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

Abstract

The invention belongs to the technical field of electric vehicle brake control, and discloses a vehicle anti-skid method and system based on distributed traction force control. The method comprises the steps that a motor controller obtains 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 obtains a motor torque request based on PID algorithm conversion; the torque arbitration unit acquires a motor torque request, a driver torque request and a VCU torque request, and takes a torque amount in the corresponding request as a target torque based on the state of the dTCS system; and inputting the target torque into the motor for torque control. According to the invention, the signal feedback real-time performance is high, and the driving state stability in the transient state is effectively guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicle braking control, and in particular to a vehicle anti-skid method and system based on distributed traction control. Background Art

[0002] Traction control systems are commonly used in internal combustion engine vehicles to ensure optimal traction in various driving conditions. With the promotion and development of electric vehicles, distributed traction control systems (dTCS) have been developed to meet the needs of electric motor-driven power modes.

[0003] The distributed traction control system, primarily composed of various sensors, decision-making units, and actuators, ensures driving safety through a three-layer closed-loop mechanism of multi-dimensional perception, real-time decision-making, and precise execution. Specifically, wheel speed sensors monitor the status of the drive wheels in real time. Combined with body posture sensors, steering angle sensors, and an inertial measurement unit, the system comprehensively analyzes the driver's operating intentions, road adhesion coefficient, and vehicle motion. When the system detects a tendency for the drive wheels to slip due to excessive torque, it simultaneously triggers a two-dimensional intervention strategy—applying dynamic braking torque (BTC) through the braking system and directly adjusting the electric drive unit's output torque (MTC), effectively responding to the vehicle's dynamic characteristics.

[0004] However, the dTCS system has the following obvious defects in the actual control process of electric vehicles: (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) 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 borrowed, and the high dynamic response of the motor during operation and the low-speed and high-torque characteristics are not fully considered. Therefore, although the control based on the dTCS system improves the power performance of electric vehicles, it exacerbates the risk of transient instability in various working conditions, especially low-adhesion conditions. Summary of the Invention

[0005] The present invention aims 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 when the existing dTCS system performs traction control on electric vehicles.

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

[0007] In a first aspect, a vehicle anti-skid method based on distributed traction control is provided, comprising a motor controller in which a torque conversion unit and a torque arbitration unit are integrated;

[0008] include:

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

[0010] The torque conversion unit obtains the motor torque request based on the PID algorithm;

[0011] The integral term in torque conversion is obtained by:

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

[0013] Secondly, when a uniform slip state is determined, the product of the sum of the proportional term and the differential term and the integral coefficient is used as the integral sub-term. When a slip state is determined on an open road, the difference between the actual motor speed and the reference motor speed is used as an index to traverse the first pre-constructed table to obtain the integral sub-term. When a stable slip state is determined, the slip duration is used as an index to traverse the second pre-constructed table to obtain the integral sub-term. Both the first and second pre-constructed tables are obtained based on calibration.

[0014] Then, the sum of the integral sub-term 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, and the feedforward value is the difference between the actual torque of the motor and the axle torque loss;

[0015] The torque arbitration unit obtains the motor torque request, the driver torque request, and the VCU torque request. When the dTCS system is determined to be in an active state, the smaller of the motor torque request and the VCU torque request is used as the target torque in a forward gear; the larger of the motor torque request and the VCU torque request is used as the target torque in a reverse gear; when the dTCS system is determined to be in an inactive state, the torque amount requested by the driver is used as the target torque; and when the dTCS system is determined to be in a degraded control state, the dynamic value obtained by gradually converting the torque amount corresponding to the motor torque request or the VCU torque request to the torque amount corresponding to the driver torque request according to a preset gradient algorithm is used as the target torque;

[0016] The target torque is input to 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] Obtaining a main target torque corresponding to the main motor and a secondary target torque corresponding to the secondary motor based on the torque conversion unit and the torque arbitration unit;

[0020] When it is determined that a main torque difference between the main target torque and the actual torque of the main motor, and a secondary torque difference between the secondary target torque and the actual torque of the secondary motor are both smaller 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 to perform torque control;

[0021] When it is determined that the main torque difference and / or the secondary torque difference is greater than a preset difference, the product of the main torque difference and the calibration amount is calculated as the main correction value, and the product of the secondary torque difference and the calibration amount is calculated as the secondary correction value;

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

[0023] Further, including:

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

[0025] Process various input signals based on the vehicle slip detector to obtain the corresponding slip status;

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

[0027] Further, the following steps are included:

[0028] Switching the state of the dTCS system based on a state machine;

[0029] When it is determined that the actual speed of the motor is greater than the speed threshold, the dTCS system is controlled to enter an active state from an 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 predetermined time period, and the sum of the torque corresponding to the driver torque request and the calibrated offset is less than the torque corresponding to the motor torque request and continues for a second predetermined time period, the dTCS system changes from an active state to an inactive state;

[0031] When it is determined that 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 enters the inactive state from the degraded control state;

[0032] When it is determined that the motor target speed flag or the various input signal flags of the torque conversion unit are false or the degraded activation flag is true, the dTCS system enters the degraded control state from the activated state or enters the degraded control state from the inactivated state;

[0033] The current state of the switched dTCS system is input into 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 emergency suppression of wheel slip or vehicle body loss of 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 working condition is determined to be smooth control of vehicle acceleration, the signal flag of the slow torque reduction interface between the torque arbitration unit and the motor controller is true;

[0037] When it is determined that the current working condition is to quickly restore power output, the signal flag of the fast torque increase interface between the torque arbitration unit and the motor controller is true;

[0038] When it is determined that the current working condition is to gradually recover the motor torque, the signal flag of the slow torque increase interface between the torque arbitration unit and the motor controller is true.

[0039] In a second aspect, a vehicle anti-skid system based on distributed traction control is provided, comprising a motor controller in which a torque conversion unit and a torque arbitration unit are integrated;

[0040] Includes the following functional modules:

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

[0042] A torque conversion module, used to control the torque conversion unit to obtain the motor torque request based on the PID algorithm;

[0043] The integral term in torque conversion is obtained by:

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

[0045] Secondly, when a uniform slip state is determined, the product of the sum of the proportional term and the differential term and the integral coefficient is used as the integral sub-term. When a slip state is determined on an open road, the difference between the actual motor speed and the reference motor speed is used as an index to traverse the first pre-constructed table to obtain the integral sub-term. When a stable slip state is determined, the slip duration is used as an index to traverse the second pre-constructed table to obtain the integral sub-term. Both the first and second pre-constructed tables are obtained based on calibration.

[0046] Then, the sum of the integral sub-term 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, and the feedforward value is the difference between the actual torque of the motor and the axle torque loss;

[0047] a torque arbitration module, configured to obtain a motor torque request, a driver torque request, and a VCU torque request from a torque arbitration unit, and, when determining that the dTCS system is in an active state, to use the smaller of the motor torque request and the VCU torque request as the target torque in a forward gear; and to use the larger of the motor torque request and the VCU torque request as the target torque in a reverse gear; to use the driver torque request as the target torque when determining that the system is in an inactive state; and to use the dynamic value obtained by gradually converting the torque corresponding to the motor torque request or the VCU torque request to the torque corresponding to the driver torque request according to a preset gradient algorithm as the target torque when determining that the system is in a degraded control state;

[0048] The torque control module is configured to input the target torque to the motor to perform 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 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 into the main motor controller;

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

[0051] a first determining unit, configured to determine that a main torque difference between the main target torque and the actual torque of the main motor, as well as a secondary torque difference between the secondary target torque and the actual torque of the secondary motor, are both smaller than a preset difference, and input the main target torque to the main motor and the secondary target torque to the secondary motor for torque control;

[0052] a second determining unit, configured to, when determining that the primary torque difference and / or the secondary torque difference is greater than a preset difference, calculate a product of the primary torque difference and a calibration amount as a primary correction value, and calculate a product of the secondary torque difference and the calibration amount as a 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 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 to the secondary motor for torque control.

[0054] Further, including:

[0055] MTC input module, used to control the MTC unit to obtain driver input signals, wheel end and vehicle signals, motor input signals, brake pressure feedback signals and arbitration input signals;

[0056] A state processing unit, configured to process various input signals based on the vehicle slip detector to obtain corresponding slip states;

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

[0058] In a third aspect, the present technical solution provides an electronic device comprising at least one processor, wherein the processor is coupled to a memory, wherein a computer program is stored in the memory, and wherein the computer program is configured to execute the method described when executed by the processor.

[0059] In a fourth aspect, the present technical solution provides a computer-readable storage medium, characterized in that a computer program is stored thereon, and the computer program is used to be executed by a processor to implement the described method.

[0060] Beneficial effects:

[0061] It can be seen from the above technical solutions that 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 when the dTCS system performs traction control on electric vehicles.

[0062] First, this technical solution redesigns and integrates the torque conversion unit, originally integrated into the ESP or MTC unit, and the torque arbitration unit, which is partially in the MTC unit and partially in the VCU, into the motor controller (i.e., MCU). Accordingly, during the torque processing process, the motor controller obtains the motor target speed output by the MTC unit and simultaneously transmits it to the torque conversion unit. This converts the closed-loop control of the motor's actual torque from the original control chain from MCU to ESP to VCU and then to MCU, directly into the current operation within the MCU. This significantly shortens the code's execution cycle, and reduces control and response time, resulting in faster and more accurate responses.

[0063] Secondly, when performing torque conversion within the MCU, the traditional PID algorithm has been improved. Specifically, when obtaining the integral term, the influence of road resistance, an external factor on torque control, is taken into account. The difference between the actual motor torque and the axle torque loss is used as the feedforward value. Furthermore, different sub-integral term calculation methods are introduced for different slip conditions. Specifically, in the uniform slip condition, all drive wheels are slipping. Therefore, the velocity difference in the proportional term and the velocity rate difference in the differential term reflect their past errors at any moment. Therefore, the product of the sum of the proportional and differential terms and the integral coefficient is used as the integral sub-term in this case. The slip conditions in split-road and stable slip conditions are relatively simple, so a table lookup method is used. This ensures integral reliability while also improving computational speed, further shortening the code execution cycle and enhancing responsiveness. Specifically, in the slip state on the split road, only the drive wheel on one side is in a slip state. Therefore, the first pre-constructed table is traversed using the difference between the actual motor speed and the reference motor speed as an index to obtain the integral sub-item for this situation. In the stable slip state, all wheels have slight slip (do not exceed the judged slip threshold but still slip slightly) or even no slip. Therefore, the exponential slip amount in the slip phase is directly obtained by looking up the table as the integral sub-item. Among them, the first pre-constructed table and the second pre-constructed table are both obtained by calibration. Then, the sum of the integral sub-item under the corresponding slip state and the integral item of the previous cycle is used as the integral item of this cycle; and the feedforward value is included in the integral item of the first cycle. Therefore, it can be quickly adjusted in real time according to the working conditions and the wheel slip state to achieve better control accuracy and avoid the occurrence of transient imbalance.

[0064] Then, when torque arbitration is performed within the MCU, different torque arbitration logic is adopted based on the current state of the dTCS system. Specifically, when the current state of the dTCS system is active, it indicates that the dTCS function is controlling the torque of the motor, but it needs to take into account the torque requests (VCU torque request) of other functions (such as YSC) to avoid transient imbalances under steering, emergency, or complex conditions. When the forward gear is set, the smaller of the motor torque request and the VCU torque request is used as the target torque; when the reverse gear is set, the larger of the motor torque request and the VCU torque request is used as the target torque. When the dTCS system is judged to be in an inactive state, it means that the system is in a monitoring state, but the dTCS function is not triggered. Therefore, the torque amount requested by the driver is directly used as the target torque. When it is judged to be in a degraded control state, the target torque is gradually converted from the torque amount corresponding to the motor torque request or VCU torque request to the torque amount corresponding to the driver torque request according to a preset gradient algorithm to achieve a smooth torque transition.

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

[0066] It should be appreciated that all combinations of the foregoing concepts, as well as additional concepts described in greater detail below, to the extent such concepts are not mutually inconsistent, can be considered to be part of the inventive subject matter of this disclosure.

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

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

[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 flow chart of the vehicle anti-skid method based on distributed traction control according to this embodiment;

[0071] Figure 3 Flowchart for obtaining slip status for a torque conversion unit;

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

[0073] Figure 5 Flowchart for output signal control related to target torque;

[0074] Figure 6 A flowchart for dual motor torque request processing;

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

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

[0077] In order to make the purpose, 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 in conjunction with the drawings of the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the described embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention. Unless otherwise defined, the technical terms or scientific terms used herein should be the common meanings understood by people with ordinary skills in the field to which the present invention belongs.

[0078] The words “first”, “second” and similar terms used in the specification and claims of this application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, unless the context clearly indicates otherwise, the singular forms of “a”, “an” or “the” and similar words do not indicate a quantitative limitation, but rather indicate the presence of at least one. Words such as “include” or “comprise” mean that the elements or objects appearing before “include” or “comprises” cover the features, wholes, steps, operations, elements and / or components listed after “include” or “comprises”, and do not exclude the existence or addition of one or more other features, wholes, steps, operations, elements, components and / or their collections. “Up”, “down”, “left”, “right” and the like are only used 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 (DTCs) can effectively respond to vehicle dynamics when applied to electric vehicles, they also suffer from the drawbacks of delayed signal feedback, which makes it difficult to match the high dynamic characteristics of the motor, and a high risk of transient instability under low-adhesion conditions. This embodiment aims to provide a vehicle anti-skid method based on DTC to simultaneously address these technical limitations.

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

[0081] Combine Figure 1As shown, the dTCS system primarily consists of two components: BTC and MTC, which perform braking and torque control, respectively. The BTC (Brake Traction Control) component primarily maintains appropriate wheel slip by requesting braking force from the vehicle's EMB actuator, fully utilizing ground friction. The MTC (Motor Torque Control) component primarily maintains appropriate torque output by requesting torque reduction from the motor, avoiding significant slip and maintaining stable acceleration. To address the motor's rapid response characteristics and signal latency, this embodiment integrates motor torque control within the motor controller (MCU). Accordingly, a torque conversion unit and a torque arbitration unit are added to the MCU framework. The existing dTCS system's brake control module (BTC) remains unchanged, outputting braking force requests to the EMB under specific operating conditions for braking control of the electric vehicle. The signal interfaces between the dTCS system and the VCU, and between the VCU and the MCU, remain unchanged. The motor target speed input to the MCU is passed through the torque conversion module, where it is controlled using a PID algorithm to obtain the motor target torque. The motor target torque and VCU drive torque requests from other functions are arbitrated in the torque arbitration module. The final torque arbitration result is output to the MCU_Func function in the motor control MCU, which then sends the final result to the actuator (Motor) for execution. The existing dTCS torque control signal transmission chain is TCS (ESP)-VCU-MCU-Motor, with a signal cycle of 100ms. In this embodiment, the torque control signal transmission chain is TCS (ESP)-FMCU (RMCU)-FMotor (RMotor), with a signal cycle of 10ms.

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

[0083] Step S202 : The motor controller obtains the motor target 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 torque conversion is performed based on the PID algorithm,

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

[0087] The differential term is the product of the difference between the actual motor speed rate of change and the target motor speed rate of change and the differential coefficient. In specific implementations, the differential term is set to 0 if the actual motor speed signal is invalid or if the corresponding sensor detects that the vehicle is on a bumpy road. In the former case, the wheel speed will fluctuate erratically, which can result in a very large differential term. In the latter case, the speed rate of change on a bumpy road fluctuates frequently, and the differential term has a significant impact on control. Therefore, to prevent calculated torque fluctuations, the differential term is set to 0. When the vehicle speed exceeds a calibrated threshold, the differential term gradually decreases to 0. Specifically, the differential term is gradually reduced to 0 using the formula AxleDterm = Previous cycle differential term * (maximum vehicle speed differential adjustment value - actual vehicle speed) / (maximum vehicle speed differential adjustment value - vehicle speed differential decrement start value). The maximum vehicle speed differential adjustment value and vehicle speed differential decrement start value are both calibrated.

[0088] In each signal cycle, the acquisition of the integral term includes the following steps:

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

[0090] Secondly, when it is judged to be a uniform slip state (all driving wheels are in a slip state), the sum of the proportional term and the differential term, and the product of the integral coefficient are used as the integral sub-term; when it is a slip state on an open road (only the driving wheel on one side is in a slip state), the difference between the actual motor speed and the reference motor speed is used as an index to traverse the first pre-constructed table to obtain the integral sub-term; when it is a stable slip state (all wheels are slightly slipping or even not slipping), the slip duration is used as an index to traverse the second pre-constructed table to obtain the integral sub-term.

[0091] In actual implementation, both the first and second pre-constructed tables are obtained through calibration and include a series of scattered two-dimensional data. Specifically, for the first pre-constructed table, the difference between the actual motor speed and the reference motor speed (i.e., the no-slip speed) 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-constructed table, the slip duration is used as the horizontal data, in seconds; the corresponding torque (i.e., the torque of the current 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 scattered data in the table, the target value is output in direct proportion to the distance. Specifically, the horizontal data of the first pre-structured table and the second pre-structured table are both recorded as x, and the vertical data are recorded as f(x). When the index value (i.e., the difference between the actual motor speed and the reference motor speed or the slip time) is x t , and the first pre-structured table or the second pre-structured table does not have the index, the corresponding f(x t) is obtained by 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 scattered point f(x t+1 )-f(x t )x t+1 -x t The horizontal data value, f(x t-1 ) is the same as x t-1 Corresponding vertical data value; x t+1 For x t The horizontal data value of the adjacent next scatter point, f(x t+1 ) is the same as x t+1 The corresponding vertical data value.

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

[0094] Specifically, the axle torque loss is obtained as follows:

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

[0096] Among them, T loss is the axle torque loss, A min is the minimum acceleration of the drive shaft under low load conditions, W low is the weight coefficient of low load condition, A max is the maximum acceleration of the drive shaft under high load conditions, and G is the gear ratio.

[0097] At this time, since the feedforward value related to the 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 method, the MTC unit in this embodiment mainly includes six modules: dTcsInput, WheelSlipDetection, SurfaceDetection, ControlActivation, GeneralControl, and EngineTargetSpeed. Among them, dTcsInput mainly includes driver input signals, wheel-end and vehicle signals, motor input signals, brake pressure feedback signals, and arbitration input signals; WheelSlipDetection mainly includes calculating wheel slip thresholds, wheel slip status, and driver request torque processing; SurfaceDetection mainly includes uniform and split road surface recognition, split road surface or alternating split road surface high-side wheel slip recognition, long-term road surface recognition, and other working conditions; ControlActivation mainly includes dTcs state machine and motor speed control module; GeneralControl mainly includes wheel slip time and dTcs function working time; EngineTargetSpeed mainly includes wheel control reference wheel speed and motor target speed control module. It mainly outputs the motor target speed to the torque conversion module in the MCU for speed-to-torque processing.

[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 obtains 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 corresponding slip states.

[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, the driver torque request, and the VCU torque request, and performs arbitration according to the current state of the dTCS system to obtain the target torque.

[0104] In specific implementations, 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 gears; the target torque is the larger of the motor torque request and the VCU torque request in reverse gears. When the system is determined to be inactive, the target torque is the driver's torque request. When the system is determined to be in a degraded control state, the target torque is the dynamic value obtained by gradually converting the torque corresponding to the motor torque request or the VCU torque request to the torque corresponding to the driver's torque request according to a preset gradient algorithm.

[0105] As a specific implementation method, based on the framework deployment of the above 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 dTCS system's state transition logic is as follows: When the actual motor speed is determined to be greater than a speed threshold, the dTCS system is controlled to switch from an inactive state to an active state. When the actual motor speed is determined to be less than the speed threshold for a first preset duration, and the sum of the torque corresponding to the driver's torque request and the calibrated offset is less than the torque corresponding to the motor torque request for a second preset duration, the dTCS system switches from an active state to an inactive state. In a 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 demotion activation flag is false, the dTCS system switches 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 demotion activation flag is true, the dTCS system switches 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 to the torque arbitration unit.

[0109] At this time, based on steps S20602 to S20604 , the dTCS system state can be accurately switched and controlled according to the current working conditions, thereby improving the reliability of the specific arbitration result.

[0110] Step S208: Input the target torque into the motor to perform 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 it is determined that the current working condition is emergency suppression of wheel slip or vehicle body loss of control, the signal flag of the fast torque reduction interface between the torque arbitration unit and the motor controller is true.

[0113] Step S20704: When it is determined that the current working condition is smooth control of vehicle acceleration, the signal flag of the slow torque reduction interface between the torque arbitration unit and the motor controller is true.

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

[0116] Steps S20702 to S20708 are then performed within the torque arbitration unit. By configuring different torque control signal logics, the dTCS function output effectively interacts with other functions, and different torque arbitration outputs are implemented based on functional priority. This further avoids transient imbalances and improves driving stability.

[0117] As a preferred embodiment, considering the dual-motor control requirements of actual electric vehicles, 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, while 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. In this embodiment, the front motor serves as the main motor, and the rear motor serves as the secondary motor.

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

[0119] Step S302 : obtaining a main target torque corresponding to the main motor and a secondary target torque corresponding to the secondary motor based on the torque conversion unit and the torque arbitration unit.

[0120] Step S304: When it is determined that the main torque difference between the main target torque and the actual torque of the main motor, and the secondary torque difference between the secondary target torque and the actual torque of the secondary motor are both less than the 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 it is determined that 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 amount is calculated as the main correction value, and the product of the secondary torque difference and the calibration amount is calculated as the secondary correction value.

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

[0123] At this point, based on steps S302 to S308, the torque arbitration module distributes the torque requests of the front and rear motors according to energy balance and power balance. Specifically, taking the front motor as the main motor as an example, the torque requests of the dual motors are distributed in the front motor MCU through signal interaction between the front motor MCU and the rear motor MCU, based on the principles of energy balance and power balance. Specifically, in the main motor controller, the torque conversion unit and the torque arbitration unit can be placed in a 5ms operating cycle. In this way, in the dual-motor scenario, the closed-loop control of the actual torque of the motor can also be directly converted from the original MCU to ESP to VCU and then to MCU to run within the MCU, greatly shortening the code operation cycle, and shortening the control and response time, and responding faster and more accurately.

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

[0125] The above program can be executed in a processor or stored in a memory (or computer-readable storage medium). Computer-readable media include permanent and non-permanent, removable and non-removable media that can implement information storage 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 technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassettes, magnetic tape, disk storage or other magnetic storage devices, or any other non-transmission medium that can be used to store information that can be accessed 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 can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for executing on the computer or other programmable device to implement the process. Figure 1 a process or multiple processes and / or boxes Figure 1 The steps of the functions specified in one or more blocks can be implemented by different modules corresponding to different steps.

[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 obtain the motor target 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 obtain the motor torque request based on the PID algorithm.

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

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

[0132] Secondly, when it is judged to be a uniform slip state, the sum of the proportional term and the differential term, and the product of the integral coefficient are used as the integral sub-term; when it is judged to be a slip state on an open road, the difference between the actual motor speed and the reference motor speed is used as the index to traverse the first pre-constructed table to obtain the integral sub-term; when it is judged to be a stable slip state, the slip duration is used as the index to traverse the second pre-constructed table to obtain the integral sub-term; among them, the first pre-constructed table and the second pre-constructed table are both obtained based on calibration.

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

[0134] The torque arbitration module is used for the torque arbitration unit to obtain the motor torque request, the driver torque request and the VCU torque request. When it is determined that the dTCS system is in an activated state, the smaller of the motor torque request and the VCU torque request is used as the target torque in the forward gear; the larger of the motor torque request and the VCU torque request is used as the target torque in the reverse gear; when it is determined that the system is in an inactivated state, the torque amount of the driver torque request is used as the target torque; when it is determined that the system is in a degraded control state, the dynamic value when the torque amount corresponding to the motor torque request or the VCU torque request is gradually converted to the torque amount corresponding to the driver torque request according to a preset gradient algorithm is used as the target torque.

[0135] The torque control module is configured to input the target torque to the motor to perform torque control.

[0136] Since the system is built based on the method, the above description 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 into the main motor controller. Accordingly, the torque control module includes the following functional units:

[0138] The first judgment unit is used to judge that when the main torque difference between the main target torque and the actual torque of the main motor, and the secondary torque difference between the secondary target torque and the actual torque of the secondary motor are both less than the 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 calculate the product of the main torque difference and the calibration amount as the main correction value and calculate the product of the secondary torque difference and the calibration amount as the secondary correction value when determining that the main torque difference and / or the secondary torque difference is greater than the preset difference.

[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 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 to the secondary motor for torque control.

[0141] Another example includes:

[0142] The MTC input module is used to control the MTC unit to obtain 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 corresponding slip states.

[0144] The state 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 further provides an electronic device, including at least one processor, wherein the processor is coupled to a memory, wherein a computer program is stored in the memory, and the computer program is configured to execute the method when executed by the processor.

[0146] Furthermore, a computer-readable storage medium stores a computer program thereon, wherein the computer program is configured to be executed by a processor to implement the method.

[0147] Since the system, electronic device and storage medium 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, this is not intended to limit the present invention. Persons skilled in the art will readily appreciate that various modifications and variations can be made without departing from the spirit and scope of the present 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 is integrated with a torque conversion unit and a torque arbitration unit; include: The motor controller obtains the motor target speed output by the MTC unit and transmits it to the torque conversion unit; The torque conversion unit obtains the motor torque request based on the PID algorithm; The integral term in torque conversion is obtained by: First, obtain the slip state output by the MTC unit; Secondly, when a uniform slip state is determined, the product of the sum of the proportional term and the differential term and the integral coefficient is used as the integral sub-term. When a slip state is determined on an open road, the difference between the actual motor speed and the reference motor speed is used as an index to traverse the first pre-constructed table to obtain the integral sub-term. When a stable slip state is determined, the slip duration is used as an index to traverse the second pre-constructed table to obtain the integral sub-term. Both the first and second pre-constructed tables are obtained based on calibration. Then, the sum of the integral sub-term 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, and the feedforward value is the difference between the actual torque of the motor and the axle torque loss; The axle torque loss is obtained as follows: T loss =(A min *W low )+A max *(1-W low )*G; Among them, T loss is the axle torque loss, A min is the minimum acceleration of the drive shaft under low load conditions, W low is the weight coefficient of low load condition, A max is the maximum acceleration of the drive shaft under high load conditions, G is the gear ratio; The torque arbitration unit obtains the motor torque request, the driver torque request, and the VCU torque request. When the dTCS system is determined to be in an active state, the smaller of the motor torque request and the VCU torque request is used as the target torque in a forward gear; the larger of the motor torque request and the VCU torque request is used as the target torque in a reverse gear; when the dTCS system is in an inactive state, the torque amount requested by the driver is used as the target torque; and when the dTCS system is in a degraded control state, the dynamic value obtained by gradually converting the torque amount corresponding to the motor torque request or the VCU torque request to the torque amount corresponding to the driver torque request according to a preset gradient algorithm is used 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; wherein the torque conversion unit and the torque arbitration unit are both integrated into the main motor controller; The steps include: Obtaining a main target torque corresponding to the main motor and a secondary target torque corresponding to the secondary motor based on the torque conversion unit and the torque arbitration unit; When it is determined that a main torque difference between the main target torque and the actual torque of the main motor, and a secondary torque difference between the secondary target torque and the actual torque of the secondary motor are both smaller 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 to perform torque control; When it is determined that the main torque difference and / or the secondary torque difference is greater than a preset difference, the product of the main torque difference and the calibration amount is calculated as the main correction value, and the product of the secondary torque difference and the calibration amount is calculated as the secondary correction value; The sum of the main target torque and the main correction value is input as the final main torque to the main motor for torque control, and the difference between the sub-target torque and the sub-correction value is input as the final sub-torque to the sub-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 obtains driver input signals, wheel-end and vehicle signals, motor input signals, brake pressure feedback signals and arbitration input signals; Process various input signals based on the vehicle slip detector to obtain the corresponding slip status; 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: The steps include: Switching the state of the dTCS system based on a state machine; When it is determined that the actual speed of the motor is greater than the speed threshold, the dTCS system is controlled to enter an active state from an inactive state; When it is determined that the actual speed of the motor is less than the speed threshold and continues for a first predetermined time period, and the sum of the torque corresponding to the driver torque request and the calibrated offset is less than the torque corresponding to the motor torque request and continues for a second predetermined time period, the dTCS system changes from an active state to an inactive state; When it is determined that 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 enters the inactive state from the degraded control state; When it is determined that the motor target speed flag or the various input signal flags of the torque conversion unit are false or the degraded activation flag is true, the dTCS system enters the degraded control state from the activated state or enters the degraded control state from the inactivated state; The current state of the switched dTCS system is input into the torque arbitration unit.

5. The vehicle anti-skid method based on distributed traction control according to claim 1, characterized in that: Before torque control is performed based on the target torque, the following steps are included: When the current working condition is determined to be emergency suppression of wheel slip or vehicle body loss of control, the signal flag of the fast torque reduction interface between the torque arbitration unit and the motor controller is true; When the current working condition is determined to be smooth control of vehicle acceleration, the signal flag of the slow torque reduction interface between the torque arbitration unit and the motor controller is true; When it is determined that the current working condition is to quickly restore power output, the signal flag of the fast torque increase interface between the torque arbitration unit and the motor controller is true; When it is determined that the current working condition is to gradually recover the motor torque, the signal flag 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: It 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 obtain the motor target speed output by the MTC unit and transmit it to the torque conversion unit; A torque conversion module, used to control the torque conversion unit to 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 a uniform slip state is determined, the product of the sum of the proportional term and the differential term and the integral coefficient is used as the integral sub-term. When a slip state is determined on an open road, the difference between the actual motor speed and the reference motor speed is used as an index to traverse the first pre-constructed table to obtain the integral sub-term. When a stable slip state is determined, the slip duration is used as an index to traverse the second pre-constructed table to obtain the integral sub-term. Both the first and second pre-constructed tables are obtained based on calibration. Then, the sum of the integral sub-term 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, and the feedforward value is the difference between the actual torque of the motor and the axle torque loss; The axle torque loss is obtained as follows: T loss =(A min *W low )+A max *(1-W low )*G; Among them, T loss is the axle torque loss, A min is the minimum acceleration of the drive shaft under low load conditions, W low is the weight coefficient of low load condition, A max is the maximum acceleration of the drive shaft under high load conditions, G is the gear ratio; a torque arbitration module, configured to obtain a motor torque request, a driver torque request, and a VCU torque request from a torque arbitration unit, and, when determining that the dTCS system is in an active state, to use the smaller of the motor torque request and the VCU torque request as the target torque in a forward gear; and to use the larger of the motor torque request and the VCU torque request as the target torque in a reverse gear; to use the driver torque request as the target torque when determining that the system is in an inactive state; and to use the dynamic value obtained by gradually converting the torque corresponding to the motor torque request or the VCU torque request to the torque corresponding to the driver torque request according to a preset gradient algorithm as the target torque when determining that the system is in a degraded control state; The torque control module is configured to input the target torque to the motor to perform 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 any one of the front motor and 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 into the main motor controller; The torque control module includes the following functional units: a first determining unit, configured to determine that a main torque difference between the main target torque and the actual torque of the main motor, as well as a secondary torque difference between the secondary target torque and the actual torque of the secondary motor, are both smaller than a preset difference, and input the main target torque to the main motor and the secondary target torque to the secondary motor for torque control; a second determining unit, configured to, when determining that the primary torque difference and / or the secondary torque difference is greater than a preset difference, calculate a product of the primary torque difference and a calibration amount as a primary correction value, and calculate a product of the secondary torque difference and the calibration amount as a 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 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 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: MTC input module, used to control the MTC unit to obtain driver input signals, wheel end and vehicle signals, motor input signals, brake pressure feedback signals and arbitration input signals; A state processing unit, configured to process various input signals based on a vehicle slip detector to obtain corresponding slip states; The state output unit is used to input the corresponding slip state to the torque conversion unit.

9. An electronic device, characterized in that: The method comprises at least one processor coupled to a memory, wherein a computer program is stored in the memory, and the computer program is configured to execute the method according to any one of claims 1 to 5 when executed by the processor.

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

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