy-saving effects.

[0071] In an exemplary embodiment, the present application also provides an electric loader, on which the oil pump control device of the electric loader is mounted. When the vehicle is performing relevant operations, once the bucket or the arm has a corresponding action, the pressure at the outlet of the hydraulic oil pump will change according to the load of the operation. The internal algorithm of the vehicle controller detects the required speed of the oil pump according to the changed oil pump outlet pressure, and then cooperates with PI control to realize the calculation of the speed of the final oil pump motor. The algorithm realizes the optimal oil pump speed matching under each working condition, and maximizes the avoidance of energy waste.

[0072] In an exemplary embodiment, the present application also provides a vehicle controller, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the oil pump control method of the electric loader. The vehicle controller divides the electric loader into one of three working modes (initial working mode, speed real-time control mode, and oil pump pressure overshoot mode) according to the vehicle state and the feedback of the oil pump outlet pressure sensor. The three working modes can match the optimal oil pump speed to achieve maximum energy saving.

[0073] The vehicle controller may be a server or a terminal. The vehicle controller may include a processor, a memory, an input / output interface and a communication interface. The processor, the memory and the input / output interface are connected via a system bus, and the communication interface is connected to the system bus via the input / output interface. The processor of the vehicle controller is used to provide computing and control capabilities. The memory of the vehicle controller includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the vehicle controller is used to exchange information between the processor and an external device. The communication interface of the vehicle controller is used to communicate with an external device via a network connection. When the computer program is executed by the processor, the oil pump control method of the electric loader is implemented.

[0074] It can be understood by a person of ordinary skill in the art that all or part of the processes in the above-mentioned embodiment method can be completed by hardware related to computer program instructions, and the computer program can be stored in a non-volatile computer-readable storage medium, and the computer program can include the process of the embodiment of the above-mentioned method when executed. Among them, any reference to memory or other media in each embodiment provided in the present application can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, optical memory, high-density embedded non-volatile memory, resistive random access memory (ReRAM), magnetic random access memory (MRAM), ferroelectric random access memory (FRAM), phase change memory (PCM), graphene memory, etc. Volatile memory can include random access memory (RAM) or external cache memory, etc. By way of illustration and not limitation, RAM may be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0075] It should be noted that the information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant regulations.

[0076] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0077] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.

Claims

1. A method for controlling an oil pump of an electric loader, characterized in that: include: The vehicle controller determines the working mode of the electric loader according to the vehicle status, including the initial working mode, the speed real-time control mode and the oil pump pressure overshoot mode; When the electric loader is in the initial working mode, the vehicle controller controls the oil pump through the oil pump motor controller to keep the oil pump running at the minimum designed speed; When the electric loader is in the real-time speed control mode, the vehicle controller calculates the optimal oil pump speed according to the change of the oil pump outlet pressure, and controls the oil pump to run at the optimal oil pump speed through the oil pump motor controller; When the electric loader is in the oil pump pressure overshoot mode, the vehicle controller controls the oil pump to run at the designed minimum speed of the oil pump through the oil pump motor controller.

2. The oil pump control method of the electric loader according to claim 1, characterized in that: The vehicle controller determines the working mode of the electric loader according to the vehicle status, specifically including: When the vehicle is in neutral and ready state and the boom and bucket are not moving, it is determined that the electric loader is in the initial working mode; When the vehicle has a boom or bucket in motion and the boom or bucket has not reached its limit position, it is determined that the electric loader is in real-time speed control mode; When the boom or bucket runs to the limit position, the oil pump outlet pressure no longer changes, and the oil pump speed exceeds the speed threshold, it is determined that the electric loader is in the oil pump pressure overshoot mode.

3. The oil pump control method of the electric loader according to claim 2, characterized in that: The oil pump outlet pressure no longer changes means that the oil pump outlet pressure change rate r p Less than or equal to the rate of change threshold R.

4. The oil pump control method of the electric loader according to claim 2, characterized in that: Before the vehicle controller controls the oil pump through the oil pump motor controller to keep the oil pump running at the designed minimum speed, the vehicle controller also includes: Obtain the minimum pressure required by the hydraulic system to maintain the operation of the entire vehicle; Determine the minimum design speed v of the oil pump corresponding to the minimum pressure required by the hydraulic system min .

5. The oil pump control method of the electric loader according to claim 2, characterized in that: Before the vehicle controller calculates the optimal oil pump speed according to the change of the oil pump outlet pressure, the method further includes: According to the design of the oil pump or the actual measurement of the whole vehicle, a corresponding relationship table between the oil pump speed and the oil pump outlet pressure is obtained.

6. The oil pump control method for an electric loader according to claim 5, characterized in that: The vehicle controller calculates the optimal oil pump speed according to the change of the oil pump outlet pressure, specifically including: The vehicle controller obtains the oil pump outlet pressure p detected by the oil pump outlet pressure sensor in real time o ; Find p from the corresponding relationship table of oil pump speed and oil pump outlet pressure o Corresponding required oil pump speed v req ; Using the formula v e =v req -v o Calculate the speed deviation value v e ; where v o is the actual oil pump speed; Using the formula v opt =k p v e +k i ∫v e dt calculates the optimal oil pump speed v opt ; where k p and k i are the proportional coefficient and integral coefficient of the PI controller respectively; t represents time.

7. The oil pump control method for an electric loader according to claim 6, characterized in that: The step of controlling the oil pump to operate at an optimal oil pump speed by using the oil pump motor controller specifically includes: The vehicle controller will calculate the optimal oil pump speed v opt Send to the oil pump motor controller via CAN communication; The oil pump motor controller determines v according to the one-dimensional linear relationship between the oil pump motor speed and the oil pump speed. opt Corresponding oil pump motor speed v motor ; The oil pump motor controller controls the oil pump motor according to the oil pump motor speed v motor Run, thereby driving the oil pump to run at the optimal oil pump speed v opt run.

8. An oil pump control device for an electric loader, characterized in that: include: A vehicle controller, an oil pump motor controller, an oil pump motor and an oil pump outlet pressure sensor; the vehicle controller is communicatively connected to the oil pump motor controller and the oil pump outlet pressure sensor respectively; the oil pump outlet pressure sensor is installed at the oil pump outlet for detecting the oil pump outlet pressure; the oil pump motor controller is connected to the oil pump motor for controlling the oil pump motor speed; the oil pump motor and the oil pump are connected via a constant ratio gearbox, and there is a one-dimensional linear relationship between the oil pump motor speed and the oil pump speed; the vehicle controller is used to execute the oil pump control method for an electric loader according to any one of claims 1 to 7.

9. An electric loader, characterized in that: An oil pump control device for an electric loader according to claim 8 is mounted thereon.

10. A vehicle controller, characterized in that: include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the oil pump control method for an electric loader according to any one of claims 1 to 7.

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