Torque distribution method and device for double electric drive axles in different gears

Abstract

The invention discloses a torque distribution method and device for double electric drive axles in different gears, and the method comprises the following steps: setting a first threshold value T1 and a second threshold value T2 of torque, and enabling the first threshold value T1 to be smaller than the second threshold value T2; when the torque values of the two motors do not reach the first threshold value T1, the total torque value is distributed to the two motors based on the principle that the bridge end torques are equal; when the torque value of any motor reaches a first threshold value T1, the residual torque value of the theoretical torque value which should be distributed to the motor is distributed to the other motor, and when the torque value of the other motor reaches the first threshold value T1, the residual torque value of the total torque value is distributed based on the principle that the bridge end torques are equal; and when the torque value of any motor reaches a second threshold value T2, distributing the residual torque value of the theoretical torque value which should be distributed to the motor to the other motor, and finishing torque distribution until the torque value of the other motor reaches the second threshold value T2. According to the invention, the loads of the two motors are balanced, the smooth increase of the axle end torque is realized, the sudden change of the torque is effectively avoided, and the driving experience is optimized.

Description

Technical Field

[0001] The present application relates to the technical field of electric vehicles, and in particular to a method and device for distributing torque when a dual electric drive axle is in different gears. Background Art

[0002] Common powertrain systems for pure electric tractors include single and dual motors. Existing dual-motor torque control methods generally calculate the total required torque value based on the maximum output torque capacity of the dual motors at the current speed and the throttle opening ratio. This is then divided equally between the dual motors, which can meet actual driving needs under most operating conditions. However, some models currently equipped with dual electric drive axles have different shift points set to ensure uninterrupted power during gear shifts. This results in a situation where one axle shifts up first during actual driving, resulting in inconsistent gear positions on the two axles. Furthermore, depending on the difference in the shift points between the two axles, this inconsistent gear position can persist for some time. Therefore, a torque distribution strategy tailored to these operating conditions is crucial. If the dual-motor torque is divided equally, the torque at both axles will differ due to the different speed ratios, making slip more likely.

[0003] The current torque distribution strategy for dual-motor drive only sets a maximum torque limit for the auxiliary control bridge motor capacity. Under uphill and heavy-load conditions, the single auxiliary control bridge motor will run at full load for a long time, resulting in a large load difference between the two motors. Summary of the Invention

[0004] The present application provides a method and device for distributing torque of a dual electric drive axle in different gears, which can solve the technical problem of long-term high load on one motor in the current torque control technology of dual motor drive.

[0005] To achieve the above objectives, in a first aspect, the present application provides a method for distributing torque when a dual electric drive axle is in different gears, the method comprising:

[0006] A first threshold value T1 and a second threshold value T2 of the torque are set, and the first threshold value T1 is smaller than the second threshold value T2.

[0007] When the torque values of the two motors do not reach the first threshold value T1, the total torque value is distributed to the two motors based on the principle of equal bridge end torque.

[0008] When the torque value of any motor reaches the first threshold value T1, the remaining torque value of the theoretical torque value that should be allocated to this motor is allocated to the other motor until the torque value of the other motor reaches the first threshold value T1, and the remaining torque value of the total torque value is allocated based on the principle of equal bridge end torque.

[0009] When the torque value of any motor reaches the second threshold value T2, the remaining torque value of the theoretical torque value to be allocated to this motor is allocated to the other motor until the torque value of the other motor reaches the second threshold value T2, and the torque distribution is completed.

[0010] Furthermore, in one embodiment, the motor whose torque value reaches any threshold value first among the two motors is the first motor, corresponding to the first bridge speed ratio; the motor that reaches any threshold value later is the second motor, corresponding to the second bridge speed ratio.

[0011] The first bridge speed ratio and the second bridge speed ratio change with the change of gear position.

[0012] Furthermore, in one embodiment, when the torque values of the two motors do not reach the first threshold value T1, the total torque value is distributed to the two motors based on the principle of equal torque at the bridge end, and the torque values distributed to each motor are respectively:

[0013] The first motor torque value=the total torque value*the second bridge speed ratio / (the first bridge speed ratio+the second bridge speed ratio).

[0014] The second motor torque value=total torque value*first bridge speed ratio / (first bridge speed ratio+second bridge speed ratio).

[0015] Furthermore, in one embodiment, when the torque value of any motor reaches the first threshold value T1, the remaining torque value of the theoretical torque value to be allocated to the motor is allocated to the other motor, including:

[0016] When the torque value of the first motor equals the first threshold value T1, the remaining torque value of the first theoretical torque value that should be allocated to the first motor is allocated to the second motor. The torque value allocated to the second motor is:

[0017] The second motor torque value=(the first theoretical torque value of the first motor−the first threshold value T1 )*the first axle speed ratio / (the first axle speed ratio+the second axle speed ratio).

[0018] The first theoretical torque value of the first motor=total torque value*second bridge speed ratio / (first bridge speed ratio+second bridge speed ratio).

[0019] Furthermore, in one embodiment, the remaining torque value of the total torque value is distributed based on the principle of equal bridge end torque until the torque value of the other motor reaches the first threshold value T1, including:

[0020] The first motor torque value = the second motor torque value = the first threshold value T1. The remaining torque value of the total torque value is: the portion of the total torque value that exceeds the sum of the theoretical torque values to be allocated to the first motor and the second motor. The torque values allocated to the first motor and the second motor are respectively:

[0021] The first motor torque value=[total torque value−(theoretical torque value of the first motor+theoretical torque value of the second motor)]*second axle speed ratio / (first axle speed ratio+second axle speed ratio).

[0022] The second motor torque value=[total torque value−(theoretical torque value of the first motor+theoretical torque value of the second motor)]*first axle speed ratio / (first axle speed ratio+second axle speed ratio).

[0023] The theoretical torque value of the first motor + the theoretical torque value of the second motor = 2*first threshold value T1 + first threshold value T1*(1-η) 2 / 2*η, η=first bridge speed ratio / second bridge speed ratio.

[0024] Furthermore, in one embodiment, the principle based on equal axle-end torque is that, in the process of distributing the torque value, the axle-end torque of the electric drive axle corresponding to each motor increases in the same amount.

[0025] Furthermore, in one embodiment, based on the principle of equal axle end torque, the axle end torque value of the first electric drive axle corresponding to the first motor and the axle end torque value of the second electric drive axle corresponding to the second motor are respectively:

[0026] The first bridge end torque value=the first motor torque value*the first bridge speed ratio.

[0027] The second bridge end torque value=the second motor torque value*the second bridge speed ratio.

[0028] Furthermore, in one embodiment, when the torque value of any motor reaches the second threshold value T2, the remaining torque value of the theoretical torque value to be allocated to the motor is allocated to the other motor, including:

[0029] When the torque value of the first motor equals the second threshold value T2, the remaining torque value of the second theoretical torque value that should be allocated to the first motor is allocated to the second motor. The torque value allocated to the second motor is:

[0030] The second motor torque value=(the second theoretical torque value of the first motor−the second threshold value T2 )*the first axle speed ratio / (the first axle speed ratio+the second axle speed ratio).

[0031] Among them, the second theoretical torque value of the first motor = the first threshold T1 + [total torque value - (theoretical torque value of the first motor + theoretical torque value of the second motor)] * second bridge speed ratio / (first bridge speed ratio + second bridge speed ratio).

[0032] Furthermore, in one embodiment, the total torque value is a variable value. During acceleration, the greater the accelerator pedal is depressed and the greater the throttle opening is, the greater the total torque value is.

[0033] In a second aspect, based on the above-mentioned torque distribution method for dual electric drive axles in different gears, the present application provides a distribution device for the torque distribution method for dual electric drive axles in different gears, the device comprising:

[0034] The setting module is used to set a first threshold value T1 and a second threshold value T2 of the torque, and the first threshold value T1 is smaller than the second threshold value T2.

[0035] The comparison module is used to compare the torque value of each motor with the threshold value.

[0036] The distribution module is used to distribute the total torque value to the two motors based on the principle of equal bridge-end torque when the torque values of both motors have not reached the first threshold value T1; it is also used to distribute the remaining torque value of the theoretical torque value that should be distributed to the other motor when the torque value of any motor reaches the first threshold value T1, until the torque value of the other motor reaches the first threshold value T1, and then distribute the remaining torque value of the total torque value based on the principle of equal bridge-end torque; it is also used to distribute the remaining torque value of the theoretical torque value that should be distributed to the other motor when the torque value of any motor reaches the second threshold value T2, until the torque value of the other motor reaches the second threshold value T2, completing the torque distribution.

[0037] The beneficial effects of the technical solutions provided in the embodiments of the present application include:

[0038] This application adjusts the dual motors to work within the same torque range by setting the first threshold value T1 and the second threshold value T2 of the torque, effectively reducing the situation where a single motor outputs at the maximum peak power for a long time. Based on the principle of equal torque at the bridge end, the total torque value is distributed to the two motors, so that the torque at the dual bridge ends remains equivalent. Compared with the distribution based on the principle of equal torque at the motor ends, the drive wheel slippage is effectively reduced. By transplanting the equivalent torque at the bridge end, part of the torque of the high-load motor is distributed to the low-load motor, balancing the loads of the two motors, effectively avoiding the high load of a single motor for a long time, and keeping the two motors in the same load range as much as possible; the low-load motor is used to compensate for the excess of the high-load motor, so that the bridge where the low-load motor is located can quickly shift up, achieving a smooth increase in the torque at the bridge end, effectively avoiding torque mutations, and optimizing the driving experience. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a flow chart of the torque distribution method of the dual electric drive axle in different gears according to an embodiment of the present application.

[0040] Figure 2 Schematic diagram of torque control under different throttle openings of the dual electric drive axle in the embodiment of the present application.

[0041] Figure 3 This is a block diagram of the torque distribution device of the dual electric drive axle in different gears according to an embodiment of the present application. DETAILED DESCRIPTION

[0042] In order to enable those skilled in the art to better understand the present invention, the following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0043] First, some technical terms in this application are explained to facilitate those skilled in the art to understand this application.

[0044] Dual electric drive axle: An advanced electric vehicle drive system whose working principle is based on efficient electric motors, advanced electronic control systems and reliable transmission devices. It can achieve smooth acceleration and efficient driving of electric vehicles under different driving conditions, with high power output and energy efficiency.

[0045] Motor torque: The torque output from the vehicle engine at the crankshaft end.

[0046] In order to make the objectives, technical solutions and advantages of this application clearer, the implementation methods of this application will be further described in detail below with reference to the accompanying drawings.

[0047] In a first aspect, an embodiment of the present application provides a method for distributing torque when a dual electric drive axle is in different gears.

[0048] In one embodiment, see Figure 1 As shown, the torque distribution method includes:

[0049] S1 , a first threshold value T1 and a second threshold value T2 of the set torque, wherein the first threshold value T1 is smaller than the second threshold value T2 .

[0050] S2. When the torque values of the two motors do not reach the first threshold value T1, it means that the torque values of the two motors are both less than the first threshold value T1. Based on the principle of equal torque at the bridge end, the total torque value is distributed to the two motors.

[0051] S3. When the torque value of any motor reaches the first threshold value T1, the remaining torque value of the theoretical torque value that should be allocated to this motor is allocated to the other motor until the torque value of the other motor reaches the first threshold value T1, and the remaining torque value of the total torque value is allocated based on the principle of equal bridge end torque.

[0052] Specifically, when the torque value of one motor reaches the first threshold value T1, the torque value of the other motor is less than the first threshold value T1, and the remaining torque value of the theoretical torque value that should be allocated to this motor is allocated to the other motor; until the torque value of the other motor also reaches the first threshold value T1, the torque values of the two motors have reached the first threshold value T1, then the remaining torque value of the total torque value is allocated based on the principle of equal bridge end torque.

[0053] S4. When the torque value of any motor reaches the second threshold value T2, the remaining torque value of the theoretical torque value to be allocated to this motor is allocated to the other motor until the torque value of the other motor reaches the second threshold value T2, and the torque allocation is completed.

[0054] Specifically, when the torque value of one motor reaches the second threshold value T2, the torque value of the other motor is less than the second threshold value T2, and the remaining torque value of the theoretical torque value that should be allocated to this motor is allocated to the other motor; until the torque value of the other motor also reaches the second threshold value T2, the torque values of the two motors have reached the second threshold value T2, and the torque distribution is completed.

[0055] The torque distribution method for the dual electric drive axle in different gears provided in this application sets the torque threshold and adjusts the dual motors to operate within the same torque range, effectively reducing the situation where a single motor outputs at maximum peak power for a long time.

[0056] When the torque values of the two motors do not reach the first threshold value T1, or the torque values of the two motors reach the first threshold value T1 but do not reach the second threshold value T2, the torque values are distributed to the two motors based on the principle of equal torque at the bridge ends, so that the torque at both bridge ends remains equivalent. Compared with the distribution based on the principle of equal torque at the motor ends, the slippage of the drive wheels is effectively reduced.

[0057] When only one motor reaches the first threshold value T1, or only one motor reaches the second threshold value T2, part of the torque of the high-load motor is distributed to the low-load motor through the equivalent transfer of bridge-end torque, balancing the loads of the two motors. To a certain extent, this avoids long-term high load of a single motor, allowing the two motors to be in the same load range as much as possible; the low-load motor is used to compensate for the excess of the high-load motor, so that the bridge where the low-load motor is located can quickly shift gears, achieving a smooth increase in bridge-end torque, effectively avoiding torque mutations, and optimizing the driving experience.

[0058] Furthermore, in one embodiment, the torque threshold strategy according to step S1 includes:

[0059] Two torque thresholds are set: the first threshold, T1, is p% of the peak torque (in this embodiment, p ranges from 80-85%), and the second threshold, T2, is the peak torque. When the torque values of both motors reach the first threshold, T1, the torque values of both motors continue to increase until they both reach the second threshold, T2. This strategy ensures that both motors operate under similar load conditions, effectively avoiding the problem of one motor being overloaded while the other is underloaded.

[0060] Furthermore, in one embodiment, of the two motors, the motor whose torque reaches any threshold value first is designated as the first motor, corresponding to the first axle speed ratio. The motor whose torque reaches any threshold value later is designated as the second motor, corresponding to the second axle speed ratio. The first and second axle speed ratios vary with the gear position.

[0061] The motor torque value reaches any threshold value first, which means that the motor torque value reaches the first threshold value T1 or the second threshold value T2 first, and the motor is set to the first motor, corresponding to the first bridge speed ratio. The motor torque value reaches any threshold value later, which means that the motor torque value reaches the first threshold value T1 or the second threshold value T2 later, and the motor is set to the second motor, corresponding to the second bridge speed ratio.

[0062] For example, a dual motor includes motor 1 and motor 2. If motor 1 reaches the first threshold value T1 first, it is the first motor, corresponding to the first bridge speed ratio. Subsequently, motor 2 reaches the first threshold value T1 and is the second motor, corresponding to the second bridge speed ratio. If motor 2 reaches the first threshold value T1 first, it is the first motor, corresponding to the first bridge speed ratio. Subsequently, motor 1 reaches the first threshold value T1 and is the second motor, corresponding to the second bridge speed ratio. Similarly, if motor 1 reaches the second threshold value T2 first, it is the first motor, corresponding to the first bridge speed ratio. Subsequently, motor 2 reaches the second threshold value T2 and is the second motor, corresponding to the second bridge speed ratio. If motor 2 reaches the second threshold value T2 first, it is the first motor, corresponding to the first bridge speed ratio. Subsequently, motor 1 reaches the second threshold value T2 and is the second motor, corresponding to the second bridge speed ratio.

[0063] Furthermore, in one embodiment, in step S2, when the torque values of both motors do not reach the first threshold value T1, the total torque value is distributed to the two motors based on the principle of equal axle-end torque. In this embodiment, the principle of equal axle-end torque is that during the torque distribution process, the axle-end torques of the electric drive axles corresponding to the motors are consistent.

[0064] The bridge end torque value of the first electric drive bridge corresponding to the first motor is the first bridge end torque value, which is calculated as follows:

[0065] The first bridge end torque value=the first motor torque value*the first bridge speed ratio.

[0066] The bridge end torque value of the second electric drive bridge corresponding to the second motor is the second bridge end torque value, which is calculated as follows:

[0067] The second bridge end torque value=the second motor torque value*the second bridge speed ratio.

[0068] In this embodiment, when the speed ratios of the two electric drive axles are unequal, the total torque value is distributed to the two motors based on the equal torque at the axle ends, so that the torque at the axle ends of the two axles is consistent, which helps to increase the torque of the vehicle smoothly and avoids the increase in the torque difference between the center and rear axles causing slippage.

[0069] Therefore, based on the principle of equal torque at the bridge end, the torque values allocated to each motor are:

[0070] The first motor torque value=the total torque value*the second bridge speed ratio / (the first bridge speed ratio+the second bridge speed ratio).

[0071] The second motor torque value=total torque value*first bridge speed ratio / (first bridge speed ratio+second bridge speed ratio).

[0072] The order in which the second motor reaches the first threshold and the second threshold will not be affected by the order in which the first threshold reaches the first threshold and the second threshold.

[0073] In this embodiment, when the total torque value is less than the first threshold value T1, the torque values of the two motors have not reached the first threshold value T1. By distributing the total torque value to the two motors based on the principle of equal bridge-end torque, the bridge-end torque of the electric drive bridge corresponding to each motor remains equivalent. Compared with distributing the torque value based on the principle of equal motor-end torque, the slippage of the drive wheel is effectively reduced.

[0074] Optional, combined Figure 2 To provide a clear example, Figure 2 In FIG, the horizontal axis represents the accelerator pedal opening, the vertical axis represents the torque, the dotted line n represents the relationship between the torque of the first motor and the accelerator pedal opening, and the straight line q represents the relationship between the second motor and the accelerator pedal opening.

[0075] In the OA and OB segments, the accelerator pedal opening value starts to increase from 0. Before the accelerator pedal opening value reaches point G, point A and point B are found on the dotted line n and the straight line q respectively. The torque values of the two motors corresponding to these two points are both less than the first threshold value T1. According to the principle of equal torque at the bridge end, the total torque value is distributed to the two motors, and the torque values of the two motors increase at the same time until reaching point A on the dotted line n. At this time, the torque value of the first motor is equal to the first threshold value T1, and the torque value of the second motor is less than the first threshold value T1.

[0076] The first motor torque value during the distribution process=total torque value*second bridge speed ratio / (first bridge speed ratio+second bridge speed ratio).

[0077] The torque value of the second motor during the distribution process=total torque value*first axle speed ratio / (first axle speed ratio+second axle speed ratio).

[0078] Furthermore, in one embodiment, in the above step S3, when the torque value of any motor reaches the first threshold value T1, at this time, the torque value of the first motor = the first threshold value T1, the remaining torque value of the theoretical torque value to be allocated to the motor is allocated to the other motor, including:

[0079] When the torque value of the first motor equals the first threshold value T1, the remaining torque value of the first theoretical torque value that should be allocated to the first motor is allocated to the second motor. The torque value allocated to the second motor is:

[0080] The second motor torque value=(the first theoretical torque value of the first motor−the first threshold value T1 )*the first axle speed ratio / (the first axle speed ratio+the second axle speed ratio).

[0081] The first theoretical torque value of the first motor=total torque value*second bridge speed ratio / (first bridge speed ratio+second bridge speed ratio).

[0082] In this embodiment, when the torque value of the first motor is equal to the first threshold value T1 and the torque value of the second motor is less than the first threshold value T1, the torque distribution to the first motor is suspended, and the part of the first theoretical torque value of the first motor that exceeds the first threshold value T1 is distributed to the second motor, thereby effectively reducing the load of the first motor and increasing the load of the second motor. To a certain extent, it avoids long-term high load of the first motor and keeps the two motors in the same load range as much as possible.

[0083] Optional, combined Figure 2 A clear embodiment is provided. Point A is found on the dotted line n. At point A, the torque value of the first motor is equal to the first threshold value T1. In order to reduce the load of the first motor, the torque value allocation to it is suspended at this time. In the AC segment, the torque value of the first motor no longer increases. According to the principle of equal bridge end torque, the first theoretical torque value of the first motor that exceeds the first threshold value T1 is allocated to the second motor. Corresponding to the BC segment, the torque value of the second motor continues to increase until it reaches point C of the straight line q. At this time, the torque values of the first and second motors are equal to the first threshold value T1.

[0084] The first motor torque value during the distribution process=the first threshold value T1.

[0085] The second motor torque value during the distribution process = total torque value * first bridge speed ratio / (first bridge speed ratio + second bridge speed ratio) + (first theoretical torque value of the first motor - first threshold T1) * first bridge speed ratio / (first bridge speed ratio + second bridge speed ratio).

[0086] Furthermore, in one embodiment, in the above step S3, until the torque value of the other motor reaches the first threshold value T1, the remaining torque value of the total torque value is distributed based on the principle of equal bridge end torque. That is, when the torque value of the first motor and the second torque value are both equal to the first threshold value T1, the portion of the total torque value that exceeds the sum of the theoretical torque values to be distributed to the first motor and the second motor is distributed to the two motors. The torque values distributed to the first motor and the second motor are respectively:

[0087] The first motor torque value=[total torque value−(theoretical torque value of the first motor+theoretical torque value of the second motor)]*second axle speed ratio / (first axle speed ratio+second axle speed ratio).

[0088] The second motor torque value=[total torque value−(theoretical torque value of the first motor+theoretical torque value of the second motor)]*first axle speed ratio / (first axle speed ratio+second axle speed ratio).

[0089] The theoretical torque value of the first motor + the theoretical torque value of the second motor = 2*first threshold value T1 + first threshold value T1*(1-η) 2 / 2*η, η=first bridge speed ratio / second bridge speed ratio.

[0090] In this embodiment, when the torque value of the first motor and the torque value of the second motor are both equal to the first threshold value T1, the torque values are allocated to the two motors based on the principle of equal axle end torque, so that the axle end torques of the electric drive axles corresponding to the motors remain equal. The principle of equal axle end torque is the same as the principle described above and will not be repeated here.

[0091] Optional, combined Figure 2 A clear embodiment is provided. At point C, the torque value of the first motor and the torque value of the second motor are both equal to the first threshold value T1. At this time, the part of the total torque value that exceeds the sum of the theoretical torque values that should be allocated to the first motor and the second motor is allocated to the two motors. Corresponding to the CD segment and the CE segment, the torque values of the two motors continue to increase until reaching point D of the dotted line n. At this time, the torque value of the first motor is equal to the second threshold value T2, and the torque value of the second motor is less than the second threshold value T2.

[0092] The first motor torque value during the distribution process=first threshold value T1+[total torque value−(theoretical torque value of the first motor+theoretical torque value of the second motor)]*second axle speed ratio / (first axle speed ratio+second axle speed ratio).

[0093] The torque value of the second motor during the distribution process=the first threshold T1+[total torque value−(theoretical torque value of the first motor+theoretical torque value of the second motor)]*first axle speed ratio / (first axle speed ratio+second axle speed ratio).

[0094] Furthermore, in one embodiment, in the above step S4, when the torque value of any motor reaches the second threshold value T2, the remaining torque value of the theoretical torque value to be allocated to the motor is allocated to the other motor, including:

[0095] When the torque value of the first motor equals the second threshold value T2, the remaining torque value of the second theoretical torque value that should be allocated to the first motor is allocated to the second motor. The torque value allocated to the second motor is:

[0096] The second motor torque value=(the second theoretical torque value of the first motor−the second threshold value T2 )*the first axle speed ratio / the second axle speed ratio.

[0097] Among them, the second theoretical torque value of the first motor = the first threshold T1 + [total torque value - (theoretical torque value of the first motor + theoretical torque value of the second motor)] * second bridge speed ratio / (first bridge speed ratio + second bridge speed ratio).

[0098] In this embodiment, when the torque value of the first motor is equal to the second threshold value T2, the torque distribution to the first motor is suspended, and the part of the second theoretical torque value of the first motor that exceeds the second threshold value T2 is distributed to the second motor, so that the low-load motor compensates for the excess part of the high-load motor. The bridge where the low-load motor is located quickly shifts up, achieving a smooth increase in the torque at the bridge end, effectively avoiding torque mutations, and optimizing the driving experience.

[0099] Optional, combined Figure 2 A clear embodiment is provided. Point D is found on the dotted line n. At point D, the torque value of the first motor is equal to the second threshold value T2. In order to reduce the load of the first motor, the torque value allocation to it is suspended at this time. In the DF section, the torque value of the first motor no longer increases. According to the principle of equal torque at the bridge end, the part of the second theoretical torque value of the first motor that exceeds the second threshold value T2 is allocated to the second motor. Corresponding to the EF section, the torque value of the second motor continues to increase until it reaches point F on the straight line q. At this time, the torque values of the first and second motors are equal to the second threshold value T2. At this time, both motors reach their maximum output capacity.

[0100] The first motor torque value during the distribution process=the second threshold value T2.

[0101] The torque value of the second motor during the distribution process = first threshold value T1 + [total torque value - (theoretical torque value of the first motor + theoretical torque value of the second motor)] * first axle speed ratio / (first axle speed ratio + second axle speed ratio) + (second theoretical torque value of the first motor - second threshold value T2) * first axle speed ratio / second axle speed ratio.

[0102] Furthermore, in one embodiment, the total torque value is a variable value. During acceleration, the greater the accelerator pedal opening, the greater the total torque value.

[0103] Furthermore, in one embodiment, the allocated residual torque values are all theoretical torque values.

[0104] It should be noted that the embodiment of the present application provides a method for distributing torque when a dual electric drive axle is in different gears, which is also applicable to the torque distribution in the following situations:

[0105] Two different positive thresholds are set for the torques of the two motors: a first threshold and a second threshold. The first threshold of each motor can be the same value or different values, the second threshold can be the same value or different values, and the first threshold of each motor is smaller than its second threshold.

[0106] In the second aspect, based on the above embodiment of the torque distribution method for dual electric drive axles in different gears, the present application provides an embodiment of a distribution device for the torque distribution method for dual electric drive axles in different gears. Figure 3 As shown, the above device includes a setting module, a comparison module and an allocation module, specifically:

[0107] The setting module is used to set a first threshold value T1 and a second threshold value T2 of the torque, and the first threshold value T1 is smaller than the second threshold value T2.

[0108] The comparison module is used to compare the torque value of each motor with the threshold value.

[0109] The distribution module is used to distribute the total torque value to the two motors based on the principle of equal bridge-end torque when the torque values of both motors have not reached the first threshold value T1; it is also used to distribute the remaining torque value of the theoretical torque value that should be distributed to the other motor when the torque value of any motor reaches the first threshold value T1, until the torque value of the other motor reaches the first threshold value T1, and then distribute the remaining torque value of the total torque value based on the principle of equal bridge-end torque; it is also used to distribute the remaining torque value of the theoretical torque value that should be distributed to the other motor when the torque value of any motor reaches the second threshold value T2, until the torque value of the other motor reaches the second threshold value T2, completing the torque distribution.

[0110] It should be noted that the serial numbers of the above-mentioned embodiments of the present application are for description only and do not represent the advantages or disadvantages of the embodiments.

[0111] The terms "including" and "having" and any variations thereof in the specification and claims of this application and the above-mentioned drawings are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally includes steps or units that are not listed, or optionally includes other steps or units inherent to these processes, methods, products or devices. The terms "first", "second" and "third" are used to distinguish different objects, etc., and do not represent a sequence, nor do they limit the "first", "second" and "third" to different types.

[0112] In the description of the embodiments of the present application, the words "exemplary", "for example" or "for example" are used to indicate examples, illustrations or descriptions. Any embodiment or design described in the embodiments of the present application as "exemplary", "for example" or "for example" should not be interpreted as being more preferred or advantageous than other embodiments or designs. Specifically, the use of words such as "exemplary", "for example" or "for example" is intended to present related concepts in a concrete way. In the description of the embodiments of the present application, "plurality" refers to two or more than two.

[0113] In some processes described in the embodiments of the present application, multiple operations or steps are included that appear in a specific order. However, it should be understood that these operations or steps may not be performed in the order in which they appear in the embodiments of the present application or may be performed in parallel. The sequence numbers of the operations are only used to distinguish between different operations, and the sequence numbers themselves do not represent any order of execution. In addition, these processes may include more or fewer operations, and these operations or steps may be performed in sequence or in parallel, and these operations or steps may be combined.

[0114] Through the description of the above implementation methods, those skilled in the art can clearly understand that the above-mentioned embodiment methods can be implemented by means of software plus the necessary general hardware platform, of course, it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present application, or the part that contributes to the prior art, can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes a number of instructions for enabling a terminal device to execute the methods described in each embodiment of the present application.

[0115] The above are only preferred embodiments of the present application and do not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method for distributing torque when a dual electric drive axle is in different gears, characterized in that: The torque distribution method includes: A first threshold value T1 and a second threshold value T2 of the torque are set, and the first threshold value T1 is smaller than the second threshold value T2; When the torque values of the two motors do not reach the first threshold value T1, the total torque value is distributed to the two motors based on the principle of equal torque at the bridge end; When the torque value of any motor reaches the first threshold value T1, the remaining torque value of the theoretical torque value that should be allocated to this motor is allocated to the other motor until the torque value of the other motor reaches the first threshold value T1, and the remaining torque value of the total torque value is allocated based on the principle of equal bridge end torque; When the torque value of any motor reaches the second threshold value T2, the remaining torque value of the theoretical torque value to be allocated to this motor is allocated to the other motor until the torque value of the other motor reaches the second threshold value T2, and the torque distribution is completed.

2. The torque distribution method for dual electric drive axles in different gears according to claim 1, characterized in that: Also includes: The motor whose torque value reaches any threshold value first among the two motors is the first motor, corresponding to the first bridge speed ratio; The motor that reaches any threshold later is the second motor, corresponding to the second bridge speed ratio; The first bridge speed ratio and the second bridge speed ratio change with the change of gear position.

3. The torque distribution method for dual electric drive axles in different gears according to claim 2, characterized in that: When the torque values of the two motors do not reach the first threshold value T1, the total torque value is distributed to the two motors based on the principle of equal torque at the bridge end, and the torque values distributed to each motor are: First motor torque value = total torque value * second bridge speed ratio / (first bridge speed ratio + second bridge speed ratio); The second motor torque value=total torque value*first bridge speed ratio / (first bridge speed ratio+second bridge speed ratio).

4. The torque distribution method for a dual electric drive axle in different gears according to claim 2, characterized in that: When the torque value of any motor reaches the first threshold value T1, the remaining torque value of the theoretical torque value that should be allocated to the motor is allocated to the other motor, including: When the torque value of the first motor equals the first threshold value T1, the remaining torque value of the first theoretical torque value that should be allocated to the first motor is allocated to the second motor. The torque value allocated to the second motor is: Second motor torque value=(first theoretical torque value of the first motor-first threshold value T1)*first bridge speed ratio / (first bridge speed ratio+second bridge speed ratio); The first theoretical torque value of the first motor=total torque value*second bridge speed ratio / (first bridge speed ratio+second bridge speed ratio).

5. The torque distribution method for dual electric drive axles in different gears according to claim 2, characterized in that: The method of distributing the remaining torque value of the total torque value based on the principle of equal bridge end torque until the torque value of the other motor reaches the first threshold value T1 includes: The first motor torque value = the second motor torque value = the first threshold value T1. The remaining torque value of the total torque value is: the portion of the total torque value that exceeds the sum of the theoretical torque values to be allocated to the first motor and the second motor. The torque values allocated to the first motor and the second motor are respectively: First motor torque value = [total torque value - (theoretical torque value of the first motor + theoretical torque value of the second motor)] * second bridge speed ratio / (first bridge speed ratio + second bridge speed ratio); Second motor torque value = [total torque value - (theoretical torque value of the first motor + theoretical torque value of the second motor)] * first bridge speed ratio / (first bridge speed ratio + second bridge speed ratio); The theoretical torque value of the first motor + the theoretical torque value of the second motor = 2*first threshold value T1 + first threshold value T1*(1-η) 2 / 2*η, η=first bridge speed ratio / second bridge speed ratio.

6. The method for distributing torque of a dual electric drive axle in different gears according to claim 2, characterized in that: The principle based on equal axle-end torque is that, in the process of distributing the torque value, the axle-end torque of the electric drive axle corresponding to each motor increases in the same amount.

7. The torque distribution method for dual electric drive axles in different gears according to claim 6, characterized in that: Based on the principle of equal axle-end torque, the axle-end torque value of the first electric drive axle corresponding to the first motor and the axle-end torque value of the second electric drive axle corresponding to the second motor are respectively: First bridge end torque value = first motor torque value * first bridge speed ratio; The second bridge end torque value=the second motor torque value*the second bridge speed ratio.

8. The torque distribution method for dual electric drive axles in different gears according to claim 2, characterized in that: When the torque value of any motor reaches the second threshold value T2, the remaining torque value of the theoretical torque value that should be allocated to the motor is allocated to the other motor, including: When the torque value of the first motor equals the second threshold value T2, the remaining torque value of the second theoretical torque value that should be allocated to the first motor is allocated to the second motor. The torque value allocated to the second motor is: Second motor torque value=(second theoretical torque value of the first motor-second threshold value T2)*first bridge speed ratio / (first bridge speed ratio+second bridge speed ratio); Among them, the second theoretical torque value of the first motor = the first threshold T1 + [total torque value - (theoretical torque value of the first motor + theoretical torque value of the second motor)] * second bridge speed ratio / (first bridge speed ratio + second bridge speed ratio).

9. The method for distributing torque of a dual electric drive axle in different gears according to any one of claims 1 to 8, characterized in that: The total torque value is a variable value. During the acceleration process, the greater the accelerator pedal is depressed and the greater the throttle opening is, the greater the total torque value is.

10. A torque distribution device based on the torque distribution method of the dual electric drive axle in different gears according to any one of claims 1 to 8, characterized in that: The device comprises: a setting module, configured to set a first threshold value T1 and a second threshold value T2 of the torque, wherein the first threshold value T1 is smaller than the second threshold value T2; A comparison module, which is used to compare the torque value of each motor with the size of the threshold; The distribution module is used to distribute the total torque value to the two motors based on the principle of equal bridge-end torque when the torque values of both motors have not reached the first threshold value T1; it is also used to distribute the remaining torque value of the theoretical torque value that should be distributed to the other motor when the torque value of any motor reaches the first threshold value T1, until the torque value of the other motor reaches the first threshold value T1, and then distribute the remaining torque value of the total torque value based on the principle of equal bridge-end torque; it is also used to distribute the remaining torque value of the theoretical torque value that should be distributed to the other motor when the torque value of any motor reaches the second threshold value T2, until the torque value of the other motor reaches the second threshold value T2, completing the torque distribution.

Images