Torque distribution control method for multi-motor drive assembly and vehicle

Abstract

The application belongs to the technical field of vehicles and discloses a multi-motor drive assembly torque distribution control method and a vehicle. total and efficient motor torque T eff , judges the interval in which T total is located, if T total is located in the interval range of [mT eff , (m+1)T eff ], m=1, 2, 3, …, n-1, then the size of |T eff -T total / (m+1) and |T eff -T total / m is compared, if |T eff -T total / (m+1) > |T eff -T total / m, then it is indicated that the actual torque of a single motor is closer to the efficient motor torque when m motors are driven, and m motors are controlled to participate in driving; otherwise, (m+1) motors are controlled to participate in driving.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and more particularly to a torque distribution control method for a multi-motor drive assembly and a vehicle thereof. Background Technology

[0002] An electric drive axle is a drive axle that integrates components such as motors and gearboxes. An electric drive axle typically contains 1-2 motors, which output torque through 1-2 gearboxes. Currently, a torque uniform distribution scheme is commonly used for torque distribution, which distributes the torque demanded by the driver evenly to multiple motors, with each motor operating at the same speed. However, this scheme results in poor overall vehicle fuel economy.

[0003] To address this, existing technology provides a vehicle control method where each drive axle is driven by a motor. Multiple preset threshold curves are established based on the motor's torque and speed. In this control method, the target torque is obtained and compared with each preset threshold curve to determine the output torque of each of the two drive axles, thereby rationally allocating power between them. However, this approach heavily relies on the calibration of the preset threshold curves and does not consider the efficient output torque of a single motor, resulting in relatively poor fuel economy. Summary of the Invention

[0004] According to one aspect of the present invention, the present invention provides a torque distribution control method for a multi-motor drive assembly to solve the problem that the prior art does not consider the efficient output torque of a single motor, resulting in poor vehicle economy.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A torque distribution control method for a multi-motor drive assembly, wherein the multi-motor drive assembly includes an output shaft and multiple motors, each of which can drive the output shaft to rotate, and the number of motors is n;

[0007] The multi-motor drive torque distribution control method includes:

[0008] S100: Obtain the driver's required torque T total and the high-efficiency torque T of the motor eff ;

[0009] S200: Determine T total The interval in which it is located, the interval includes [T eff 2T eff ), [2T eff 3T eff ), ..., [(n-1)T eff nT eff );

[0010] If T totalIn [mT eff (m+1)T eff If m = 1, 2, 3, ..., n-1 within the interval, then execute step S300;

[0011] S300: Comparison | T eff -T total / (m+1)| and |T eff -T total The size of / m|;

[0012] If |T eff -T total / (m+1)|>|T eff -T total If / m|, then control m of the motors to participate in the drive;

[0013] If |T eff -T total / (m+1)|≤|T eff -T total If / m|, then control (m+1) of the motors to participate in the drive.

[0014] As a preferred solution for torque distribution control methods in multi-motor drive assemblies,

[0015] The interval also includes [nT] eff (, +∞);

[0016] In step S200, if T total In [nT eff Within the range of (+∞), all n motors mentioned above will be controlled to participate in the drive.

[0017] As a preferred solution for torque distribution control methods in multi-motor drive assemblies,

[0018] The interval also includes [0, T] eff );

[0019] In step S200, if T total In [0, T eff Within the specified range, one of the motors will be controlled to participate in the drive.

[0020] As a preferred solution for torque distribution control methods in multi-motor drive assemblies,

[0021] When controlling m of the aforementioned motors to participate in the drive, the single-motor torque demand T of the m motors is... out All are T total / m and T max The smaller value in, where T max This refers to the maximum allowable torque of the motor.

[0022] When controlling (m+1) of the motors to participate in the drive, the single-motor torque demand T of (m+1) of the motors is... out All are T total / (m+1) and T max The smaller value in, where T max This is the maximum allowable torque for the motor.

[0023] As a preferred embodiment of the torque distribution control method for multi-motor drive assemblies, it also includes the following steps prior to S300:

[0024] S400: Sequentially obtain the cumulative working time t1, t2, ..., t3 of the n motors under severe operating conditions. n The severe operating conditions include high-speed operating conditions, high-torque operating conditions, and / or high-temperature operating conditions.

[0025] S410: Compare t1, t2, ..., t n The size of the n motors is determined, and their usage priorities are sorted.

[0026] When controlling m of the motors to participate in driving or controlling (m+1) of the motors to participate in driving, the motors to participate in driving are selected based on the usage priority of each motor.

[0027] As a preferred solution for torque distribution control methods in multi-motor drive assemblies,

[0028] In step S400, the cumulative working time t under adverse conditions for the i-th motor is obtained. i , 1≤i≤n, including steps S4001-S4004:

[0029] S4001: Obtain the high-speed operating time t of the i-th motor. iN ;

[0030] S4002: Obtain the high-torque operating time t of the i-th motor. iT ;

[0031] S4003: Obtain the high-temperature operating time t of the i-th motor. iC ;

[0032] S4004: Calculate the cumulative operating time t under severe conditions for the i-th motor. i , where t i =t iN +t iT +t iC .

[0033] As a preferred solution for torque distribution control methods in multi-motor drive assemblies,

[0034] Step S4001 includes:

[0035] Obtain the rotational speed N of the i-th motor during this operation. i Above the speed threshold N threshold Duration Δt iN ;

[0036] For duration Δt iN The weighted and accumulated high-speed operating time t of the i-th motor iN In the middle, the weighting coefficient is k a k a =(N i -N threshold ) / N threshold ; and / or,

[0037] Step S4002 includes:

[0038] Obtain the torque T of the i-th motor during this operation. i Above the torque threshold T threshold Duration Δt iT ;

[0039] For duration Δt iT The weighted and accumulated high-speed operating time t of the i-th motor iT In the middle, the weighting coefficient is k b k b =(T i -T threshold ) / T threshold ; and / or,

[0040] Step S4003 includes:

[0041] Obtain the temperature C of the i-th motor during this operation. i Above the temperature threshold C Chreshold Duration Δt iC ;

[0042] For duration Δt iT The weighted and accumulated high-speed operating time t of the i-th motor iT In the middle, the weighting coefficient is k c k c =(C i -C Chreshold ) / C Chreshold .

[0043] As a preferred embodiment of the torque distribution control method for a multi-motor drive assembly, the multi-motor drive assembly further includes multiple gearboxes, with each motor connected to a gearbox in a one-to-one correspondence, the output shaft being a drive axle, and multiple output shafts being provided, with each output shaft connected to several gearboxes.

[0044] In the torque distribution control method for a multi-motor drive assembly, when the motors in the control section participate in driving, the gearbox corresponding to the motors that do not participate in driving is controlled to be in neutral.

[0045] As a preferred embodiment of the torque distribution control method for a multi-motor drive assembly, the multi-motor drive assembly further includes multiple central drive assemblies. Each central drive assembly includes a drive shaft and a central drive gearbox. The drive shaft of any central drive assembly is connected to several motors. The input end of the central drive gearbox is connected to the drive shaft. The output ends of the central drive gearboxes of the multiple central drive assemblies are all connected to the output shaft.

[0046] According to another aspect of the present invention, a vehicle is provided, including a multi-motor drive assembly, the multi-motor drive assembly including an output shaft and a plurality of motors, each of which is capable of driving the output shaft to rotate, the number of motors being n;

[0047] The vehicle also includes:

[0048] Controller;

[0049] A vehicle speed sensor is used to detect the vehicle speed and send the detected speed to the controller;

[0050] A throttle sensor is used to detect the throttle opening and send the detected throttle opening to the controller. The controller can obtain the driver's required torque T based on the vehicle speed and the throttle opening. total ;

[0051] A motor speed sensor is used to detect the motor speed and send the detected speed to the controller, which can then obtain the motor's high-efficiency torque T based on the speed. eff ;

[0052] Memory, used to store one or more programs;

[0053] When the controller executes one or more programs, it causes the controller to control the vehicle to implement the above-described multi-motor drive assembly torque distribution control method.

[0054] The beneficial effects of this invention are:

[0055] This invention provides a torque distribution control method for a multi-motor drive assembly and a vehicle. The torque distribution control method for the multi-motor drive assembly includes obtaining the driver's required torque T. total and the high-efficiency torque T of the motor eff And determine T total The interval in which T is located, if T total In [mT eff (m+1)T eff If m = 1, 2, 3, ..., n-1 within the interval, then m motors or (m+1) motors can meet the torque requirement. Further determination of the required number of motors is needed, specifically by comparing |T eff -T total / (m+1)| and |T eff -T total The size of / m|, if |T eff -T total / (m+1)|>|T eff -T total / m| indicates that when using m motors for driving, the actual torque of a single motor is closer to the motor's high-efficiency torque, theoretically resulting in higher efficiency. Therefore, m motors are controlled to participate in the driving process. If |T eff -T total / (m+1)|≤|T eff -T total The value / m| indicates that when using (m+1) motors for driving, the actual torque of a single motor is closer to the high-efficiency torque of the motor, theoretically resulting in higher efficiency. Therefore, (m+1) motors are controlled to participate in the drive. Through the above process, the output torque of the motors can be distributed by controlling the number of motors involved in the drive, and it can be ensured that the actual torque of a single motor is close to the high-efficiency torque of the motor system, thereby improving economy. Attached Figure Description

[0056] Figure 1 This is the flowchart of the torque distribution control method for a multi-motor drive assembly in an embodiment of the present invention. Figure 1 ;

[0057] Figure 2 This is the flowchart of the torque distribution control method for a multi-motor drive assembly in an embodiment of the present invention. Figure 2 ;

[0058] Figure 3 This is a schematic diagram of the structure of the torque distribution control device for the multi-motor drive assembly in an embodiment of the present invention;

[0059] Figure 4 This is a schematic diagram of the structure of a multi-motor drive assembly in an embodiment of the present invention;

[0060] Figure 5This is a schematic diagram of another multi-motor drive assembly in an embodiment of the present invention;

[0061] Figure 6 This is a schematic diagram of the vehicle structure in an embodiment of the present invention.

[0062] In the picture:

[0063] 1100 Driver's required torque acquisition module; 1200 Motor high-efficiency torque acquisition module; 1300 Interval judgment module; 1400 Magnitude comparison module; 1500 First motor drive control module; 1600 Second motor drive control module;

[0064] 11. Motor; 12. Output shaft; 13. Wheel;

[0065] 21. Gearbox; 22. Differential; 23. Transmission mechanism;

[0066] 31. Drive shaft; 32. Central drive gearbox; 33. Shift sleeve;

[0067] 2000, Multi-motor drive assembly; 2100, Controller; 2200, Vehicle speed sensor; 2300, Throttle sensor; 2400, Motor speed sensor; 2500, Memory. Detailed Implementation

[0068] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0069] In the description of this invention, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0070] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0071] In the description of this embodiment, the terms "upper," "lower," "left," and "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first" and "second" are used only for distinction in description and have no special meaning.

[0072] Example 1

[0073] An electric drive axle integrates components such as a motor and gearbox. Currently, a common torque distribution scheme is uniform torque distribution, where the driver's required torque is evenly distributed among multiple motors, each operating at the same speed. However, this scheme results in poor overall vehicle fuel economy. To address this, existing technology offers a vehicle control method where each drive axle is driven by a motor. Multiple preset threshold curves are established based on the motor's torque and speed. This control method acquires the target torque and compares it with these preset threshold curves to determine the output torque of each drive axle, thus rationally distributing power between the two axles. However, this scheme heavily relies on the calibration of the preset threshold curves and does not consider the efficient output torque of individual motors, resulting in continued poor fuel economy.

[0074] To address the aforementioned issues, this embodiment provides a torque distribution control method for a multi-motor drive assembly. This method solves the problem that existing technologies do not consider the efficient output torque of a single motor, resulting in poor overall vehicle economy. It can be applied in the field of vehicle technology, specifically to pure electric or range-extended trucks.

[0075] Reference Figure 1 The multi-motor drive assembly torque distribution control method can be executed by a multi-motor drive assembly torque distribution control device. This method can be implemented through software and / or hardware and integrated into the vehicle. The multi-motor drive assembly includes an output shaft and multiple motors, each capable of driving the output shaft to rotate; the number of motors is n.

[0076] The torque distribution control method for the multi-motor drive assembly includes the following steps.

[0077] S100: Obtain the driver's required torque T total and the high-efficiency torque T of the motor eff .

[0078] In this embodiment, the driver's required torque T total The required torque T can be obtained by pre-setting a first relationship graph or table between vehicle speed, throttle opening, and driver's torque demand in the controller. Specifically, the vehicle speed is detected by a vehicle speed sensor, and the throttle opening is detected by a throttle sensor. The controller then uses the detected vehicle speed and throttle opening to query the first relationship graph or table to obtain the driver's required torque T. total The first relational diagram or first relational table can be obtained through extensive prior experiments.

[0079] High-efficiency torque T motor eff This refers to the torque value at which the motor system achieves the highest efficiency at a given speed. When the motor's output torque approaches this efficient torque, the system is more economical. In this embodiment, this can be obtained through a second relationship graph or table preset in the controller, which maps motor speed to efficient torque. Specifically, the motor speed is detected by a motor speed sensor, and the controller uses this detected speed to query the second relationship graph or table to obtain the efficient torque T. eff The second relationship diagram or second relationship table can be obtained through extensive prior experiments.

[0080] S200: Determine T total The interval it is located in, the interval includes [T] eff 2T eff ), [2T eff 3T eff ), ..., [(n-1)T eff nT eff Optionally, the interval also includes [0, T]. eff ) and [nT eff (+∞).

[0081] If T total In [mT eff (m+1)T eff If m = 1, 2, 3, ..., n-1 within the interval, then execute step S300.

[0082] T can be obtained through the above steps. total With T eff The relationship, if T total In [mT eff (m+1)T effIf the range is within the specified range, it indicates that using m motors or (m+1) motors can meet the torque requirement, and the required number of motors needs to be further determined.

[0083] Optionally, if T total In [nT eff If the value is within the range of (+∞), it indicates that the driver has a large torque requirement, and n motors need to participate in the drive at the same time to meet the torque requirement. Therefore, all n motors are controlled to participate in the drive.

[0084] Optionally, if T total In [0, T eff If the torque is within the specified range, it indicates that the driver's torque requirement is relatively low, and the torque requirement can be met by using only one motor for driving. Therefore, only one motor is controlled to participate in driving.

[0085] S300: Comparison | T eff -T total / (m+1)| and |T eff -T total The size of / m|.

[0086] If |T eff -T total / (m+1)|>|T eff -T total / m| indicates that when m motors are used for driving, the actual torque of a single motor is closer to the high-efficiency torque of the motor, and theoretically the efficiency is higher. Therefore, m motors are controlled to participate in the driving.

[0087] If |T eff -T total / (m+1)|≤|T eff -T total / m| indicates that when using (m+1) motors for driving, the actual torque of a single motor is closer to the high-efficiency torque of the motor, and theoretically the efficiency is higher. Therefore, (m+1) motors are controlled to participate in the driving.

[0088] Through the above process, the output torque of the motors can be distributed by controlling the number of motors involved in the drive, and the actual torque of a single motor can be ensured to be close to the efficient torque of the motor system, thereby improving economy.

[0089] Optionally, when controlling m motors to participate in the drive, the single motor torque T of the m motors is... out All are T total / m and T max The smaller value in, where T max This refers to the maximum allowable torque for the motor; additionally, the torque required for a single motor is T. out This is the required torque value sent to the motor, and the motor is based on the required torque T for that single motor.out Adjust the output torque. T max This represents the maximum allowable torque for the motor. Exceeding this value will prevent the motor from outputting torque and may even damage the motor. The single-motor torque requirement T for m motors is then expressed as follows. out Set to T total / m and T max The smaller value in the range can be used as the torque T required by a single motor. out Set an upper limit to prevent damage to the motor when the required torque value is too high.

[0090] Similarly, when controlling (m+1) of the motors to participate in the drive, the single-motor torque T of (m+1) motors is... out All are T total / (m+1) and T max The smaller value in

[0091] Similarly, when controlling all n motors to participate in the drive, the single-motor torque T of the n motors is... out All are T total / n and T max The smaller value in

[0092] Similarly, when controlling one of the motors to participate in the drive, the single-motor torque T of that motor is required. out For T total and T max The smaller value in the range.

[0093] This embodiment exemplifies the application of the above-described multi-motor drive assembly torque distribution control method to a multi-motor drive assembly with four motors, as follows:

[0094] First, obtain the driver's required torque T. total and the high-efficiency torque T of the motor eff Then, the interval is divided, including [0, T]. eff ), [T eff 2T eff ), [2T eff 3T eff ), [3T eff 4T eff ) and [4T eff The five intervals are: , +∞, etc.

[0095] Then determine T total The interval it is located in can be categorized into the following five situations:

[0096] 1) If T total In [nT effWithin the range of (+∞), it indicates that the driver's torque demand is relatively high, requiring all four motors to participate in the drive simultaneously to meet the torque demand. Therefore, the four motors are controlled to participate in the drive simultaneously.

[0097] 2) If T total In [3T] eff 4T eff If the range is within a certain range, it is necessary to further determine whether all four motors need to participate in the drive simultaneously. Specifically, determine |T eff -T total / 4|and|T eff -T total The size of / 3|.

[0098] If |T eff -T total / 4|≤|T eff -T total / 3| indicates that when four motors are used for driving, the actual torque of a single motor is closer to the high-efficiency torque of the motor, and the efficiency is theoretically higher. Therefore, four motors are controlled to participate in the driving at the same time.

[0099] If |T eff -T total / 4|>|T eff -T total / 3| indicates that when three motors are used for driving, the actual torque of a single motor is closer to the high-efficiency torque of the motor, so three of the motors are controlled to participate in the driving.

[0100] 3) If T total In [2T] eff 3T eff If the range is within a certain range, it is necessary to further determine whether three motors are needed for driving. Specifically, determine |T eff -T total / 3|and|T eff -T total The size of / 2|.

[0101] If |T eff -T total / 3|≤|T eff -T total / 2| indicates that when three motors are used for driving, the actual torque of a single motor is closer to the high-efficiency torque of the motor, so three of the motors are controlled to participate in the driving.

[0102] If |T eff -T total / 3|≤|T eff -T total / 2| indicates that when two motors are used for driving, the actual torque of a single motor is closer to the high-efficiency torque of the motor, so two of the motors are controlled to participate in the driving.

[0103] 4) If T total In [T] eff 2T eff If the range is within a certain range, it is necessary to further determine whether two motors are needed for driving. Specifically, determine |T eff -T total / 2|and|T eff -T total The size of |.

[0104] If |T eff -T total / 2|≤|T eff -T total | indicates that when two motors are used for driving, the actual torque of a single motor is closer to the high-efficiency torque of the motor, so two of the motors are controlled to participate in the driving.

[0105] If |T eff -T total / 2|>|T eff -T total | indicates that when a single motor is used for driving, the actual torque of the single motor is closer to the high-efficiency torque of the motor, so one of the motors is controlled to participate in the driving.

[0106] 5) If T total In [0, T eff Within the specified range, it indicates that the driver's torque requirement is relatively low, and the torque requirement can be met by using only one motor for driving. Therefore, only one motor is controlled to participate in driving.

[0107] Reference Figures 1-2 Another problem with the existing technology is that it can only control the torque of the drive axle and does not take into account the differences in the working conditions of different motors on the same drive axle, which leads to a large difference in the degree of performance degradation of different motors.

[0108] In this regard, the multi-motor drive assembly torque distribution control method provided in this embodiment also includes steps S400-S410 located before step S300.

[0109] S400: Sequentially obtain the cumulative working time t1, t2, ..., t3 of n motors under severe operating conditions. n Harsh operating conditions include high-speed operating conditions, high-torque operating conditions, and / or high-temperature operating conditions.

[0110] High speed, high torque and high temperature are harsh operating conditions that can affect the reliability of motors. Therefore, motors with low cumulative working time should be selected for driving.

[0111] Among them, the cumulative working time t under severe operating conditions of the i-th motor is obtained. i, 1≤i≤n, including steps S4001-S4004.

[0112] S4001: Obtain the high-speed operating time t of the i-th motor. iN .

[0113] Specifically, step S4001 includes:

[0114] Obtain the rotational speed N of the i-th motor during this operation. i Above the speed threshold N threshold Duration Δt iN ; for duration Δt iN The weighted and accumulated high-speed operating time t of the i-th motor iN In the middle, the weighting coefficient is k a k a =(N i -N threshold ) / N threshold .

[0115] The above steps can be used to obtain the rotational speed N of the i-th motor after this run. i Above the speed threshold N threshold Duration Δt iN And for the duration Δt iN The weighted and accumulated high-speed operating time t of the i-th motor iN In this way, the rotational speed N of the i-th motor can be fully considered. i The impact on the reliability of the motor, if the speed N of the i-th motor... i If k is smaller, then a The value is relatively small, and the working time (t) is long under high-speed conditions. iN The increase is small; if the speed N of the i-th motor is small... i If k is larger, then a The value is relatively large, and the working time (t) is long under high-speed conditions. iN The increase was substantial.

[0116] S4002: Obtain the operating time t of the i-th motor under high torque conditions. iT .

[0117] Specifically, step S4002 includes:

[0118] Obtain the torque T of the i-th motor during this operation. i Above the torque threshold T threshold Duration Δt iT ; for duration Δt iT The weighted and accumulated high-speed operating time t of the i-th motor iT In the middle, the weighting coefficient is k b k b =(T i-T threshold ) / T threshold .

[0119] The above steps can be used to obtain the torque T of the i-th motor after this operation. i Above the torque threshold T threshold Duration Δt iT And for the duration Δt iT Weighted and accumulated working time t for the i-th motor under high torque conditions iT In this way, the torque T of the i-th motor can be fully considered. i The impact on the reliability of the motor, if the torque T of the i-th motor i If k is smaller, then b The value is relatively small, and the working time is long under high torque conditions (t). iT The increase is small; if the torque T of the i-th motor is small... i If k is larger, then b The value is relatively large, and the working time (t) is long under high torque conditions. iT The increase was substantial.

[0120] S4003: Obtain the high-temperature operating time t of the i-th motor. iC .

[0121] Specifically, step S4003 includes:

[0122] Get the temperature C of the i-th motor during this operation. i Above the temperature threshold C Chreshold Duration Δt iC ; for duration Δt iT The weighted and accumulated high-speed operating time t of the i-th motor iT In the middle, the weighting coefficient is k c k c =(C i -C Chreshold ) / C Chreshold .

[0123] The temperature C of the i-th motor after this operation can be obtained through the above steps. i Above the temperature threshold C Chreshold Duration Δt iC And for the duration Δt iC The weighted and accumulated high-temperature operating time t of the i-th motor iC In this way, the temperature C of the i-th motor can be fully considered. i The impact on motor reliability, if the temperature C of the i-th motor... i If it is lower, then k c The value is relatively small, and the working time (t) is long under high temperature conditions. iC The increase is small; if the temperature C of the i-th motor...i If it is higher, then k c The value is relatively large, and the working time is long (t) under high temperature conditions. iC The increase was substantial.

[0124] S4004: Calculate the cumulative working time t under severe operating conditions for the i-th motor. i , where t i =t iN +t iT +t iC .

[0125] The cumulative working time t under severe operating conditions for the i-th motor i That is, the working time t under the above high-speed operating conditions. iN High torque working time (t) iT and working hours in high-temperature conditions (t) iC The sum of these parameters gives the cumulative working time t of the i-th motor under severe operating conditions. i .

[0126] S410: Compare t1, t2, ..., t n The size of the n motors is determined, and their usage priority is sorted.

[0127] Specifically, t1, t2, ..., t n The motors are sorted from smallest to largest, with the priority of each motor increasing sequentially.

[0128] Optionally, when controlling m motors to participate in the drive or controlling (m+1) motors to participate in the drive, the motors participating in the drive are selected based on the usage priority of each motor, that is, the motors with higher priority are selected, which is also the cumulative working time t under severe working conditions. i A shorter motor is used for driving, ensuring balanced motor usage and improving system reliability.

[0129] Optionally, steps S400-S410 are performed before step S200. When controlling one of the motors to participate in the drive, the motor with the highest priority is selected to participate in the drive, and it has similar beneficial effects.

[0130] This embodiment also provides a multi-motor drive assembly torque distribution control device, which is used to execute the above-described multi-motor drive assembly torque distribution control method. The multi-motor drive assembly includes multiple multi-motor drives, each including a drive shaft and several motors. The motors drive the drive shaft to rotate. The drive shaft is connected to both the left and right wheels. The total number of motors in the multiple multi-motor drives is n. Any motor in one multi-motor drive can drive the drive shafts of other multi-motor drives to rotate.

[0131] Reference Figure 3The multi-motor drive assembly torque distribution control device includes a driver demand torque acquisition module 1100, a motor high-efficiency torque acquisition module 1200, an interval judgment module 1300, a magnitude comparison module 1400, a first motor drive control module 1500, and a second motor drive control module 1600.

[0132] Among them, the driver demand torque acquisition module 1100 is used to acquire the driver demand torque T. total The high-efficiency torque acquisition module 1200 is used to acquire the high-efficiency torque T of the motor. eff The interval judgment module 1300 is used to judge T. total The interval it is located in, the interval includes [T] eff 2T eff ), [2T eff 3T eff ), ..., [(n-1)T eff nT eff ); Size comparison module 1400 is used when T total In [mT eff (m+1)T eff When the interval is within the range, compare |T eff -T total / (m+1)| and |T eff -T total The size of / m|; the first motor drive control module 1500 is used when |T eff -T total / (m+1)|>|T eff -T total When / m|, control m motors to participate in the drive; the second motor drive control module 1600 is used when |T eff -T total / (m+1)|≤|T eff -T total When / m|, control (m+1) of the motors to participate in the drive.

[0133] The multi-motor drive assembly torque distribution control device provided in this embodiment obtains the driver's required torque T through the driver's required torque acquisition module 1100. total The high-efficiency torque T of the motor is obtained through the high-efficiency torque acquisition module 1200. eff ; Determine T through interval judgment module 1300 total The interval in which it is located; when T total In [mT eff (m+1)T eff When the range is within the specified range, compare |T using the size comparison module 1400. eff -T total / (m+1)| and |Teff -T total The size of / m|; when |T eff -T total / (m+1)|>|T eff -T total When / m|, the first motor drive control module 1500 controls m motors to participate in the drive; when |T eff -T total / (m+1)|≤|T eff -T total When / m|, the second motor drive control module 1600 controls (m+1) of the motors to participate in the drive, thereby distributing the output torque of the motors by controlling the number of motors participating in the drive, and ensuring that the actual torque of a single motor is close to the efficient torque of the motor system, so as to improve economy.

[0134] Example 2

[0135] The multi-motor drive assembly torque distribution control device in this embodiment can be implemented through a multi-motor drive assembly, which has the following two optional structures:

[0136] One type of structure is as follows Figure 4 As shown, the multi-motor drive assembly also includes multiple gearboxes 21, with each motor 11 connected to a gearbox 21 in a one-to-one correspondence. The output shaft 12 serves as the drive axle and is used to connect the wheels 13. Multiple output shafts 12 are provided, and each output shaft 12 is connected to several gearboxes 21. In this design, the drive axle integrates the motor 11, gearboxes 21, and other structures to form an electric drive axle. Optionally, the motor 11 can drive any output shaft 12 to rotate.

[0137] Optionally, a differential 22 is provided in the middle of the output shaft 12 to allow the left and right wheels to rotate at different speeds. The output end of the gearbox 12 connected to the same output shaft 12 is coupled and connected to the differential 22. Optionally, there are two output shafts 12, each connected to two gearboxes 21 and two motors 11. The two output shafts 12 are connected by a transmission mechanism 23. The above solution has been widely used in the field, and its specific structure and transmission principle will not be described in detail.

[0138] Generally, permanent magnet synchronous motor rotors have permanent magnets. Under reverse towing conditions, the vehicle drives the motor to rotate at high speed, generating a high back electromotive force (EMF) that can damage the motor. To counteract this back EMF, a field-weakening current is actively applied, resulting in energy consumption, known as motor field-weakening consumption. In the multi-motor drive assembly torque distribution control method provided in this embodiment, when controlling some motors to participate in driving, for example, controlling m motors to participate in driving or controlling (m+1) motors to participate in driving, the gearbox 21 corresponding to the motor 11 that is not participating in driving is shifted to neutral to avoid additional field-weakening consumption by the motor 11 that is not participating in driving.

[0139] Another structure, such as Figure 5 As shown, the multi-motor drive assembly also includes multiple central drive assemblies. Each central drive assembly includes a drive shaft 31 and a central drive gearbox 32. The drive shaft 31 of any central drive assembly is connected to several motors 11. The input end of the central drive gearbox 32 is connected to the drive shaft 31, and the output ends of the central drive gearboxes 32 of all central drive assemblies are connected to an output shaft 12. This also enables the transmission of torque from the motors 11, and each motor 11 can drive the output shaft 12 to rotate. In this embodiment, two central drive assemblies are provided, each connected to two motors 11.

[0140] Example 3

[0141] Reference Figure 6 This embodiment provides a vehicle, which is a pure electric or range-extended heavy-duty truck. The vehicle includes a multi-motor drive assembly 2000, which includes an output shaft and multiple motors, each capable of driving the output shaft to rotate. The number of motors is n. Furthermore, the vehicle includes a controller 2100, a vehicle speed sensor 2200, a throttle sensor 2300, a motor speed sensor 2400, and a memory 2500. The controller 2100, vehicle speed sensor 2200, throttle sensor 2300, motor speed sensor 2400, and memory 2500 can be connected via a bus.

[0142] Specifically, the vehicle speed sensor 2200 is used to detect the vehicle speed and send the detected speed to the controller 2100; the throttle sensor 2300 is used to detect the throttle opening and send the detected throttle opening to the controller 2100, which can obtain the torque T required by the driver based on the vehicle speed and throttle opening. total The motor speed sensor 2400 is used to detect the motor speed and send the detected speed to the controller 2100. The controller 2100 can obtain the motor's high-efficiency torque T based on the speed. eff .

[0143] The memory 2500, as a computer-readable storage medium, can be used to store software programs, computer-executable programs, and modules, such as the program instructions / modules corresponding to the multi-motor drive assembly torque distribution control method in this embodiment of the invention. The controller 2100 executes various vehicle functions and data processing by running the software programs, instructions, and modules stored in the memory 2500, thereby implementing the multi-motor drive assembly torque distribution control method described above.

[0144] The memory 2500 primarily includes a program storage area and a data storage area. The program storage area stores the operating system and at least one application program required for a given function; the data storage area stores data created based on terminal usage. Furthermore, the memory 2500 may include high-speed random access memory and non-volatile memory, such as at least one disk storage device, flash memory, or other non-volatile solid-state storage device. In some instances, the memory 2500 may further include remotely configured memories 2500 relative to the controller 2100, which can be connected to the vehicle via a network. Examples of such networks include, but are not limited to, the Internet, intranets, local area networks, mobile communication networks, and combinations thereof.

[0145] The vehicle provided in Embodiment 3 of the present invention and the multi-motor drive assembly torque distribution control method provided in the above embodiments belong to the same inventive concept. Technical details not described in detail in this embodiment can be found in the above embodiments. Furthermore, this embodiment has the same beneficial effects as the multi-motor drive assembly torque distribution control method.

[0146] Optionally, embodiments of the present invention also provide a storage medium storing a computer program thereon, which, when executed by a controller, enables the vehicle to implement the multi-motor drive assembly torque distribution control method as described in the above embodiments of the present invention.

[0147] Of course, the computer-executable instructions provided in the embodiments of the present invention are not limited to the operations in the multi-motor drive assembly torque distribution control method as described above, but can also execute related operations in the multi-motor drive assembly torque distribution control device provided in the embodiments of the present invention, and have corresponding functions and beneficial effects.

[0148] Based on the above description of the implementation methods, those skilled in the art can clearly understand that the present invention can be implemented using software and necessary general-purpose hardware, and of course, it can also be implemented using hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product can be stored in a computer-readable storage medium, such as a computer floppy disk, read-only memory (ROM), random access memory (RAM), flash memory, hard disk, or optical disk, etc., including several instructions to cause a computer device (which may be a robot, personal computer, server, or network device, etc.) to execute the multi-motor drive assembly torque distribution control method described in the various embodiments of the present invention.

[0149] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art will be able to make various obvious changes, readjustments, and substitutions without departing from the scope of protection of the present invention. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A torque distribution control method for a multi-motor drive assembly, wherein the multi-motor drive assembly includes an output shaft and multiple motors, each of which can drive the output shaft to rotate, and the number of motors is n; Its features are, The multi-motor drive assembly torque distribution control method includes: S100: Obtain the driver's required torque T total and the high-efficiency torque T of the motor eff ; S200: Determine T total The interval in which it is located, the interval includes [T eff 2T eff ), [2T eff 3T eff ), ..., [(n-1)T eff nT eff ); If T total In [mT eff (m+1)T eff If m = 1, 2, 3, ..., n-1 within the interval, then execute step S300; S300: Comparison | T eff -T total / (m+1)| and |T eff -T total The size of / m|; If |T eff -T total / (m+1)|>|T eff -T total If / m|, then control m of the motors to participate in the drive; If |T eff -T total / (m+1)|≤|T eff -T total If / m|, then control (m+1) of the motors to participate in the drive; It also includes the steps preceding step S300: S400: Sequentially obtain the cumulative working time t1, t2, ..., t3 of the n motors under severe operating conditions. n The severe operating conditions include high-speed operating conditions, high-torque operating conditions, and / or high-temperature operating conditions. S410: Compare t1, t2, ..., t n The size of the n motors is determined, and their usage priorities are sorted. When controlling m of the motors to participate in driving or controlling (m+1) of the motors to participate in driving, the motors to participate in driving are selected based on the usage priority of each motor.

2. The torque distribution control method for a multi-motor drive assembly according to claim 1, characterized in that, The interval also includes [nT] eff (+∞) In step S200, if T total In [nT eff Within the range of (+∞), all n motors mentioned above are controlled to participate in the drive.

3. The torque distribution control method for a multi-motor drive assembly according to claim 1, characterized in that, The interval also includes [0, T] eff ); In step S200, if T total In [0, T eff Within the specified range, one of the motors will be controlled to participate in the drive.

4. The torque distribution control method for a multi-motor drive assembly according to claim 1, characterized in that, When controlling m of the aforementioned motors to participate in the drive, the single-motor torque demand T of the m motors is... out All are T total / m and T max The smaller value in, where T max This refers to the maximum allowable torque of the motor. When controlling (m+1) of the motors to participate in the drive, the single-motor torque demand T of (m+1) of the motors is... out All are T total / (m+1) and T max The smaller value in, where T max This represents the maximum allowable torque for the motor.

5. The torque distribution control method for a multi-motor drive assembly according to claim 1, characterized in that, In step S400, the cumulative working time t under adverse conditions for the i-th motor is obtained. i , 1≤i≤n, including steps S4001-S4004: S4001: Obtain the high-speed operating time t of the i-th motor. iN ; S4002: Obtain the high-torque operating time t of the i-th motor. iT ; S4003: Obtain the high-temperature operating time t of the i-th motor. iC ; S4004: Calculate the cumulative operating time t under severe conditions for the i-th motor. i , where t i =t iN +t iT +t iC .

6. The torque distribution control method for a multi-motor drive assembly according to claim 5, characterized in that, Step S4001 includes: Obtain the rotational speed N of the i-th motor during this operation. i Above the speed threshold N threshold Duration Δt iN ; For duration Δt iN The weighted and accumulated high-speed operating time t of the i-th motor iN In the middle, the weighting coefficient is k a k a =(N i -N threshold ) / N threshold ; and / or, Step S4002 includes: Obtain the torque T of the i-th motor during this operation. i Above the torque threshold T threshold Duration Δt iT ; For duration Δt iT The weighted and accumulated high-speed operating time t of the i-th motor iT In the middle, the weighting coefficient is k b k b =(T i -T threshold ) / T threshold ; and / or, Step S4003 includes: Obtain the temperature C of the i-th motor during this operation. i Above the temperature threshold C Chreshold Duration Δt iC ; For duration Δt iT The weighted and accumulated high-speed operating time t of the i-th motor iT In the middle, the weighting coefficient is k c k c =(C i -C Chreshold ) / C Chreshold .

7. The torque distribution control method for a multi-motor drive assembly according to any one of claims 1-4, characterized in that, The multi-motor drive assembly also includes multiple gearboxes, with each motor connected to a gearbox in a one-to-one correspondence. The output shaft is a drive axle, and multiple output shafts are provided, with each output shaft connected to several gearboxes. In the torque distribution control method for a multi-motor drive assembly, when the motors in the control section participate in driving, the gearbox corresponding to the motors that do not participate in driving is controlled to be in neutral.

8. The torque distribution control method for a multi-motor drive assembly according to any one of claims 1-4, characterized in that, The multi-motor drive assembly also includes multiple central drive assemblies. Each central drive assembly includes a drive shaft and a central drive gearbox. The drive shaft of any central drive assembly is connected to several motors. The input end of the central drive gearbox is connected to the drive shaft. The output ends of the central drive gearboxes of the multiple central drive assemblies are all connected to the output shaft.

9. A vehicle, comprising a multi-motor drive assembly, the multi-motor drive assembly including an output shaft and a plurality of motors, each of the motors being capable of driving the output shaft to rotate, the number of the motors being n; Its features are, The vehicle also includes: Controller; A vehicle speed sensor is used to detect the vehicle speed and send the detected speed to the controller; A throttle sensor is used to detect the throttle opening and send the detected throttle opening to the controller. The controller can obtain the driver's required torque T based on the vehicle speed and the throttle opening. total ; A motor speed sensor is used to detect the motor speed and send the detected speed to the controller, which can then obtain the motor's high-efficiency torque T based on the speed. eff ; Memory, used to store one or more programs; When the controller executes one or more of the programs, it causes the controller to control the vehicle to implement the multi-motor drive assembly torque distribution control method as described in any one of claims 1-8.

Images