Off-road vehicle distributed electric drive axle double oil pump control method, device, equipment and medium

Abstract

The invention discloses an off-road vehicle distributed electric drive axle double-oil-pump control method, device and equipment and a medium. The method comprises the steps that the rotating speed and torque of current double motors are obtained, and the heat dissipation required flow of the motors and a speed reducer is calculated; acquiring speed reducer output shaft rotating speed, and determining speed reducer lubrication demand flow according to the speed reducer output shaft rotating speed range; calculating the heat dissipation and lubrication required total flow of the motor and the speed reducer, and determining the basic rotating speed of the oil pump through the rotating speed-flow curve of the oil pump; real-time motor temperature is obtained, and adjustment rotating speeds of a first oil pump and a second oil pump are calculated according to the current first motor temperature, the second motor temperature, the dual-motor temperature difference allowable range and the temperature difference duration; and calculating a first oil pump rotating speed and a second oil pump rotating speed based on the obtained oil pump basic rotating speed and the oil pump adjusting rotating speed. According to the method, lubrication and cooling of the motors and the speed reducer can be guaranteed, the temperature difference between the left motor and the right motor can be within a reasonable range, and the efficiency and reliability of the distributed electric drive axle assembly are improved.

Description

Technical Field

[0001] The present invention belongs to the field of vehicle control technology, and more specifically, relates to a method, device, equipment and medium for controlling dual oil pumps of a distributed electric drive axle of an off-road vehicle. Background Art

[0002] In recent years, electric drive technology has gradually become a core development direction for off-road vehicle powertrains, thanks to its high response speed, precise torque distribution, and energy efficiency. This is particularly true for distributed electric drive axles, which utilize a dual-motor + dual-oil pump + independent reducer architecture (such as the electric drive axles developed by BYD Yangwang U8 and Dongfeng Off-Road Vehicle Company). By independently driving the left and right wheels, the vehicle's maneuverability, maneuverability, and adaptability to complex road conditions are significantly improved. Its performance and reliability are highly dependent on the effectiveness of the lubrication and cooling system. Compared to water-cooled motors, oil-cooled motors have higher heat dissipation efficiency and are currently a hot topic in motor cooling technology research. The motor and reducer of an oil-cooled distributed electric drive axle share a common housing and utilize integrated lubrication. By controlling the speed of the left and right oil pumps to adjust the flow rate of the assembly's cooling circuit, the oil-cooled motor effectively solves the lubrication and heat dissipation issues of the motor and reducer. However, due to the complex driving conditions of off-road vehicles, the left and right motors of the distributed electric drive axle are often in different working states. For example: (1) When the off-road vehicle turns in place, the left and right motors output reverse torque, resulting in power differences and causing local high temperatures; (2) When the vehicle is getting out of trouble on a bumpy road, one motor reduces torque due to wheel slippage, while the other motor needs to increase torque output at high load, exacerbating the temperature imbalance between the left and right motors. If the heat dissipation is insufficient, it will directly lead to reduced motor efficiency, insulation aging, or even failure, seriously threatening system reliability. In addition, under different working conditions, the temperature difference between the left and right motors is large, affecting the efficiency and life of the assembly. Therefore, developing an efficient lubrication and cooling control strategy adapted to the distributed electric drive axle to control the temperature difference between the left and right motors has become the key to breaking through the bottleneck of off-road electric drive technology. Summary of the Invention

[0003] In response to the above-mentioned defects or improvement needs of the prior art, the present invention provides a method, device, equipment and medium for controlling the dual oil pumps of a distributed electric drive axle of an off-road vehicle. The method takes into account the temperature difference between the dual motors under different working conditions, controls the speed of the distributed electric drive axle oil pump, and ensures that the flow rate of the oil pump can meet the lubrication and cooling of the motor and reducer while ensuring that the temperature difference between the left and right motors is within a reasonable range, thereby improving the efficiency and reliability of the distributed electric drive axle assembly.

[0004] To achieve the above objectives, according to one aspect of the present invention, a method for controlling dual oil pumps in a distributed electric drive axle of an off-road vehicle is provided, comprising the following specific steps:

[0005] S100: Obtain the current speed and torque parameters of the dual motors and calculate the required heat dissipation flow of the motors and reducers;

[0006] S200: Obtain the speed of the output shaft of the reducer and determine the required lubrication flow rate of the reducer based on the speed range of the output shaft of the reducer;

[0007] S300: Calculates the total flow required for heat dissipation and lubrication of the motor and reducer, and determines the base speed of the oil pump using the oil pump speed-flow curve.

[0008] S400: Acquire real-time temperatures of the first motor and the second motor, and calculate adjusted speeds of the first oil pump and the second oil pump based on the current temperature of the first motor, the temperature of the second motor, the permissible range of the temperature difference between the first motor and the second motor, and the duration of the temperature difference between the first motor and the second motor;

[0009] S500: Calculating a first oil pump speed and a second oil pump speed based on the oil pump base speed and oil pump adjusted speed obtained in steps S300 and S400;

[0010] S600: Based on the calculated oil pump speed, a speed command is directly given to the oil pump controller, and the two oil pumps work together according to the command.

[0011] Furthermore, the step S100 includes:

[0012] S101: Obtain the speed and torque of the first motor and the speed and torque of the second motor, and calculate the real-time output power P of the first motor and the second motor respectively according to the following formula ml 、P mr :

[0013] P ml =N ml ×T ml / 9550 (1)

[0014] P mr =N mr ×T mr / 9550 (2)

[0015] Among them, N ml is the speed of the first motor, T ml is the torque of the first motor, N mr is the speed of the second motor, T mr is the torque of the second motor, P ml is the output power of the first motor, P mr is the output power of the second motor;

[0016] S102: Obtain the efficiency η of the first motor by looking up the motor efficiency MAP table ml and the efficiency η of the second motor mr , calculate the total heat dissipation of the first motor and the second motor according to formula (3):

[0017] P m =P ml ×(1-η ml )+P mr ×(1-η mr ) (3)

[0018] According to the relationship curve between oil pump flow and heat dissipation, the motor heat dissipation demand flow Q1 is obtained;

[0019] S103: Calculate the input speed N of the reducer according to formula (4) re-in , calculate the input torque T of the reducer according to formula (5) re-in :

[0020] N re-in =(|N ml |+|N mr |) / 2 (4)

[0021] T re-in =(|T ml |+|T mr |) / 2 (5)

[0022] S104: Obtain the efficiency η of the reducer at the current reducer speed and torque by looking up the reducer efficiency MAP table. re , and calculate the heat dissipation of the reducer according to formula (6):

[0023] P re =T re-in ×N re-in / 9550×(1—η re ) (6)

[0024] According to the relationship curve between oil pump flow and heat dissipation, the reducer heat dissipation demand flow Q2 is obtained.

[0025] Furthermore, in step S200, the required flow rate of reducer lubrication for different speed ranges of the reducer output shaft is calculated as follows:

[0026] When N re-out ≤N re-low hour,

[0027] Q3=Q oil-min (7)

[0028] When N re-low <N re-out ≤N re-mid hour,

[0029]

[0030] When N re-mid <N re-out ≤N re-hihour,

[0031]

[0032] When N re-hi <N re-out ≤N re-max hour,

[0033] Q3=Q oil-hi (10)

[0034] Among them, N re-out is the speed of the reducer output shaft; N re-low is the first speed of the reducer output shaft; N re-mid is the second speed of the reducer output shaft; N re-hi The third speed of the output shaft of the reducer; N re-max is the fourth speed of the reducer output shaft; Q oil-min is the oil pump flow rate at the first speed; Q oil-mid Q is the oil pump flow rate at the second speed; oil-hi is the oil pump's third speed flow rate; k1 and k2 are correction coefficients.

[0035] Furthermore, the total flow required for heat dissipation and lubrication in step S300 is calculated as follows:

[0036] Q4=Q1+Q2+Q3 (11)

[0037] Among them, Q1 is the required flow rate for motor heat dissipation, Q2 is the required flow rate for reducer heat dissipation, and Q3 is the required flow rate for reducer lubrication.

[0038] Furthermore, the step S400 includes:

[0039] The motor operating temperature condition is divided into the operating temperature zone, over-temperature zone 1 and over-temperature zone 2;

[0040] When the first motor temperature and the second motor temperature are both within the operating temperature range, the temperature difference between the first motor temperature and the second motor temperature exceeds the temperature difference threshold, the temperature difference duration exceeds the time threshold, and the first motor temperature is greater than the second motor temperature, the second oil pump adjustment speed is calculated:

[0041] ΔN oil-r =(t ml -t mr )×n (12)

[0042] Where, ΔN oil-r Adjust the speed of the second oil pump, t ml is the first motor temperature, t mr is the temperature of the second motor, n is the oil pump speed adjustment step;

[0043] When the first motor temperature and the second motor temperature are both within the operating temperature range, the temperature difference between the first motor temperature and the second motor temperature exceeds the temperature difference threshold, the temperature difference duration exceeds the time threshold, and the first motor temperature is lower than the second motor temperature, the first oil pump adjustment speed is calculated:

[0044] ΔN oil-l =(t mr -t ml )×n (13)

[0045] Where, ΔN oil-l Adjust the speed of the first oil pump;

[0046] When the temperature of the first motor and the temperature of the second motor are both within the operating temperature range, and the temperature difference between the temperature of the first motor and the temperature of the second motor does not exceed the temperature difference threshold or the duration of the temperature difference does not exceed the time threshold, there is no need to adjust the speeds of the first oil pump and the second oil pump;

[0047] When the temperature of the first motor is in over-temperature zone 1 or over-temperature zone 2, the speed of the first oil pump is adjusted to the maximum speed, and the oil pump current is monitored at the same time;

[0048] When the temperature of the second motor is over temperature zone 1 or over temperature zone 2, the speed of the second oil pump is adjusted to the maximum speed, and the oil pump current is monitored at the same time.

[0049] Furthermore, the step S400 includes: when the motor exceeds over-temperature point 1, the controller will issue an over-temperature warning; when the motor exceeds over-temperature point 2, the controller will directly shut down.

[0050] Furthermore, in step S500,

[0051] The first oil pump speed is:

[0052] N oil-l =N oil-0 +ΔN oil-l (14)

[0053] The speed of the second oil pump is:

[0054] N oil-r =N oil-0 +ΔN oil-r (15)

[0055] Among them, N oil-0 is the basic speed of the oil pump; ΔN oil-l Adjust the speed of the first oil pump; N oil-r Adjust the speed for the second oil pump.

[0056] According to a second aspect of the present invention, the present invention provides an off-road vehicle distributed electric drive axle dual oil pump coordinated control device, which is used to implement the above-mentioned off-road vehicle distributed electric drive axle dual oil pump coordinated control method, including:

[0057] Data acquisition module: used to obtain vehicle parameters in real time, including dual motor speed, torque, motor stator temperature and reducer output shaft speed;

[0058] Calibration database module: stores motor efficiency MAP, reducer efficiency MAP, oil pump flow-heat dissipation curve, oil pump speed-flow curve, temperature threshold parameters, reducer output shaft speed range segmentation parameters, supports dynamic automatic query and update, and obtains relevant calculation parameters;

[0059] Calculation module: This module is used to comprehensively calculate the heat dissipation and lubrication requirements of the motor and reducer, summarize the total required flow rate to determine the base oil pump speed, and dynamically adjust the oil pump speed based on the temperature difference between the two motors and the over-temperature status. This achieves precise coordinated control of the speeds of the two oil pumps, ensuring optimal heat dissipation and lubrication efficiency.

[0060] Control execution module: responsible for generating the final speed command of the dual oil pumps from the oil pump speed output by the calculation module and converting it into actual control signals to drive the dual oil pumps to work together.

[0061] As another aspect of the present invention, the present invention further provides an electronic device, comprising:

[0062] at least one memory for storing a computer program;

[0063] At least one processor is used to implement the steps of the above-mentioned off-road vehicle distributed electric drive axle dual oil pump coordinated control method when executing the computer program.

[0064] The present invention also provides a computer-readable storage medium, on which a computer program is stored. When the computer program is executed by a processor, the steps of the above-mentioned method for coordinated control of dual oil pumps of a distributed electric drive axle of an off-road vehicle are implemented.

[0065] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0066] 1. The off-road vehicle distributed electric drive axle dual oil pump coordinated control method of the present invention obtains parameters such as the dual motor speed, torque, and reducer output shaft speed in real time, calculates the total required flow rate for motor and reducer heat dissipation and reducer lubrication, determines the basic speed of the oil pump, and adjusts the dual oil pump speed according to the real-time temperature, temperature difference, and temperature difference duration of the dual motors in different working conditions, and finally reaches the target speed. The control execution module sends a speed control signal to the dual oil pump according to the calculation results and adjustment instructions, thereby realizing precise coordinated control of the dual oil pump speeds, meeting the lubrication and cooling requirements of the left and right motors and reducer of the distributed electric drive axle, and improving assembly efficiency.

[0067] 2. The off-road vehicle distributed electric drive axle dual oil pump coordinated control method of the present invention adjusts the dual oil pump speed according to the real-time temperature, temperature difference and temperature difference duration of the dual motors in different working conditions. It can adapt to the complex working conditions of off-road vehicles, ensure that the temperature difference of the dual motors in the distributed electric drive axle is within a reasonable range, reduce the impact of excessive temperature difference between the dual motors on each other, and improve the performance and life of the assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0068] Figure 1 This is a flow chart of a method for coordinated control of dual oil pumps in a distributed electric drive axle of an off-road vehicle according to an embodiment of the present invention;

[0069] Figure 2 The motor efficiency MAP of the embodiment of the present invention;

[0070] Figure 3 is the efficiency MAP of the reducer according to the embodiment of the present invention;

[0071] Figure 4 This is a curve showing the relationship between oil pump flow rate and heat dissipation in an embodiment of the present invention;

[0072] Figure 5 This is the oil pump speed-flow curve of the embodiment of the present invention;

[0073] Figure 6 This is a schematic diagram showing the classification of the operating temperature conditions of a motor according to an embodiment of the present invention;

[0074] Figure 7 This is a structural diagram of a data processing device for a coordinated control method of dual oil pumps in a distributed electric drive axle of an off-road vehicle according to an embodiment of the present invention;

[0075] Figure 8 This is a schematic diagram of the electronic device structure for implementing the off-road vehicle distributed electric drive axle dual oil pump coordinated control method of the present invention. DETAILED DESCRIPTION

[0076] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to illustrate the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0077] It should be noted that the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the fact that ordinary technicians in this field can implement it. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0078] In the present invention, the terms "comprises," "comprising," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus that includes a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus that includes the element.

[0079] Example 1

[0080] like Figure 1 As shown, the embodiment of the present invention provides a flow chart of a method for coordinated control of dual oil pumps in a distributed electric drive axle of an off-road vehicle, including the following specific steps:

[0081] S100: Calculating the required heat dissipation flow of the motor and reducer: Obtaining the current speed and torque parameters of the dual motors and calculating the required heat dissipation flow of the motor and reducer; specifically, including:

[0082] S101: Obtaining the rotation speed N of the first motor ml and the torque T of the first motor ml , and the speed N of the second motor mr and the torque T of the second motor mr , calculate the real-time output power P of the first motor according to the following formulas (1) and (2) respectively: ml , the real-time output power P of the second motor mr :

[0083] P ml =N ml ×T ml / 9550 (1)

[0084] P mr =N mr ×Tmr / 9550 (2)

[0085] S102: Through the motor efficiency MAP (provided by the manufacturer, such as Figure 2 The figure shows the efficiency MAP of a certain type of motor. The efficiency η of the first motor is obtained by looking up the table. ml and the efficiency η of the second motor mr , calculate the total heat dissipation of the first motor and the second motor (the sum of the efficiency loss) according to formula (3)

[0086] P m =P ml ×(1-η ml )+P mr ×(1-η mr ) (3)

[0087] According to the relationship curve between oil pump flow and heat dissipation (the oil pump manufacturer provides test data, such as Figure 4 The figure shows the relationship curve between the flow rate and heat dissipation of a certain type of oil pump, and the required heat dissipation flow rate Q1 of the motor is obtained;

[0088] S103: The average of the absolute values of the speeds of the first motor and the second motor is used as the input speed of the reducer. The calculation formula (4) is as follows:

[0089] N re-in =(|N ml |+|N mr |) / 2 (4)

[0090] The average of the absolute values of the torques of the first motor and the second motor is used as the input torque of the reducer. The calculation formula (5) is as follows:

[0091] T re-in =(|T ml |+|T mr |) / 2 (5)

[0092] S104: The efficiency MAP table of the reducer is provided by the manufacturer, such as Figure 3 The figure shows the efficiency MAP of a certain type of reducer. The table shows the efficiency η of the reducer at the current reducer speed and torque. re , calculate the heat dissipation of the reducer (efficiency loss part) according to formula (6):

[0093] P re =T re-in ×N re-in / 9550×(1—η re ) (6)

[0094] According to the relationship curve between oil pump flow and heat dissipation (the oil pump manufacturer provides test data, such as Figure 4As shown), the heat dissipation demand flow rate Q2 of the reducer is obtained.

[0095] S200: Calculate the required lubrication flow rate of the reducer: obtain the speed of the reducer output shaft from the speed sensor of the reducer output shaft, and determine the required lubrication flow rate of the reducer according to the speed range of the reducer output shaft. Specifically,

[0096] The required flow rate for reducer lubrication in different speed ranges of reducer output shaft is calculated as follows:

[0097] When N re-out ≤N re-low When , the reducer lubrication demand flow Q3 is calculated according to formula (7):

[0098] Q3=Q oil-min (7)

[0099] When N re-low <N re-out ≤N re-mid When , the reducer lubrication demand flow Q3 is calculated according to formula (8):

[0100]

[0101] When N re-mid <N re-out ≤N re-hi When , the reducer lubrication demand flow Q3 is calculated according to formula (9):

[0102]

[0103] When N re-hi <N re-out ≤N re-max When , the reducer lubrication demand flow Q3 is calculated according to formula (10):

[0104] Q3=Q oil-hi (10)

[0105] Among them, N re-out is the speed of the reducer output shaft; N re-low is the first speed of the reducer output shaft; N re-mid is the second speed of the reducer output shaft; N re-hi The third speed of the output shaft of the reducer; N re-max is the fourth speed of the reducer output shaft; Q oil-min is the oil pump flow rate at the first speed; Q oil-mid Q is the oil pump flow rate at the second speed; oil-hi is the flow rate of the oil pump at the third speed; k1 and k2 are correction coefficients, which can be obtained by bench test calibration.

[0106] The fourth speed of the reducer output shaft is the designed maximum speed of the output shaft. The first speed of the reducer output shaft refers to the speed at the corresponding lowest vehicle speed, and its value is 5%-15% of the fourth speed of the reducer output shaft. The second speed of the reducer output shaft corresponds to the speed at medium and low vehicle speeds, and its value is 15%-60% of the fourth speed of the reducer output shaft. The third speed of the reducer output shaft corresponds to the speed at high vehicle speed, and its value is 60%-90% of the fourth speed of the reducer output shaft.

[0107] The oil pump first speed flow rate, the oil pump second speed flow rate, and the oil pump third speed flow rate correspond to the oil pump output flow rates at the first speed of the reducer output shaft, the second speed of the reducer output shaft, and the third speed of the reducer output shaft, respectively, and are obtained through bench test calibration.

[0108] S300: Calculate the basic speed of the oil pump: Calculate the total flow required for heat dissipation and lubrication of the motor and reducer according to formula (11), and use the oil pump speed-flow curve (such as Figure 5 For a certain type of oil pump speed-flow curve), determine the basic speed N of the oil pump oil-0 .

[0109] Q4=Q1+Q2+Q3 (11)

[0110] Among them, Q1 is the required flow rate for motor heat dissipation, Q2 is the required flow rate for reducer heat dissipation, and Q3 is the required flow rate for reducer lubrication.

[0111] S400: Calculating the adjusted speeds of the first and second oil pumps: Obtaining the real-time temperatures of the first and second motors through the motor stator temperature sensors, and calculating the adjusted speeds of the first and second oil pumps based on the current first and second motor temperatures, the permitted range of the temperature difference between the first and second motors, and the duration of the temperature difference between the first and second motors, such as Figure 6 The figure shows the motor operating temperature, which is divided into the operating temperature zone, over-temperature zone 1 and over-temperature zone 2. Over-temperature point 1 and over-temperature point 2 are set according to the temperature resistance of the motor's electromagnetic material and are directly given by the manufacturer. Specifically:

[0112] (1) When the first motor temperature and the second motor temperature are both in the operating temperature range, and:

[0113] a) If the temperature difference between the first motor temperature and the second motor temperature exceeds the temperature difference threshold and the temperature difference duration exceeds the time threshold, and the first motor temperature is greater than the second motor temperature, the second oil pump adjustment speed is calculated according to formula (12):

[0114] ΔN oil-r =(t ml -t mr )×n (12)

[0115] Where, ΔN oil-r Adjust the speed of the second oil pump, t ml is the first motor temperature, t mr is the temperature of the second motor, n is the oil pump speed adjustment step, which is determined by the control accuracy and manufacturer calibration and can be defined as 10% of the speed at the minimum flow rate of the oil pump;

[0116] b) If the temperature difference between the first motor temperature and the second motor temperature exceeds the temperature difference threshold and the temperature difference duration exceeds the time threshold, and the first motor temperature is lower than the second motor temperature, the first oil pump adjustment speed is calculated. The first oil pump adjustment speed is calculated according to formula (13):

[0117] ΔN oil-l =(t mr -t ml )×n (13)

[0118] Where, ΔN oil-l Adjust the speed of the first oil pump;

[0119] c) If the temperature difference between the first motor and the second motor does not exceed the temperature difference threshold or the temperature difference duration does not exceed the time threshold, there is no need to adjust the speed of the first oil pump and the second oil pump, that is, ΔN oil =0;

[0120] (2) When the temperature of the first motor or the second motor is in the overtemperature zone (overtemperature zone 1 or overtemperature zone 2), the controller will issue an overtemperature warning when the motor exceeds overtemperature point 1, and the controller will directly shut down when the motor exceeds overtemperature point 2:

[0121] a) When the first motor temperature is overheated, adjust the speed of the first oil pump to the maximum speed N oil-max , while monitoring the oil pump current;

[0122] b) When the second motor temperature is overheated, adjust the second oil pump speed to the maximum speed N oil-max , while monitoring the oil pump current.

[0123] When the temperature reaches overtemperature point 2 and the motor stops, the first oil pump and the second oil pump still need to continue running to prevent hardware damage due to overheating of the assembly.

[0124] S500: Calculate the first oil pump speed N based on the basic oil pump speed and oil pump adjustment speed obtained in steps S300 and S400 oil-l and the second oil pump speed N oil-r

[0125] N oil-l =N oil-0 +ΔN oil-l (14)

[0126] N oil-r =N oil-0 +ΔN oil-r (15)

[0127] Among them, N oil-0 is the basic speed of the oil pump; ΔN oil-l Adjust the speed of the first oil pump; N oil-r Adjust the speed for the second oil pump.

[0128] S600: Based on the calculated oil pump speed, the speed command is directly given to the oil pump controller, which effectively solves the lubrication and heat dissipation problems of the motor and reducer by controlling the oil pump speed.

[0129] Example 2

[0130] like Figure 7 As shown, an embodiment of the present invention provides an off-road vehicle distributed electric drive axle dual oil pump coordinated control data processing device, which is used to implement the above-mentioned off-road vehicle distributed electric drive axle dual oil pump coordinated control method, including:

[0131] Data acquisition module: used to obtain vehicle parameters in real time, including dual motor speed, torque, motor stator temperature, and reducer output shaft speed, monitor oil pump current, and provide input for subsequent calculations;

[0132] Calibration database module: stores motor efficiency MAP table, reducer efficiency MAP table, oil pump characteristic curve (oil pump flow-heat dissipation curve, oil pump speed-flow curve), temperature threshold parameters (overtemperature point 1, overtemperature point 2), reducer output shaft speed range segmentation parameters, etc., supports dynamic automatic query and update, and obtains relevant calculation parameters.

[0133] Calculation module: This module is used to comprehensively calculate the heat dissipation and lubrication requirements of the motor and reducer, summarize the total required flow rate to determine the basic oil pump speed, and dynamically adjust the oil pump speed based on the temperature difference and over-temperature status of the dual motors to achieve precise coordinated control of the dual oil pump speeds, ensuring optimal heat dissipation and lubrication efficiency.

[0134] Control execution module: responsible for generating the final speed command of the dual oil pumps from the oil pump speed output by the calculation module and converting it into actual control signals to drive the dual oil pumps to work together.

[0135] According to the above examples, the present application also provides an electronic device, including: a memory, a processor, and a program or instruction stored in the memory and executable on the processor. When the processor executes the program or instruction, the data device of the present invention may further include a communication interface and a bus. Figure 8, which is a schematic diagram of the structure of the electronic device provided by the present invention, includes: at least one processor 100, at least one memory 101, a communication interface 102 and a bus 103.

[0136] Among them, the processor 100, the memory 101 and the communication interface 102 communicate with each other through the bus 103, and the communication interface 102 is used for information transmission between the data device and the database device; the memory 101 stores a program or instruction that can be run on the processor 100. When the processor 100 executes the program or instruction, the steps of the above-mentioned off-road vehicle distributed electric drive axle dual oil pump coordinated control method are implemented.

[0137] In one possible implementation, the memory 101 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and applications required for at least one function, etc.; the data storage area may store data created during use.

[0138] In addition, the memory 101 may include a high-speed random access memory and may also include a non-volatile memory, such as at least one disk storage device or other volatile solid-state storage device.

[0139] The communication interface 102 may be an interface of a communication module, used to connect to other devices or systems.

[0140] Of course, it needs to be explained that Figure 8 The structure shown does not constitute a limitation on the electronic device in the embodiment of the present application. In actual applications, the electronic device may include Figure 7 More or fewer components than shown, or combinations of certain components.

[0141] An embodiment of the present invention also provides a computer-readable storage medium based on the above examples, on which a computer program is stored. When the computer program is executed by a processor, the steps of the off-road vehicle distributed electric drive axle dual oil pump coordinated control method described in the above embodiment are implemented.

[0142] The computer-readable storage medium may include: a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, etc., which can store program codes.

[0143] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method, device, equipment and medium for controlling dual oil pumps of a distributed electric drive axle of an off-road vehicle, characterized in that: The specific steps include: S100: Obtain the current speed and torque parameters of the dual motors and calculate the required heat dissipation flow of the motors and reducers; S200: Obtain the speed of the output shaft of the reducer and determine the required lubrication flow rate of the reducer based on the speed range of the output shaft of the reducer; S300: Calculates the total flow required for heat dissipation and lubrication of the motor and reducer, and determines the base speed of the oil pump using the oil pump speed-flow curve. S400: Acquire real-time temperatures of the first motor and the second motor, and calculate adjusted speeds of the first oil pump and the second oil pump based on the current temperature of the first motor, the temperature of the second motor, the permissible range of the temperature difference between the first motor and the second motor, and the duration of the temperature difference between the first motor and the second motor; S500: Calculating a first oil pump speed and a second oil pump speed based on the oil pump base speed and oil pump adjusted speed obtained in steps S300 and S400; S600: Based on the calculated oil pump speed, a speed command is directly given to the oil pump controller, and the two oil pumps work together according to the command.

2. The off-road vehicle distributed electric drive axle dual oil pump coordinated control method according to claim 1, characterized in that: The step S100 includes: S101: Obtain the speed and torque of the first motor and the speed and torque of the second motor, and calculate the real-time output power P of the first motor and the second motor respectively according to the following formula ml 、P mr : P ml =N ml ×T ml / 9550 (1) P mr =N mr ×T mr / 9550 (2) Among them, N ml is the speed of the first motor, T ml is the torque of the first motor, N mr is the speed of the second motor, T mr is the torque of the second motor, P ml is the output power of the first motor, P mr is the output power of the second motor; S102: Obtain the efficiency η of the first motor by looking up the motor efficiency MAP table ml and the efficiency η of the second motor mr , calculate the total heat dissipation of the first motor and the second motor according to formula (3): P m =P ml ×(1-n) ml )+P mr ×(1-n) mr ) (3) According to the relationship curve between oil pump flow and heat dissipation, the motor heat dissipation demand flow Q1 is obtained; S103: Calculate the input speed N of the reducer according to formula (4) re-in , calculate the input torque T of the reducer according to formula (5) re-in : N re-in =(|N ml |+|N mr |) / 2 (4) T re-in =(|T ml |+|T mr |) / 2 (5) S104: Obtain the efficiency η of the reducer at the current reducer speed and torque by looking up the reducer efficiency MAP table. re , and calculate the heat dissipation of the reducer according to formula (6): P re =T re-in ×N re-in / 9550×(1—n re ) (6) According to the relationship curve between oil pump flow and heat dissipation, the reducer heat dissipation demand flow Q2 is obtained.

3. The off-road vehicle distributed electric drive axle dual oil pump coordinated control method according to claim 2, characterized in that: In step S200, the required flow rate of reducer lubrication for different speed ranges of the reducer output shaft is calculated as follows: When N re-out ≤N re-low hour, Q3=Q oil-min (7) When N re-low <N re-out ≤N re-mid hour, When N re-mid <N re-out ≤N re-hi hour, When N re-hi <N re-out ≤N re-max hour, Q3=Q oil-hi (10) Among them, N re-out is the speed of the reducer output shaft; N re-low is the first speed of the reducer output shaft; N re-mid is the second speed of the reducer output shaft; N re-hi The third speed of the output shaft of the reducer; N re-max is the fourth speed of the reducer output shaft; Q oil-min is the oil pump flow rate at the first speed; Q oil-mid Q is the oil pump flow rate at the second speed; oil-hi is the oil pump's third speed flow rate; k1 and k2 are correction coefficients.

4. The off-road vehicle distributed electric drive axle dual oil pump coordinated control method according to claim 3, characterized in that: The total flow rate required for heat dissipation and lubrication in step S300 is calculated as follows: Q4=Q1+Q2+Q3 (11) Among them, Q1 is the required flow rate for motor heat dissipation, Q2 is the required flow rate for reducer heat dissipation, and Q3 is the required flow rate for reducer lubrication.

5. The off-road vehicle distributed electric drive axle dual oil pump coordinated control method according to claim 4 is characterized in that: The step S400 includes: The motor operating temperature condition is divided into the operating temperature zone, over-temperature zone 1 and over-temperature zone 2; When the first motor temperature and the second motor temperature are both within the operating temperature range, the temperature difference between the first motor temperature and the second motor temperature exceeds the temperature difference threshold, the temperature difference duration exceeds the time threshold, and the first motor temperature is greater than the second motor temperature, the second oil pump adjustment speed is calculated: ΔN oil-r =(t ml -t mr )×n (12) Where, ΔN oil-r Adjust the speed of the second oil pump, t ml is the first motor temperature, t mr is the temperature of the second motor, n is the oil pump speed adjustment step; When the first motor temperature and the second motor temperature are both within the operating temperature range, the temperature difference between the first motor temperature and the second motor temperature exceeds the temperature difference threshold, the temperature difference duration exceeds the time threshold, and the first motor temperature is lower than the second motor temperature, the first oil pump adjustment speed is calculated: ΔN oil-l =(t mr -t ml )×n (13) Where, ΔN oil-l Adjust the speed of the first oil pump; When the temperature of the first motor and the temperature of the second motor are both within the operating temperature range, and the temperature difference between the temperature of the first motor and the temperature of the second motor does not exceed the temperature difference threshold or the duration of the temperature difference does not exceed the time threshold, there is no need to adjust the speeds of the first oil pump and the second oil pump; When the temperature of the first motor is in over-temperature zone 1 or over-temperature zone 2, the speed of the first oil pump is adjusted to the maximum speed, and the oil pump current is monitored at the same time; When the temperature of the second motor is over temperature zone 1 or over temperature zone 2, the speed of the second oil pump is adjusted to the maximum speed, and the oil pump current is monitored at the same time.

6. The off-road vehicle distributed electric drive axle dual oil pump coordinated control method according to claim 5, characterized in that: The step S400 includes: when the motor exceeds over-temperature point 1, the controller will issue an over-temperature warning; when the motor exceeds over-temperature point 2, the controller will directly shut down.

7. The off-road vehicle distributed electric drive axle dual oil pump coordinated control method according to claim 6, characterized in that: In the step S500, The first oil pump speed is: N oil-l =N oil-0 +ΔN oil-l (14) The speed of the second oil pump is: N oil-r =N oil-0 +ΔN oil-r (15) Among them, N oil-0 is the basic speed of the oil pump; ΔN oil-l Adjust the speed of the first oil pump; N oil-r Adjust the speed for the second oil pump.

8. A coordinated control device for dual oil pumps of a distributed electric drive axle of an off-road vehicle, used to implement the steps of a coordinated control method for dual oil pumps of a distributed electric drive axle of an off-road vehicle as described in any one of claims 1 to 7, characterized in that: include: Data acquisition module: used to obtain vehicle parameters in real time, including dual motor speed, torque, motor stator temperature and reducer output shaft speed; Calibration database module: stores motor efficiency MAP, reducer efficiency MAP, oil pump flow-heat dissipation curve, oil pump speed-flow curve, temperature threshold parameters, reducer output shaft speed range segmentation parameters, supports dynamic automatic query and update, and obtains relevant calculation parameters; Calculation module: This module is used to comprehensively calculate the heat dissipation and lubrication requirements of the motor and reducer, summarize the total required flow rate to determine the base oil pump speed, and dynamically adjust the oil pump speed based on the temperature difference between the two motors and the over-temperature status. This achieves precise coordinated control of the speeds of the two oil pumps, ensuring optimal heat dissipation and lubrication efficiency. Control execution module: responsible for generating the final speed command of the dual oil pumps from the oil pump speed output by the calculation module and converting it into actual control signals to drive the dual oil pumps to work together.

9. An electronic device, characterized in that: include: at least one memory for storing a computer program; At least one processor is configured to implement the steps of a method for collaboratively controlling dual oil pumps of a distributed electric drive axle of an off-road vehicle as described in any one of claims 1 to 7 when executing the computer program.

10. A computer-readable storage medium, characterized in that The computer-readable storage medium stores a computer program, and when the computer program is executed by the processor, the steps of the off-road vehicle distributed electric drive axle dual oil pump coordinated control method according to any one of claims 1 to 7 are implemented.

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