Vehicle anti-skid method and system based on distributed traction force control

Abstract

The application belongs to the technical field of electric vehicle braking control, and discloses a vehicle anti-skid method and system based on distributed traction force control. The method comprises the following steps: a motor controller acquires a motor target rotating speed output by an MTC unit and then transmits the motor target rotating speed to a torque conversion unit; the torque conversion unit converts and acquires a motor torque request based on a PID algorithm; a torque arbitration unit acquires the motor torque request, a driver torque request and a VCU torque request, and takes the torque amount in the corresponding request as a target torque based on the state of a dTCS system; and the target torque is input into a motor for torque control. The application has high real-time signal feedback and effectively guarantees the driving state stability under transient state.

Description

Technical Field

[0001] This invention relates to the field of electric vehicle braking control technology, specifically to a vehicle anti-skid method and system based on distributed traction control. Background Technology

[0002] Traction control systems are commonly used in internal combustion engine vehicles to ensure optimal traction under various driving conditions. With the increasing popularity and development of electric vehicles, distributed traction control systems (dTCS) have been developed and are used to meet the power requirements of electric motor drive.

[0003] The distributed traction control system mainly consists of various sensors, decision-making units, and actuators, and ensures driving safety through a three-layer closed-loop mechanism of multi-dimensional perception, real-time decision-making, and precise execution. Specifically, the system monitors the drive wheel status in real time based on wheel speed sensors, and combines this with vehicle attitude sensors, steering angle sensors, and inertial measurement units to comprehensively analyze the driver's operating intentions, road adhesion coefficient, and vehicle motion state. When the system detects that the drive wheels are slipping due to excessive torque, it will simultaneously trigger a two-dimensional intervention strategy—applying dynamic braking torque (BTC) through the braking system and directly adjusting the output torque (MTC) of the electric drive unit, thereby achieving an effective response to the vehicle's dynamic characteristics.

[0004] However, the following obvious defects exist in the actual control process of electric vehicles based on the dTCS system: (1) Although the dTCS system is specifically improved for the driving characteristics of electric vehicles, the transmission link of the traditional TCS system is still used in the entire signal transmission process. The signal delay (about 100ms level) caused by this traditional signal transmission link is difficult to match the high dynamic characteristics of the motor; (2) In the development of the existing dTCS system, the control process of the traditional TCS system is still referenced, and the high dynamic response of the motor during operation and the characteristics of low speed and high torque are not fully considered. Therefore, although the power performance of electric vehicles is improved when the control is based on the dTCS system, the risk of transient instability under various working conditions, especially under low adhesion conditions, is aggravated. Summary of the Invention

[0005] The purpose of this invention is to provide a vehicle anti-skid method and system based on distributed traction control, so as to solve the technical problems of poor real-time signal feedback and high risk of transient instability in existing dTCS systems for traction control of electric vehicles.

[0006] To achieve the above objectives, the present invention proposes the following technical solution:

[0007] Firstly, a vehicle anti-skid method based on distributed traction control is provided, including a motor controller that integrates a torque conversion unit and a torque arbitration unit.

[0008] include:

[0009] The motor controller obtains the target motor speed output by the MTC unit and transmits it to the torque conversion unit;

[0010] The torque conversion unit uses a PID algorithm to convert and obtain the motor torque request;

[0011] The integral term in torque conversion includes:

[0012] First, obtain the slip state output by the MTC unit;

[0013] Secondly, when the slip condition is determined to be uniform, the product of the sum of the proportional and differential terms and the integral coefficient is used as the integral term; when the slip condition is determined to be split-road slip, the integral term is obtained by traversing the first pre-structured table using the difference between the actual motor speed and the reference motor speed as the index; when the slip condition is determined to be stable slip, the integral term is obtained by traversing the second pre-structured table using the slip duration as the index; wherein, both the first and second pre-structured tables are obtained based on calibration.

[0014] Then, the sum of the integral sub-terms in the corresponding slip state and the integral term of the previous cycle is used as the integral term of the current cycle; wherein, the integral term of the first cycle includes a feedforward value, which is the difference between the actual torque of the motor and the torque loss of the axle.

[0015] The torque arbitration unit acquires the motor torque request, driver torque request, and VCU torque request. When the dTCS system is active, it uses the smaller of the motor torque request and VCU torque request as the target torque in forward gear and the larger of the motor torque request and VCU torque request as the target torque in reverse gear. When the system is inactive, it uses the torque amount of the driver torque request as the target torque. When the system is in degraded control, it uses the dynamic value of the torque amount corresponding to the motor torque request or VCU torque request as the target torque when the torque amount gradually transforms to the torque amount corresponding to the driver torque request according to a preset gradient algorithm.

[0016] The target torque is input into the motor for torque control.

[0017] Furthermore, the motor controller includes a main motor controller and a secondary motor controller; the main motor controller corresponds to either the front motor or the rear motor, and the secondary motor controller corresponds to the remaining motor; wherein, the torque conversion unit and the torque arbitration unit are both integrated into the main motor controller;

[0018] And includes the following steps:

[0019] The main target torque corresponding to the main motor and the secondary target torque corresponding to the auxiliary motor are obtained based on the torque conversion unit and the torque arbitration unit.

[0020] When the difference between the main target torque and the actual torque of the main motor, and the difference between the secondary target torque and the actual torque of the secondary motor are both less than a preset difference, the main target torque is input to the main motor and the secondary target torque is input to the secondary motor for torque control.

[0021] When the main torque difference and / or secondary torque difference are determined to be greater than the preset difference, the product of the main torque difference and the calibration value is calculated as the main correction value, and the product of the secondary torque difference and the calibration value is calculated as the secondary correction value.

[0022] The sum of the primary target torque and the primary correction value is used as the final primary torque input to the primary motor for torque control, and the difference between the secondary target torque and the secondary correction value is used as the final secondary torque input to the secondary motor for torque control.

[0023] Furthermore, including:

[0024] The MTC unit acquires driver input signals, wheel-end and vehicle signals, motor input signals, brake pressure feedback signals, and arbitration input signals.

[0025] The vehicle slip detector processes various input signals to obtain the corresponding slip state;

[0026] The corresponding slip state is input to the torque conversion unit.

[0027] Further steps include the following:

[0028] The state of the dTCS system is switched based on a state machine;

[0029] Specifically, when the actual speed of the motor is determined to be greater than the speed threshold, the dTCS system is controlled to enter the active state from the inactive state.

[0030] When it is determined that the actual speed of the motor is less than the speed threshold and continues for a first preset time, and the sum of the torque amount corresponding to the driver's torque request and the calibration offset is less than the torque amount corresponding to the motor torque request and continues for a second preset time, the dTCS system changes from the active state to the inactive state.

[0031] When the target speed flag of the motor and the various input signal flags of the torque conversion unit are all true or the degraded activation flag is false, the dTCS system enters the inactive state from the degraded control state.

[0032] When the motor target speed flag or various input signal flags of the torque conversion unit are false or the degrade activation flag is true, the dTCS system enters the degrade control state from the active state or from the inactive state.

[0033] The current state of the switched dTCS system is input to the torque arbitration unit.

[0034] Furthermore, before performing torque control based on the target torque, the following steps are included:

[0035] When the current working condition is determined to be an emergency suppression of wheel slippage or loss of vehicle control, the signal flag of the fast torque reduction interface between the torque arbitration unit and the motor controller is true.

[0036] When the current operating condition is determined to be smooth vehicle acceleration, the signal flag bit of the slow torque reduction interface between the torque arbitration unit and the motor controller is true.

[0037] When the current operating condition is determined to be a rapid restoration of power output, the signal flag bit of the rapid torque increase interface between the torque arbitration unit and the motor controller is true;

[0038] When the current operating condition is determined to be a gradual recovery of motor torque, the signal flag bit of the slow torque increase interface between the torque arbitration unit and the motor controller is true.

[0039] Secondly, a vehicle anti-skid system based on distributed traction control is provided, including a motor controller that integrates a torque conversion unit and a torque arbitration unit.

[0040] Includes the following functional modules:

[0041] The signal acquisition module is used to control the motor controller to acquire the target motor speed output by the MTC unit and then transmit it to the torque conversion unit;

[0042] The torque conversion module is used to control the torque conversion unit to convert and obtain the motor torque request based on the PID algorithm.

[0043] The integral term in torque conversion includes:

[0044] First, obtain the slip state output by the MTC unit;

[0045] Secondly, when the slip condition is determined to be uniform, the product of the sum of the proportional and differential terms and the integral coefficient is used as the integral term; when the slip condition is determined to be split-road slip, the integral term is obtained by traversing the first pre-structured table using the difference between the actual motor speed and the reference motor speed as the index; when the slip condition is determined to be stable slip, the integral term is obtained by traversing the second pre-structured table using the slip duration as the index; wherein, both the first and second pre-structured tables are obtained based on calibration.

[0046] Then, the sum of the integral sub-terms in the corresponding slip state and the integral term of the previous cycle is used as the integral term of the current cycle; wherein, the integral term of the first cycle includes a feedforward value, which is the difference between the actual torque of the motor and the torque loss of the axle.

[0047] The torque arbitration module is used by the torque arbitration unit to acquire the motor torque request, driver torque request, and VCU torque request. When the dTCS system is active, it uses the smaller of the motor torque request and VCU torque request as the target torque in forward gear and the larger of the motor torque request and VCU torque request as the target torque in reverse gear. When the system is inactive, it uses the torque amount of the driver torque request as the target torque. When the system is in degraded control, it uses the dynamic value of the torque amount corresponding to the motor torque request or VCU torque request, which is gradually converted to the torque amount corresponding to the driver torque request according to a preset gradient algorithm, as the target torque.

[0048] A torque control module is used to input the target torque to the motor for torque control.

[0049] Furthermore, the motor controller includes a main motor controller and a secondary motor controller; wherein the main motor controller corresponds to any one of the front or rear motors, and the secondary motor controller corresponds to the remaining motor; wherein the torque conversion unit and the torque arbitration unit are integrated into the main motor controller;

[0050] The torque control module includes the following functional units:

[0051] The first judgment unit is used to determine that when the difference between the main target torque and the actual torque of the main motor, and the difference between the secondary target torque and the actual torque of the secondary motor are both less than a preset difference, the main target torque is input to the main motor and the secondary target torque is input to the secondary motor for torque control.

[0052] The second judgment unit is used to determine that when the main torque difference and / or the secondary torque difference is greater than the preset difference, the product of the main torque difference and the calibration value is calculated as the main correction value, and the product of the secondary torque difference and the calibration value is calculated as the secondary correction value.

[0053] The dynamic compensation unit is used to input the sum of the main target torque and the main correction value as the final main torque input to the main motor for torque control, and to input the difference between the secondary target torque and the secondary correction value as the final secondary torque input to the secondary motor for torque control.

[0054] Furthermore, including:

[0055] The MTC input module is used to control the MTC unit to acquire driver input signals, wheel-end and vehicle signals, motor input signals, brake pressure feedback signals, and arbitration input signals.

[0056] The state processing unit is used to process various input signals based on the vehicle slip detector to obtain the corresponding slip state;

[0057] A status output unit is used to input the corresponding slip state to the torque conversion unit.

[0058] Thirdly, this technical solution provides an electronic device including at least one processor coupled to a memory, the memory storing a computer program configured to be executed by the processor when it is run.

[0059] Fourthly, this technical solution provides a computer-readable storage medium, characterized in that it stores a computer program thereon, the computer program being executed by a processor to implement the method described thereon.

[0060] Beneficial effects:

[0061] As can be seen from the above technical solutions, the technical solution of the present invention provides a vehicle anti-skid method based on distributed traction control to simultaneously improve the defects of poor real-time signal feedback and high risk of transient instability in electric vehicle traction control by dTCS system.

[0062] Firstly, this technical solution redesigns and integrates the torque conversion unit, originally integrated into the ESP or MTC unit, and the torque arbitration unit, which was partially in the MTC unit and partially in the VCU, into the motor controller (i.e., the MCU). Correspondingly, during torque processing, the motor controller obtains the target motor speed output by the MTC unit and simultaneously transmits it to the torque conversion unit. This transforms the closed-loop control of the motor's actual torque from the original control chain of MCU to ESP to VCU to MCU into operation directly within the MCU, significantly shortening the code execution cycle and resulting in shorter, faster, and more accurate control and response times.

[0063] Secondly, the traditional PID algorithm was improved when performing torque conversion within the MCU. Specifically, in the acquisition of the integral term, the influence of road resistance on torque control was considered, and the difference between the actual motor torque and the axle torque loss was used as the feedforward value. Simultaneously, different sub-integral term calculation methods were introduced for different slip states. Specifically, in uniform slip state, all drive wheels are slipping; therefore, the speed difference in the proportional term and the speed change rate difference in the derivative term can reflect the past error at any given moment. Thus, the product of the sum of the proportional and derivative terms and the integral coefficient is used as the integral sub-term in this case. In the case of split-road surfaces and stable slip, the slip situation is relatively simple; therefore, a lookup table method is used. This ensures the reliability of the integral while also improving the calculation speed and further shortening the code's execution cycle, thus improving response speed. Specifically, in the split-road slip state, only one drive wheel is slipping. Therefore, the first pre-structured table is traversed using the difference between the actual motor speed and the reference motor speed as an index to obtain the integral term for this condition. In the stable slip state, all wheels slip slightly (not exceeding the judged slip threshold but still slipping slightly) or even not slipping at all. Therefore, the exponential slip amount within the slip stage is directly obtained from the table as the integral term. Both the first and second pre-structured tables are obtained through calibration. Then, the integral term for the current cycle is the sum of the integral term for the corresponding slip state and the integral term for the previous cycle; and the feedforward value is included in the integral term for the first cycle. This allows for rapid real-time adjustments based on the operating conditions and wheel slippage state, achieving better control accuracy and avoiding transient imbalances.

[0064] Then, during torque arbitration within the MCU, different torque arbitration logics are adopted based on the current state of the dTCS system. Specifically, when the dTCS system is active, it indicates that the dTCS function is controlling the motor's torque, but it also needs to consider the torque requests (VCU torque requests) of other functions (such as YSC) to avoid transient imbalances during steering, emergency, or complex conditions. In forward gear, the smaller of the motor torque request and the VCU torque request is used as the target torque; in reverse gear, the larger of the motor torque request and the VCU torque request is used as the target torque. When the dTCS system is inactive, it means the system is in monitoring mode but the dTCS function is not triggered, so the torque requested by the driver is directly used as the target torque. When the system is in degraded control mode, the target torque is gradually converted from the torque corresponding to the motor torque request or VCU torque request to the torque corresponding to the driver torque request according to a preset gradient algorithm to achieve a smooth torque transition.

[0065] In summary, this technical solution optimizes the communication link, torque conversion algorithm, and arbitration logic to achieve full-process optimization of dTCS slip control, thereby improving vehicle stability under transient control while increasing feedback efficiency.

[0066] It should be understood that all combinations of the foregoing concepts and the additional concepts described in more detail below can be considered part of the inventive subject matter of this disclosure, provided that such concepts do not contradict each other.

[0067] The foregoing and other aspects, embodiments, and features of the teachings of the present invention will be more fully understood from the following description in conjunction with the accompanying drawings. Other additional aspects of the invention, such as features and / or beneficial effects of exemplary embodiments, will become apparent from the following description or may be learned through practice of specific embodiments according to the teachings of the present invention. Attached Figure Description

[0068] The accompanying drawings are not intended to be drawn to scale. In the drawings, each identical or nearly identical component shown in the various figures may be denoted by the same reference numeral. For clarity, not every component is labeled in each figure. Embodiments of various aspects of the invention will now be described by way of example and with reference to the accompanying drawings, wherein:

[0069] Figure 1 This is a communication link topology diagram of the vehicle anti-skid method based on distributed traction control described in this embodiment;

[0070] Figure 2 This is a flowchart of the vehicle anti-skid method based on distributed traction control described in this embodiment;

[0071] Figure 3 A flowchart for obtaining the slip state of the torque conversion unit;

[0072] Figure 4 A flowchart for setting the current state of the dTCS system;

[0073] Figure 5 A flowchart for controlling the output signal related to the target torque;

[0074] Figure 6 A flowchart for processing torque requests from two motors;

[0075] Figure 7 This is a structural block diagram of the vehicle anti-skid system based on distributed traction control described in this embodiment;

[0076] Figure 8 This is a structural block diagram of the electronic device described in this embodiment. Detailed Implementation

[0077] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention. Unless otherwise defined, the technical or scientific terms used herein should have the ordinary meaning understood by those skilled in the art to which this invention pertains.

[0078] The terms "first," "second," and similar words used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, unless the context clearly indicates otherwise, the singular forms of "an," "a," or "the," etc., do not indicate a quantity limitation, but rather indicate the presence of at least one. Terms such as "comprising" or "including" mean that the element or object preceding "comprising" encompasses the features, wholes, steps, operations, elements, and / or components listed following "comprising" or "including," and do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or sets thereof. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0079] While distributed traction control systems (DTSCs) can effectively respond to vehicle dynamics when applied to electric vehicles, they also suffer from drawbacks such as signal delay feedback that is difficult to match the high dynamic characteristics of the motor, and a high risk of transient instability under low-adhesion conditions. Therefore, this embodiment aims to provide a vehicle anti-skid method based on distributed traction control to simultaneously improve upon the aforementioned technical shortcomings.

[0080] The vehicle anti-skid method based on distributed traction control described in this embodiment will be specifically introduced below with reference to the accompanying drawings.

[0081] Combination Figure 1As shown, the dTCS system mainly consists of two parts: BTC (Brake Traction Control) and MTC (Motor Torque Control), which perform braking control and torque control respectively. The BTC part primarily requests braking force from the vehicle's EMB actuator to maintain a suitable wheel slip ratio, fully utilizing ground friction. The MTC part primarily requests torque reduction from the motor to maintain a suitable torque output, avoiding large slippage and maintaining stable acceleration. To address the motor's rapid response characteristics and signal delay, this embodiment places motor torque control within the motor controller (MCU). Correspondingly, a torque conversion unit and a torque arbitration unit are added to the MCU framework. The original dTCS system's braking control module (BTC) remains unchanged, outputting braking force requests to the EMB for braking control of the electric vehicle under corresponding operating conditions. The signal interfaces between the dTCS system and the VCU, and between the VCU and the MCU, remain unchanged. The target motor speed input to the MCU is converted into the target motor torque by the torque conversion module, which uses a PID algorithm to control the motor. The target motor torque and other VCU drive torque requests input to the VCU are arbitrated in the torque arbitration module. The final torque arbitration result is output to the MCU_Func module in the motor control MCU, and then the final result is output to the actuator (Motor) for execution. The existing dTCS torque control signal transmission link is TCS(ESP)-VCU-MCU-Motor, with a signal period of 100ms. In this embodiment, however, the torque control signal transmission link is TCS(ESP)-FMCU(RMCU)-FMotor(RMotor), with a signal period of 10ms.

[0082] Specifically, in actual torque control, combined with Figure 2 As shown, it includes the following steps:

[0083] Step S202: The motor controller obtains the target motor speed output by the MTC unit and transmits it to the torque conversion unit.

[0084] Step S204: The torque conversion unit obtains the motor torque request based on the PID algorithm.

[0085] Specifically, when performing torque conversion based on the PID algorithm,

[0086] The proportional term is the product of the difference between the actual speed of the motor and the target speed of the motor and the proportional coefficient.

[0087] The differential term is the product of the difference between the actual rate of change of motor speed and the target rate of change of motor speed and the differential coefficient. In specific implementation, the following settings are also included: when the actual motor speed signal is invalid, or when the corresponding sensor detects that the vehicle is on a bumpy road, the differential term is set to 0. This is because the former (invalid wheel speed) results in irregular speed changes, which may lead to a very large differential term value; the latter (frequent changes in speed on bumpy roads) has a significant impact on control, so the differential term is set to 0 to prevent calculated torque fluctuations. When the vehicle speed exceeds the calibration threshold, the differential term gradually decreases to 0. Specifically, this is controlled by AxleDterm = (Differential term of the previous cycle * (Maximum vehicle speed differential adjustment value - Actual vehicle speed) / (Maximum vehicle speed differential adjustment value - Vehicle speed differential decrease start value)) to gradually reduce the differential term to 0. The maximum vehicle speed differential adjustment value and the vehicle speed differential decrease start value are both obtained through calibration.

[0088] The integral term is obtained within each signal period through the following steps:

[0089] First, obtain the slip state output by the MTC unit.

[0090] Secondly, when the condition is determined to be uniform slip (all drive wheels are slipping), the product of the sum of the proportional and differential terms and the integral coefficient is used as the integral sub-term; when the condition is split-road slip (only one drive wheel is slipping), the first pre-structured table is traversed using the difference between the actual motor speed and the reference motor speed as the index to obtain the integral sub-term; when the condition is stable slip (all wheels are slightly slipping or even not slipping), the second pre-structured table is traversed using the slip duration as the index to obtain the integral sub-term.

[0091] In actual implementation, both the first and second pre-structured tables are obtained through calibration and each includes a series of two-dimensional data points distributed scatterably. Specifically, for the first pre-structured table, the difference between the actual motor speed and the reference motor speed (i.e., the speed without slippage) is used as the horizontal data, in m / s; the corresponding torque (i.e., the base value) is used as the vertical data, in N·m / s. For the second pre-structured table, the slippage duration is used as the horizontal data, in seconds; the corresponding torque (i.e., the torque of this cycle) is used as the vertical data, in N·m / s.

[0092] More specifically, when the horizontal data used for indexing does not have corresponding scatter data in the table, the output is proportional to the target value and distance. Specifically, the horizontal data in both the first and second pre-structured tables is denoted as x, and the vertical data is denoted as f(x). When the index quantity (i.e., the difference between the actual motor speed and the reference motor speed, or the slippage time) is x... t And when the first or second pre-built table does not contain this index, the corresponding f(x) tIt can be obtained through the following formula: f(x t )-f(x t-1 ) = x t -x t-1 ; where x t-1 For x t The adjacent previous scatter point f(x) t+1 )-f(x t )x t+1 -x t The horizontal data value, f(x) t-1 ) for x t-1 The corresponding vertical data value; x t+1 For x t The horizontal data value of the next adjacent scatter point, f(x) t+1 ) for x t+1 The corresponding vertical data values.

[0093] Then, the sum of the integral term in the corresponding slip state and the integral term of the previous cycle is used as the integral term for the current cycle. To improve the accuracy of subsequent control, a feedforward value is also set in the integral term of the first cycle. Specifically, the feedforward value is the difference between the actual torque of the motor and the axle torque loss.

[0094] Specifically, the axle torque loss is obtained in the following way:

[0095] T loss =(A min *W low )+A max *(1-W low )*G;

[0096] Among them, T loss For axle torque loss, A min W is the minimum acceleration of the drive shaft under low load conditions. low A is the weighting factor for low-load operating conditions. max G represents the maximum acceleration of the drive shaft under high load conditions, and G is the gear ratio.

[0097] At this point, because a feedforward value related to road resistance is introduced and the integral term is divided according to the slip state, the control accuracy can be effectively improved, thereby avoiding transient slip imbalance.

[0098] As a specific implementation, the MTC unit in this embodiment mainly includes six modules: dTcsInput, WheelSlipDetection, SurfaceDetection, ControlActivation, GeneralControl, and EngineTargetSpeed. Specifically, dTcsInput mainly includes driver input signals, wheel-end and vehicle-wide signals, motor input signals, brake pressure feedback signals, and arbitration input signals; WheelSlipDetection mainly includes calculating wheel slip thresholds, wheel slippage states, and processing driver-requested torque; SurfaceDetection mainly includes uniform and split-slip road surface recognition, high-side wheel slippage recognition on split-slip or alternating split-slip roads, long-term road surface recognition, and other operating conditions; ControlActivation mainly includes the dTcs state machine and a motor speed control module; GeneralControl mainly includes wheel slippage time and dTcs function operating time; and EngineTargetSpeed ​​mainly includes wheel control reference wheel speed and a motor target speed control module. It primarily outputs the motor target speed to the torque conversion module in the MCU for speed-to-torque conversion.

[0099] Based on this, as a specific implementation method, combined with Figure 3 As shown, the torque conversion unit obtains the slip state in the following manner:

[0100] Step S20402: The MTC unit acquires the driver input signal, wheel end and vehicle signals, motor input signal, brake pressure feedback signal and arbitration input signal.

[0101] Step S20404: Process various input signals based on the vehicle slip detector to obtain the corresponding slip state.

[0102] Step S20406: Input the corresponding slip state to the torque conversion unit.

[0103] Step S206: The torque arbitration unit obtains the motor torque request, driver torque request, and VCU torque request, and arbitrates them according to the current state of the dTCS system to obtain the target torque.

[0104] In practical implementation, when the dTCS system is determined to be active, the target torque is the smaller of the motor torque request and the VCU torque request in forward gear; and the larger of the motor torque request and the VCU torque request in reverse gear. When the system is determined to be inactive, the target torque is the torque requested by the driver. When the system is determined to be in degraded control mode, the target torque is the dynamic value of the torque corresponding to the motor torque request or VCU torque request, which is gradually converted to the torque corresponding to the driver torque request according to a preset gradient algorithm.

[0105] As a specific implementation method, it is deployed based on the framework of the aforementioned MTC unit, and combined with Figure 4 As shown, the current state of the dTCS system is set and sent to the torque arbitration unit in the following manner:

[0106] Step S20602: Switch the state of the dTCS system based on the state machine.

[0107] Specifically, the state switching logic of the dTCS system is as follows: When the actual motor speed is greater than a speed threshold, the dTCS system is controlled to transition from an inactive state to an active state. When the actual motor speed is less than the speed threshold for a first preset duration, and the sum of the torque amount corresponding to the driver's torque request and the calibration offset is less than the torque amount corresponding to the motor torque request for a second preset duration, the dTCS system transitions from an active state to an inactive state. In specific implementation, the first preset duration is 200ms, and the second preset duration is 400ms. When the motor target speed flag and various input signal flags of the torque conversion unit are all true or the degraded activation flag is false, the dTCS system transitions from a degraded control state to an inactive state. When the motor target speed flag or various input signal flags of the torque conversion unit are false or the degraded activation flag is true, the dTCS system transitions from an active state to a degraded control state, or from an inactive state to a degraded control state.

[0108] Step S20604: Input the current state of the switched dTCS system into the torque arbitration unit.

[0109] At this point, based on steps S20602 to S20604, the state of the dTCS system can be accurately switched according to the current operating conditions, thereby improving the reliability of the specific arbitration results.

[0110] Step S208: Input the target torque into the motor for torque control.

[0111] In specific implementation, combined with Figure 5 As shown, before step S208, the torque arbitration unit further includes the following steps to perform corresponding signal control output:

[0112] Step S20702: When the current working condition is determined to be emergency suppression of wheel slippage or vehicle body loss of control, the signal flag bit of the fast torque reduction interface between the torque arbitration unit and the motor controller is true.

[0113] Step S20704: When the current operating condition is stable control of vehicle acceleration, the signal flag bit of the slow torque reduction interface between the torque arbitration unit and the motor controller is true.

[0114] Step S20706: When the current working condition is to quickly restore power output, the signal flag bit of the fast torque increase interface between the torque arbitration unit and the motor controller is true.

[0115] Step S20708: When it is determined that the current working condition is gradually restoring the motor torque, the signal flag bit of the slow torque increase interface between the torque arbitration unit and the motor controller is true.

[0116] At this point, steps S20702 to S20708 are performed within the torque arbitration unit. By setting different torque control signal logic, effective interaction between the dTCS function output and other functions is achieved, and different torque arbitration outputs are implemented according to functional priority. This further avoids transient imbalance and improves driving stability.

[0117] As a preferred implementation, considering the dual-motor control requirements of actual trams, the motor controller includes a main motor controller and an auxiliary motor controller; the main motor controller corresponds to either the front or rear motor, and the auxiliary motor controller corresponds to the remaining motor. The torque conversion unit and torque arbitration unit are both integrated within the main motor controller. In this embodiment, the front motor is specifically used as the main motor, and the rear motor as the auxiliary motor.

[0118] At this time, combine Figure 6 As shown, based on dual-motor control logic, the following steps are included:

[0119] Step S302: Based on the torque conversion unit and the torque arbitration unit, obtain the main target torque corresponding to the main motor and the secondary target torque corresponding to the secondary motor.

[0120] Step S304: When the difference between the main target torque and the actual torque of the main motor, and the difference between the secondary target torque and the actual torque of the secondary motor are both less than a preset difference, the main target torque is input to the main motor and the secondary target torque is input to the secondary motor for torque control.

[0121] Step S306: When the main torque difference and / or secondary torque difference are greater than the preset difference, calculate the product of the main torque difference and the calibration value as the main correction value, and calculate the product of the secondary torque difference and the calibration value as the secondary correction value.

[0122] Step S308: The sum of the main target torque and the main correction value is used as the final main torque input to the main motor for torque control, and the difference between the secondary target torque and the secondary correction value is used as the final secondary torque input to the secondary motor for torque control.

[0123] At this point, based on steps S302 to S308, the torque arbitration module allocates the torque requests from the front and rear motors according to energy balance and dynamic balance. Specifically, taking the front motor as the main motor as an example, the torque requests of the two motors are allocated in the front motor MCU based on the energy balance and dynamic balance principles through signal interaction between the front motor MCU and the rear motor MCU. Specifically, in the main motor controller, the torque conversion unit and the torque arbitration unit can be placed in a 5ms running cycle. In this way, in the dual-motor scenario, the closed-loop control of the actual motor torque can be directly converted from the original MCU to ESP to VCU to MCU to run directly within the MCU, which greatly shortens the code running cycle and makes the control and response time shorter, faster and more accurate.

[0124] In summary, this embodiment optimizes the communication link, torque conversion algorithm, and arbitration logic to achieve full-process optimization of dTCS slip control, thereby improving vehicle stability under transient control while increasing feedback efficiency.

[0125] The aforementioned program can run in a processor or be stored in memory (or a computer-readable storage medium). Computer-readable media includes both permanent and non-permanent, removable and non-removable media, and information storage can be implemented by any method or technology. Information can be computer-readable instructions, data structures, program modules, or other data. Examples of computer storage media include, but are not limited to, phase-change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technologies, CD-ROM, digital versatile optical disc (DVD) or other optical storage, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other non-transfer medium that can be used to store information accessible by a computing device. As defined herein, computer-readable media does not include temporary computer-readable media, such as modulated data signals and carrier waves.

[0126] These computer programs may also be loaded onto a computer or other programmable data processing equipment to cause a series of operational steps to be performed on the computer or other programmable equipment to produce a computer-implemented process, thereby providing instructions that execute on the computer or other programmable equipment for implementing the process. Figure 1 One or more processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes can be implemented using different modules, and different steps can be implemented using different modules.

[0127] This embodiment also provides a vehicle anti-skid system based on distributed traction control, combined with Figure 7 As shown, it includes a motor controller, which integrates a torque conversion unit and a torque arbitration unit. It also includes the following functional modules:

[0128] The signal acquisition module is used to control the motor controller to acquire the target motor speed output by the MTC unit and then transmit it to the torque conversion unit.

[0129] The torque conversion module is used to control the torque conversion unit to convert and obtain the motor torque request based on the PID algorithm.

[0130] The acquisition of the integral term in torque conversion includes:

[0131] First, obtain the slip state output by the MTC unit.

[0132] Secondly, when the slip condition is uniform, the product of the sum of the proportional and differential terms and the integral coefficient is used as the integral term; when the slip condition is split-road slip, the first pre-structured table is traversed using the difference between the actual motor speed and the reference motor speed as the index to obtain the integral term; when the slip condition is stable, the second pre-structured table is traversed using the slip duration as the index to obtain the integral term; wherein, both the first and second pre-structured tables are obtained based on calibration.

[0133] Then, the sum of the integral sub-terms in the corresponding slip state and the integral term of the previous cycle is used as the integral term of the current cycle; wherein, the integral term of the first cycle includes a feedforward value, which is the difference between the actual torque of the motor and the torque loss of the axle.

[0134] The torque arbitration module is used by the torque arbitration unit to acquire the motor torque request, driver torque request, and VCU torque request. When the dTCS system is active, it uses the smaller of the motor torque request and VCU torque request as the target torque in forward gear; and the larger of the motor torque request and VCU torque request as the target torque in reverse gear. When the system is inactive, it uses the torque amount of the driver torque request as the target torque. When the system is in degraded control, it uses the dynamic value of the torque amount corresponding to the motor torque request or VCU torque request, which is gradually converted to the torque amount corresponding to the driver torque request according to a preset gradient algorithm, as the target torque.

[0135] A torque control module is used to input the target torque to the motor for torque control.

[0136] Since the system is built based on the method described above, it will not be repeated here.

[0137] For example, the motor controller includes a main motor controller and a secondary motor controller; wherein the main motor controller corresponds to either the front motor or the rear motor, and the secondary motor controller corresponds to the remaining motor; wherein the torque conversion unit and the torque arbitration unit are integrated within the main motor controller. Correspondingly, the torque control module includes the following functional units:

[0138] The first judgment unit is used to determine whether the difference between the main target torque and the actual torque of the main motor, and the difference between the secondary target torque and the actual torque of the secondary motor are both less than a preset difference. When both are less than a preset difference, the main target torque is input to the main motor and the secondary target torque is input to the secondary motor for torque control.

[0139] The second judgment unit is used to determine that when the main torque difference and / or the secondary torque difference is greater than the preset difference, it calculates the product of the main torque difference and the calibration value as the main correction value, and calculates the product of the secondary torque difference and the calibration value as the secondary correction value.

[0140] The dynamic compensation unit is used to input the sum of the main target torque and the main correction value as the final main torque input to the main motor for torque control, and to input the difference between the secondary target torque and the secondary correction value as the final secondary torque input to the secondary motor for torque control.

[0141] For example, including:

[0142] The MTC input module is used to control the MTC unit to acquire driver input signals, wheel end and vehicle signals, motor input signals, brake pressure feedback signals and arbitration input signals.

[0143] The state processing unit is used to process various input signals based on the vehicle slip detector to obtain the corresponding slip state.

[0144] A status output unit is used to input the corresponding slip state to the torque conversion unit.

[0145] At the same time, combined Figure 8 As shown, this embodiment also provides an electronic device, including at least one processor coupled to a memory, the memory storing a computer program configured to be executed by the processor when run.

[0146] Furthermore, a computer-readable storage medium having a computer program stored thereon, the computer program being executed by a processor to implement the method.

[0147] Since the system, electronic devices, and storage media are all used to implement the above method, they also have the advantages of high real-time feedback and high slip control accuracy in practical applications.

[0148] While the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Those skilled in the art can make various modifications and refinements without departing from the spirit and scope of the invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A vehicle anti-skid method based on distributed traction control, characterized in that, The motor controller integrates a torque conversion unit and a torque arbitration unit; include: The motor controller obtains the target motor speed output by the MTC unit and transmits it to the torque conversion unit; The torque conversion unit uses a PID algorithm to convert and obtain the motor torque request; The integral term in torque conversion includes: First, obtain the slip state output by the MTC unit; Secondly, when the slip condition is determined to be uniform, the product of the sum of the proportional and differential terms and the integral coefficient is used as the integral term; when the slip condition is determined to be split-road slip, the integral term is obtained by traversing the first pre-structured table using the difference between the actual motor speed and the reference motor speed as the index; when the slip condition is determined to be stable slip, the integral term is obtained by traversing the second pre-structured table using the slip duration as the index; wherein, both the first and second pre-structured tables are obtained based on calibration. Then, the sum of the integral sub-terms in the corresponding slip state and the integral term of the previous cycle is used as the integral term of the current cycle; wherein, the integral term of the first cycle includes a feedforward value, which is the difference between the actual torque of the motor and the torque loss of the axle. The axle torque loss is obtained in the following way: T loss =(A min *W low )+A max *(1-W low )*G; Among them, T loss For axle torque loss, A min W is the minimum acceleration of the drive shaft under low load conditions. low A is the weighting factor for low-load operating conditions. max G represents the maximum acceleration of the drive shaft under high load conditions, and G is the gear ratio. The torque arbitration unit acquires the motor torque request, driver torque request, and VCU torque request. When the dTCS system is active, it uses the smaller of the motor torque request and VCU torque request as the target torque in forward gear; and the larger of the motor torque request and VCU torque request as the target torque in reverse gear. When it is inactive, it uses the torque amount requested by the driver as the target torque. When it is in degraded control mode, it uses the dynamic value of the torque amount corresponding to the motor torque request or VCU torque request, which is gradually converted to the torque amount corresponding to the driver torque request according to a preset gradient algorithm, as the target torque. Torque control is performed based on the target torque.

2. The vehicle anti-skid method based on distributed traction control according to claim 1, characterized in that, The motor controller includes a main motor controller and a secondary motor controller; the main motor controller corresponds to either the front motor or the rear motor, and the secondary motor controller corresponds to the remaining motor; the torque conversion unit and the torque arbitration unit are both integrated into the main motor controller. Includes the following steps: The main target torque corresponding to the main motor and the secondary target torque corresponding to the auxiliary motor are obtained based on the torque conversion unit and the torque arbitration unit. When the difference between the main target torque and the actual torque of the main motor, and the difference between the secondary target torque and the actual torque of the secondary motor are both less than a preset difference, the main target torque is input to the main motor and the secondary target torque is input to the secondary motor for torque control. When the main torque difference and / or secondary torque difference are determined to be greater than the preset difference, the product of the main torque difference and the calibration value is calculated as the main correction value, and the product of the secondary torque difference and the calibration value is calculated as the secondary correction value. The sum of the primary target torque and the primary correction value is used as the final primary torque input to the primary motor for torque control, and the difference between the secondary target torque and the secondary correction value is used as the final secondary torque input to the secondary motor for torque control.

3. The vehicle anti-skid method based on distributed traction control according to claim 1, characterized in that, include: The MTC unit acquires driver input signals, wheel-end and vehicle signals, motor input signals, brake pressure feedback signals, and arbitration input signals. The vehicle slip detector processes various input signals to obtain the corresponding slip state; The corresponding slip state is input to the torque conversion unit.

4. The vehicle anti-skid method based on distributed traction control according to claim 1, characterized in that, Includes the following steps: The state of the dTCS system is switched based on a state machine; Specifically, when the actual speed of the motor is determined to be greater than the speed threshold, the dTCS system is controlled to enter the active state from the inactive state. When it is determined that the actual speed of the motor is less than the speed threshold and continues for a first preset time, and the sum of the torque amount corresponding to the driver's torque request and the calibration offset is less than the torque amount corresponding to the motor torque request and continues for a second preset time, the dTCS system changes from the active state to the inactive state. When the target speed flag of the motor and the various input signal flags of the torque conversion unit are all true or the degraded activation flag is false, the dTCS system enters the inactive state from the degraded control state. When the motor target speed flag or various input signal flags of the torque conversion unit are false or the degrade activation flag is true, the dTCS system enters the degrade control state from the active state or from the inactive state. The current state of the switched dTCS system is input to the torque arbitration unit.

5. The vehicle anti-skid method based on distributed traction control according to claim 1, characterized in that, Before performing torque control based on the target torque, the following steps are included: When the current working condition is determined to be an emergency suppression of wheel slippage or loss of vehicle control, the signal flag of the fast torque reduction interface between the torque arbitration unit and the motor controller is true. When the current operating condition is determined to be smooth vehicle acceleration, the signal flag bit of the slow torque reduction interface between the torque arbitration unit and the motor controller is true. When the current operating condition is determined to be a rapid restoration of power output, the signal flag bit of the rapid torque increase interface between the torque arbitration unit and the motor controller is true; When the current operating condition is determined to be a gradual recovery of motor torque, the signal flag bit of the slow torque increase interface between the torque arbitration unit and the motor controller is true.

6. A vehicle anti-skid system based on distributed traction control, characterized in that, This includes a motor controller, which integrates a torque conversion unit and a torque arbitration unit. Includes the following functional modules: The signal acquisition module is used to control the motor controller to acquire the target motor speed output by the MTC unit and then transmit it to the torque conversion unit; The torque conversion module is used to control the torque conversion unit to convert and obtain the motor torque request based on the PID algorithm. The acquisition of the integral term in torque conversion includes: First, obtain the slip state output by the MTC unit; Secondly, when the slip condition is determined to be uniform, the product of the sum of the proportional and differential terms and the integral coefficient is used as the integral term; when the slip condition is determined to be split-road slip, the integral term is obtained by traversing the first pre-structured table using the difference between the actual motor speed and the reference motor speed as the index; when the slip condition is determined to be stable slip, the integral term is obtained by traversing the second pre-structured table using the slip duration as the index; wherein, both the first and second pre-structured tables are obtained based on calibration. Then, the sum of the integral sub-terms in the corresponding slip state and the integral term of the previous cycle is used as the integral term of the current cycle; wherein, the integral term of the first cycle includes a feedforward value, which is the difference between the actual torque of the motor and the torque loss of the axle. The axle torque loss is obtained in the following way: T loss =(A min *W low )+A max *(1-W low )*G; Among them, T loss For axle torque loss, A min W is the minimum acceleration of the drive shaft under low load conditions. low A is the weighting factor for low-load operating conditions. max G represents the maximum acceleration of the drive shaft under high load conditions, and G is the gear ratio. The torque arbitration module is used by the torque arbitration unit to acquire the motor torque request, driver torque request, and VCU torque request. When the dTCS system is active, it uses the smaller of the motor torque request and VCU torque request as the target torque in forward gear and the larger of the motor torque request and VCU torque request as the target torque in reverse gear. When the system is inactive, it uses the torque amount of the driver torque request as the target torque. When the system is in degraded control, it uses the dynamic value of the torque amount corresponding to the motor torque request or VCU torque request, which is gradually converted to the torque amount corresponding to the driver torque request according to a preset gradient algorithm, as the target torque. A torque control module is used to input the target torque to the motor for torque control.

7. The vehicle anti-skid system based on distributed traction control according to claim 6, characterized in that, The motor controller includes a main motor controller and a secondary motor controller; wherein the main motor controller corresponds to either the front motor or the rear motor, and the secondary motor controller corresponds to the remaining motor; wherein the torque conversion unit and the torque arbitration unit are integrated within the main motor controller; The torque control module includes the following functional units: The first judgment unit is used to determine that when the difference between the main target torque and the actual torque of the main motor, and the difference between the secondary target torque and the actual torque of the secondary motor are both less than a preset difference, the main target torque is input to the main motor and the secondary target torque is input to the secondary motor for torque control. The second judgment unit is used to determine that when the main torque difference and / or the secondary torque difference is greater than the preset difference, the product of the main torque difference and the calibration value is calculated as the main correction value, and the product of the secondary torque difference and the calibration value is calculated as the secondary correction value. The dynamic compensation unit is used to input the sum of the main target torque and the main correction value as the final main torque input to the main motor for torque control, and to input the difference between the secondary target torque and the secondary correction value as the final secondary torque input to the secondary motor for torque control.

8. The vehicle anti-skid system based on distributed traction control according to claim 6, characterized in that, include: The MTC input module is used to control the MTC unit to acquire driver input signals, wheel-end and vehicle signals, motor input signals, brake pressure feedback signals, and arbitration input signals. The state processing unit is used to process various input signals based on the vehicle slip detector to obtain the corresponding slip state; A status output unit is used to input the corresponding slip state to the torque conversion unit.

9. An electronic device, characterized in that, It includes at least one processor coupled to a memory storing a computer program configured to be executed by the processor to perform the method of any one of claims 1-5.

10. A computer-readable storage medium, characterized in that, It stores a computer program thereon, which is used to be executed by a processor to implement the method of any one of claims 1-5.

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