Control system for a distributed drive vehicle and method of controlling the same

Abstract

The application discloses a control system of a distributed drive vehicle and a control method thereof, and comprises a whole vehicle integrated brake controller and a motor controller. The whole vehicle integrated brake controller is used for acquiring vehicle state signals, and the vehicle state signals at least include vehicle speed, wheel speed and motor rotating speed. The motor controller is in communication connection with the whole vehicle integrated brake controller, and the motor controller is integrated with a direct torque control module. The application realizes millisecond-level fast response by sinking the slip rate control to the inside of the motor controller through the direct torque control module, and solves the problems of long control period and slow response of the traditional traction control system.

Description

Technical Field

[0001] This invention relates to the field of power control technology for new energy vehicles, specifically to a control system and control method for distributed drive vehicles. Background Technology

[0002] With the development of new energy vehicle technology, distributed drive electric vehicles (such as four-motor independent drive models) have become a research hotspot due to their advantages such as fast response speed and flexible control. However, the logic of traditional traction control systems (TCS) is usually monitored by the vehicle integrated brake controller (IBC) to monitor wheel slip ratio. When wheel slippage is detected, the IBC calculates the slip ratio and sends a torque reduction request to the vehicle controller (VCU), which then forwards it to the motor controller (MCU) to finally complete the torque reduction action. This control path is relatively long, with a cycle of approximately 100ms.

[0003] For pure electric or hybrid vehicles, the steep acceleration and rapid torque rise of the motors often result in untimely control response and significant wheel slippage, posing safety hazards. Furthermore, for vehicles with four independently driven motors, coordinating the torque output of the motors on both sides of the same axle to prevent vehicle yaw, and ensuring the robustness of the control logic under special operating conditions (such as motor reversal or combinations of positive and negative torque), are pressing issues that need to be addressed in current technologies. Summary of the Invention

[0004] This invention aims to at least solve the problem of long control paths in existing traction control systems. To this end, this invention provides a control system and method for distributed drive vehicles.

[0005] A control system for a distributed drive vehicle according to a first aspect of an embodiment of the present invention includes: The vehicle integrated brake controller is used to acquire vehicle status signals, which include at least vehicle speed, wheel speed, and motor speed. The motor controller is communicatively connected to the vehicle integrated brake controller, and the motor controller integrates a direct torque control module. The vehicle integrated brake controller calculates and corrects the upper and lower limits of the target speed of the motor in real time based on the vehicle speed and wheel speed signals, and sends them to the direct torque control module. The direct torque control module obtains the actual speed of the motor and determines: When the actual rotational speed is greater than the target rotational speed limit, it is determined that the wheel is slipping, and the direct torque control module directly executes torque reduction control. When the actual speed is less than the target speed lower limit, it is determined that the vehicle has locked up, and the direct torque control module directly executes torque increase control.

[0006] A control system for a distributed drive vehicle according to an embodiment of the present invention has at least the following beneficial effects: This invention solves the problems of long control cycles and slow response in traditional traction control systems by integrating slip ratio control into the motor controller and enabling millisecond-level rapid response through the direct torque control module.

[0007] According to some embodiments of the present invention, the vehicle integrated brake controller is further configured to calculate the maximum permissible torque difference between the coaxial motors on both sides in real time based on the vehicle speed and yaw rate signals; when the actual yaw rate of the vehicle exceeds the theoretical threshold, the vehicle integrated brake controller controls the torque of the coaxial motors on both sides according to the maximum permissible torque difference until the yaw rate returns to the normal value.

[0008] According to some embodiments of the present invention, the control system further includes quadrant monitoring logic, specifically: Define the motor's operating quadrants, including: the first quadrant for forward rotation and positive torque, the second quadrant for forward rotation and negative torque, the third quadrant for reverse rotation and positive torque, and the fourth quadrant for reverse rotation and negative torque; The coaxial dual motors monitor each other's quadrant and perform function exit and alarm according to the following strategy: When both motors are in the same quadrant, or in a combination of the first and fourth quadrants, or a combination of the second and third quadrants, the function is considered normal. When both motors are in other quadrant combinations, the function is deemed to be degraded and an alarm is triggered.

[0009] According to some embodiments of the present invention, when the actual torque of the motor is within a preset threshold range, the torque difference between the two motors is not greater than the maximum allowable torque difference, and the two motors are not in an abnormal quadrant combination, but the vehicle still experiences yaw instability, the vehicle integrated brake controller performs active torque intervention and braking control based on the torque requested by the direct torque control module until the vehicle stabilizes.

[0010] According to a second aspect of the present invention, a control method for a distributed drive vehicle is characterized in that the control method is applied to any of the control systems described above, and includes the following steps: The vehicle integrated brake controller calculates the upper and lower limits of the target speed of the motor in real time based on the wheel speed and vehicle speed signals, and sends them to the direct torque control module. The direct torque control module acquires the actual speed of the motor in real time. When the actual speed is greater than the upper limit of the target speed, torque reduction control is directly executed inside the motor controller. When the actual speed is less than the lower limit of the target speed, torque increase control is directly executed inside the motor controller.

[0011] According to some embodiments of the present invention, a coaxial torque difference control step is also included: The vehicle integrated brake controller calculates the maximum permissible torque difference between the motors on both sides of the coaxial axis in real time based on vehicle speed and yaw rate signals. When the actual yaw rate of the vehicle exceeds the theoretical threshold, the vehicle integrated brake controller adjusts the torque of the coaxial dual motors to ensure that the actual torque difference between the two sides is not greater than the maximum allowable torque difference.

[0012] According to some embodiments of the present invention, a quadrant monitoring step is also included: Define the motor's operating quadrants, including: the first quadrant for forward rotation and positive torque, the second quadrant for forward rotation and negative torque, the third quadrant for reverse rotation and positive torque, and the fourth quadrant for reverse rotation and negative torque; The system monitors the working quadrant combination of the coaxial dual-side motors. When the two motors are in the combination of the first and second quadrants, the first and third quadrants, the second and fourth quadrants, or the third and fourth quadrants, it is determined to be an abnormal quadrant combination, and a function degradation alarm is triggered.

[0013] According to some embodiments of the present invention, a stability coordination control step is also included: When the actual torque of the motor is within the preset threshold range, the torque difference between the two motors is not greater than the maximum allowable torque difference, and the two motors are not in an abnormal quadrant combination, but the vehicle still experiences yaw instability, the vehicle integrated brake controller performs active torque intervention and braking control based on the torque requested by the direct torque control module until the vehicle stabilizes.

[0014] According to some embodiments of the present invention, the upper limit of the target rotational speed is a threshold for preventing wheel slippage, and the lower limit of the target rotational speed is a threshold for preventing wheel lockup.

[0015] According to some embodiments of the present invention, the vehicle integrated brake controller gradually adjusts the torque of the coaxial dual motors according to a preset gradient until the yaw rate returns to the normal value.

[0016] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Attached Figure Description

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is a structural diagram of the control system for a distributed drive vehicle. Figure 2 This is a flowchart of the control method for a distributed drive vehicle control system. Detailed Implementation

[0018] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0019] In the description of this invention, it should be understood that the orientation descriptions, such as up, down, etc., are based on the orientation or positional relationship shown in the drawings and are only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention.

[0020] In the description of this invention, "multiple" refers to two or more. The use of "first" and "second" is for distinguishing technical features only and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features or their sequential relationship.

[0021] In the description of this invention, unless otherwise explicitly defined, terms such as "setting," "installing," and "connecting" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this invention in conjunction with the specific content of the technical solution.

[0022] The technical solution of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described below are some embodiments of the present invention, not all embodiments.

[0023] In this embodiment, as Figure 1 As shown, the integrated vehicle brake controller, acting as the upper-level decision-making unit, collects real-time signals from the wheel speed sensors of all four wheels and the overall vehicle speed. Using a classic slip ratio algorithm, it calculates the optimal motor speed range to prevent slippage and lock-up under current road conditions. Specifically, the integrated vehicle brake controller calculates the upper limit of the target motor speed (to prevent slippage) and the lower limit of the target motor speed (to prevent lock-up), and periodically sends these values ​​to the motor controller via the controller area network bus.

[0024] In traditional solutions, the motor controller receives torque requests, which need to be forwarded by the vehicle controller, resulting in a response delay. In this solution, the direct torque control module integrated within the motor controller directly receives the speed threshold. The direct torque control module samples the motor resolver signal at high speed with a period of tens of milliseconds (e.g., ten to fifty milliseconds) to obtain the actual speed.

[0025] When the vehicle accelerates rapidly, if the road surface is slippery and the actual speed momentarily exceeds the target speed limit, the direct torque control module immediately triggers an internal interrupt, directly reducing the duty cycle of the power switch to decrease the motor torque, without waiting for secondary commands from the vehicle's integrated brake controller or the vehicle controller. Similarly, during regenerative braking or braking on icy or snowy roads, if the actual speed is lower than the target speed limit, the direct torque control module immediately increases torque or reduces the regenerative braking intensity to prevent wheel lock-up. This closed-loop control is completed within the motor controller, shortening the control cycle from the traditional one hundred milliseconds to tens of milliseconds, significantly improving the real-time performance of anti-skid control.

[0026] In some embodiments, for a four-motor driven vehicle, the integrated vehicle brake controller calculates in real time the deviation between the vehicle's actual yaw rate and the driver's intention (the theoretical yaw rate calculated from the steering wheel angle). When the deviation exceeds a safety threshold, the system initiates yaw moment control.

[0027] The integrated vehicle brake controller calculates the maximum permissible torque difference between the motors on both sides of the front (or rear) axle under the current conditions, based on the current vehicle speed and road adhesion coefficient. Assuming that at a certain moment, the torque of the left front axle motor is 500 Nm and the right front axle motor torque is 1600 Nm, the calculated maximum permissible torque difference is 1000 Nm. However, the actual torque difference is 1100 Nm, which is greater than the maximum permissible torque difference. If the vehicle oversteers at this time (actual yaw rate greater than the theoretical value), the integrated vehicle brake controller sends a torque reduction command to the right motor controller, gradually reducing the right motor torque in a certain gradient, for example, by 20 Nm each time, until the right motor torque drops below 1500 Nm. This brings the actual torque difference back to within the maximum permissible torque difference range, thereby generating a counter-torque to correct the yaw and restore vehicle stability.

[0028] In some embodiments, since the four motors can operate independently in the four quadrants, the motors on both sides of the coaxial axis may exhibit multiple combinations of operating states. The system monitors the torque direction and rotation direction of the left and right motors in real time.

[0029] The motor operating quadrants are defined as follows: Quadrant 1: Forward rotation plus positive torque, i.e., driving forward. Second quadrant: Positive rotation plus negative torque, i.e., energy recovery during forward movement. Third quadrant: Reverse torque plus forward torque, i.e., reverse drive. Quadrant 4: Reverse torque with negative torque, i.e., energy recovery during reversing. The safety combination is determined as follows: If the left side is in the first quadrant (forward drive) and the right side is in the first quadrant, this is a normal combination.

[0030] If the left side is in the first quadrant (forward drive) and the right side is in the fourth quadrant (reverse retraction), the left side drives the vehicle forward while the right side attempts to drag the vehicle backward. This combination will generate a violent yaw moment and is considered an unsafe combination.

[0031] When the system detects an unsafe combination (such as the first and second quadrants, the first and third quadrants, the second and fourth quadrants, or the third and fourth quadrants), it determines that the function should be downgraded. At this point, the system sends an alarm signal to the vehicle controller and forcibly relinquishes the autonomous control authority of the direct torque control module, allowing the integrated vehicle brake controller to intervene and perform comprehensive control. The integrated vehicle brake controller, based on the baseline torque originally requested by the direct torque control module, rapidly unloads or applies braking to the motor on the abnormal side of the integrated braking system and motor system, forcibly pulling the vehicle back to a stable state.

[0032] In some embodiments, under certain special operating conditions, the following situation may occur: the actual torque of the motor is within the software calculation threshold range, the torque difference between the two motors does not exceed the maximum allowable torque difference, and the working quadrant combination of the two motors is a safe combination (such as the first quadrant, or the combination of the first and fourth quadrants, or the combination of the second and third quadrants), but the vehicle still experiences yaw instability.

[0033] For example, when a vehicle is traveling on a split road surface (the left side has a very low coefficient of friction, while the right side has a higher coefficient of friction), even though all parameters are within preset thresholds, the vehicle may still experience unexpected yaw motion. In this case, the vehicle's integrated brake controller activates a fallback control strategy, actively adding torque correction on top of the base torque requested by the direct torque control module, and applying braking control as needed to intervene in the yaw torque until the vehicle's state returns to stability.

[0034] This fallback control strategy ensures that even under extremely complex operating conditions, when all conventional monitoring parameters are within the normal range, the system can still guarantee the vehicle's driving stability through the comprehensive judgment and intervention of the vehicle's integrated brake controller.

[0035] In summary, this invention solves the problems of long control cycles and lag in traditional traction control systems by decentralizing slip ratio control within the motor controller and achieving millisecond-level rapid response through the direct torque control module. It effectively suppresses vehicle yaw by real-time monitoring and correction of the torque difference between the motors on both sides of the same axle through the integrated vehicle brake controller. Furthermore, it identifies and addresses safety hazards caused by motor reversal and positive / negative torque combinations through a quadrant combination monitoring strategy. Finally, it ensures vehicle stability even under extreme conditions through comprehensive stability coordination control. This invention comprehensively improves the dynamic response speed and stability control capabilities of multi-axle distributed drive electric vehicles under complex conditions.

[0036] This embodiment provides a control method for a distributed drive vehicle, applied to a vehicle control system including a vehicle integrated brake controller and a motor controller, wherein the motor controller integrates a direct torque control module. This method achieves traction and stability control of the vehicle under different operating conditions through coordinated control at four levels.

[0037] like Figure 1 As shown, the control system in this embodiment includes: The vehicle integrated brake controller is used to acquire vehicle status signals, including vehicle speed, wheel speed, motor speed, yaw rate, steering wheel angle, etc. Four motor controllers, each corresponding to one of the four drive motors, and each motor controller integrates a direct torque control module. Vehicle controller, used for vehicle-level coordination; The controllers communicate with each other via the controller local area network bus.

[0038] In this embodiment, the integrated vehicle braking controller acts as the upper-level decision-making unit, collecting wheel speed sensor signals from all four wheels and the vehicle speed signal in real time. Based on the wheel speed and vehicle speed, the integrated vehicle braking controller calculates the slip ratio of each wheel and, combined with the current road surface adhesion coefficient, dynamically calculates the upper and lower limit of the target speed for each motor under the current operating conditions.

[0039] The specific calculation method is as follows: Target speed limit = Theoretical wheel speed corresponding to the current vehicle speed × (1 + Maximum allowable slip ratio) Target speed lower limit = Theoretical wheel speed corresponding to the current vehicle speed × (1 - Maximum allowable slip ratio) The vehicle integrated brake controller sends the calculated upper and lower limits of the target speed for each motor to the direct torque control module of each motor controller at a period of ten milliseconds via the controller local area network bus.

[0040] The direct torque control module samples the motor resolver signal at a high speed with a five-millisecond cycle to obtain the actual speed of the motor in real time, and performs the following judgments and controls: When the actual rotational speed exceeds the target speed limit, wheel slippage is detected. The direct torque control module immediately triggers an internal interrupt, directly reducing the duty cycle of the power switch to decrease the motor torque. For example, when a rear-wheel-drive vehicle accelerates rapidly on a slippery surface, the actual rotational speed of the left rear wheel instantaneously reaches 50 radians per second, while the target speed limit is 45 radians per second. Within five milliseconds, the direct torque control module reduces the torque from 300 Nm to 200 Nm, bringing the actual rotational speed back to the target range.

[0041] When the actual speed is lower than the target speed lower limit, the vehicle is determined to be prone to wheel lockup. The direct torque control module immediately increases torque or reduces the regenerative braking intensity. For example, when the vehicle is performing energy recovery braking on an icy or snowy road, if the actual speed of a front wheel drops to 10 radians per second, while the target speed lower limit is 12 radians per second, the direct torque control module will adjust the regenerative torque from -80 Nm to -50 Nm within 10 milliseconds to prevent wheel lockup.

[0042] This closed-loop control is completed inside the motor controller, reducing the anti-slip control cycle from the traditional 100 milliseconds to less than 10 milliseconds, significantly improving the real-time performance and accuracy of the control.

[0043] The integrated vehicle brake controller also monitors the vehicle's yaw stability in real time. Specifically, the integrated vehicle brake controller calculates the theoretical yaw rate based on the steering wheel angle signal and vehicle speed using a two-degree-of-freedom reference model of the vehicle; at the same time, it obtains the actual yaw rate of the vehicle through a yaw rate sensor.

[0044] The integrated vehicle brake controller calculates the maximum permissible torque difference between the motors on both sides of the coaxial shaft in real time based on the current vehicle speed and road surface adhesion coefficient. The formula for calculating the maximum permissible torque difference is: Maximum permissible torque difference = Coefficient of adhesion × Axle load × Track width / Tire rolling radius × Safety factor When the deviation between the actual yaw rate and the theoretical yaw rate exceeds a preset threshold (e.g., three degrees per second), the vehicle is determined to have yaw instability, and the vehicle integrated brake controller initiates coaxial torque difference control.

[0045] For example, when a four-wheel drive vehicle travels at 60 km / h on a dry road surface with a coefficient of friction of 0.8, the front axle load is 8,000 N, the wheelbase is 1.6 meters, the tire rolling radius is 0.32 meters, and the safety factor is 0.6. The calculated maximum permissible torque difference of the front axle is 1,920 Nm. At this time, the torque of the left motor on the front axle is 600 Nm, and the torque of the right motor is 1,600 Nm, with an actual torque difference of 1,000 Nm, which is within the permissible range, and the vehicle is stable.

[0046] When the vehicle travels on a slippery surface with a coefficient of friction of 0.3, the maximum permissible torque difference is recalculated to be 720 Nm. If the left motor torque is still 600 Nm and the right motor torque is 1600 Nm, the actual torque difference is 1000 Nm, exceeding the permissible range. Simultaneously, the actual yaw rate is detected to exceed the theoretical value by 5 degrees per second, indicating oversteer. The integrated vehicle brake controller immediately sends a torque reduction command to the right motor controller, gradually reducing the right motor torque in increments of 50 Nm until it drops below 1300 Nm, bringing the actual torque difference back below 720 Nm. This generates a counter-torque to correct the yaw and restore vehicle stability.

[0047] In this embodiment, since the four motors can operate independently in four quadrants, the system monitors the quadrant combination of the motors on both sides of the coaxial axis in real time. The motor operating quadrants are defined as follows: Quadrant 1: The motor rotates forward (speed is positive) and outputs positive torque, i.e., driving forward. Second quadrant: The motor rotates forward (positive speed) and outputs negative torque, i.e., energy recovery condition during forward movement. Third quadrant: Motor reverses (speed is negative) and outputs positive torque, i.e., reverse drive condition. Quadrant 4: Motor reverses (negative speed) and outputs negative torque, i.e., energy recovery mode during reversing. The direct torque control module monitors the speed and torque directions of the motor in real time and sends the quadrant information to the vehicle integrated brake controller via the controller area network bus. The vehicle integrated brake controller compares and analyzes the quadrants of the motors on both sides of the coaxial axis.

[0048] The safety combination is determined as follows: The motors on both sides are in the same quadrant (e.g., both are in the first quadrant). The motors on both sides are a combination of the first and fourth quadrants. The motors on both sides are a combination of the second and third quadrants. The above situations are considered to indicate normal function.

[0049] Abnormal combinations are determined as follows: Combinations of the first and second quadrants: For example, the left motor rotates forward with positive torque to drive forward, while the right motor rotates forward with negative torque to recover energy. This results in torques in opposite directions on both sides, which can easily cause yaw. Combinations of the first and third quadrants: For example, the left motor drives forward while the right motor drives reverse, causing the vehicle to yaw violently. Combination of the second and fourth quadrants Combination of the third and fourth quadrants The above situations are identified as abnormal quadrant combinations, and a function degradation alarm will be triggered.

[0050] When an abnormal quadrant combination is detected, the vehicle integrated brake controller sends an alarm signal to the vehicle controller to alert the driver or the upper system that there is a potential safety hazard. At the same time, it forcibly relinquishes the autonomous control authority of the direct torque control module, and the vehicle integrated brake controller takes over torque management.

[0051] For example, when a vehicle starts on an incline, due to gravity, the left motor is in the first quadrant (positive torque) attempting to drive the vehicle uphill, while the right motor, dragged by gravity, is in the second quadrant (positive torque) recovering energy, creating an abnormal combination. Upon detecting this, the system immediately issues an alarm and the vehicle's integrated brake controller compensates for the right motor's torque, bringing both motors back into the first quadrant and restoring normal driving operation.

[0052] Under certain complex operating conditions, the following special circumstances may occur: the actual torque of the motor is within the software calculation threshold range, the actual torque difference between the two motors does not exceed the maximum allowable torque difference, and the two motors are not in an abnormal quadrant combination, but the vehicle still experiences yaw instability.

[0053] For example, when a vehicle is traveling on a split road surface (left wheel on ice, coefficient of friction 0.1; right wheel on dry road surface, coefficient of friction 0.8), even though all parameters are within the preset thresholds, the vehicle may still experience unexpected yaw motion due to the large difference in the coefficients of friction between the two sides. Similarly, when a vehicle encounters strong crosswinds or travels over an arched road surface, even if the powertrain control is normal, the vehicle may still yaw.

[0054] At this point, the vehicle's integrated brake controller activates a fallback control strategy, with the following specific steps: The vehicle's integrated brake controller continuously monitors the deviation between the actual yaw rate and the theoretical yaw rate; When the deviation exceeds the safety threshold (e.g., four degrees per second) and the duration exceeds the set time (e.g., two hundred milliseconds), it is determined to be yaw instability; The vehicle integrated brake controller actively adds a torque correction amount on top of the base torque requested by the direct torque control module; At the same time, depending on the degree and direction of instability, braking pressure is applied to the corresponding wheels to generate additional yaw moment; Continue adjusting until the yaw rate deviation returns to within the safe threshold.

[0055] For example, a vehicle encounters a strong crosswind while traveling at high speed, with the actual yaw rate instantly reaching eight degrees per second, exceeding the theoretical value of six degrees per second. Although the motor torque, torque difference, and quadrant are all normal at this time, the vehicle has already shown signs of instability. The vehicle's integrated brake controller immediately applies a braking pressure of twenty bar to the left wheel, while simultaneously reducing the torque of the left motor by fifty Nm and increasing the torque of the right motor by fifty Nm, generating a counter-torque to correct the yaw and pulling the vehicle back to a stable state within one second.

[0056] like Figure 2 As shown, the complete process of the method in this embodiment is as follows: Step S101: The vehicle integrated brake controller collects vehicle speed, wheel speed, motor speed, yaw rate, and steering wheel angle signals; Step S102: The vehicle integrated brake controller calculates the upper limit and lower limit of the target speed for each motor and sends them to the direct torque control module; Step S103: The direct torque control module monitors the actual speed. If it exceeds the target speed threshold, the torque is adjusted directly in the motor controller; otherwise, proceed to the next step. Step S104: The vehicle integrated brake controller calculates the maximum allowable torque difference on both sides of the coaxial axis, monitors the actual yaw rate, and if the yaw rate exceeds the limit and the torque difference exceeds the limit, adjusts the torque of the motors on both sides of the coaxial axis. Step S105: The vehicle integrated brake controller monitors the quadrant combination of the motors on both sides of the coaxial axis. If an abnormal quadrant combination is detected, a function degradation alarm is triggered. Step S106: If all the above parameters are normal, but the vehicle still experiences yaw instability, the vehicle integrated brake controller will activate the fallback control to perform active torque intervention and braking control. Step S107: After the vehicle status returns to stability, return to step S101 to continue the loop monitoring.

[0057] The method provided in this embodiment has the following beneficial effects: First, by integrating a direct torque control module into the motor controller, the anti-slip control cycle is shortened from the traditional 100 milliseconds to less than 10 milliseconds, significantly improving the response speed and accuracy of traction control and effectively suppressing wheel slippage.

[0058] Secondly, by using the vehicle-integrated brake controller to monitor and correct the torque difference between the motors on both sides of the coaxial axis in real time, the vehicle can actively suppress yaw and improve driving stability.

[0059] Third, by using a quadrant combination monitoring strategy, safety hazards caused by motor reversal and positive / negative torque combinations are identified and addressed, thus preventing vehicle instability due to abnormal motor operation.

[0060] Fourth, through bottom-line stability coordination control, it ensures that even under extremely complex operating conditions, when all conventional monitoring parameters are within the normal range, the system can still guarantee vehicle driving safety through the comprehensive judgment and intervention of the vehicle integrated brake controller.

[0061] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. 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.

[0062] The embodiments of the present invention have been described in detail above with reference to the accompanying drawings. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention.

Claims

1. A control system for a distributed drive vehicle, characterized in that, include: The vehicle integrated brake controller is used to acquire vehicle status signals, which include at least vehicle speed, wheel speed, and motor speed. The motor controller is communicatively connected to the vehicle integrated brake controller, and the motor controller integrates a direct torque control module. The vehicle integrated brake controller calculates and corrects the upper and lower limits of the target speed of the motor in real time based on the vehicle speed and wheel speed signals, and sends them to the direct torque control module. The direct torque control module obtains the actual speed of the motor and determines: When the actual rotational speed is greater than the target rotational speed limit, it is determined that the wheel is slipping, and the direct torque control module directly executes torque reduction control. When the actual speed is less than the target speed lower limit, it is determined that the vehicle has locked up, and the direct torque control module directly executes torque increase control.

2. The control system according to claim 1, characterized in that, The integrated vehicle braking controller is also used to calculate the maximum allowable torque difference between the two motors on the same axis in real time based on the vehicle speed and yaw rate signals. When the actual yaw rate of the vehicle exceeds the theoretical threshold, the integrated vehicle braking controller controls the torque of the two motors on the same axis according to the maximum allowable torque difference until the yaw rate returns to the normal value.

3. The control system according to claim 2, characterized in that, The control system also includes quadrant monitoring logic, specifically: Define the motor's operating quadrants, including: the first quadrant for forward rotation and positive torque, the second quadrant for forward rotation and negative torque, the third quadrant for reverse rotation and positive torque, and the fourth quadrant for reverse rotation and negative torque; The coaxial dual motors monitor each other's quadrant and perform function exit and alarm according to the following strategy: When both motors are in the same quadrant, or in a combination of the first and fourth quadrants, or a combination of the second and third quadrants, the function is considered normal. When both motors are in other quadrant combinations, the function is deemed to be degraded and an alarm is triggered.

4. The control system according to claim 3, characterized in that, When the actual torque of the motor is within the preset threshold range, the torque difference between the two motors is not greater than the maximum allowable torque difference, and the two motors are not in an abnormal quadrant combination, but the vehicle still experiences yaw instability, the vehicle integrated brake controller performs active torque intervention and braking control based on the torque requested by the direct torque control module until the vehicle stabilizes.

5. A control method for a distributed drive vehicle, characterized in that, The control method, when applied to the control system according to any one of claims 1 to 4, includes the following steps: The vehicle integrated brake controller calculates the upper and lower limits of the target speed of the motor in real time based on the wheel speed and vehicle speed signals, and sends them to the direct torque control module. The direct torque control module acquires the actual speed of the motor in real time. When the actual speed is greater than the upper limit of the target speed, torque reduction control is directly executed inside the motor controller. When the actual speed is less than the lower limit of the target speed, torque increase control is directly executed inside the motor controller.

6. The control method according to claim 5, characterized in that, It also includes a coaxial torque difference control step: The vehicle integrated brake controller calculates the maximum permissible torque difference between the motors on both sides of the coaxial axis in real time based on vehicle speed and yaw rate signals. When the actual yaw rate of the vehicle exceeds the theoretical threshold, the vehicle integrated brake controller adjusts the torque of the coaxial dual motors to ensure that the actual torque difference between the two sides is not greater than the maximum allowable torque difference.

7. The control method according to claim 6, characterized in that, It also includes quadrant monitoring steps: Define the motor's operating quadrants, including: the first quadrant for forward rotation and positive torque, the second quadrant for forward rotation and negative torque, the third quadrant for reverse rotation and positive torque, and the fourth quadrant for reverse rotation and negative torque; The system monitors the working quadrant combination of the coaxial dual-side motors. When the two motors are in the combination of the first and second quadrants, the first and third quadrants, the second and fourth quadrants, or the third and fourth quadrants, it is determined to be an abnormal quadrant combination, and a function degradation alarm is triggered.

8. The control method according to claim 7, characterized in that, It also includes stability coordination control steps: When the actual torque of the motor is within the preset threshold range, the torque difference between the two motors is not greater than the maximum allowable torque difference, and the two motors are not in an abnormal quadrant combination, but the vehicle still experiences yaw instability, the vehicle integrated brake controller performs active torque intervention and braking control based on the torque requested by the direct torque control module until the vehicle stabilizes.

9. The control method according to claim 5, characterized in that, The upper limit of the target rotational speed is a threshold value for preventing wheel slippage, and the lower limit of the target rotational speed is a threshold value for preventing wheel lockup.

10. The control method according to claim 6, characterized in that, The vehicle integrated brake controller gradually adjusts the torque of the coaxial dual motors according to a preset gradient until the yaw rate returns to its normal value.

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