An oil pump control method, device, electric loader and vehicle controller for an electric loader

Abstract

The present application discloses an oil pump control method, device, electric wheel loader and vehicle controller, relating to the field of new energy construction machinery. Among them, the vehicle controller first determines the working mode of the electric wheel loader according to the vehicle state, including the initial working mode, the real-time speed control mode and the oil pump pressure overshoot mode; when the electric wheel loader is in the initial working mode, the vehicle controller controls the oil pump to run at the minimum designed speed of the oil pump through the oil pump motor controller; when the electric wheel 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 wheel loader is in the oil pump pressure overshoot mode, the vehicle controller controls the oil pump to run at the minimum designed 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, achieving a better energy-saving and consumption-reducing effect.

Description

Technical Field

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

[0002] With the continuous maturity of battery, motor and electronic control technologies, the manufacturing cost of electrified products has been continuously reduced, and pure electric new energy construction machinery replacing fuel power has become a development trend. During the operation of a traditional power loader, the engine serves as the power source of the vehicle's hydraulic system and provides power for the hydraulic oil pump. The engine and the oil pump cannot be completely decoupled, and in some working conditions, the power redundancy provided by the engine to the oil pump is very large, resulting in waste of power and affecting the engine life at the same time. With the emergence of electric loaders replacing traditional power, certain progress has been made in terms of environmental protection, energy conservation, low noise and high efficiency. On this basis, there is an urgent need in this field for an oil pump control scheme that can better adapt to electric loaders, in order to further optimize the vehicle's energy consumption and avoid waste of energy. Summary of the Invention

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

[0004] To achieve the above purpose, the present application provides the following solutions.

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

[0006] The vehicle controller determines the working mode of the electric loader according to the vehicle state, including the initial working mode, the rotational 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 to run at the minimum designed rotational speed of the oil pump through the oil pump motor controller;

[0008] When the electric loader is in the rotational speed real-time control mode, the vehicle controller calculates the optimal oil pump rotational speed according to the change in the oil pump outlet pressure, and controls the oil pump to run at the optimal oil pump rotational 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 minimum designed rotational 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 whole vehicle is in the neutral ready state and there is no movement of the boom and bucket, it is determined that the electric loader is in the initial working mode;

[0012] When there is movement of the boom or bucket on the whole vehicle and the boom or bucket has not reached the limit position, it is determined that the electric loader is in the real-time speed control mode;

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

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

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

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

[0017] Determine the minimum designed rotational speed v of the oil pump corresponding to the minimum pressure required for the hydraulic system min .

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

[0019] Obtain the correspondence table between the rotational speed of the oil pump and the outlet pressure of the oil pump according to the design of the oil pump or the actual measurement of the whole vehicle.

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

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

[0022] Search for the required rotational speed v of the oil pump corresponding to p from the correspondence table between the rotational speed of the oil pump and the outlet pressure of the oil pump o ; req ;

[0023] Use the formula v e = v req - v o to calculate the rotational speed deviation value v e ; where v o is the actual rotational speed of the oil pump;

[0024] Use 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 the optimal oil pump speed by the oil pump motor controller specifically includes:

[0026] The vehicle controller sends the calculated optimal oil pump speed v opt to the oil pump motor controller through CAN communication;

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

[0028] The oil pump motor controller controls the oil pump motor to operate at the oil pump motor speed v motor so as to drive the oil pump to operate at the optimal oil pump speed v opt operation.

[0029] In a second aspect, the present application provides an oil pump control device for an electric loader, including: 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 through 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 configured to execute the oil pump control method of the electric loader.

[0030] In a third aspect, the present application provides an electric loader equipped with the oil pump control device of the electric loader.

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

[0032] According to the specific embodiments provided by the present application, the following technical effects are disclosed in the present application.

[0033] A method and device for controlling an oil pump of an electric loader, the electric loader, and a vehicle controller provided by this application are for the development of the entire vehicle of a pure electric loader and can meet the requirements for the oil pump speed in three different working modes of the electric loader. The three modes are as follows: 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 overshoots. Compared with the situation in traditional excavator loaders where the engine frequently operates under variable working conditions, resulting in low engine fuel efficiency and high energy consumption, by using the oil pump control method and device of this application, the vehicle controller can automatically match the corresponding oil pump speed according to the working mode and working load of the vehicle, greatly reducing the output of ineffective power consumption and achieving excellent energy-saving effects. BRIEF DESCRIPTION OF THE DRAWINGS

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

[0035] Figure 1 It is a schematic flowchart of a method for controlling an oil pump of an electric loader according to this application;

[0036] Figure 2 It is a schematic structural diagram of a device for controlling an oil pump of an electric loader according to this application;

[0037] Figure 3 It is a schematic control logic diagram of a method for controlling an oil pump of an electric loader according to this application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] The following will clearly and completely describe the technical solutions in the embodiments of this application with reference to the drawings in the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, rather than all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of this application.

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

[0040] To make the above objects, features, and advantages of this application more obvious and understandable, the following will further describe this application in detail with reference to the drawings and specific embodiments.

[0041] In an exemplary embodiment, asFigure 1 As shown, a method for controlling an oil pump of an electric loader is provided, including the following steps 1 to 4.

[0042] The oil pump control method proposed in this application is based on an oil pump control device for an electric loader. As Figure 2 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. Among them, the vehicle control unit 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 p o . The oil pump motor controller is connected to the oil pump motor for controlling the rotational speed v of the oil pump motor motor . The oil pump motor and the oil pump are connected by a constant ratio gearbox, and there is a one-dimensional linear relationship between the rotational speed of the oil pump motor and the rotational speed of the oil pump. The vehicle control unit is used to execute the oil pump control method of the electric loader.

[0043] The oil pump in this application is a hydraulic oil pump for an electric loader, and the oil pump motor is a variable frequency motor. This 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 control unit calculates the optimal oil pump rotational speed v through a PI control algorithm according to the required oil pump pressure opt , and transmits it to the oil pump motor controller through the J1939 protocol. The oil pump motor controller controls the rotational speed of the oil pump motor, thereby completing the entire control of the oil pump rotational speed. Through this kind of control, the rotational speed of the oil pump better adapts to the operation requirements, further optimizing the energy consumption of the whole vehicle and avoiding waste of energy.

[0044] The following will refer to Figures 1 to 3 to introduce in detail the control logic of the oil pump control method for the electric loader of this application.

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

[0046] In the oil pump control scheme adapted to the electric loader in this application, the vehicle control unit calculates the corresponding optimal oil pump rotational speed according to the vehicle state and the change of the hydraulic oil pump outlet pressure, and sends the optimal oil pump rotational speed to the oil pump motor controller through the J1939 protocol. The oil pump motor controller controls the oil pump motor to achieve the rotational 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 rotational speed of the hydraulic oil pump and providing appropriate power for the whole vehicle hydraulic system.

[0047] The working modes of the electric wheel loader determined by the vehicle controller according to the vehicle state include three working modes: the initial working mode, the real-time speed control mode, and the oil pump pressure overshoot mode. The specific steps of Step 1 are as follows:

[0048] Step 1.1: When the vehicle is in the neutral ready state and the boom and bucket are not moving, it is determined that the electric wheel loader is in the initial working mode.

[0049] The initial working mode of the oil pump speed control means that after the vehicle is pressurized to high pressure and is in the neutral ready 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 of the initial demand of the oil pump motor opt = v min where v min represents the minimum designed speed of the oil pump. This speed is obtained from the design parameters of the vehicle's hydraulic system and is an inherent characteristic. This speed value only needs to maintain the minimum pressure required by the hydraulic system during vehicle operation.

[0050] Based on the CAN communication between the vehicle controller and the oil pump motor controller, the minimum designed speed v of the oil pump min is sent to the oil pump motor controller through the J1939 protocol. The oil pump motor controller controls the oil pump motor to run at the corresponding initial motor speed v min . This speed value v int only needs to maintain the minimum pressure required by the hydraulic system during vehicle operation. This minimum pressure is determined by the vehicle's hydraulic system 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 is shown in int the Swich1 part of Figure 3 . Figure 3 In min , Swich represents a switching device, AND represents an AND gate, and Add represents an adder. In the embodiment of the present application, the minimum designed speed v of the oil pump o = 400 r / min. When the vehicle is pressurized to high pressure and is in the neutral ready state and the boom and bucket are not moving, the output of the AND gate is 1. The final output oil pump speed v min = v

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

[0052] After the whole vehicle is powered on with high voltage and the system self-check is completed, if the pilot valve rod 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 spool inside it. When the pressure oil generated by the hydraulic pump enters the pilot valve, the pressure oil will cause the spool to move, changing the passage between the spool and the valve seat, thereby controlling the flow path and flow rate of the hydraulic oil. The hydraulic oil enters the boom and bucket hydraulic cylinders of the bucket, thus realizing various actions. When the whole vehicle has boom or bucket actions and the boom or bucket has not reached the limit position, it is determined that the electric loader is in the real-time speed control mode. In the real-time speed control mode, it is necessary to calculate the optimal pump speed in real time according to the change of the oil pump outlet pressure.

[0053] In the real-time speed control mode, first, according to the design of the oil pump or the actual measurement of the whole vehicle, a corresponding relationship table between the pump speed and the oil pump outlet pressure is obtained, so that the vehicle controller can reverse the speed according to the pressure through this relationship table. When the vehicle operates the pilot valve rod, the bucket or the boom has corresponding actions. According to the pilot control principle, at this time, the pressure at the outlet of the hydraulic pump will change according to the load of the operation. The control algorithm stored in the vehicle controller corresponds to the changed oil pump outlet pressure to find out the required pump speed v req , and then cooperate with PI control to achieve the calculation of the optimal pump speed v opt . The optimal pump speed v calculated by the vehicle controller opt is sent to the oil pump motor controller through CAN communication. The oil pump motor controller then controls the oil pump motor to the corresponding speed. The control logic of this part is shown in Figure 3 the upper half of Swich2 shown in

[0054] Step 1.3: When the boom or bucket reaches the limit position, the oil pump outlet pressure no longer changes, and the 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 the boom 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 supplied hydraulic oil will be completely bypassed and will not be used by the hydraulic system, resulting in a waste of energy. Therefore, when the oil pump outlet pressure no longer changes (r p ≤ R), and at the same time the pump speed exceeds a certain speed threshold (v o ≥ V), the VCU control algorithm believes that the hydraulic system has reached the limit, and it is determined that the electric loader is in the oil pump pressure overshoot mode. According to the characteristics of the hydraulic system, at this time, it is not necessary for the oil pump to continue to maintain a high speed to maintain the oil pressure. The VCU control algorithm controls the oil pump motor to return to the initial required pump speed (i.e., the minimum pump speed v designed for the oil pump min ), thereby realizing the energy saving of the whole vehicle. The control logic of this part is shown in Figure 3The lower part of Swich2 in China

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

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

[0058] First, obtain the minimum pressure required by the hydraulic system to maintain the operation of the whole vehicle, and then determine the minimum designed rotation speed v of the oil pump corresponding to the minimum pressure required by the hydraulic system min . As Figure 3 shown in the Swich1 part, when the whole vehicle is in neutral and the boom or the bucket does not need to work (no action), the oil pump maintains the minimum designed rotation speed v min That's it, and the energy-saving effect is the best in this state. At this time, the finally output rotation speed of the oil pump is the actual rotation speed v of the oil pump o = v min .

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

[0060] As Figure 3 shown in the upper part of Swich2, before the vehicle controller calculates the optimal rotation speed of the oil pump according to the change of the outlet pressure of the oil pump, first, according to the design of the oil pump or the actual measurement of the whole vehicle, obtain the corresponding relationship table or relationship curve between the rotation speed of the oil pump and the outlet pressure of the oil pump, denoted as 1-D T(u).

[0061] The oil pump outlet pressure sensor is installed at the outlet of the hydraulic oil pump, and the oil pump outlet pressure sensor is connected to the vehicle controller through a hard wire. As Figure 2 shown, 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. Then, according to the outlet pressure p of the oil pump o and the working state of the whole vehicle, calculate the corresponding optimal rotation speed v of the oil pump through 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. Among them, the oil pump motor speed is sent from the oil pump motor controller to the vehicle controller through the J1939 protocol. Since the oil pump motor and the oil pump are connected by 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 real-time speed control mode, the vehicle controller obtains the oil pump outlet pressure p detected by the oil pump outlet pressure sensor in real time o , and then looks up the required oil pump speed v corresponding to p from the corresponding relationship table or curve of the oil pump speed and the oil pump outlet pressure o . This step can be implemented by a 1-D Lookup Table look-up module. At the adder Add1, the formula v req = v e - v req is used to calculate the speed deviation value v o ; where v e is the actual oil pump speed, that is, the final output oil pump speed. o

[0063] Further, the PI control algorithm and the adder Add2 are adopted, and according to the formula v opt = k p v e + k i ∫v e dt is used to calculate the optimal oil pump speed v opt . Among them, k p and k i are the proportional coefficient and integral coefficient of the PI controller respectively, and the two are obtained through calibration; t represents time.

[0064] The vehicle controller sends the calculated optimal oil pump speed v opt to the oil pump motor controller through CAN communication. The oil pump motor controller determines the oil pump motor speed v opt corresponding to v according to the one-dimensional linear relationship between the oil pump motor speed and the oil pump speed motor . The oil pump motor controller controls the oil pump motor to run at the oil pump motor speed v motor , so as to drive the oil pump to run at the optimal oil pump speed v opt . At this time, the final output oil pump speed v o = v opt . When the vehicle has working actions of the boom or bucket, 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 operate at the minimum designed speed of the oil pump through the oil pump motor controller.

[0066] As Figure 3 shown in the lower part of Swich2 in the figure, when the boom or bucket runs to the limit position, if the outlet pressure of the oil pump no longer changes (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 to reduce to the minimum designed speed v min of the oil pump through the oil pump motor controller, effectively avoiding energy waste.

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

[0068] In an exemplary embodiment, the present application further provides an oil pump control device for an electric loader, including: a vehicle controller, an oil pump motor controller, an oil pump motor, and an oil pump outlet pressure sensor. Among them, the vehicle controller is respectively communicatively connected with 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 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 through 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 of the electric loader.

[0069] This oil pump control device is developed for the whole vehicle of a pure electric loader, meeting the oil pump speed requirements under three different working modes of the electric loader. The three modes are: ① the initial working mode of oil pump speed control; ② the speed real-time control mode of calculating the optimal oil pump speed in real time according to the change of the oil pump outlet pressure; ③ the oil pump pressure overshoot mode after the oil pump pressure overshoots.

[0070] Compared with the situation in traditional excavating loaders where the engine runs under frequently changing working conditions, resulting in low engine fuel efficiency and high energy consumption, by adopting the oil pump control method and device of the present application, the vehicle controller can automatically match the corresponding oil pump speed according to the working mode and working load of the vehicle, greatly reducing the output of ineffective power consumption and achieving excellent energy-saving effects.

[0071] In an exemplary embodiment, the present application further provides an electric loader, on which the oil pump control device of the electric loader is mounted. When the vehicle is performing related operations, once there are corresponding movements of the bucket or the boom, 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 checks the required speed of the oil pump according to the changed outlet pressure of the oil pump, and then cooperates with PI control to calculate the speed of the final oil pump motor. The algorithm realizes the optimal oil pump speed matching under each working condition, and maximally avoids energy waste.

[0072] In an exemplary embodiment, the present application further provides a vehicle controller, including: a memory, a processor, and a computer program stored on the memory and executable on the processor. 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, real-time speed control mode, and oil pump pressure overshoot mode) according to the vehicle state and the feedback of the oil pump outlet pressure sensor. The optimal oil pump speed can be matched under the three working modes, achieving maximum energy saving.

[0073] The vehicle controller can be a server or a terminal. The vehicle controller can include a processor, a memory, an input / output interface, and a communication interface. Among them, the processor, the memory, and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. Among them, 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 external devices. The communication interface of the vehicle controller is used to communicate with external devices through a network connection. The computer program, when executed by the processor, implements the oil pump control method of the electric loader.

[0074] Those of ordinary skill in the art can understand that all or part of the processes in the above-described embodiment methods can be completed by hardware related to computer program instructions. The computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above methods. Among them, any reference to a memory or other medium provided in the embodiments of the present application can include at least one of non-volatile and volatile memories. Non-volatile memories can include read-only memory (ROM), magnetic tapes, floppy disks, flash memories, optical memories, high-density embedded non-volatile memories, resistive random access memories (ReRAM), magnetoresistive random access memories (MRAM), ferroelectric random access memories (FRAM), phase change memories (PCM), graphene memories, etc. Volatile memories can include random access memory (RAM) or external cache memories, etc. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[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 for analysis, stored data, displayed data, etc.) involved in the present application are all information and data that have been authorized by the user or fully authorized by all parties, and the collection, use, and processing of relevant data need to comply with relevant regulations.

[0076] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity of description, 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, it should be considered as the scope described in this specification.

[0077] Specific examples are used in this article to elaborate on the principles and implementation manners of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manners and application scopes. In summary, the content of this specification should not be construed as a limitation to the present application.

Claims

1. A control method for an oil pump of an electric loader, characterized in that, including: The vehicle controller determines the working mode of the electric loader according to the vehicle state, including the initial working mode, the real-time speed control mode, and the oil pump pressure overshoot mode; The oil pump control method of the electric loader is developed for the whole vehicle of the pure electric loader; The oil pump is the hydraulic oil pump of the electric loader; The vehicle controller determines the working mode of the electric loader according to the vehicle state, specifically including: When the vehicle is in the neutral gear ready state and the boom and bucket have no movement, it is determined that the electric loader is in the initial working mode; When the vehicle has boom or bucket movement and the boom or bucket has not reached the limit position, it is determined that the electric loader is in the real-time speed control mode; When the boom or bucket reaches 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; The fact that the outlet pressure of the oil pump no longer changes means the change rate of the outlet pressure of the oil pump is less than or equal to the change rate threshold ; Rotational speed threshold Determined by measurement. Due to the characteristics of the hydraulic system, only after the bucket or the boom reaches the limit position will the rotational speed of the oil pump maintain a high speed all the time. This value is obtained through measurement and used as the threshold for rotational speed judgment ; When the electric loader is in the initial working mode, the vehicle controller controls the oil pump to run at the minimum designed speed of the oil pump through the oil pump motor controller; 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 minimum designed 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, Before the vehicle controller controls the oil pump to run at the minimum designed speed of the oil pump through the oil pump motor controller, it further includes: Obtaining the minimum pressure required for the hydraulic system to maintain vehicle operation; Determine the minimum rotational speed of the oil pump design corresponding to the minimum pressure required for the hydraulic system .

3. The oil pump control method of the electric loader according to claim 1, wherein Before the vehicle controller calculates the optimal oil pump speed according to the change of the oil pump outlet pressure, it further includes: According to the design of the oil pump or the actual measurement of the vehicle, obtaining the corresponding relationship table between the oil pump speed and the oil pump outlet pressure.

4. The oil pump control method of the electric loader according to claim 3, 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 outlet pressure of the oil pump detected in real time by the oil pump outlet pressure sensor ; Find from the correspondence table of the oil pump speed and the oil pump outlet pressure The corresponding required oil pump speed ; Use the formula to calculate the rotational speed deviation value ; where is the actual rotational speed of the oil pump; Use the formula to calculate the optimal oil pump speed ; where and are the proportional coefficient and integral coefficient of the PI controller respectively; represents time.

5. The oil pump control method of the electric loader according to claim 4, characterized in that, The control of the oil pump to run at the optimal oil pump speed through the oil pump motor controller specifically includes: The vehicle controller sends the calculated optimal fuel pump speed to the fuel pump motor controller via CAN communication; The oil pump motor controller determines according to the one-dimensional linear relationship between the oil pump motor speed and the oil pump speed the corresponding oil pump motor speed ; The oil pump motor controller controls the oil pump motor to run at the oil pump motor speed so as to drive the oil pump to run at the optimal oil pump speed and operate.

6. An oil pump control device for an electric loader, characterized in that, including: 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 through 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 of the electric loader according to any one of claims 1-5.

7. An electric loader, characterized in that, An electric loader is equipped with the oil pump control device according to claim 6.

8. A vehicle controller, characterized in that, including: A memory, a processor, and a computer program stored on the memory and executable on the processor, and the processor executes the computer program to implement the oil pump control method of the electric loader according to any one of claims 1-5.

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