Multi-motor cooperative control method and system and storage medium

Abstract

The invention provides a multi-motor cooperative control method and system and a storage medium, and relates to the technical field of vehicle control, and the method comprises the steps that after a rotating speed control mode instruction is received, a main motor control unit is controlled to enter a rotating speed control mode and operate a preset torque distribution strategy, the torque distribution strategy is configured to generate a first target torque of the main motor and a second target torque of the slave motor based on the current target rotating speed, and send the second target torque to the slave motor control unit; controlling a main motor control unit to operate a main motor based on the first target torque; and controlling the slave motor control unit to operate the slave motor based on the second target torque. The method is suitable for a dual-motor wheel edge cooperative control scheme, in the rotating speed control mode, the main motor controller directly processes the second target torque of the slave motor, the coaxial main motor and the slave motor cooperatively carry out torque output, and the phenomenon of vehicle head swinging is avoided.

Description

Technical Field

[0001] This disclosure belongs to the field of vehicle control technology, specifically relating to a multi-motor cooperative control method, system, and storage medium. Background Technology

[0002] To obtain greater driving torque, new energy low-speed heavy-duty vehicles typically employ wheel-side drive systems. In coaxial dual-motor wheel-side drive configurations, the motors on the same side are rigidly connected to the same gear, making simultaneous speed control impossible. However, the vehicle control unit (VCU) requires speed control of the motors. Therefore, one motor uses speed control mode, while the other uses torque control mode. Since the torque adjusted by the speed control motor must be transmitted to the torque control motor via CAN communication after passing through the VCU, excessive communication delays during this process can cause the coaxially connected motors to move in opposite directions, resulting in the motors twisting the shaft in opposite directions. In severe cases, this can lead to shaft breakage. Summary of the Invention

[0003] This disclosure provides a multi-motor cooperative control method, system, and storage medium, aiming to at least partially solve the technical problem of poor synchronous control effect of coaxial dual motors due to communication delays in related technologies.

[0004] At least one embodiment of this disclosure provides a multi-motor cooperative control method applied to a vehicle having multiple motors and multiple motor control units. The multiple motors include a coaxial master motor and a slave motor. The multiple motor control units include a master motor control unit for driving the master motor and a slave motor control unit for driving the slave motor. The method includes: Upon receiving a speed control mode command, the main motor control unit is controlled to enter the speed control mode and run a preset torque distribution strategy. The torque distribution strategy is used to generate a first target torque of the main motor and a second target torque of the slave motor based on the current target speed, and send the second target torque to the slave motor control unit. The main motor control unit is controlled to operate the main motor based on the first target torque; and, The slave motor control unit controls the slave motor to operate based on the second target torque.

[0005] The above solution offers the following technical advantages: It proposes a scheme suitable for dual-motor wheel-side collaborative control, establishing a short-time communication mechanism between the master motor control unit and the slave motor control unit. Compared to existing related technologies, this solution effectively reduces communication latency through this short-time communication mechanism. After receiving the target speed, the master motor control unit processes the required torque without needing to feed back the speed or torque of the master and slave motors for adjustment, thus saving the dynamic torque module of the vehicle controller. Through the short-time communication between the master and slave motor control units, the coaxial master and slave motors collaboratively output the required torque, ensuring that the master and slave motors move in the same direction to simultaneously perform commutation or acceleration / deceleration, avoiding axle breakage. Furthermore, the control of the master and slave motor control units is highly correlated, requiring only one software version to implement speed control, torque control, and collaborative control. The master and slave motors can be arbitrarily selected from multiple motors, allowing the master and slave control units to be distinguished by calibration, or to interchange master and slave through calibration, all achieved with a single switch. The calibration process is simple and flexible. The above solution saves costs and makes the torque output of the coaxial dual motors more coordinated.

[0006] In at least one embodiment of the method provided in this disclosure, a dedicated communication link for unidirectional message transmission is provided between the master motor control unit and the slave motor control unit, and the torque distribution strategy includes: Obtain the current target rotational speed; The total required torque for the main motor and the slave motor is generated based on the target rotational speed. The total required torque is allocated according to a torque allocation rule matching the current operating conditions, generating a first target torque for the main motor and a second target torque for the slave motor; and, A message containing the second target torque is generated and sent to the slave motor control unit via the dedicated communication link, wherein the communication cycle between the master motor control unit and the slave motor control unit is less than the communication cycle between the slave motor control unit and the vehicle controller.

[0007] The above solution has the following technical advantages: it adopts different torque distribution processing methods and eliminates the need for the dynamic torque distribution module of the vehicle controller, thus eliminating the need to feed back the speed of the dual motors.

[0008] In at least one embodiment of the method provided in this disclosure, the torque distribution rule includes: Obtain the current torque output capability parameters of the main motor and the slave motor respectively; A coordinated control torque coefficient is generated based on the torque output capability parameters; and... The first target torque and the second target torque are generated based on the total demand torque and the cooperative control torque coefficient, wherein the first target torque is positively correlated with the cooperative control torque coefficient and the second target torque is negatively correlated with the cooperative control torque coefficient.

[0009] The above solution has the following technical effects: the main motor control unit can allocate torque based on the current torque output capabilities of the main motor and the slave motor, and generate a suitable first target torque and second target torque.

[0010] In at least one embodiment of the method provided in this disclosure, the torque distribution rule further includes: Obtain the fault status parameters from the motor control unit; and, The second target torque is adjusted based on the fault state parameters so that the second target torque adapts adaptively to changes in the fault state parameters.

[0011] The above solution has the following technical effects: the main motor control unit can reduce the second target torque to different degrees according to the fault status parameters of the slave motor control unit, thereby enhancing the reliability of torque distribution.

[0012] In at least one embodiment of the method provided in this disclosure, adjusting the second target torque based on the fault state parameter includes: The fault level of the slave motor control unit is determined based on the fault status parameters; Obtain the reduction factor corresponding to the fault level; and, The second target torque is adjusted based on the reduction factor so that the second target torque decreases as the fault level increases.

[0013] The above solution has the following technical effects: it avoids damage to the multi-motor drive mechanism caused by the failure of the slave motor, and ensures the safety and stability of the multi-motor drive mechanism of the vehicle in the event of a slave motor failure.

[0014] In at least one embodiment of the method provided in this disclosure, controlling the main motor control unit to operate the main motor based on the first target torque includes: controlling the main motor control unit to perform torque gradient processing and amplitude limiting processing on the main motor, so that the main motor outputs the first target torque; and, The step of controlling the slave motor control unit to operate the slave motor based on the second target torque includes: controlling the slave motor control unit to perform torque gradient processing and amplitude limiting processing on the slave motor so that the slave motor outputs the second target torque.

[0015] The above solution has the following technical effects: after torque gradient processing and amplitude limiting processing, the outputs of the main motor and the slave motor meet the requirements.

[0016] The method provided in at least one embodiment of this disclosure further includes: After receiving the speed control mode command, determine whether a cooperative control enable command has been received from the vehicle controller; If so, a first control instruction is generated to control the main motor control unit to start the torque distribution strategy, and a second control instruction is generated to control the slave motor control unit to run the slave motor based on the second target torque, so that the main motor and the slave motor can operate in coordination. If not, control the main motor control unit to operate the main motor based on the total required torque, and control the slave motor control unit to operate the slave motor based on the set required torque of the original control cycle.

[0017] The above solution has the following technical effects: it improves the flexibility of vehicle control, and torque distribution will only occur when the speed control mode is entered and the cooperative control is enabled.

[0018] In at least one embodiment of the method provided in this disclosure, the communication period of the dedicated communication link is 2-5 ms, and the method further includes: Identify the master motor and slave motor among the plurality of motors; The motor control unit driving the main motor is designated as the main motor control unit, and the main motor control unit is configured in a unidirectional transmission mode to communicate with the slave motor control unit via the dedicated communication link; and... The motor control unit that drives the slave motor is set as the slave motor control unit, and the slave motor control unit is configured in a one-way receiving mode to communicate with the master motor control unit through the dedicated communication link.

[0019] The above solution has the following technical effects: it improves the reliability of multi-motor collaborative control.

[0020] At least one embodiment of this disclosure also provides a multi-motor cooperative control system applied to a vehicle having multiple motors and multiple motor control units, including: The main motor is configured as one of the plurality of motors; The motor is configured to be coaxially connected to the main motor among the plurality of motors; The main motor control unit is configured to run a preset torque distribution strategy after receiving a speed control mode command. The torque distribution strategy is used to generate a first target torque of the main motor and a second target torque of the slave motor based on the current target speed and send the second target torque to the slave motor control unit, and to run the main motor based on the first target torque. The slave motor control unit is configured to receive the second target torque and operate the slave motor based on the second target torque.

[0021] At least one embodiment of this disclosure also provides a storage medium storing a program or instructions, wherein the program or instructions, when executed by a processor, implement the steps of the method provided in any embodiment of this disclosure.

[0022] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this disclosure. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A schematic diagram of the dual-motor drive mechanism for a vehicle. Figure 2 A schematic diagram of the CAN architecture for communication between the vehicle controller and the motor control unit in a vehicle; Figure 3 A flowchart of a multi-motor cooperative control method provided in at least one embodiment of this disclosure; Figure 4 A flowchart illustrating a torque distribution strategy provided in at least one embodiment of this disclosure; Figure 5 A flowchart of a torque distribution rule provided for at least one embodiment of this disclosure; Figure 6 Another torque distribution rule flowchart provided for at least one embodiment of this disclosure; Figure 7 A flowchart illustrating an example of a dual-motor cooperative control method provided in at least one embodiment of this disclosure; Figure 8 A structural block diagram of a multi-motor cooperative control system provided in at least one embodiment of this disclosure; Figure 9 A schematic diagram illustrating the composition of a program product provided for at least one embodiment of this disclosure.

[0025] Figure label: 10- Multi-motor cooperative control system; 11- Master motor; 12- Slave motor; 13- Master motor control unit; 14- Slave motor control unit. Detailed Implementation

[0026] The present disclosure will now be described in further detail with reference to the accompanying drawings and embodiments. It should be particularly noted that the following embodiments are for illustrative purposes only and do not limit the scope of the disclosure. Similarly, the following embodiments are only some, not all, embodiments of the present disclosure, and all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0027] The terms "first," "second," and "third" used in the embodiments of this disclosure are for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first," "second," and "third" may explicitly or implicitly include at least one of that feature.

[0028] In the description of this disclosure, "multiple" means at least two, such as two or three, unless otherwise expressly and specifically limited.

[0029] In this disclosure, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this disclosure. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0030] The terms “comprising” and “having”, and any variations thereof, used in this disclosure are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or components inherent to such processes, methods, products, or devices.

[0031] The term "motor control unit" in this disclosure is abbreviated as MCU.

[0032] The term "vehicle controller" in this disclosure is abbreviated as VCU.

[0033] In this disclosure, the term "short-cycle message" refers to a message with a faster transmission speed compared to the original message transmitted between the VCU and the MCU. The communication cycle between the VCU and the MCU is 10ms, referred to as the original cycle. The message transmitted between the master motor control unit and the slave motor control unit in this disclosure uses a shorter cycle than the original cycle. The specific value of the short cycle is determined by the CAN bus load capacity and the MCU program execution scheduling cycle. For example, a 5ms communication cycle can be selected. Within the allowable range of the CAN load capacity, this cycle should be kept as consistent as possible with the scheduling time in the MCU program, keeping the delay within 10ms, thereby reducing communication latency. The communication time delay between the VCU and the MCU includes the CAN transmission delay (approximately 10ms), the VCU processing delay (approximately 10ms), and the CAN reception delay (approximately 10ms), with a total delay of at least 30ms. The method of this disclosure can reduce this delay by more than 20ms.

[0034] In this embodiment of the disclosure, the term "wheel-side drive" refers to a situation where the wheels on both sides of the vehicle are not coaxial, and the rotational speeds of the two wheels can be controlled independently. During steering, the steering action is achieved by relying on the speed difference between the two wheels; during straight-line driving, straight-line driving is maintained by relying on the two wheels maintaining the same rotational speed.

[0035] In the embodiments of this disclosure, the term "speed control mode" refers to inputting a target speed and causing multiple motors to output the target speed.

[0036] In the embodiments of this disclosure, the term "torque control mode" refers to inputting a target torque, causing multiple motors to output the target torque.

[0037] The theoretical basis of this disclosure will be introduced first.

[0038] Figure 1 This is a schematic diagram of the dual-motor drive mechanism for a vehicle. Figure 1 As shown, in multi-MCU, multi-motor drives for new energy low-speed heavy-duty vehicles, especially in coaxial dual-motor wheel-side drive scenarios, the motors on the same side are rigidly connected to a single gear. Under this connection method, the coaxially connected dual motors cannot simultaneously achieve speed control, yet the vehicle control unit (VCU) requires speed control of the motors. Therefore, the multi-motor cooperative control method proposed in this disclosure can be adopted. The master motor control unit and the master-slave motor control units use the same control software, but they need to be calibrated for differentiation. Through the cooperative work of the master motor control unit and the slave motor control unit, the speed cooperative control of the coaxial dual motors is achieved.

[0039] Figure 2 This is a schematic diagram of the CAN architecture for communication between the vehicle controller and the motor control unit in a vehicle. Figure 2 As shown, the vehicle control unit (VCU) and all motor control units (MCUs) are connected to the same CAN bus. The coaxial dual motors can be divided into a master motor and a slave motor. The master motor uses a speed loop control strategy, while the slave motor continues to use a torque control strategy. This disclosure establishes a dedicated communication link between the master MCU and the slave MCU for unidirectional transmission of short-cycle messages, directly generating the second target torque for the slave motor in the master MCU, thus shortening the communication cycle of the entire control process. After receiving the target speed sent by the vehicle control unit (VCU), the master MCU outputs the total required torque through the speed loop. The master MCU allocates the total required torque, operates the master motor based on the generated first target torque, and sends the generated second target torque to the CAN bus. After obtaining the second target torque from the master MCU through the CAN bus, the slave MCU performs torque output control, enabling the master motor and slave motor to collaboratively output the total required torque adjusted by the speed loop.

[0040] Figure 3 This is a flowchart illustrating a multi-motor cooperative control method provided in at least one embodiment of the present disclosure. The method can be applied to a vehicle having multiple motors and multiple motor control units. The multiple motors include a coaxial master motor and a slave motor (also called an auxiliary motor), and the multiple motor control units include a master motor control unit for driving the master motor and a slave motor control unit (also called an auxiliary motor control unit) for driving the slave motor. Figure 3 As shown, the method may include the following steps S10-S30.

[0041] Step S10: After receiving the speed control mode command, control the main motor control unit to enter the speed control mode and run the preset torque distribution strategy. The torque distribution strategy is used to generate the first target torque of the main motor and the second target torque of the slave motor based on the current target speed, and send the second target torque to the slave motor control unit.

[0042] Step S20: Control the main motor control unit to run the main motor based on the first target torque.

[0043] Step S30: Control the motor control unit to run the slave motor based on the second target torque.

[0044] It should be noted that multiple motor control units can be different controllers, different control boards of the same controller, or different chips on the same control board of the same controller. Furthermore, the number of main motors, main motor control units, slave motors, and slave motor control units can be one or more. The main motor and slave motors have coaxial output. The main motor can be controlled using its existing speed loop, and the slave motor can be controlled using its existing torque loop. The target speed of the main motor control unit can be obtained from the vehicle controller (VCU) or a remote controller. The second target torque (also called the required torque) of the slave motor control unit is obtained from the main motor control unit. The main motor and slave motors jointly output torque so that each motor reaches the target speed.

[0045] In the above scheme, this disclosure does not specifically limit how the torque distribution strategy in step S10 generates the first target torque and the second target torque based on the target speed. In practical application scenarios, in addition to the torque distribution strategy described in the following embodiments, the torque distribution strategy can also be flexibly adjusted according to various factors such as different driving states, load conditions, and power demands of the vehicle. For example, during the vehicle's starting phase, in order to obtain better acceleration performance, a larger first target torque can be allocated to the main motor, while a relatively smaller second target torque can be allocated to the slave motor; when the vehicle is traveling at a constant speed, the target torques of the main motor and the slave motor are reasonably allocated according to the vehicle's load conditions to achieve energy saving; when the vehicle needs to climb a hill or overtake, the torque distribution is adjusted again to provide a larger torque output to the main motor to ensure that the vehicle has sufficient power.

[0046] When executing step S10, the system dynamically generates a first target torque and a second target torque based on a preset torque distribution strategy, taking into account the performance characteristics of the main motor and the slave motor. This process not only ensures the rationality and efficiency of torque distribution but also significantly improves the vehicle's adaptability and stability under different driving conditions.

[0047] In the above scheme, this disclosure does not limit the method of operating the main motor based on the first target torque in step S20. In practical application scenarios, the main motor's operating strategy can follow the original control strategy, such as speed loop PI regulation, or it can make a comprehensive decision based on the vehicle's real-time status, driving intention, and battery management system status. For example, when the first target torque is low, the torque-speed curve of the main motor can be optimized to make it operate in the high-efficiency range to reduce energy consumption; under complex road conditions, the main motor and the slave motor can also achieve differential control through torque vector distribution technology to improve the vehicle's handling stability.

[0048] When executing step S20, the system can precisely control the operating status of the main motor based on the first target torque and the vehicle's real-time operating data. This control method not only considers the power demand of the main motor but also takes energy efficiency into account.

[0049] In the above scheme, this disclosure does not limit how the slave motor operates based on the second target torque in step S30. In practical applications, the slave motor's operating strategy can follow the original control strategy, such as the torque loop. The slave motor's operating control strategy also needs to comprehensively consider multiple factors, such as the vehicle's real-time status, the driver's intention, and the battery management system's status. Specifically, when the second target torque demand is at a low level, the slave motor's torque-speed curve can be optimized to allow it to operate in the high-efficiency range, thereby reducing energy consumption. In complex road conditions, the slave motor and the master motor can achieve differential control using torque vectoring technology, enhancing the vehicle's handling stability.

[0050] When executing step S30, the system can precisely control the operating status of the slave motor based on the second target torque and the vehicle's real-time operating data. This control method not only considers the power demand of the slave motor but also takes energy efficiency into account.

[0051] Through steps S10-S30, in multi-motor coaxial output, the CAN bus contains the vehicle controller and multiple motor control units. Communication between the master motor control unit and the slave motor control unit shortens the communication cycle of related technical solutions, effectively solving the communication delay problem. After receiving the target speed, the master motor control unit can directly perform total torque distribution without feeding back the speed or torque of the master and slave motors to the vehicle controller for adjustment, thus eliminating the need for the vehicle controller's dynamic torque distribution module. The slave motor control unit operates based on the second target torque obtained through communication with the master motor control unit. The master and slave motor control units can use the same version of control software, and the calibration process is simple, saving costs. Direct communication between the master and slave motor control units achieves short-cycle communication, enabling them to work together to complete the total torque output, thus solving the technical problem of poor synchronous control of coaxial dual motors due to communication delays in related technologies.

[0052] In some embodiments, Figure 3 To ensure communication stability and reliability, a dedicated communication link for unidirectional message transmission exists between the main motor control unit and the slave motor control unit. The main motor control unit acts as the sender, responsible for unidirectionally transmitting a message containing the second target torque to the slave motor control unit. The slave motor control unit, as the receiver, only receives these messages and performs corresponding operations based on their content. This dedicated unidirectional message transmission link design avoids signal interference and data conflicts that may occur in bidirectional communication, further improving communication stability and reliability, and ensuring the accurate execution of critical operations such as torque distribution during multi-motor coordinated control.

[0053] In some embodiments, to ensure the coordinated control effect between the master motor and the slave motor, the communication cycle of the dedicated communication link is 2-5 ms. This communication cycle is designed to fully consider the system's response speed and stability requirements. The 2-5 ms communication cycle ensures fast and accurate message transmission between the master motor control unit and the slave motor control unit without increasing system load and power consumption due to excessively frequent communication. This short communication cycle design enables the multi-motor coordinated control system to respond more promptly to external commands and load changes, improving the overall system's dynamic performance and stability.

[0054] Figure 4 A flowchart illustrating a torque distribution strategy provided for at least one embodiment of this disclosure. Figure 3 Based on this, in order to ensure the coordinated control effect of the master motor and the slave motor, such as Figure 4 As shown, the torque distribution strategy in step S10 is refined into sub-steps S101-S104.

[0055] Sub-step S101: Obtain the current target rotational speed.

[0056] Sub-step S102: Generate the total required torque for the master motor and slave motor based on the target speed.

[0057] Sub-step S103: Distribute the total required torque according to the torque distribution rules that match the current operating conditions, and generate the first target torque for the main motor and the second target torque for the slave motor.

[0058] Sub-step S104: Generate a message containing the second target torque and send the message to the slave motor control unit through a dedicated communication link, wherein the communication cycle between the master motor control unit and the slave motor control unit is shorter than the communication cycle between the slave motor control unit and the vehicle controller.

[0059] The message is a one-way short-cycle message. After receiving the target speed sent by the vehicle controller (VCU), the main motor control unit enters the speed loop PI regulation to obtain the total required torque. Then, based on the preset torque distribution rules, it generates the first target torque and the second target torque. The first target torque is the required torque allocated to the main motor in the cooperative control mode, and the second target torque is the required torque allocated to the slave motor in the cooperative control mode.

[0060] Figure 5 A flowchart illustrating a torque distribution rule is provided for at least one embodiment of this disclosure. Figure 4 Based on this, in order to ensure the stable operation and efficient work of the multi-motor drive mechanism, the torque distribution rule includes the following sub-steps S103a-S103c.

[0061] Sub-step S103a: Obtain the current torque output capability parameters of the main motor and the slave motor.

[0062] Sub-step S103b: Generate the collaborative control torque coefficient based on the torque output capability parameter.

[0063] Sub-step S103c: Generate a first target torque and a second target torque based on the total demand torque and the cooperative control torque coefficient, wherein the first target torque is positively correlated with the cooperative control torque coefficient and the second target torque is negatively correlated with the cooperative control torque coefficient.

[0064] The collaborative control torque coefficient is used to dynamically adjust the torque distribution ratio between the master motor and the slave motor in collaborative control mode, ensuring that both motors can reasonably share the total required torque according to their respective torque output capabilities. When the master motor has a strong torque output capability, the collaborative control torque coefficient will increase accordingly, increasing the first target torque and decreasing the second target torque, thereby fully utilizing the performance advantage of the master motor. Conversely, when the slave motor has a strong torque output capability, the collaborative control torque coefficient will decrease, decreasing the first target torque and increasing the second target torque, to fully utilize the performance of the slave motor. This dynamic adjustment mechanism can effectively improve the overall operating efficiency and stability of the multi-motor drive mechanism.

[0065] In the above scheme, the total required torque is processed by torque coefficient in the main motor control unit. The torque coefficient includes, but is not limited to, the collaborative control torque coefficient.

[0066] In some embodiments, the cooperative control torque coefficient is between 0 and 1, and the sum of the first target torque and the second target torque equals the total required torque. Specifically, when the cooperative control torque coefficient is 0, it means that the slave motor bears all the required torque, and the master motor does not output torque; in this case, the performance of the slave motor is mainly relied upon to meet the working requirements. When the cooperative control torque coefficient is 1, it indicates that the master motor bears all the required torque, and the slave motor does not output torque; in this case, the performance of the master motor is mainly utilized. By limiting the cooperative control torque coefficient to this range, the reasonable distribution of torque between the master and slave motors can be achieved more accurately, further optimizing the operation of the multi-motor drive mechanism.

[0067] In some embodiments, Figure 5 Based on this, the first target torque Second target torque The following formulas can be used to obtain the results:

[0068]

[0069] In the formula, This represents the torque coefficient for coordinated control. This indicates the total torque demand.

[0070] The first target torque is the product of the total required torque and the collaborative control torque coefficient. This means that the torque required by the main motor can be proportionally allocated according to the magnitude of the collaborative control torque coefficient to fully utilize the performance advantages of the main motor. The second target torque is equal to the total required torque minus the first target torque. In other words, the remaining torque after deducting the portion borne by the main motor from the total required torque is borne by the slave motor. This achieves a reasonable torque distribution between the main and slave motors in the collaborative control mode, ensuring the stable operation and efficient work of the multi-motor drive mechanism.

[0071] The aforementioned torque output capability parameters include, but are not limited to, extreme torque output value, rated torque output value, and torque response time. The extreme torque output value reflects the torque limit that the motor can provide under extreme operating conditions and is an important indicator for measuring the motor's torque output capability. The rated torque output value represents the torque that the motor can continuously and stably output under normal operating conditions, which is crucial for ensuring the stable operation of the system. The torque response time reflects the time required for the motor to actually output torque after receiving a torque command, and is a key parameter for measuring the motor's dynamic response performance.

[0072] Figure 6 A flowchart illustrating another torque distribution rule provided for at least one embodiment of this disclosure. Figure 5 Based on this, in order to further ensure the stable operation and efficient work of the multi-motor drive mechanism, the torque distribution rule also includes the following sub-steps S103d and S103e.

[0073] Sub-step S103d: Obtain fault status parameters from the motor control unit.

[0074] Sub-step S103e: Adjust the second target torque based on the fault state parameters so that the second target torque can be adaptively adjusted as the fault state parameters change.

[0075] When the slave motor control unit is in normal operation, the fault status parameters are within the preset normal range. In this case, the second target torque is obtained by subtracting the first target torque from the total required torque, maintaining the normal torque distribution ratio between the master and slave motors and ensuring stable and efficient system operation. When the slave motor control unit malfunctions, the fault status parameters exceed the normal range. Depending on the severity of the fault, the second target torque is adjusted accordingly. If the fault is minor, the second target torque is appropriately reduced, allowing the master motor to bear more torque to ensure the system can still maintain a certain level of operation. If the fault is severe, the second target torque is adjusted to a minimum or even zero, allowing the master motor to bear the majority of the torque, preventing further damage to the entire multi-motor drive mechanism from a slave motor failure, and ensuring the system operates as safely and stably as possible under fault conditions.

[0076] In the above scheme, the fault status parameters include, but are not limited to, fault level, fault occurrence frequency, fault duration, and fault type identifier. The main motor control unit receives the fault status parameters from the slave motor control unit sent by the vehicle controller, and performs different degrees of reduction processing on the second target torque according to the fault status parameters of the slave motor control unit.

[0077] In some embodiments, Figure 6 Based on this, to ensure the safety and stability of the system under the condition of a slave motor failure, sub-step S103e further includes: determining the fault level of the slave motor control unit based on the fault state parameters; obtaining the reduction processing coefficient corresponding to the fault level; and adjusting the second target torque based on the reduction processing coefficient so that the second target torque decreases as the fault level increases. The reduction processing coefficient is a variable value between 0 and 1. The fault level can be set according to the degree to which the fault state parameters deviate from the normal range, for example, it can be set to three levels: warning fault, general fault, and severe fault. A warning fault is a fault with minor risk, and the reduction processing coefficient can be 1, so that the output second target torque is not processed. A general fault is a fault with moderate risk, and the reduction processing coefficient can be set between 0 and 1, so that the second target torque will decrease significantly, ensuring that the system can still maintain certain functions under the influence of the fault. A severe fault is a high-risk fault, and the reduction processing coefficient can be set to 0, so that the slave motor stops, allowing the master motor to bear the total required torque, avoiding damage to the multi-motor drive mechanism caused by the slave motor failure, and ensuring the safety and stability of the vehicle's multi-motor drive mechanism under the condition of a slave motor failure.

[0078] In the above scheme, serious faults include, but are not limited to, communication timeouts and IGBT failures, which severely affect the operation of the slave motor control unit and the slave motor. Over-temperature faults are classified into different degrees of over-temperature, with different fault levels corresponding to different temperature rises, including warning faults, general faults, and serious faults.

[0079] In some embodiments, Figure 6 Based on this, in order to ensure the response effect, the adjusted second target torque generated in sub-step S103e... Configured as:

[0080] In the formula, This represents the reduction factor.

[0081] Among them, the reduction processing coefficient The specific value needs to be dynamically adjusted based on the fault level. This graded torque control mechanism not only avoids the escalation of faults but also largely preserves the system's operational capabilities. Through this refined control, the system can respond appropriately to faults of different levels. For example, in the event of a severe fault... =0, during a general fault =0.5, only when warning of faults. =1.

[0082] The final result obtained by the above scheme The set torque is sent from the main motor control unit to the CAN bus and received from the motor control unit in the CAN bus by the main motor control unit under the corresponding ID. .

[0083] In some embodiments, to ensure that the main motor outputs a first target torque that meets the requirements, step S20 is refined to include: controlling the main motor control unit to perform torque gradient processing and limiting processing on the main motor, so that the main motor outputs the first target torque. The torque gradient processing gradually adjusts the output torque of the main motor using a preset gradient curve to ensure smooth torque changes and avoid impacts on the system caused by sudden torque changes. The limiting processing includes: determining the limiting indicators corresponding to the vehicle's limiting requirements, the motor's external characteristics, and fault degradation, and taking the minimum limit among the three to limit the output torque of the main motor. After the torque gradient processing and limiting processing, the main motor outputs the first target torque that meets the requirements.

[0084] The above scheme addresses the first target torque. After torque gradient processing and amplitude limiting by the main motor control unit, the output is delivered by the main motor.

[0085] In some embodiments, step S30 is further refined to include: controlling the slave motor control unit to perform torque gradient processing and limiting processing on the slave motor, so that the slave motor outputs a second target torque. The torque gradient processing also adjusts the output torque of the slave motor step-by-step according to a preset specific gradient curve, thereby ensuring a smooth and stable torque change process and preventing adverse impacts on the entire system due to sudden torque changes. The limiting processing includes: determining the limiting indicators corresponding to the vehicle's limiting requirements, the motor's external characteristics, and fault degradation, and taking the minimum limit among the three to limit the output torque of the master motor. After the torque gradient processing and limiting processing of the slave motor, the slave motor can output the required second target torque, thereby achieving coordinated operation between the master motor and the slave motor.

[0086] The above scheme addresses the second target torque. or After torque gradient processing and amplitude limiting by the motor control unit, the output is provided by the slave motor.

[0087] As an exemplary implementation, the limiting process may include the following: 1) If a fault is detected in the main motor control unit or the slave motor control unit, the output torque of the corresponding motor will be downgraded. 2) When a fault is detected in the slave motor control unit, the second target torque received from the master motor control unit will first be degraded by the master motor control unit. That is, for the slave motor control unit, the second target torque received after the fault is degraded, and finally its output torque will also be degraded and limited by itself to prevent it from exceeding the output capacity range under the fault condition.

[0088] 3) If a serious fault is detected in the main motor control unit, the main motor control unit will stop, and the second target torque will not be received from the motor control unit, and no torque will be output.

[0089] In some embodiments, Figures 3-6 In order to ensure the normal operation of the vehicle, the method further includes the following steps S01-S03.

[0090] Step S01: Determine the master motor and slave motor among the multiple motors.

[0091] Step S02: Set the motor control unit that drives the main motor as the main motor control unit, and configure the main motor control unit in unidirectional transmission mode to communicate with the slave motor control unit through a dedicated communication link.

[0092] Step S03: Set the motor control unit that drives the slave motor as the slave motor control unit, and configure the slave motor control unit in one-way receiving mode to communicate with the master motor control unit through a dedicated communication link.

[0093] Steps S01-S03 can be placed before step S10. The unidirectional communication mode between the main motor control unit and the slave motor control unit effectively avoids signal interference and conflicts, ensuring the accuracy and real-time performance of data transmission. The main motor control unit is responsible for unidirectionally sending key information such as the main motor's operating status and torque commands to the slave motor control unit, while the slave motor control unit focuses on receiving this information and adjusting the slave motor's operating status according to a preset control strategy to achieve coordinated control with the main motor. This configuration not only simplifies the system architecture but also improves the reliability and efficiency of multi-motor coordinated control.

[0094] In some embodiments, Figures 3-6 In order to further ensure the normal operation of the vehicle, the method also includes the following steps S04-S06.

[0095] Step S04: After receiving the speed control mode command, determine whether a collaborative control enable command issued by the vehicle controller has been received. If yes, proceed to step S05; otherwise, proceed to step S06.

[0096] Step S05: Generate a first control command for controlling the main motor control unit to start the torque distribution strategy, and generate a second control command for controlling the slave motor control unit to run the slave motor based on the second target torque, so that the main motor and the slave motor can operate in coordination.

[0097] Step S06: Control the main motor control unit to run the main motor based on the total required torque, and control the slave motor control unit to run the slave motor based on the set required torque of the original control cycle.

[0098] Steps S04-S06 can be set before step S10. Only when the cooperative control is enabled will the output torque of the main motor control unit switch from the total demand torque to the first target torque, and the output torque of the slave motor control unit switch from the demand torque sent by the vehicle controller (VCU) to the second target torque. Otherwise, the main motor control unit and the slave motor control unit maintain the original control mode. That is, the main motor control unit continues to operate the main motor based on the total demand torque, and the slave motor control unit continues to operate the slave motor based on the set demand torque of the original control cycle. This ensures that each motor can still work stably according to the predetermined parameters in the non-cooperative control state, and ensures the normal operation of the vehicle or related equipment.

[0099] Figure 7 A flowchart illustrating an example of a dual-motor cooperative control method provided in at least one embodiment of this disclosure. Figure 7 As shown, the main motor control unit executes the following program: 1) After receiving the speed control mode command sent by the VCU, receive the target speed sent by the VCU; 2) Input the target speed into the speed loop and perform PI regulation to obtain the total required torque; 3) Determine whether a collaborative control enable command has been received from the VCU. If so, perform torque coefficient processing, send out a short-cycle message containing the second target torque, and control the main motor through torque limiting and gradient processing to make the main motor output the first target torque. If not, directly control the main motor through torque limiting and gradient processing to make the main motor output the total required torque.

[0100] The following procedure is executed from the motor control unit: 1) After receiving the speed control mode command sent by the VCU, determine whether the cooperative control enable command sent by the VCU has been received. If yes, execute 2); otherwise, execute 3). 2) Receive a short-cycle message containing the second target torque, and control the slave motor through torque limiting and gradient processing to make the slave motor output the second target torque; 3) Receive the set torque requirement from the original cycle VCU, and control the slave motor through torque limiting and gradient processing so that the slave motor outputs the set torque requirement.

[0101] Figure 8 This is a structural block diagram of a multi-motor cooperative control system provided in at least one embodiment of the present disclosure. This multi-motor cooperative control system can be applied to vehicles having multiple motors and multiple motor control units. Figure 8 As shown, the multi-motor cooperative control system 10 includes a master motor 11, a slave motor 12, a master motor control unit 13, and a slave motor control unit 14.

[0102] The main motor 11 is configured as one of a plurality of motors.

[0103] Motor 12 is configured as one of a plurality of motors that is coaxially connected to the main motor.

[0104] The main motor control unit 13 is configured to enter the speed control mode and run a preset torque distribution strategy after receiving a speed control mode command. The torque distribution strategy is configured to generate a first target torque of the main motor and a second target torque of the slave motor based on the current target speed, send the second target torque to the slave motor control unit, and run the main motor based on the first target torque.

[0105] The slave motor control unit 14 is configured to receive a second target torque and operate the slave motor based on the second target torque.

[0106] The specific execution methods of each unit in the above system embodiments have been described in detail in the embodiments related to the method, and will not be elaborated here.

[0107] In some embodiments, Figure 8 Based on this, the main motor control unit and the slave motor control unit have the same software built in, and are distinguished by a calibration switch C. In the main motor control unit, C=0, it only transmits and does not receive, that is, the main motor control unit enters a single transmit mode. In the slave motor control unit, C=1, it only receives and does not transmit, that is, the slave motor control unit enters a single receive mode.

[0108] In some embodiments, Figure 8Based on this, both the main motor control unit and the slave motor control unit receive the original cycle of the collaborative control enable command and other original message commands from the vehicle controller (VCU). After receiving the speed control mode command from the VCU, the main motor control unit enters the speed control mode, and after receiving the speed control mode command from the VCU, the slave motor control unit enters the torque control mode. When the collaborative control enable command from the VCU is received, the short cycle one-way communication function between the main motor control unit and the slave motor control unit can be enabled.

[0109] This disclosure also provides a storage medium storing a program or instructions that, when executed by a processor, implement the steps of the method embodiments described above.

[0110] This disclosure also provides a program product, such as... Figure 9 As shown, the program product includes one or more processors 21 and memory 22. Figure 9 Take a processor 21 as an example.

[0111] The controller may also include an input device 23 and an output device 24.

[0112] The processor 21, memory 22, input device 23, and output device 24 can be connected via a bus or other means. Figure 9 Taking the example of a connection between China and Israel via a bus.

[0113] The processor 21 can be a central processing unit (CPU), or it can be other general-purpose processors, digital signal processors (DSPs), application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, or combinations of the above types of chips. The general-purpose processor can be a microprocessor or any conventional processor.

[0114] The memory 22, as a non-transitory computer-readable storage medium, can be used to store non-transitory software programs, non-transitory computer-executable programs, and modules, such as the program instructions / modules corresponding to the methods in the embodiments of this disclosure. The processor 21 executes various functional applications and data processing of the server by running the non-transitory software programs, instructions, and modules stored in the memory 22, thereby implementing the steps of the above-described method embodiments.

[0115] The memory 22 may include a program storage area and a data storage area. The program storage area may store the operating system and applications required for at least one function; the data storage area may store data created by the use of the processing device operated by the server. Furthermore, the memory 22 may include high-speed random access memory and may also include non-transitory memory, such as at least one disk storage device, flash memory device, or other non-transitory solid-state storage device. In some embodiments, the memory 22 may optionally include memory remotely located relative to the processor 21, and these remote memories may be connected to a network connection device 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.

[0116] Input device 23 can receive input digital or character information, and generate key signal inputs related to driver settings and function control of the server's processing unit. Output device 24 may include display devices such as a display screen.

[0117] One or more modules are stored in memory 22, and when executed by one or more processors 21, they perform actions such as... Figure 1 The method shown.

[0118] Those skilled in the art will understand that all or part of the processes in the above method embodiments can be implemented by a computer program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, it can include the processes described in the above method embodiments. The storage medium can be a magnetic disk, optical disk, read-only memory (ROM), random access memory (RAM), flash memory (FM), hard disk drive (HDD), or solid-state drive (SSD), etc.; the storage medium can also include combinations of the above types of memory.

[0119] Although embodiments of the present disclosure have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present disclosure, and such modifications and variations all fall within the scope defined by the appended claims.

[0120] Although embodiments of the present disclosure have been shown and described above, it is to be understood that the above embodiments are exemplary and should not be construed as limiting the present disclosure. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present disclosure.

Claims

1. A multi-motor cooperative control method applied to a vehicle having a plurality of motors and a plurality of motor control units, the plurality of motors including a main motor and a slave motor that are coaxial, the plurality of motor control units including a main motor control unit for driving the main motor and a slave motor control unit for driving the slave motor, characterized by, The method comprises: After receiving the speed control mode instruction, the main motor control unit is controlled to enter the speed control mode and run a preset torque distribution strategy, wherein the torque distribution strategy is used to generate a first target torque of the main motor and a second target torque of the slave motor based on a current target speed, and send the second target torque to the slave motor control unit; The main motor control unit is controlled to run the main motor based on the first target torque; and The slave motor control unit is controlled to run the slave motor based on the second target torque.

2. The method of claim 1, wherein, The main motor control unit and the slave motor control unit have a dedicated communication link for one-way transmission of messages, and the torque distribution strategy comprises: Obtaining a current target speed; Generating a total demand torque of the main motor and the slave motor based on the target speed; Distributing the total demand torque according to a torque distribution rule matched with a current working condition to generate a first target torque for the main motor and a second target torque for the slave motor; and Generating a message containing the second target torque and sending the message to the slave motor control unit through the dedicated communication link, wherein the communication period of the main motor control unit and the slave motor control unit is less than the communication period of the slave motor control unit and the vehicle controller.

3. The method of claim 2, wherein, The torque distribution rule comprises: Obtaining current torque output capability parameters of the main motor and the slave motor respectively; Generating a cooperative control torque coefficient based on the torque output capability parameters; and Generating the first target torque and the second target torque based on the total demand torque and the cooperative control torque coefficient, wherein the first target torque is positively correlated with the cooperative control torque coefficient, and the second target torque is negatively correlated with the cooperative control torque coefficient.

4. The method of claim 3, wherein, The torque distribution rule further comprises: Obtaining a fault state parameter of the slave motor control unit; and Adjusting the second target torque based on the fault state parameter, so that the second target torque is adaptively adjusted with the change of the fault state parameter.

5. The method of claim 4, wherein, The adjustment of the second target torque based on the fault state parameter comprises: Determining a fault level of the slave motor control unit based on the fault state parameter; Obtaining a drop processing coefficient corresponding to the fault level; and Adjusting the second target torque based on the drop processing coefficient, so that the second target torque decreases with the increase of the fault level.

6. The method according to any one of claims 1 to 5, characterized in that, The control of the main motor control unit to run the main motor based on the first target torque comprises: controlling the main motor control unit to perform torque gradient processing and amplitude limiting processing on the main motor, so that the main motor outputs the first target torque; and The control of the slave motor control unit to run the slave motor based on the second target torque comprises: controlling the slave motor control unit to perform torque gradient processing and amplitude limiting processing on the slave motor, so that the slave motor outputs the second target torque.

7. The method according to any one of claims 1 to 5, characterized in that, Further comprising: After receiving the rotating speed control mode instruction, it is determined whether a cooperative control enabling instruction sent by the vehicle controller is received; If yes, a first control instruction for controlling the main motor control unit to start a torque distribution strategy is generated, and a second control instruction for controlling the slave motor control unit to operate the slave motor based on the second target torque is generated, so that the main motor and the slave motor operate cooperatively; If no, the main motor control unit is controlled to operate the main motor based on the total demand torque, and the slave motor control unit is controlled to operate the slave motor based on the set demand torque of the original control period.

8. The method according to any one of claims 2-5, characterized in that, The communication period of the dedicated communication link is 2-5 ms, and the method further comprises: Determining a main motor and a slave motor in the plurality of motors; Setting a motor control unit driving the main motor as a main motor control unit, and configuring the main motor control unit in a one-way sending mode to communicate with the slave motor control unit through the dedicated communication link; and Setting a motor control unit driving the slave motor as a slave motor control unit, and configuring the slave motor control unit in a one-way receiving mode to communicate with the main motor control unit through the dedicated communication link.

9. A multi-motor cooperative control system applied to a vehicle having a plurality of motors and a plurality of motor control units, characterized by, The system comprises: A main motor configured as one of the plurality of motors; A slave motor configured as a motor coaxially connected with the main motor in the plurality of motors; A main motor control unit configured to operate a preset torque distribution strategy after receiving a rotating speed control mode instruction, wherein the torque distribution strategy is used to generate a first target torque of the main motor and a second target torque of the slave motor based on a current target rotating speed and send the second target torque to a slave motor control unit, and operate the main motor based on the first target torque; A slave motor control unit configured to receive the second target torque and operate the slave motor based on the second target torque.

10. A storage medium, characterized by The storage medium stores programs or instructions, wherein the programs or instructions are executed by the processor to implement the steps of the method of any one of claims 1-8.

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