Dual-motor torque output control method and system and dual-motor electric vehicle

Abstract

The invention discloses a dual-motor torque output control method and system and a dual-motor electric vehicle. The dual-motor torque output control method is applied to the dual-motor electric vehicle, the required torque corresponding to the current vehicle speed is determined according to the current accelerator pedal opening degree of the dual-motor electric vehicle, and whether the first motor rated output torque with a first motor as an execution motor can meet the torque output of the required torque or not is judged; whether the sum of the rated output torque of the first motor and the rated output torque of the second motor taking the second motor as an execution motor can meet the torque output result of the required torque or not is judged, torque distribution is reasonably conducted, the dual-motor torque output of the dual-motor electric automobile is determined, the required power of the whole automobile is minimum, energy consumption is optimal, and meanwhile, energy consumption is reduced. The torque distribution strategy is simple, and the torque response time is short.

Description

Technical Field

[0001] The present invention relates to the technical field of motor torque distribution, and in particular to a dual-motor torque output control method and system and a dual-motor electric vehicle. Background Art

[0002] For electric vehicles, dual motors have considerable advantages over single motor plus main reducer or gearbox in improving driving efficiency. For electric vehicles driven by multiple motors, reasonable distribution of motor torque can reduce energy consumption and improve vehicle economy when the total torque demand of electric vehicles is certain. At present, the simplest way to distribute torque for multiple motors is to distribute torque equally. However, due to the characteristics of the motors, when the total torque demand is low, equal torque distribution causes each motor to work in a low efficiency area, resulting in poor energy consumption. Using other mathematical formulas to continuously iterate and solve torque distribution has a complicated calculation process and will cause torque response lag. Summary of the invention

[0003] The present invention provides a dual-motor torque output control method, system and dual-motor electric vehicle to solve the problem that a reasonable torque distribution method cannot be provided at present, resulting in torque response lag and poor motor energy consumption.

[0004] According to one aspect of the present invention, a dual-motor torque output control method is provided, which is applied to a dual-motor electric vehicle, wherein the dual-motor electric vehicle comprises a first motor and a second motor, and the dual-motor torque output control method comprises:

[0005] Determine the required torque corresponding to the current vehicle speed according to the current accelerator pedal opening of the dual-motor electric vehicle, and when the required torque is greater than the rated output torque of the first motor with the first motor as the execution motor, determine whether the required torque is less than or equal to the sum of the rated output torque of the first motor and the rated output torque of the second motor with the second motor as the execution motor;

[0006] The dual-motor torque output of the dual-motor electric vehicle is determined based on a result of determining whether it is less than or equal to the sum of the rated output torque of the first motor and the rated output torque of the second motor with the second motor as the execution motor.

[0007] Optionally, after determining the required torque corresponding to the current vehicle speed according to the current accelerator pedal opening of the dual-motor electric vehicle, the method further includes:

[0008] When the required torque is less than or equal to the rated output torque of the first motor with the first motor serving as the executing motor, the first motor is controlled to output the torque with the required torque.

[0009] Optionally, whether the required torque is less than or equal to the sum of the rated output torque of the first motor and the rated output torque of a second motor with the second motor as the execution motor is determined as follows:

[0010] T req ≤i1T 1n +i2T 2n

[0011] Among them, T req is the required torque; i1T 1n is the rated output torque of the first motor; i2T 2n is the rated output torque of the second motor; i1 is the reduction ratio of the first motor; T 1n is the rated torque of the first motor; i2 is the reduction ratio of the second motor; T 2n is the rated torque of the second motor.

[0012] Optionally, determining the dual-motor torque output of the dual-motor electric vehicle according to a result of determining whether the torque output is less than or equal to the sum of the rated output torque of the first motor and the rated output torque of the second motor with the second motor as the execution motor includes:

[0013] If the required torque is less than or equal to the sum of the rated output torque of the first motor and the rated output torque of the second motor with the second motor as the execution motor, a first output power of the first motor with the first motor rated torque as the torque output and the second motor with the second motor execution torque as the torque output, a second output power of the first motor with the first motor allocated torque as the torque output and the second motor with the second motor allocated torque as the torque output, and a third output power of the first motor with the first motor execution torque as the torque output and the second motor with the second motor rated torque as the torque output are respectively obtained;

[0014] The dual-motor torque output of the dual-motor electric vehicle is determined according to the first output power, the second output power and the third output power.

[0015] Optionally, determining the dual-motor torque output of the dual-motor electric vehicle according to the first output power, the second output power, and the third output power includes:

[0016] If the smallest output power among the first output power, the second output power and the third output power is the first output power, determining that the dual-motor torque output of the dual-motor electric vehicle is that the first motor outputs the first motor rated torque as the torque output and the second motor outputs the second motor executed torque as the torque output;

[0017] If the smallest output power among the first output power, the second output power and the third output power is the second output power, determining that the dual-motor torque output of the dual-motor electric vehicle is that the first motor outputs the first motor allocated torque as the torque output and the second motor outputs the second motor allocated torque as the torque output;

[0018] If the smallest output power among the first output power, the second output power and the third output power is the third output power, it is determined that the dual-motor torque output of the dual-motor electric vehicle is that the first motor outputs the first motor execution torque as the torque output and the second motor outputs the second motor rated torque as the torque output.

[0019] Optionally, determining the dual-motor torque output of the dual-motor electric vehicle according to a result of determining whether the torque output is less than or equal to the sum of the rated output torque of the first motor and the rated output torque of the second motor with the second motor as the execution motor includes:

[0020] If the required torque is greater than the sum of the rated output torque of the first motor and the rated output torque of the second motor with the second motor as the execution motor, then determining whether the required torque is less than the sum of the peak output torque of the first motor with the first motor as the execution motor and the peak output torque of the second motor with the second motor as the execution motor;

[0021] The dual-motor torque output of the dual-motor electric vehicle is determined based on a result of determining whether it is less than the sum of a first motor peak output torque with the first motor as the execution motor and a second motor peak output torque with the second motor as the execution motor.

[0022] Optionally, determining the dual-motor torque output of the dual-motor electric vehicle according to a result of judging whether it is less than the sum of a first motor peak output torque with the first motor as the execution motor and a second motor peak output torque with the second motor as the execution motor comprises:

[0023] If the required torque is less than the sum of the peak output torque of the first motor with the first motor as the execution motor and the peak output torque of the second motor with the second motor as the execution motor, then determining that the dual-motor torque output of the dual-motor electric vehicle is that the first motor outputs the first motor average torque as the torque output and the second motor outputs the second motor average torque as the torque output;

[0024] If the required torque is greater than or equal to the sum of the peak output torque of the first motor with the first motor as the executing motor and the peak output torque of the second motor with the second motor as the executing motor, it is determined that the dual-motor torque output of the dual-motor electric vehicle is the first motor outputting the first motor peak torque as the torque output and the second motor outputting the second motor peak torque as the torque output.

[0025] Optionally, the dual-motor torque output control method further includes:

[0026] If the average torque of the first motor is greater than the peak target torque of the first motor, the first motor outputs the peak target torque of the first motor, and the second motor outputs the remaining torque of the second motor;

[0027] If the average torque of the second motor is greater than the peak target torque of the second motor, the first motor outputs the residual torque of the first motor as the torque, and the second motor outputs the peak target torque of the second motor as the torque.

[0028] According to another aspect of the present invention, a dual-motor torque output control system is provided, characterized in that the dual-motor torque output control system can execute the dual-motor torque output control method described in any embodiment of the present invention.

[0029] According to another aspect of the present invention, a dual-motor torque output control system is provided, characterized in that the dual-motor torque output control system can execute the dual-motor torque output control method described in any embodiment of the present invention.

[0030] The technical solution of the embodiment of the present invention determines the required torque corresponding to the current vehicle speed according to the current accelerator pedal opening of the dual-motor electric vehicle, determines whether the rated output torque of the first motor with the first motor as the execution motor can meet the torque output of the required torque, and then determines whether the sum of the rated output torque of the first motor and the rated output torque of the second motor with the second motor as the execution motor can meet the torque output result of the required torque, and reasonably distributes the torque to determine the dual-motor torque output of the dual-motor electric vehicle, so that the required power of the whole vehicle is minimized, thereby optimizing the energy consumption. At the same time, the torque distribution strategy is simple and the torque response time is fast.

[0031] It should be understood that the contents described in this section are not intended to identify the key or important features of the embodiments of the present invention, nor are they intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1is a flow chart of a dual-motor torque output control method provided according to an embodiment of the present invention;

[0034] Figure 2 It is a flow chart of a dual-motor torque output control method provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the scheme of the present invention, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. 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 should fall within the scope of protection of the present invention.

[0036] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof 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 necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0037] Figure 1 A flowchart of a dual-motor torque output control method is provided for an embodiment of the present invention, which is applied to a dual-motor electric vehicle. The dual-motor electric vehicle includes a first motor and a second motor. This embodiment can be applied to the case where the motor torque of the dual-motor electric vehicle is reasonably distributed. The dual-motor torque output control method can be executed by a dual-motor torque output control system. The dual-motor torque output control system can be implemented in the form of hardware and / or software. The dual-motor torque output control system can be configured in a dual-motor electric vehicle. Figure 1 As shown, the dual-motor torque output control method includes:

[0038] S110. Determine the required torque corresponding to the current vehicle speed based on the current accelerator pedal opening of the dual-motor electric vehicle, and when the required torque is greater than the rated output torque of the first motor with the first motor as the executing motor, determine whether the required torque is less than or equal to the sum of the rated output torque of the first motor and the rated output torque of the second motor with the second motor as the executing motor.

[0039] Among them, the current accelerator pedal opening is the accelerator pedal opening corresponding to the current vehicle speed. The current accelerator pedal opening is obtained through the accelerator pedal opening acquisition method of the existing dual-motor electric vehicle, and this embodiment does not impose any limitation on this.

[0040] In this embodiment, based on the relationship between the required torque and the pedal opening, the required torque corresponding to the current vehicle speed is determined, specifically:

[0041] T req =αT max (v x )

[0042] Among them, T req The current vehicle speed is v x The required torque corresponding to the time; α is the current accelerator pedal opening; T max (v x ) is the current vehicle speed v x The sum of the peak torques that can be output by each motor at the same time.

[0043] Specifically, first determine whether the required torque corresponding to the current vehicle speed can be achieved by using one motor as an executing motor to meet the current torque output of the electric vehicle, that is, using the first motor as the executing motor or the second motor as the executing motor to meet the current torque output of the electric vehicle; if the first motor is used as the executing motor, when the required torque is less than or equal to the rated output torque of the first motor with the first motor as the executing motor, the first motor can be used as the executing motor to meet the torque output requirement of the whole vehicle, and the first motor can be controlled to output the torque with the required torque. Similarly, if the second motor is used as the executing motor, when the required torque is less than or equal to the rated output torque of the second motor with the second motor as the executing motor, the second motor can be used as the executing motor to meet the torque output requirement of the whole vehicle, and the second motor can be controlled to output the torque with the required torque.

[0044] It can be understood that, in this embodiment, the first motor and the second motor do not limit the motors of the dual-motor electric vehicle, but are merely illustrative of the dual motors.

[0045] On the basis of the above, when the required torque is greater than the rated output torque of the first motor with the first motor as the executing motor, that is, the first motor as the executing motor cannot meet the torque output demand of the whole vehicle, it is further judged whether the required torque is less than or equal to the sum of the rated output torque of the first motor and the rated output torque of the second motor with the second motor as the executing motor, so as to determine whether the required torque can be met by jointly distributing the required torque by the first motor and the second motor.

[0046] S120. Determine the dual-motor torque output of the dual-motor electric vehicle based on a result of determining whether the torque output is less than or equal to the sum of the rated output torque of the first motor and the rated output torque of the second motor with the second motor as the execution motor.

[0047] Specifically, when the required torque is greater than the rated output torque of the first motor with the first motor as the executing motor, and the required torque is less than or equal to the sum of the rated output torque of the first motor and the rated output torque of the second motor with the second motor as the executing motor, the optimal solution is confirmed by calculating three torque distribution methods, specifically: respectively obtaining the first output power of the first motor with the rated torque of the first motor as the torque output and the second motor with the executing torque of the second motor as the torque output, that is, distributing the first motor with the rated torque of the first motor as the torque output and the second motor with the allocated torque of the second motor as the torque output, that is, the first motor and the second motor evenly distribute the torque, and the third output power of the first motor with the executing torque of the first motor as the torque output and the second motor with the rated torque of the second motor as the torque output, that is, distributing the second motor with the rated torque of the second motor as the torque output, that is, the rated torque of the second motor is the highest efficiency.

[0048] It should be noted that, in the method of evenly distributing torque between the first motor and the second motor, if the average torque of the first motor is greater than the peak target torque of the first motor, that is, the first motor peak target torque of the first motor cannot meet the torque output allocated by the first motor, then the first motor can only be controlled to use the peak target torque of the first motor as the torque output, and the second motor to use the remaining torque of the second motor as the torque output, that is, the remaining torque output is compensated by the second motor; if the average torque of the second motor is greater than the peak target torque of the second motor, that is, the second motor peak target torque of the second motor cannot meet the torque output allocated by the second motor, then the second motor can only be controlled to use the peak target torque of the second motor as the torque output, and the first motor to use the remaining torque of the first motor as the torque output, that is, the remaining torque output is compensated by the first motor.

[0049] If the smallest output power among the first output power, the second output power and the third output power is the first output power, then the dual-motor torque output of the dual-motor electric vehicle is determined to be the first motor outputting the first motor rated torque as the torque output and the second motor outputting the second motor execution torque as the torque output; if the smallest output power among the first output power, the second output power and the third output power is the second output power, then the dual-motor torque output of the dual-motor electric vehicle is determined to be the first motor outputting the first motor allocated torque as the torque output and the second motor outputting the second motor allocated torque as the torque output; if the smallest output power among the first output power, the second output power and the third output power is the third output power, then the dual-motor torque output of the dual-motor electric vehicle is determined to be the first motor outputting the first motor execution torque as the torque output and the second motor outputting the second motor rated torque as the torque output.

[0050] On the basis of the above, if the required torque is greater than the sum of the rated output torque of the first motor and the rated output torque of the second motor with the second motor as the executing motor, the torque output executed by the first motor and the second motor together still cannot meet the normal torque output requirement. At this time, it is further determined whether the required torque is less than the sum of the peak output torque of the first motor with the first motor as the executing motor and the peak output torque of the second motor with the second motor as the executing motor.

[0051] Specifically, if the required torque is less than the sum of the peak output torque of the first motor with the first motor as the executing motor and the peak output torque of the second motor with the second motor as the executing motor, then the torque output executed by the first motor and the second motor together can meet the normal torque output requirement, and the dual-motor torque output of the dual-motor electric vehicle is determined as the first motor outputting the first motor's average torque as the torque output and the second motor outputting the second motor's average torque as the torque output; if the required torque is greater than or equal to the sum of the peak output torque of the first motor with the first motor as the executing motor and the peak output torque of the second motor with the second motor as the executing motor, then the dual-motor torque output of the dual-motor electric vehicle is determined as the first motor outputting the first motor's peak torque as the torque output and the second motor outputting the second motor's peak torque as the torque output.

[0052] The technical solution of the embodiment of the present invention determines the required torque corresponding to the current vehicle speed according to the current accelerator pedal opening of the dual-motor electric vehicle, determines whether the rated output torque of the first motor with the first motor as the execution motor can meet the torque output of the required torque, and then determines whether the sum of the rated output torque of the first motor and the rated output torque of the second motor with the second motor as the execution motor can meet the torque output result of the required torque, and reasonably distributes the torque to determine the dual-motor torque output of the dual-motor electric vehicle, so that the required power of the whole vehicle is minimized, thereby optimizing the energy consumption. At the same time, the torque distribution strategy is simple and the torque response time is fast.

[0053] Based on the same inventive concept, Figure 2 This is a flow chart of a dual-motor torque output control method provided by an embodiment of the present invention. This embodiment provides an optional implementation method based on the above embodiment. Figure 2 As shown, the dual-motor torque output control method includes:

[0054] S210: Determine a required torque corresponding to a current vehicle speed according to a current accelerator pedal opening of the dual-motor electric vehicle.

[0055] S211, determine whether the required torque is less than or equal to the rated output torque of the first motor with the first motor as the execution motor, if so, execute step S212, if not, execute step S213.

[0056] Each motor in the dual motor has a corresponding reducer, and it is determined whether the required torque is less than or equal to the rated output torque of the first motor with the first motor as the execution motor. The rated output torque of the first motor is the motor rated torque multiplied by the speed ratio of the reducer of the corresponding motor (i.e., the reduction ratio). Here, it is determined whether the required torque is less than or equal to the rated output torque of the first motor with the first motor as the execution motor, which can be expressed by the following formula, specifically:

[0057] T req ≤i1T 1n

[0058] Among them, T req is the required torque; i1T 1n is the rated output torque of the first motor; i1 is the reduction ratio of the first motor; T 1n is the rated torque of the first motor.

[0059] S212, controlling the first motor to output torque with the required torque.

[0060] Specifically, when the required torque is less than or equal to the rated output torque of the first motor with the first motor as the executing motor, that is, the torque requirement of the whole vehicle can be met by using the first motor as the executing motor, the first motor can be controlled to output the torque with the required torque.

[0061] S213, determine whether the required torque is less than or equal to the sum of the rated output torque of the first motor and the rated output torque of the second motor with the second motor as the execution motor, if so, execute step S214, if not, execute step S216.

[0062] On the basis of the above, if the first motor as the execution motor cannot meet the torque requirement of the whole vehicle, it is further determined whether the required torque is less than or equal to the sum of the rated output torque of the first motor and the rated output torque of the second motor as the execution motor, specifically:

[0063] T req ≤i1T 1n +i2T 2n

[0064] Among them, i2T 2n is the rated output torque of the second motor; i2 is the reduction ratio of the second motor; T 2n is the rated torque of the second motor.

[0065] S214, respectively obtain the first output power of the first motor with the first motor rated torque as the torque output and the second motor with the second motor execution torque as the torque output, the second output power of the first motor with the first motor allocated torque as the torque output and the second motor with the second motor allocated torque as the torque output, and the third output power of the first motor with the first motor execution torque as the torque output and the second motor with the second motor rated torque as the torque output.

[0066] In this embodiment, if the required torque is less than or equal to the sum of the rated output torque of the first motor and the rated output torque of the second motor with the second motor as the executing motor, that is, the torque distribution performed by the first motor and the second motor together can meet the torque requirement of the whole vehicle, then three torque distribution methods can be provided, namely, the first is that the first motor outputs torque with the rated torque of the first motor and the second motor outputs torque with the executing torque of the second motor, the second is that the first motor outputs torque with the allocated torque of the first motor and the second motor outputs torque with the allocated torque of the second motor, and the third is that the first motor outputs torque with the executing torque of the first motor and the second motor outputs torque with the rated torque of the second motor.

[0067] The output power of the three torque distribution modes is further calculated as follows:

[0068] The first one:

[0069] The first motor outputs the first motor rated torque as the torque output and the second motor outputs the second motor execution torque as the torque output. That is, the execution torque of the first motor at this time is the first motor rated torque, that is, T 11 =T 1n , the execution torque of the second motor at this time is the execution torque of the second motor, which is Further, the first output power is P M1 =P 11 +P 21 .

[0070] Among them, the output power of the first motor at this time is The current vehicle speed is v x The efficiency η corresponding to the first motor is 11 =f(n1,T 11 ), the current vehicle speed is v x The speed of the first motor is

[0071] The output power of the second motor at this time The current vehicle speed is v x The efficiency η of the second motor is 21 =f(n2,T 21 ), the current vehicle speed is v x The speed of the second motor is

[0072] It can be seen that the current vehicle speed is v x The efficiency corresponding to the first motor and the efficiency corresponding to the second motor can be obtained by using the interpolation method through the motor efficiency MAP.

[0073] n1, n2, T 11 , T 21 The following constraints exist:

[0074] 0≤n1≤n 1_max

[0075] 0≤n2≤n 2_max

[0076] 0≤T 11 ≤T 1_max (n1)

[0077] 0≤T 21 ≤T 2_max (n2)

[0078] Second type:

[0079] The first motor outputs the first motor allocated torque as the torque and the second motor outputs the second motor allocated torque as the torque. That is, the execution torque of the first motor at this time is the first motor allocated torque, which is The execution torque of the second motor at this time is the second motor distribution torque, which is Further obtain the second output power P M2 =P 12 +P 22 .

[0080] Among them, the output power of the first motor at this time is The current vehicle speed is v x The efficiency η corresponding to the first motor is 12 =f(n1,T 12 ), the output power of the second motor at this time The current vehicle speed is v x The efficiency η of the second motor is 22 =f(n2,T 22 ).

[0081] T 12 , T 22 The following constraints exist:

[0082] 0≤T 12 ≤T 1_max (n1)

[0083] 0≤T 22 ≤T 2_max(n2)

[0084] It can be seen that if the average torque of the first motor is greater than the peak target torque of the first motor Right now Then the first motor outputs the first motor peak target torque as the torque, that is, And the second motor uses the remaining torque of the second motor as the torque output, that is, Among them, the peak target torque of the first motor is That is, the current vehicle speed is v x The peak torque of the first motor at .

[0085] Similarly, if the average torque of the second motor is greater than the peak target torque of the second motor Right now Then the first motor uses the remaining torque of the first motor as the torque output, that is, The second motor outputs the torque at the second motor peak target torque, that is, Among them, the peak target torque of the second motor is That is, the current vehicle speed is v x The peak torque of the second motor.

[0086] The third type:

[0087] The first motor outputs the first motor execution torque as the torque and the second motor outputs the second motor rated torque as the torque, that is, the execution torque of the first motor at this time is the execution torque of the first motor, which is

[0088] The execution torque of the second motor at this time is the rated torque of the second motor, which is T 23 =T 2n , and further obtain the third output power as P M3 =P 13 +P 23 .

[0089] Among them, the output power of the first motor at this time is The current vehicle speed is v x The efficiency η corresponding to the first motor is 13 =f(n1,T 13 ), the output power of the second motor at this time The current vehicle speed is v x The efficiency η of the second motor is 23 =f(n2,T 23 ).

[0090] T 13 、T 23 The following constraints exist:

[0091] 0≤T13 ≤T 1_max (n1)

[0092] 0≤T 23 ≤T 2_max (n2)

[0093] S215. Determine the dual-motor torque output of the dual-motor electric vehicle according to the first output power, the second output power, and the third output power.

[0094] On the basis of the above, compare the first output power P M1 , the second output power P M2 , the third output power P M3 The value is large or small, and the motor torque distribution mode corresponding to the minimum value is the current torque distribution mode, which is specifically: if the minimum output power is the first output power, the dual-motor torque output of the dual-motor electric vehicle is determined as the first motor using the rated torque of the first motor as the torque output and the second motor using the second motor execution torque as the torque output; if the minimum output power is the second output power, the dual-motor torque output of the dual-motor electric vehicle is determined as the first motor using the first motor allocated torque as the torque output and the second motor using the second motor allocated torque as the torque output; if the minimum output power is the third output power, the dual-motor torque output of the dual-motor electric vehicle is determined as the first motor using the first motor execution torque as the torque output and the second motor using the second motor rated torque as the torque output.

[0095] It can be understood that by utilizing the motor characteristics, that is, the area where the rated torque is located is the area with the highest motor efficiency, and the first motor is used as the first executive motor, when the first motor cannot meet the torque demand of the whole vehicle with its rated torque output, the optimal solution is confirmed by the above-mentioned calculation of the three torque distribution methods. The first and third of the three torque distribution methods utilize the principle that the rated torque efficiency value of the motor is the highest. The second type of average torque distribution is to prevent the first motor (or the second motor) from outputting with the rated torque, but the second motor (or the first motor) has a lower torque value, which is in the low efficiency area of ​​the motor efficiency MAP, corresponding to a larger output power and poorer energy consumption. It can be seen that the optimal solution confirmed by the three torque distribution methods is the better solution among all the current torque distribution methods.

[0096] S216, determine whether the required torque is less than the sum of the peak output torque of the first motor with the first motor as the executing motor and the peak output torque of the second motor with the second motor as the executing motor, if so, execute step S217, if not, execute step S218.

[0097] On the basis of the above, if the sum of the rated output torque of the first motor and the rated output torque of the second motor still cannot meet the torque requirement of the whole vehicle, it is further determined whether the required torque is less than the sum of the peak output torque of the first motor with the first motor as the execution motor and the peak output torque of the second motor with the second motor as the execution motor, specifically:

[0098] i1T 1n +i2T 2n <T req <i1T 1max +i2T 2max

[0099] Among them, i1T 1max is the peak output torque of the first motor; i2T 2max is the peak output torque of the second motor; T 1max is the peak torque of the first motor; T 2max is the peak torque of the second motor.

[0100] S217, determining that the dual-motor torque output of the dual-motor electric vehicle is that the first motor outputs the first motor average torque as the torque output and the second motor outputs the second motor average torque as the torque output.

[0101] Specifically, when the required torque is less than the sum of the peak output torque of the first motor with the first motor as the execution motor and the peak output torque of the second motor with the second motor as the execution motor, the motor torque is evenly distributed. At this time, the average torque of the first motor is Average torque of the second motor

[0102] It is understandable that when the rated torque output of the first motor and the second motor still cannot meet the torque demand of the whole vehicle, the torque output method at this time is to evenly distribute the torque of the first motor and the second motor, because the even distribution at this time can ensure that the torque point is basically in a higher efficiency area.

[0103] S218. Determine that the dual-motor torque output of the dual-motor electric vehicle is that the first motor outputs the first motor peak torque as the torque output and the second motor outputs the second motor peak torque as the torque output.

[0104] Specifically, when the required torque is greater than or equal to the sum of the peak output torque of the first motor with the first motor as the execution motor and the peak output torque of the second motor with the second motor as the execution motor, that is, T req ≥i1T 1max +i2T 2max , then the first motor and the second motor output torques with the first motor peak torque and the second motor peak torque respectively, that is, T1 = T 1max , T2=T 2maxAt this time, the motor system of the dual-motor electric vehicle cannot meet the torque requirements of the entire vehicle, resulting in power reduction.

[0105] Based on the same inventive concept, an embodiment of the present invention further provides a dual-motor torque output control system, which can execute the dual-motor torque output control method of any embodiment of the present invention.

[0106] The dual-motor torque output control system provided in this embodiment is applied to a dual-motor electric vehicle. The demand torque corresponding to the current vehicle speed is determined according to the current accelerator pedal opening of the dual-motor electric vehicle, and when the demand torque is greater than the rated output torque of the first motor with the first motor as the execution motor, it is judged whether the demand torque is less than or equal to the sum of the rated output torque of the first motor and the rated output torque of the second motor with the second motor as the execution motor; according to the result of judging whether it is less than or equal to the sum of the rated output torque of the first motor and the rated output torque of the second motor with the second motor as the execution motor, the dual-motor torque output of the dual-motor electric vehicle is determined. The existing multi-motor drive torque distribution method presents two states: one is that the motor distributes the demand torque evenly, which is simple to execute and responds quickly, but due to the motor characteristics (when the total demand torque is low, the equal torque distribution makes each motor work in a low efficiency area), it will cause the problem of poor energy consumption of the whole vehicle. This embodiment realizes a simple torque distribution strategy, fast torque response time, and low energy consumption of the whole vehicle, which can avoid the problem of poor energy consumption caused by average torque distribution and slow torque response caused by complex calculation.

[0107] Based on the same inventive concept, an embodiment of the present invention further provides a dual-motor electric vehicle, which includes a first motor, a second motor, and a dual-motor torque output control system as in any embodiment of the present invention.

[0108] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps described in the present invention can be executed in parallel, sequentially or in different orders, as long as the desired results of the technical solution of the present invention can be achieved, and this document does not limit this.

[0109] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A dual-motor torque output control method, applied to a dual-motor electric vehicle, wherein the dual-motor electric vehicle comprises a first motor and a second motor, characterized in that: The dual-motor torque output control method comprises: Determine the required torque corresponding to the current vehicle speed according to the current accelerator pedal opening of the dual-motor electric vehicle, and when the required torque is greater than the rated output torque of the first motor with the first motor as the execution motor, determine whether the required torque is less than or equal to the sum of the rated output torque of the first motor and the rated output torque of the second motor with the second motor as the execution motor; The dual-motor torque output of the dual-motor electric vehicle is determined based on a result of determining whether it is less than or equal to the sum of the rated output torque of the first motor and the rated output torque of the second motor with the second motor as the execution motor.

2. The dual-motor torque output control method according to claim 1, characterized in that: After determining the required torque corresponding to the current vehicle speed according to the current accelerator pedal opening of the dual-motor electric vehicle, the method further includes: When the required torque is less than or equal to the rated output torque of the first motor with the first motor serving as the executing motor, the first motor is controlled to output the torque with the required torque.

3. The dual-motor torque output control method according to claim 1, characterized in that: Determining whether the required torque is less than or equal to the sum of the rated output torque of the first motor and the rated output torque of the second motor with the second motor as the execution motor is specifically as follows: T req ≤i1T 1n +i2T 2n Among them, T req is the required torque; i1T 1n is the rated output torque of the first motor; i2T 2n is the rated output torque of the second motor; i1 is the reduction ratio of the first motor; T 1n is the rated torque of the first motor; i2 is the reduction ratio of the second motor; T 2n is the rated torque of the second motor.

4. The dual-motor torque output control method according to claim 1, characterized in that: Determining the dual-motor torque output of the dual-motor electric vehicle according to a result of determining whether the torque output is less than or equal to the sum of the rated output torque of the first motor and the rated output torque of the second motor with the second motor as the execution motor includes: If the required torque is less than or equal to the sum of the rated output torque of the first motor and the rated output torque of the second motor with the second motor as the execution motor, a first output power of the first motor with the first motor rated torque as the torque output and the second motor with the second motor execution torque as the torque output, a second output power of the first motor with the first motor allocated torque as the torque output and the second motor with the second motor allocated torque as the torque output, and a third output power of the first motor with the first motor execution torque as the torque output and the second motor with the second motor rated torque as the torque output are respectively obtained; The dual-motor torque output of the dual-motor electric vehicle is determined according to the first output power, the second output power and the third output power.

5. The dual-motor torque output control method according to claim 4, characterized in that: Determining the dual-motor torque output of the dual-motor electric vehicle according to the first output power, the second output power, and the third output power includes: If the smallest output power among the first output power, the second output power and the third output power is the first output power, determining that the dual-motor torque output of the dual-motor electric vehicle is that the first motor outputs the first motor rated torque as the torque output and the second motor outputs the second motor executed torque as the torque output; If the smallest output power among the first output power, the second output power and the third output power is the second output power, determining that the dual-motor torque output of the dual-motor electric vehicle is that the first motor outputs the first motor allocated torque as the torque output and the second motor outputs the second motor allocated torque as the torque output; If the smallest output power among the first output power, the second output power and the third output power is the third output power, it is determined that the dual-motor torque output of the dual-motor electric vehicle is that the first motor outputs the first motor execution torque as the torque output and the second motor outputs the second motor rated torque as the torque output.

6. The dual-motor torque output control method according to claim 1, characterized in that: Determining the dual-motor torque output of the dual-motor electric vehicle according to a result of determining whether the torque output is less than or equal to the sum of the rated output torque of the first motor and the rated output torque of the second motor with the second motor as the execution motor includes: If the required torque is greater than the sum of the rated output torque of the first motor and the rated output torque of the second motor with the second motor as the execution motor, then determining whether the required torque is less than the sum of the peak output torque of the first motor with the first motor as the execution motor and the peak output torque of the second motor with the second motor as the execution motor; The dual-motor torque output of the dual-motor electric vehicle is determined based on a result of determining whether it is less than the sum of a first motor peak output torque with the first motor as the execution motor and a second motor peak output torque with the second motor as the execution motor.

7. The dual-motor torque output control method according to claim 6, characterized in that: Determining the dual-motor torque output of the dual-motor electric vehicle according to a result of judging whether it is less than the sum of a first motor peak output torque with the first motor as the execution motor and a second motor peak output torque with the second motor as the execution motor includes: If the required torque is less than the sum of the peak output torque of the first motor with the first motor as the execution motor and the peak output torque of the second motor with the second motor as the execution motor, then determining that the dual-motor torque output of the dual-motor electric vehicle is that the first motor outputs the first motor average torque as the torque output and the second motor outputs the second motor average torque as the torque output; If the required torque is greater than or equal to the sum of the peak output torque of the first motor with the first motor as the executing motor and the peak output torque of the second motor with the second motor as the executing motor, it is determined that the dual-motor torque output of the dual-motor electric vehicle is the first motor outputting the first motor peak torque as the torque output and the second motor outputting the second motor peak torque as the torque output.

8. The dual-motor torque output control method according to claim 7, characterized in that: The dual-motor torque output control method further includes: If the average torque of the first motor is greater than the peak target torque of the first motor, the first motor outputs the peak target torque of the first motor, and the second motor outputs the remaining torque of the second motor; If the average torque of the second motor is greater than the peak target torque of the second motor, the first motor outputs the residual torque of the first motor as the torque, and the second motor outputs the peak target torque of the second motor as the torque.

9. A dual-motor torque output control system, characterized in that: The dual-motor torque output control system is capable of executing the dual-motor torque output control method described in any one of claims 1-8.

10. A dual-motor electric vehicle, characterized in that: The dual-motor electric vehicle comprises a first motor, a second motor and the dual-motor torque output control system as claimed in claim 9.

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