An all-electric excavator loader and torque distribution method

Abstract

The application discloses a pure electric excavator loader and a torque distribution method. The application discloses the following technical scheme: the traditional gearbox structure is abandoned, and a front traveling motor and a rear traveling motor are used to drive a front axle and a rear axle respectively. When traveling, torque distribution of the front traveling motor and the rear traveling motor is performed according to the front axle load, the rear axle load, an accelerator signal and a brake pedal signal, so that the front and rear wheel skidding can be effectively avoided, and four-wheel drive can be directly used at high speed, and driving force is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of pure electric excavator and torque distribution method, belong to engineering machinery field. BACKGROUND

[0002] Excavator is a kind of multifunctional engineering machinery equipment that can engage in excavation, shovel loading, carrying and flattening site etc.. Current excavator adopts fuel engine as power source, power is usually divided to front axle and rear axle by gearbox and front and rear transmission shaft, since excavator has the characteristics of small front wheel and large rear wheel, front wheel speed is faster than rear wheel, and front and rear wheel skid is prone to occur when driving (whether high speed or low speed), and for driving safety, it will become rear drive at high speed, and the driving force of rear drive is weak. SUMMARY

[0003] The present application provides a kind of pure electric excavator and torque distribution method, solve the problem disclosed in background art.

[0004] According to one aspect of the present disclosure, a pure electric excavator is provided, comprising a front traveling motor, a front traveling motor controller, a rear traveling motor, a rear traveling motor controller, a vehicle controller, a battery controller and a power battery;

[0005] The front traveling motor drives the front axle, and the rear traveling motor drives the rear axle;

[0006] The vehicle controller distributes the torque of the front traveling motor and the rear traveling motor according to the front axle load, the rear axle load, the throttle signal and the brake pedal signal, and sends the distribution result of the front traveling motor torque to the front traveling motor controller, sends the distribution result of the rear traveling motor torque to the rear traveling motor controller, and sends the first trigger instruction to the battery controller; Wherein, the first trigger instruction is an instruction for triggering power-on after torque distribution is completed;

[0007] The battery controller controls the power supply line of the power battery and the front traveling motor controller to be turned on and powered in response to receiving the first trigger instruction, and controls the power supply line of the power battery and the rear traveling motor controller to be turned on and powered;

[0008] The front traveling motor controller controls the front traveling motor to drive the front axle according to the distribution result of the front traveling motor torque in response to the power supply line of the power battery being turned on and powered;

[0009] The rear traveling motor controller controls the rear traveling motor to drive the rear axle according to the distribution result of the rear traveling motor torque in response to the power supply line of the power battery being turned on and powered.

[0010] Further, it further comprises a hydraulic motor and a hydraulic motor controller;

[0011] The hydraulic motor is used to drive the hydraulic pump.

[0012] The vehicle controller sends the action signal to the hydraulic motor controller and sends the second trigger instruction to the battery controller in response to receiving the action signal of the operation handle; wherein the second trigger instruction is an instruction to trigger power-on after receiving the action signal;

[0013] The battery controller controls the power supply circuit of the power battery and the hydraulic motor controller to be turned on and powered in response to receiving the second trigger instruction;

[0014] The hydraulic motor controller controls the hydraulic motor to act according to the action signal in response to the power supply circuit of the power battery being turned on and powered.

[0015] Further, the hydraulic pump includes a first pump port and a second pump port, the first pump port supplies oil to the working oil cylinder through the hydraulic valve, and the second pump port supplies oil to the brake through the steering valve.

[0016] Further, it also includes a battery cooling device and a battery heating device;

[0017] The battery controller sends the battery heating instruction to the vehicle controller and controls the power supply circuit of the power battery and the battery heating device to be turned on and powered in response to the temperature of the power battery being less than the low temperature threshold; and sends the battery cooling instruction to the vehicle controller and controls the power supply circuit of the power battery and the battery cooling device to be turned on and powered in response to the temperature of the power battery being greater than the high temperature threshold;

[0018] The vehicle controller sends the battery heating instruction to the battery heating device in response to receiving the battery heating instruction, and sends the battery cooling instruction to the battery cooling device in response to receiving the battery cooling instruction;

[0019] The battery heating device performs heating action according to the battery heating instruction in response to the power supply circuit of the power battery being turned on and powered;

[0020] The battery cooling device performs cooling action according to the battery cooling instruction in response to the power supply circuit of the power battery being turned on and powered.

[0021] Further, it also includes an environmental cooling device and an environmental heating device;

[0022] The battery controller controls the power supply circuit of the power battery and the environmental heating device to be turned on and powered in response to receiving the externally triggered environmental heating instruction, and controls the power supply circuit of the power battery and the environmental cooling device to be turned on and powered in response to receiving the externally triggered environmental cooling instruction;

[0023] The whole vehicle controller sends the environment heating instruction to the environment heating device in response to receiving the externally triggered environment heating instruction; and sends the environment refrigeration instruction to the environment refrigeration device in response to receiving the externally triggered environment refrigeration instruction.

[0024] The environment heating device performs a heating action according to the environment heating instruction in response to being powered on and powered by the power supply line of the power battery.

[0025] The environment refrigeration device performs a refrigeration action according to the environment refrigeration instruction in response to being powered on and powered by the power supply line of the power battery.

[0026] Further, the DC / DC controller is further included.

[0027] The whole vehicle controller sends the power taking instruction to the battery controller and the DC / DC controller in response to receiving the power supply demand of the low-voltage electrical equipment.

[0028] The battery controller controls the power supply line of the power battery to be powered on and powered by the DC / DC controller in response to receiving the power taking instruction.

[0029] The DC / DC controller performs a power taking action according to the power taking instruction in response to being powered on and powered by the power supply line of the power battery.

[0030] Further, the power battery is powered through the high-voltage distribution box, and the battery controller controls the power supply line to be turned on and off by controlling the high-voltage distribution box.

[0031] According to another aspect of the present disclosure, a torque distribution method is provided, which is applicable to the above-mentioned pure electric excavator loader, and the method comprises:

[0032] The requested whole vehicle torque is calculated according to the accelerator signal and the brake pedal signal;

[0033] The possible torque of the front traveling motor and the possible torque of the rear traveling motor are found out from a first torque distribution table according to the requested whole vehicle torque, the front axle load and the rear axle load; wherein the first torque distribution table stores corresponding front traveling motor torque and front axle load, corresponding rear traveling motor torque and rear axle load, and the torque values are all not greater than the adhesion of the front tire and the rear tire to the ground;

[0034] The front traveling motor torque and the rear traveling motor torque at the minimum power sum are found out from a second torque distribution table according to the possible torque of the front traveling motor and the possible torque of the rear traveling motor, and the front traveling motor torque and the rear traveling motor torque at the minimum power sum are taken as the final torque distribution result; wherein the second torque distribution table stores the power sum corresponding to different torque distributions; and the power sum is the sum of the front traveling motor power and the rear traveling motor power.

[0035] Further, the first torque distribution table is pre-constructed, and the process of pre-constructing the first torque distribution table comprises:

[0036] According to the front axle load, the rear axle load, the front traveling motor external characteristic torque and the rear traveling motor external characteristic torque, the front traveling motor possible distribution torque and the rear traveling motor possible distribution torque are calculated, and the first torque distribution table is constructed according to the front traveling motor possible distribution torque and the rear traveling motor possible distribution torque.

[0037] Wherein, the front traveling motor possible distribution torque and the rear traveling motor possible distribution torque are calculated, and the formula is:

[0038]

[0039] In the formula, T is the whole vehicle torque, T1 and T2 are the front traveling motor torque and the rear traveling motor torque respectively, m1 and m2 are the front axle load and the rear axle load respectively, k1 and k2 are the relationship parameters, T 1峰 And T 2峰 are the front traveling motor external characteristic torque and the rear traveling motor external characteristic torque respectively.

[0040] Further, the second torque distribution table is pre-constructed, and the process of pre-constructing the second torque distribution table comprises:

[0041] According to the front traveling motor and the rear traveling motor efficiency map, the power sum under different torque distribution is calculated, and the second torque distribution table is constructed according to the power sum under different torque distribution.

[0042] The present application has the following beneficial effects: The present application discards the traditional gearbox structure, and adopts the front traveling motor and the rear traveling motor to drive the front axle and the rear axle respectively, in the driving, according to the front axle load, the rear axle load, the throttle signal and the brake pedal signal, the front traveling motor and the rear traveling motor torque distribution is carried out, the front and rear wheel skidding can be effectively avoided, and the four-wheel drive can be directly used at high speed, and the driving force is improved. BRIEF DESCRIPTION OF DRAWINGS

[0043] Figure 1 It is a control module architecture diagram of the pure electric excavator loader;

[0044] Figure 2 It is a flow chart of the torque distribution method;

[0045] Figure 3 It is a motor external characteristic torque schematic diagram;

[0046] Figure 4 It is a motor efficiency map. DETAILED DESCRIPTION

[0047] ​The technical solutions in the embodiments of the present disclosure will be described clearly and completely in the embodiments of the present disclosure in combination with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only part of the embodiments of the present disclosure, rather than all the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and not intended to be limiting on the present disclosure and its applications or uses. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the scope of the present disclosure.

[0048] Unless specifically stated, the relative arrangements of the components and steps, numerical expressions, and numerical values set forth in the examples herein are not meant to limit the scope of the present disclosure.

[0049] It should be understood that the sizes of the various portions shown in the drawings are not drawn to scale for the sake of convenience of description.

[0050] The techniques, methods, and devices known to those of ordinary skill in the relevant art can not be discussed in detail, but should be considered part of the specification where appropriate.

[0051] In all the examples shown and discussed herein, any specific values should be interpreted as merely illustrative and not as a limitation. Thus, other examples of the example embodiments can have different values.

[0052] It should be noted that similar symbols and letters represent similar items in the drawings, and thus, once an item is defined in one drawing, it need not be discussed further in subsequent drawings.

[0053] Meanwhile, in the description of the embodiments of the present application, the terms "first", "second", and the like are used only to distinguish the description, and cannot be understood as indicating or implying relative importance. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more features.

[0054] In order to solve the problems of easy slipping of front and rear wheels and weak driving force of rear drive at high speed of the existing excavator loader, the present disclosure proposes a new pure electric excavator loader, specifically, the traditional gearbox structure is abandoned, the front traveling motor and the rear traveling motor are used to drive the front axle and the rear axle respectively, and the torque distribution of the front traveling motor and the rear traveling motor is performed during traveling.

[0055] Referring to Figure 1 , Figure 1 The control module architecture diagram of the pure electric excavator loader, the pure electric excavator loader can at least include a front traveling motor, a front traveling motor controller, a rear traveling motor, a rear traveling motor controller, a vehicle controller, a battery controller and a power battery.

[0056] The front traveling motor drives the front axle, and the rear traveling motor drives the rear axle. It should be noted that the front traveling motor and the rear traveling motor are driving modules of the whole vehicle, the front traveling motor is mechanically connected with the front axle to drive the front axle, the two sides of the front axle are connected with tires, the rear traveling motor is mechanically connected with the rear axle to drive the front axle, the two sides of the rear axle are connected with tires, and the front traveling motor and the rear traveling motor are not mechanically connected.

[0057] The whole vehicle controller performs torque distribution of the front traveling motor and the rear traveling motor according to the front axle load, the rear axle load, the accelerator pedal signal and the brake pedal signal, sends the distribution result of the front traveling motor torque to the front traveling motor controller, sends the distribution result of the rear traveling motor torque to the rear traveling motor controller, and sends the first trigger instruction to the battery controller. The first trigger instruction is an instruction for triggering power supply after torque distribution is completed.

[0058] It should be noted that the whole vehicle controller is the brain of the whole vehicle, which is an existing component. Its main function is to collect information, process the information, and then issue corresponding instructions.

[0059] The front axle load and the rear axle load can be obtained from the load sensor, that is, the front axle load sensor and the rear axle load sensor are respectively installed on the front axle and the rear axle. The load sensor can communicate with the whole vehicle controller through the CAN bus to realize the transmission of the load.

[0060] The accelerator pedal signal is a signal generated by the driver stepping on the accelerator pedal, and the brake pedal signal is a signal generated by the driver stepping on the brake pedal. The accelerator pedal and the brake pedal also communicate with the whole vehicle controller through the CAN bus to realize the transmission of the accelerator pedal signal and the brake pedal signal.

[0061] Similarly, the front traveling motor controller, the rear traveling motor controller and the battery controller communicate with the whole vehicle controller through the CAN bus to realize the transmission of the distribution result and the first trigger instruction. The distribution result can be used to control the output torque of the traveling motor, and the first trigger instruction is only a prompt signal, that is, a prompt signal prompting the battery controller to take corresponding action.

[0062] During driving, the whole vehicle controller performs torque distribution of the front traveling motor and the rear traveling motor according to the front axle load, the rear axle load, the accelerator pedal signal and the brake pedal signal. Through torque distribution, the front and rear wheels can be effectively prevented from slipping, and there is no risk of directly using four-wheel drive at high speed, so there is no need to switch to rear-wheel drive, thereby improving the driving force at high speed.

[0063] The battery controller, in response to receiving the first trigger instruction, controls the power supply line between the power battery and the front traveling motor controller to be conductive and supply power, and controls the power supply line between the power battery and the rear traveling motor controller to be conductive and supply power.

[0064] It should be noted that the battery controller and the power battery are necessary equipment for the current electric vehicle, and the battery controller interacts with the power battery, that is, through the low-voltage wire harness connection, the power battery voltage, power, temperature and the like can be monitored, and the power battery can also be controlled to supply power and charge externally

[0065] Referring to Figure 1 In some embodiments, the power battery can supply power through the high-voltage distribution box, and the battery controller controls the on-off of the power supply circuit by controlling the high-voltage distribution box, that is, the power battery is connected to the high-voltage distribution box through the high-voltage cable, the battery controller is connected to the high-voltage distribution box through the low-voltage wire harness, and the high-voltage relay in the high-voltage distribution box is controlled, thereby controlling the on-off of the power supply circuit.

[0066] The front walking motor controller is powered on in response to the power supply circuit of the power battery, and controls the front walking motor to drive the front axle according to the distribution result of the front walking motor torque. The rear walking motor controller is powered on in response to the power supply circuit of the power battery, and controls the rear walking motor to drive the rear axle according to the distribution result of the rear walking motor torque.

[0067] It should be noted that referring to Figure 1 , the high-voltage distribution box can be connected to the front walking motor controller and the rear walking motor controller through the high-voltage cable, when the power supply circuit is powered on, that is, the high-voltage relay between the power battery and the walking motor controller is closed, and the power battery supplies power to the walking motor controller, at this time the walking motor controller will control the walking motor to act according to the distributed torque.

[0068] It should be noted that in addition to torque distribution control, excavator loader also needs hydraulic control in some embodiments, so the excavator loader also includes a hydraulic motor and a hydraulic motor controller.

[0069] Similar to the walking motor, the hydraulic motor controller is connected to the vehicle controller through the CAN bus, the high-voltage distribution box can be connected to the hydraulic motor controller through the high-voltage cable, the hydraulic motor controller is connected to the hydraulic motor through the high-voltage wire harness, and the hydraulic motor is used to drive the hydraulic pump. The hydraulic pump includes a first pump port and a second pump port, the first pump port has a large displacement, and the first pump port supplies oil to the working oil cylinder through the hydraulic valve, such as the boom cylinder, the bucket cylinder, the arm cylinder, the stick cylinder, the bucket cylinder, the swing cylinder and the outrigger cylinder. The second pump port has a small displacement, and the second pump port supplies oil to the brake through the steering valve.

[0070] In the hydraulic control:

[0071] The whole vehicle controller sends the action signal to the hydraulic motor controller and sends the second trigger instruction to the battery controller in response to receiving the action signal of the operation handle; wherein the second trigger instruction is an instruction to trigger power-on after receiving the action signal;

[0072] The battery controller controls the power supply circuit of the power battery and the hydraulic motor controller to be conductive and supply power in response to receiving the second trigger instruction;

[0073] The hydraulic motor controller controls the hydraulic motor to act according to the action signal in response to the power supply circuit being conductive and supplying power with the power battery.

[0074] It should be noted that the operation handle and the above-mentioned accelerator are similar, connected to the whole vehicle controller through the CAN bus, and the operation handle action will send an action signal to the whole vehicle controller. The whole vehicle controller sends the action signal to the hydraulic motor controller and sends the second trigger instruction to the battery controller after receiving the action signal, that is, triggers the battery controller to control the high-voltage relay of the power battery and the hydraulic motor controller to close, and controls the power battery to supply power to the hydraulic motor controller. The hydraulic motor controller will control the hydraulic motor to act after being powered on according to the action signal. Specifically, the hydraulic motor drives the hydraulic pump to pump hydraulic oil to the hydraulic valve, steering valve, and brake. The hydraulic valve supplies oil to each hydraulic cylinder, and the steering valve supplies oil to the steering gear to realize the work of each cylinder, steering, and driving brake.

[0075] It should be noted that in addition to torque distribution control and hydraulic control, some auxiliary controls such as battery heating and refrigeration control, environmental heating and refrigeration control, and power supply control will also be performed in some embodiments.

[0076] The structure of the battery heating and refrigeration control can at least include a battery refrigeration device and a battery heating device; wherein the battery refrigeration device can adopt a battery water cooling unit, and the battery heating device can adopt a battery water heater. Both of them are connected to the high-voltage distribution box through the high-voltage cable, and are connected to the whole vehicle controller through the CAN bus.

[0077] During battery heating and refrigeration control:

[0078] The battery controller sends the battery heating instruction to the whole vehicle controller and controls the power supply circuit of the power battery and the battery heating device to be conductive and supply power in response to the power battery temperature being less than the low temperature threshold; and sends the battery refrigeration instruction to the whole vehicle controller and controls the power supply circuit of the power battery and the battery refrigeration device to be conductive and supply power in response to the power battery temperature being greater than the high temperature threshold;

[0079] The whole vehicle controller sends the battery heating instruction to the battery heating device in response to receiving the battery heating instruction; and sends the battery refrigeration instruction to the battery refrigeration device in response to receiving the battery refrigeration instruction;

[0080] The battery heating device, in response to the power supply line being connected and powered with the power battery, executes the heating action according to the battery heating instruction.

[0081] The battery refrigeration device, in response to the power supply line being connected and powered with the power battery, executes the refrigeration action according to the battery refrigeration instruction.

[0082] It should be noted that, due to the interaction between the power battery and the battery controller, when the power battery temperature is less than 0°, the battery heating instruction is sent to the vehicle controller, the high-voltage relay between the power battery and the battery heating device is controlled to be closed, and the power battery is controlled to supply power to the battery heating device. After the vehicle controller receives the battery heating instruction, the battery heating instruction is sent to the battery heating device, and the battery heating device executes the heating action according to the battery heating instruction after being powered on. Conversely, when the power battery temperature is greater than 45°, the battery refrigeration instruction is sent to the vehicle controller, the high-voltage relay between the power battery and the battery refrigeration device is controlled to be closed, and the power battery is controlled to supply power to the battery refrigeration device. After the vehicle controller receives the battery refrigeration instruction, the battery refrigeration instruction is sent to the battery refrigeration device, and the battery refrigeration device executes the refrigeration action according to the battery refrigeration instruction after being powered on.

[0083] The structure of the environment heating and refrigeration control can at least include an environment refrigeration device and an environment heating device, wherein the environment refrigeration device can adopt a refrigeration air conditioner, and the environment heating device can adopt a wind-warming PTC heater. Both of them are connected to the high-voltage distribution box through the high-voltage cable, and are connected to the vehicle controller through the CAN bus. At the same time, since the environment heating and refrigeration is triggered externally, an air conditioning panel can be matched, which is connected to the vehicle controller and the battery controller through the CAN bus, that is, the environment heating or refrigeration is triggered through the keys in the air conditioning panel.

[0084] In the environment heating and refrigeration control:

[0085] The battery controller, in response to receiving the externally triggered environment heating instruction, that is, triggering the environment heating through the air conditioning panel, controls the power supply line of the power battery and the environment heating device to be connected and powered; in response to receiving the externally triggered environment refrigeration instruction, that is, triggering the environment refrigeration through the air conditioning panel, controls the power supply line of the power battery and the environment refrigeration device to be connected and powered.

[0086] The vehicle controller, in response to receiving the externally triggered environment heating instruction, sends the environment heating instruction to the environment heating device; in response to receiving the externally triggered environment refrigeration instruction, sends the environment refrigeration instruction to the environment refrigeration device.

[0087] The environment heating device executes a heating action according to the environment heating instruction in response to being powered on and powered by the power supply line of the power battery.

[0088] The environment refrigeration device executes a refrigeration action according to the environment refrigeration instruction in response to being powered on and powered by the power supply line of the power battery.

[0089] It should be noted that when the environment temperature is low, such as 2°, the driver presses the heating button in the air conditioning panel, that is, sends the environment heating instruction to the vehicle controller and the battery controller, the battery controller receives the environment heating instruction, controls the high-voltage relay between the power battery and the environment heating device to be closed, and controls the power battery to supply power to the environment heating device, the vehicle controller receives the environment heating instruction, sends the environment heating instruction to the environment heating device, and the environment heating device executes a heating action according to the environment heating instruction after being powered on. Conversely, when the environment temperature is high, such as 30°, the driver presses the refrigeration button in the air conditioning panel, that is, sends the environment refrigeration instruction to the vehicle controller and the battery controller, the battery controller receives the environment refrigeration instruction, controls the high-voltage relay between the power battery and the environment refrigeration device to be closed, and controls the power battery to supply power to the environment refrigeration device, the vehicle controller receives the environment refrigeration instruction, sends the environment refrigeration instruction to the environment refrigeration device, and the environment refrigeration device executes a refrigeration action according to the environment refrigeration instruction after being powered on.

[0090] The power taking control structure at least includes a DC / DC controller, the DC / DC controller is connected to the high-voltage distribution box through a high-voltage cable, and is connected to the vehicle controller through a CAN bus.

[0091] When the power taking control is performed:

[0092] The vehicle controller sends a power taking instruction to the battery controller and the DC / DC controller in response to receiving a low-voltage power supply requirement of a low-voltage electrical device, such as receiving a power supply requirement of a low-voltage electrical device such as a working handle, a brake pedal, an air conditioning panel, a lead-acid storage battery, etc.

[0093] The battery controller controls the power supply line of the power battery and the DC / DC controller to be powered on and powered in response to receiving the power taking instruction.

[0094] The DC / DC controller executes a power taking action according to the power taking instruction in response to being powered on and powered by the power supply line of the power battery.

[0095] It should be noted that the power taken here is taken from the power battery through the DC / DC controller, and the high-voltage power is converted into low-voltage power to supply power to the lead-acid battery and low-voltage electrical equipment. The vehicle controller receives the power supply demand of the low-voltage electrical equipment, and sends a power taking instruction to the battery controller and the DC / DC controller. After the battery controller receives the power taking instruction, the high-voltage relay between the power battery and the DC / DC controller is closed, and the power battery supplies power to the DC / DC controller. After the DC / DC controller is powered on, the power taking action is performed according to the power taking instruction.

[0096] The above-mentioned pure electric excavator loader discards the traditional gearbox structure, and adopts front and rear traveling motors to drive the front and rear axles respectively, reduces environmental pollution, and when driving, the torque of the front and rear traveling motors is distributed according to the front axle load, the rear axle load, the throttle signal and the brake pedal signal, which can effectively avoid the front and rear wheel slipping, improve the vehicle stability, safety, efficiency and endurance, and directly use four-wheel drive at high speed to improve the driving force.

[0097] Referring to Figure 2 , Figure 1 is a flowchart of a torque distribution method provided by the embodiment of the disclosure, which is applicable to the above-mentioned pure electric excavator loader and can be executed by the vehicle controller. The method can at least include the following steps:

[0098] Step 1, calculating the requested vehicle torque according to the throttle signal and the brake pedal signal.

[0099] The vehicle controller VCU obtains the opening degree electrical signals of the throttle pedal and the brake pedal in real time, and calculates the requested torque of the vehicle according to the changes of the throttle pedal and the brake pedal electrical signals.

[0100] Step 2, finding out the possible torque of the front traveling motor and the possible torque of the rear traveling motor from the first torque distribution table according to the requested vehicle torque, the front axle load and the rear axle load; wherein the first torque distribution table stores the corresponding front traveling motor torque and the front axle load, the corresponding rear traveling motor torque and the rear axle load, and the torque values are all not greater than the adhesion of the front tire and the rear tire to the ground.

[0101] It should be noted that the first torque distribution table is a pre-constructed table, which can be stored in the machine controller after construction. The process of pre-constructing the first torque distribution table can include:

[0102] According to the possible front axle load, the possible rear axle load, the front traveling motor external characteristic torque and the rear traveling motor external characteristic torque (see Figure 3), calculate the torque that the front traveling motor can possibly distribute and the torque that the rear traveling motor can possibly distribute, construct a first torque distribution table according to the torque that the front traveling motor can possibly distribute and the torque that the rear traveling motor can possibly distribute, and distribute the front traveling motor torque and the rear traveling motor torque according to the first torque distribution table, so that the vehicle does not slip.

[0103] Calculate the torque that the front traveling motor can possibly distribute and the torque that the rear traveling motor can possibly distribute, and the formula is:

[0104] ;

[0105] In the formula, T is the vehicle torque, T1 and T2 are the torques of the front traveling motor and the rear traveling motor respectively, m1 and m2 are the front axle load and the rear axle load respectively, k1 and k2 are the relationship parameters, k1 is the relationship parameter of m1 and T1, k2 is the relationship parameter of m2 and T2, T 1峰 and T 2峰 are the external characteristic torques of the front traveling motor and the rear traveling motor respectively.

[0106] Step 3: According to the torque that the front traveling motor can possibly distribute and the torque that the rear traveling motor can possibly distribute, find the front traveling motor torque and the rear traveling motor torque with the minimum power sum from the second torque distribution table, and take the front traveling motor torque and the rear traveling motor torque with the minimum power sum as the final torque distribution result; the second torque distribution table stores the power sum corresponding to different torque distributions; the power sum is the sum of the front traveling motor power and the rear traveling motor power.

[0107] It should be noted that the second torque distribution table is a pre-constructed table, which can be stored in the machine controller after construction. The process of pre-constructing the second torque distribution table includes: calculating the power sum under different torque distributions according to the efficiency map of the front traveling motor and the rear traveling motor (see Figure 4 ), and constructing the second torque distribution table according to the power sum under different torque distributions.

[0108] The formula for determining the final torque distribution result can be expressed as:

[0109] ;

[0110] In the formula, P is the power sum, are the efficiencies of the front traveling motor and the rear traveling motor respectively, i1 and i2 are the front axle speed ratio and the rear axle speed ratio respectively, and n1 and n2 are the speeds of the front traveling motor and the rear traveling motor respectively.

[0111] According to the second torque distribution table, the front and rear traveling motor speeds and torques are distributed in real time, so that the total motor efficiency is at a high efficiency point, and the vehicle endurance is improved.

[0112] The above description is only the preferred embodiment of the present application, it should be pointed out that for those skilled in the art, without departing from the technical principles of the present application, several improvements and modifications can be made, and these improvements and modifications should also be considered as the protection scope of the present application.

Claims

1. A torque distribution method, characterized by, The method is suitable for a pure electric excavator loader, and the pure electric excavator loader comprises a front walking motor, a front walking motor controller, a rear walking motor, a rear walking motor controller, a vehicle controller, a battery controller and a power battery; the front walking motor drives a front axle, and the rear walking motor drives a rear axle; The vehicle controller distributes the torque of the front walking motor and the rear walking motor according to the front axle load, the rear axle load, an accelerator signal and a brake pedal signal, and sends the distribution result of the front walking motor torque to the front walking motor controller, sends the distribution result of the rear walking motor torque to the rear walking motor controller, and sends a first trigger instruction to the battery controller; the first trigger instruction is an instruction for triggering power supply after the torque distribution is completed; the battery controller controls the power supply line between the power battery and the front walking motor controller to be conducted and powered in response to receiving the first trigger instruction, and controls the power supply line between the power battery and the rear walking motor controller to be conducted and powered; the front walking motor controller controls the front walking motor to drive the front axle according to the distribution result of the front walking motor torque in response to the power supply line between the power battery being conducted and powered; the rear walking motor controller controls the rear walking motor to drive the rear axle according to the distribution result of the rear walking motor torque in response to the power supply line between the power battery being conducted and powered; The method comprises: According to the accelerator signal and the brake pedal signal, the requested vehicle torque is calculated; According to the requested vehicle torque, the front axle load and the rear axle load, the front walking motor torque and the rear walking motor torque that can be distributed are found out from a first torque distribution table; the first torque distribution table stores the corresponding front walking motor torque and the front axle load, the corresponding rear walking motor torque and the rear axle load, and the torque values are all not greater than the adhesion of the front tire and the rear tire to the ground; According to the front walking motor torque and the rear walking motor torque that can be distributed, the front walking motor torque and the rear walking motor torque at the minimum power and time are found out from a second torque distribution table, and the front walking motor torque and the rear walking motor torque at the minimum power and time are taken as the final torque distribution result; the second torque distribution table stores the power sum corresponding to different torque distributions; the power sum is the sum of the front walking motor power and the rear walking motor power.

2. The method of claim 1, wherein, The first torque distribution table is pre-constructed, and the process of pre-constructing the first torque distribution table comprises: According to the possible front axle load, the possible rear axle load, the front walking motor external characteristic torque and the rear walking motor external characteristic torque, the front walking motor torque and the rear walking motor torque that can be distributed are calculated, and the first torque distribution table is constructed according to the front walking motor torque and the rear walking motor torque that can be distributed; Wherein, the formula for calculating the front walking motor torque and the rear walking motor torque that can be distributed is: ； In the formula, T is the vehicle torque, T1 and T2 are the torques of the front walking motor and the rear walking motor respectively, m1 and m2 are the front axle load and the rear axle load respectively, k1 and k2 are the relationship parameters, T1 peak and T2 peak are the front walking motor external characteristic torque and the rear walking motor external characteristic torque respectively.

3. The method of claim 1, wherein, The second torque distribution table is pre-established, and a process of pre-establishing the second torque distribution table comprises: According to efficiency maps of the front traveling motor and the rear traveling motor, power sums under different torque distributions are calculated; and the second torque distribution table is established according to the power sums under the different torque distributions.

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