Control method and system for distributed drive electric vehicle, and controller and vehicle

Abstract

Provided in the present invention are a control method and system for a distributed drive electric vehicle, and a controller and a vehicle. The method comprises: determining a basic torque of each wheel on the basis of an opening degree of an accelerator pedal and a vehicle fault level; determining an additional antiskid torque and / or an additional yaw torque of a vehicle; adjusting each basic torque on the basis of the additional antiskid torque and / or the additional yaw torque, and outputting a required torque of each wheel; and determining a drive control strategy on the basis of the required torque of each wheel and the maximum output torque of each hub motor. In this way, when a vehicle is integrated with both a distributed drive system and a conventional chassis integrated control system, after a required torque of each wheel is determined, a corresponding control strategy can be determined on the basis of the maximum output torque of each hub motor, and if the maximum output torque is insufficient, compensation is then provided by the chassis integrated control system, such that overall planning and coordination for functional control over the distributed drive system and the chassis integrated control system are realized, thereby increasing the utilization rate of control resources, and ensuring a vehicle control effect.

Description

Control method, controller, system and vehicle of distributed drive electric vehicle Technical Field

[0001] The present application relates to the field of distributed drive vehicle control technology, and in particular to a control method, controller, system and vehicle for a distributed drive electric vehicle. Background Art

[0002] With the continuous deepening of electric vehicle technology research, the layout structure of the electric vehicle drive system has gradually developed from a centralized drive system with a single power source to a distributed drive system with multiple power sources.

[0003] However, when a distributed drive system and a traditional chassis integrated control system are integrated into a vehicle at the same time, the functions of the distributed drive system and the chassis integrated control system will overlap. For example, both the distributed drive system and the chassis integrated control system can realize longitudinal drive anti-skid and yaw stability control of the vehicle.

[0004] In order to improve vehicle handling and driving stability, existing technologies are unable to coordinate the functional control of the distributed drive system and the chassis integrated control system, resulting in a waste of control resources and affecting the control effect of the entire vehicle.

[0005] Summary of the Invention

[0006] In response to the problems existing in the prior art, the embodiments of the present invention provide a control method, controller, system and vehicle for a distributed drive electric vehicle to solve or partially solve the technical problem in the prior art that the functional control of the distributed drive system and the chassis integrated control system cannot be coordinated, resulting in a waste of control resources and also affecting the control effect of the entire vehicle.

[0007] A first aspect of the present invention provides a control method for a distributed drive electric vehicle, which is applied to a power chassis domain controller. The method comprises:

[0008] Obtaining an accelerator pedal opening and a vehicle fault level of the vehicle, and determining a base torque of each wheel according to the accelerator pedal opening and the vehicle fault level;

[0009] determining an additional anti-slip torque of the vehicle and / or an additional yaw torque of the vehicle;

[0010] adjusting each of the base torques based on the additional anti-slip torque and / or the additional yaw torque, and outputting a required torque for each of the wheels;

[0011] The control strategy is determined according to the required torque of each wheel and the maximum output torque of each hub motor.

[0012] In the above solution, determining the base torque of each wheel according to the accelerator pedal opening and the vehicle fault level includes:

[0013] determining a first total basic torque of the vehicle according to the accelerator pedal opening;

[0014] Adjusting the first total basic torque based on the fault level to obtain a corresponding total required torque;

[0015] Allocating the total required torque into a front axle basic torque and a rear axle basic torque according to a torque distribution method;

[0016] An average of the front axle basic torques is determined as the basic torques of the left front wheel and the right front wheel, and an average of the rear axle basic torques is determined as the basic torques of the left rear wheel and the right rear wheel.

[0017] In the above solution, determining the additional anti-slip torque of the vehicle includes:

[0018] For any wheel, determining the actual slip rate of the wheel;

[0019] Based on the PID algorithm of the additional anti-slip torque, the actual slip rate of the wheel and the ideal slip rate of the wheel are determined as input values ​​of the additional anti-slip torque PID algorithm, and a first output value is obtained accordingly; the first output value is the additional anti-slip torque.

[0020] In the above solution, determining the additional yaw torque of the vehicle includes:

[0021] When it is determined that the steering wheel angle of the vehicle is not 0, obtaining an actual yaw angular velocity of the vehicle;

[0022] determining an angular velocity difference between the actual yaw rate and the ideal yaw rate;

[0023] Based on the PID control algorithm of the additional yaw torque, the angular velocity difference is used as an input value of the additional yaw torque PID control algorithm to obtain a second output value accordingly; the second output value is the additional yaw torque of the vehicle.

[0024] In the above solution, adjusting each of the base torques based on the additional anti-slip torque and / or the additional yaw torque and outputting the required torque of each wheel includes:

[0025] For any wheel, determining a torque adjustment amount according to the additional anti-slip torque and / or the additional yaw torque;

[0026] The basic torque is adjusted according to the torque adjustment amount to obtain the required torque of the corresponding wheel; wherein,

[0027] The required torque of the wheel is a sum of the basic torque required by the wheel and the torque of the torque adjustment amount.

[0028] In the above solution, the control strategy is determined based on the required torque of each wheel and the maximum output torque of each hub motor, including:

[0029] For any wheel, if the maximum output torque of the hub motor is greater than or equal to the required torque of the corresponding wheel, the control strategy is determined as: the hub motor provides the required torque of the wheel.

[0030] In the above solution, the control strategy is determined based on the required torque of each wheel and the maximum output torque of each hub motor, including:

[0031] If the maximum output torque of the hub motor is less than the required torque of the corresponding wheel, the control strategy is determined as: controlling the hub motor to output the maximum torque and compensating the target braking torque through the hydraulic circuit; the target braking torque is the difference between the required wheel torque and the maximum output torque of the hub motor.

[0032] A second aspect of the present invention provides a power chassis domain controller, the power chassis domain controller comprising:

[0033] A driving intention analysis module is configured to obtain an accelerator pedal opening of the vehicle;

[0034] a torque distribution module configured to determine a basic torque of each wheel according to the accelerator pedal opening;

[0035] a motor drive anti-slip control module configured to determine an additional anti-slip torque for the vehicle;

[0036] a motor torque vectoring control module configured to determine an additional yaw torque of the vehicle;

[0037] The drive arbitration module is configured to adjust each of the base torques based on the additional anti-slip torque and / or the additional yaw torque, and output the required torque of each wheel; and determine the control strategy according to the required torque of each wheel and the maximum output torque of each hub motor.

[0038] A third aspect of the present invention provides a control system for a distributed drive electric vehicle, the system comprising:

[0039] The vehicle controller VCU is configured to obtain the vehicle fault level;

[0040] The power chassis domain controller according to the second aspect is configured to receive the fault level sent by the VCU and determine the base torque of each wheel based on the accelerator pedal opening of the vehicle and the vehicle fault level;

[0041] Determining an additional anti-slip torque of the vehicle and / or an additional yaw torque of the vehicle; adjusting each of the base torques based on the additional anti-slip torque and / or the additional yaw torque, and outputting a required torque for each wheel; and determining a control strategy based on the required torque for each wheel and the maximum output torque of each hub motor.

[0042] A fourth aspect of the present invention provides a vehicle, comprising the control system for the distributed drive electric vehicle according to the third aspect.

[0043] The present invention provides a control method, controller, system, and vehicle for a distributed drive electric vehicle. The method comprises: obtaining the vehicle's accelerator pedal opening and vehicle fault level, determining the base torque of each wheel based on the accelerator pedal opening and the vehicle fault level; determining the vehicle's additional anti-slip torque and / or the vehicle's additional yaw torque; adjusting each base torque based on the additional anti-slip torque and / or the additional yaw torque, and outputting the required torque of each wheel; and determining a drive control strategy based on the required torque of each wheel and the maximum output torque of each wheel hub motor. Thus, when a vehicle integrates both a distributed drive system and a traditional chassis integrated control system, after determining the required torque of each wheel, a corresponding control strategy can be determined based on the maximum output torque of each wheel hub motor. If the maximum output torque is insufficient, the chassis integrated control system provides compensation. This achieves coordinated control of the distributed drive system and the chassis integrated control system, improves vehicle control resource utilization, and ensures vehicle control effectiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiment below. The accompanying drawings are for illustration purposes only and are not to be considered as limiting the present invention. The same reference symbols are used throughout the drawings to represent the same components. In the drawings:

[0045] FIG1 shows a schematic diagram of the overall structure of a control system for a distributed drive electric vehicle according to an embodiment of the present invention;

[0046] FIG2 shows a schematic diagram of control logic of a distributed drive electric vehicle according to an embodiment of the present invention;

[0047] FIG3 shows a schematic flow chart of a control method for a distributed drive electric vehicle according to an embodiment of the present invention;

[0048] FIG4 shows a schematic structural diagram of a power chassis domain controller according to an embodiment of the present invention. DETAILED DESCRIPTION

[0049] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0050] To better understand the technical solution of this application, let's first introduce the distributed drive system. Distributed drive electric vehicles use two or more motors to drive their respective wheels. The motors drive the wheels by controlling torque and speed. Because the distributed drive system eliminates torque transmission through the center differential, it offers significant advantages such as a short drive train, high transmission efficiency, and a compact structure.

[0051] Electric vehicles equipped with distributed drive systems feature four independently controllable wheels. Pure electric vehicles can leverage this to achieve refined tire adhesion distribution, improving vehicle handling and driving stability. Distributed drive systems can also match the motor's optimal efficiency range with the vehicle's operating conditions, improving driving efficiency and energy utilization.

[0052] However, when a distributed drive electric vehicle approaches an unstable state while driving on the road, both the distributed drive system and the chassis integrated control system can effectively control the vehicle state, which leads to overlapping functions of the distributed drive system and the chassis integrated control system.

[0053] In addition, traditional chassis integrated control systems generally improve vehicle stability by reducing engine torque or independently controlling the braking force acting on the wheels. This control method requires reducing vehicle speed, which not only reduces the vehicle's driving ability, but also gives the driver a clear sense of intervention, causing driving interference to the driver.

[0054] Based on this, an embodiment of the present invention provides a control system for a distributed drive electric vehicle. As shown in FIG1 , the system includes: a vehicle control unit (VCU), a conversion and distribution unit (CDU), an integrated electronic brake control system (IBC), and four wheel hub motors; wherein,

[0055] The vehicle controller VCU is configured to determine a vehicle fault level;

[0056] a power chassis domain controller (CDU) configured to receive the fault level sent by the VCU and determine a base torque of each wheel based on an accelerator pedal opening of the vehicle and the vehicle fault level;

[0057] determining an additional anti-slip torque of the vehicle and / or an additional yaw torque of the vehicle;

[0058] The basic torques are adjusted based on the additional anti-slip torque and / or the additional yaw torque, and the required torque of each wheel is output; and a control strategy is determined according to the required torque of each wheel and the maximum output torque of each hub motor.

[0059] The IBC is configured to control each hydraulic circuit to output a corresponding target braking torque based on a control strategy, and is configured to recover braking energy according to the brake pedal opening.

[0060] Specifically, referring to Figure 2, the power chassis domain controller CDU includes: a driving intention analysis module 21, a torque distribution module 22, a vehicle state determination module 23, an electric drive anti-skid control module (ETC, Electric Traction Control), a brake drive anti-skid control module (BTC, Brake Traction Control), a motor torque vector control module (TVC, Torque Vector Control), a brake stability control module (VDC, Vehicle Dynamics Control), a drive arbitration module 24 and a brake arbitration module 25.

[0061] The overall control logic of the control system of the distributed drive electric vehicle is as follows:

[0062] Generally speaking, if the vehicle is in a good driving condition without slipping or instability, the CDU can drive the wheels directly based on their base torque without adjusting the base torque of each wheel. In this case, the base torque is a positive value.

[0063] If the vehicle is launched at full throttle on a low-grip surface (such as ice) or is moving from a high-grip surface to a low-grip surface, additional anti-slip torque is required to improve wheel adhesion and prevent the vehicle from skidding. Similarly, if the vehicle becomes unstable, additional yaw torque is required to improve vehicle stability. In this case, the base torque should be negative.

[0064] Based on this, after determining the basic torque of each wheel, it is necessary to adjust the basic torque according to the additional anti-slip torque and / or the additional yaw torque to obtain the required torque of each wheel.

[0065] The vehicle control strategy is then determined based on the required torque of each wheel and the maximum output torque of the hub motor.

[0066] Specifically, first, the VCU will monitor the fault status of various vehicle components (such as IBC, power chassis domain controller and each wheel hub motor) in real time, and determine the vehicle fault level based on the fault status.

[0067] Then, the driving intention analysis module 21 analyzes the driving intention, obtains the corresponding accelerator pedal opening, and sends the accelerator pedal opening to the torque distribution module 22 .

[0068] The torque distribution module 22 distributes torque to each wheel according to the accelerator pedal opening and the vehicle fault level, determines the basic torque of each wheel, and sends the basic torque of each wheel to the drive arbitration module 24.

[0069] Then the vehicle state determination module 23 obtains the current driving parameters of the vehicle and determines the current vehicle state according to the current driving parameters, wherein the current driving parameters may include information such as steering wheel angle, vehicle speed, and wheel speed.

[0070] The vehicle state may include a slipping state and an unstable state, but at a certain moment the vehicle may only be in a slipping state, or only be in an unstable state, or both a slipping state and an unstable state.

[0071] Therefore, if the vehicle state determination module 23 determines that the vehicle is currently in a slipping state, the ETC module will determine the additional anti-slip torque required by the vehicle and send the additional anti-slip torque to the driving arbitration module 24 .

[0072] If it is determined that the vehicle is currently in an unstable state, the TVC module will determine the additional yaw torque required by the vehicle and send the additional yaw torque to the drive arbitration module 24 .

[0073] If the vehicle is currently in both a slipping state and an unstable state, the ETC module sends an additional anti-slip torque to the drive arbitration module 24 , and the TVC module also sends an additional yaw torque to the drive arbitration module 24 .

[0074] After receiving the additional anti-slip torque and / or additional yaw torque, the drive arbitration module 24 adjusts each base torque based on the additional anti-slip torque and / or additional yaw torque, and outputs the required torque of each wheel; then, drive arbitration is performed based on the required torque of each wheel and the maximum output torque of each hub motor to determine the corresponding control strategy.

[0075] For example, if the maximum output torque of the hub motor is greater than or equal to the required torque of the corresponding wheel, the control strategy is: the hub motor provides the required torque of the wheel; then the drive arbitration module 24 will send the required torque of each wheel to the corresponding hub motor for execution.

[0076] For example, assuming the vehicle is in a slipping and unstable state at the same time, take the left front wheel as an example:

[0077] Assuming that the base torque of the left front wheel is 30 N.m, the additional anti-slip torque is -50 N.m, and the additional yaw torque is -50 N.m, the required torque of the left front wheel is: 30-50-50=-70 N.m.

[0078] That is, the left front wheel requires 70N.m of braking torque to prevent the vehicle from slipping and becoming unstable.

[0079] If the maximum output torque of the hub motor of the left front wheel is -80N.m, then the required torque of the left front wheel is provided by the hub motor.

[0080] However, when the maximum output torque of the hub motor is less than the corresponding required torque and the vehicle is currently in a slipping state, the hub motor is given priority to provide the maximum output torque, and the remaining insufficient torque is determined as the first residual braking torque, and the BTC module sends the first residual braking torque to the braking arbitration module 25.

[0081] If the maximum output torque of the hub motor is less than the corresponding required torque and the vehicle is currently in an unstable state, the hub motor will be given priority to provide the maximum output torque, and the remaining insufficient torque will be determined as the second residual braking torque, and the VDC module will send the second residual braking torque to the brake arbitration module 25.

[0082] If the vehicle is currently in both a slipping state and an unstable state, the BTC module will send the first residual braking torque to the brake arbitration module 25 , and the VDC module will also send the second residual braking torque to the brake arbitration module 25 .

[0083] The braking arbitration module 25 determines a final target braking torque according to the first residual braking torque and / or the second residual braking torque.

[0084] It is understood that if the vehicle is currently in a slipping state, the target braking torque is the first residual braking torque. If the vehicle is currently in an unstable state, the target braking torque is the second residual braking torque. If the vehicle is currently in a slipping state and an unstable state, the target braking torque is the sum of the first and second residual braking torques. The sum of the first and second residual braking torques can also be understood as the difference between the required torque and the maximum output torque of the in-wheel motor.

[0085] Then the corresponding control strategy is: control the wheel hub motor to output the maximum torque, and compensate the target braking torque through the brake hydraulic circuit.

[0086] The brake hydraulic circuit is controlled by the IBC. That is, after the brake arbitration module 25 determines the corresponding target braking torque, it will send a torque request to the IBC. After receiving the torque request, the IBC provides corresponding braking force to the wheels based on the target braking torque to prevent vehicle slippage and / or instability.

[0087] Continuing with the above example, let's assume the vehicle is both slipping and unstable. Let's take the left front wheel as an example:

[0088] Assuming that the base torque of the left front wheel is 30 N.m, the additional anti-slip torque is -50 N.m, and the additional yaw torque is -50 N.m, the required torque of the left front wheel is: 30-50-50=-70 N.m.

[0089] That is, the left front wheel requires 70N.m of braking torque to prevent the vehicle from slipping and becoming unstable.

[0090] If the maximum output torque of the left front wheel hub motor is -60N.m and the target braking torque is -10N.m, the CDU will send a torque request to the IBC, and the IBC will control the corresponding brake hydraulic pipeline to provide a target braking torque compensation of 10N.m.

[0091] In this way, this embodiment can coordinate and allocate the torque provided by the distributed drive system and the braking torque provided by the chassis integrated control system based on the vehicle status, solve the functional overlap problem of the distributed drive and chassis integrated control, realize the unified control of the distributed drive system and the chassis integrated control system, improve the utilization rate of control resources, and ensure the control effect of the whole vehicle.

[0092] Here, the specific execution logic of the power chassis domain controller CDU can refer to the specific description in the subsequent embodiments on the power chassis domain controller side, so it will not be repeated here.

[0093] Based on the same inventive concept as the previous embodiment, this embodiment further provides a control method for a distributed drive electric vehicle, which is applied in a power chassis domain controller (CDU). As shown in FIG3 , the method includes:

[0094] Step S310 , obtaining the accelerator pedal opening and the vehicle fault level of the vehicle, and determining the basic torque of each wheel according to the accelerator pedal opening and the vehicle fault level.

[0095] As mentioned above, the VCU monitors the fault status of various vehicle components (such as the IBC, power chassis domain controller, and each wheel hub motor) in real time, determines the vehicle fault level based on the fault status, and sends the vehicle fault level to the CDU.

[0096] For example, if all components inside the vehicle are fault-free, the vehicle fault level is 0; if there is a component inside the vehicle with a level 1 fault, and the fault levels of all components do not exceed level 1, the vehicle fault level is 1; if there is a component inside the vehicle with a level 2 fault, and the fault levels of all components do not exceed level 21, the vehicle fault level is 2; if there is a component inside the vehicle with a level 3 fault, the vehicle fault level is level 3.

[0097] The CDU can collect the vehicle's accelerator pedal opening in real time and receive the vehicle fault level sent by the VCU, and determine the basic torque of each wheel based on the accelerator pedal opening and the vehicle fault level.

[0098] In one embodiment, determining the base torque of each wheel according to the accelerator pedal opening and the vehicle fault level includes:

[0099] determining a first total base torque of the vehicle according to an accelerator pedal opening;

[0100] Adjusting the first total basic torque based on the fault level to obtain a corresponding total required torque;

[0101] Allocating the total required torque into a front axle basic torque and a rear axle basic torque according to a torque distribution method;

[0102] The average of the front axle base torques is determined as the base torques of the left and right front wheels, and the average of the rear axle base torques is determined as the base torques of the left and right rear wheels.

[0103] Specifically, the first total base torque expected by the vehicle is calculated based on the accelerator pedal opening and vehicle status information. The vehicle status information includes: the maximum output current I currently allowed by the system A , the current speed of each hub motor and the current I corresponding to the peak torque of each hub motor a .

[0104] First, for each hub motor, according to the current speed, query the motor speed-torque external characteristic table to obtain the corresponding maximum torque T tmaxi (i=1,2,3,4), i is the number of the hub motor. Then the total output torque T of the system can be determined by table lookup outmax for:

[0105] T outmax =T tmax1 +T tmax2 +T tmax3 +Ttmax4 ;in,

[0106] T tmax1 is the maximum torque of the first hub motor, T tmax2 is the maximum torque of the second hub motor, T tmax3 is the maximum torque of the third hub motor, T tmax4 The maximum torque of the fourth hub motor is shown in the table.

[0107] Then judge Is it greater than 1? If yes, If it is greater than or equal to 1, then it is determined that:

[0108] T outmax ′=T outmax ; Among them, T outmax ′ is the maximum output torque allowed by the system.

[0109] If confirmed If it is less than 1, then

[0110] According to the formula T outmax ″=min(T outmax ,T outmax ') Determine the final torque T outmax ″;

[0111] Finally, according to the formula T out =T outmax *Accpedal determines the first total base torque; wherein Accpedal is the accelerator pedal opening.

[0112] However, if a vehicle failure occurs, the first total base torque needs to be adjusted according to the corresponding failure level. In actual applications, there is a corresponding relationship between the failure level and the torque adjustment coefficient.

[0113] The above vehicle fault levels include 4 levels (0 to 3), and the torque adjustment coefficient also includes 4 levels correspondingly, namely 100%, 100%, 10%, and 0%.

[0114] For example, when the fault level is 0, the system operates normally and the first total base torque does not need to be adjusted; when the fault level is 1, the system issues an alarm, but the first total base torque continues to operate normally and does not need to be adjusted; when the fault level is 2, the first total base torque is reduced to 0.1 times the normal torque; when the system fault level is 3, the system does not output torque and the torque is 0.

[0115] For example, assuming the first total base torque is 1000 N.m, the fault level is level 2, and the corresponding torque adjustment coefficient is 10%, then after adjusting the first total base torque, the total required torque obtained is:

[0116] 1000*10%=100N.m.

[0117] After the total required torque is determined, the front and rear axle torque distribution ratio is determined based on the axle loads of the front and rear axles of the vehicle using a torque distribution method that is proportional to the axle load. Then, the front axle torque and rear axle torque are determined based on the front and rear axle torque distribution ratio.

[0118] For example, if the front and rear axle load ratio of the vehicle is 4:6, then the front and rear axle torque distribution ratio is also 4:6.

[0119] Then, the average of the front axle basic torques is determined as the basic torques of the left front wheel and the right front wheel, and the average of the rear axle basic torques is determined as the basic torques of the left rear wheel and the right rear wheel.

[0120] For example, assuming the total required torque is 800N.m and the front and rear axle torque distribution ratio is 4:6, then the front axle torque is 320N.m, the rear axle torque is 480N.m, the basic torque of the left front wheel and the right front wheel are 160N.m respectively, and the basic torque of the left rear wheel and the right rear wheel are 240N.m.

[0121] Step S311 : determining the additional anti-slip torque of the vehicle and / or the additional yaw torque of the vehicle.

[0122] As mentioned above, if the vehicle is in a consistently good driving state, with no slip or instability, the CDU can drive the wheels directly based on the base torque, without adjusting the base torque for each wheel. In this case, there's no need to suppress slip or instability, so the base torque is positive.

[0123] However, if the vehicle is driving on a road with a low adhesion coefficient (such as ice) or is driving from a road with a high adhesion coefficient to a road with a low adhesion coefficient, a certain amount of additional anti-skid torque is needed to increase the adhesion of the wheels and prevent the vehicle from slipping.

[0124] Similarly, if the vehicle becomes unstable, a certain amount of additional yaw torque needs to be provided to improve the stability of the vehicle.

[0125] Therefore, this embodiment also needs to determine the additional anti-slip torque of the vehicle and / or the additional yaw torque of the vehicle.

[0126] In one embodiment, determining the additional anti-slip torque of the vehicle includes:

[0127] For any wheel, determine the actual slip rate of the wheel;

[0128] Based on the PID algorithm of the additional anti-slip torque, the actual slip rate of the wheel and the ideal slip rate of the wheel are determined as input values ​​of the additional anti-slip torque PID algorithm, and a first output value is obtained accordingly; the first output value is the additional anti-slip torque.

[0129] Specifically, the actual slip rate S of each wheel can be determined according to formula (1): x :

[0130] In formula (1), x is the wheel number, r is the wheel rolling radius, ω is the wheel speed, and v is the current speed of the vehicle.

[0131] Then, the actual slip ratio of the wheel and the ideal slip ratio of the wheel are determined as input values ​​of the additional anti-slip torque PID algorithm, and a first output value is obtained accordingly. The first output value is the additional anti-slip torque T. The additional anti-slip torque PID algorithm is shown in formula (2):

[0132] In formula (2), K p , K i and K d This is a pre-calibrated proportional coefficient determined based on experience and the actual vehicle conditions, and is not limited here. The e(t) input value, i.e., e(t), represents the actual slip ratio and the ideal slip ratio of the wheel.

[0133] In one embodiment, determining an additional yaw torque of the vehicle includes:

[0134] When it is determined that the steering wheel angle of the vehicle is not 0, obtaining the actual yaw angular velocity of the vehicle;

[0135] determining an angular velocity difference between an actual yaw rate and a desired yaw rate;

[0136] Based on the PID control algorithm of the additional yaw torque, the angular velocity difference is used as an input value of the additional yaw torque PID control algorithm, and a second output value is obtained accordingly; the second output value is the additional yaw torque of the vehicle.

[0137] Specifically, when the steering wheel angle is not 0, the ideal yaw velocity of the vehicle can be determined using a two-degree-of-freedom vehicle reference model, and the actual yaw velocity of the vehicle can be determined using a gyroscope. Then, the difference between the ideal yaw velocity and the actual yaw velocity is determined to obtain the corresponding angular velocity difference.

[0138] The angular velocity difference is used as the input value of the additional yaw torque PID control algorithm, and the output value is the additional yaw torque ΔM required to suppress vehicle instability. z It should be noted that the additional yaw torque of each wheel may be different. The additional yaw torque of each wheel is determined as follows:

[0139] Since the additional yaw torque is achieved by adjusting the left and right side torque difference while keeping the longitudinal torque unchanged, assuming that the diameters of the left and right front wheels are d1 and the diameters of the left and right rear wheels are d2, we can get:

[0140] Front wheel torque adjustment ΔF f :

[0141] Rear wheel torque adjustment ΔF r :

[0142] Then the additional yaw torque of each wheel is as follows:

[0143] The additional yaw torque on the left front wheel is: -ΔF f *R FL ; The additional yaw torque of the right front wheel is: ΔF f *R FR ; The additional yaw torque of the left rear wheel is -ΔF r *R RL ; The additional yaw torque of the right rear wheel is ΔF r *R RR ; Among them, R FL is the left front wheel radius, R FR is the right front wheel radius, R RL is the left rear wheel radius, R RR is the radius of the right rear wheel.

[0144] The additional yaw torque PID control algorithm may refer to the principle of the additional anti-slip torque PID algorithm. The difference is that the additional yaw torque PID control algorithm and the additional anti-slip torque PID algorithm have different input values ​​and proportional coefficients.

[0145] Step S312: adjusting each of the basic torques based on the additional anti-slip torque and / or the additional yaw torque, and outputting a required torque for each of the wheels;

[0146] After the additional anti-slip torque and the additional yaw torque of each wheel are determined, each base torque is adjusted based on the additional anti-slip torque and / or the additional yaw torque, and the required torque of each wheel is output.

[0147] In one embodiment, adjusting each base torque based on the additional anti-slip torque and / or the additional yaw torque and outputting a required torque for each wheel includes:

[0148] For any wheel, determining a torque adjustment amount according to the additional anti-slip torque and / or the additional yaw torque;

[0149] The basic torque is adjusted according to the torque adjustment amount to obtain the required torque of the corresponding wheel; wherein,

[0150] The required torque of the wheel is the sum of the basic torque of the wheel and the torque adjustment amount.

[0151] As described above, the vehicle state may include a slipping state and an unstable state, but at a certain moment the vehicle may only be in a slipping state, or only be in an unstable state, or both a slipping state and an unstable state.

[0152] For example, if the vehicle is currently in a slipping and unstable state, taking the left front wheel as an example:

[0153] Assuming that the base torque of the left front wheel is 30 N.m, the additional anti-slip torque is -50 N.m, and the additional yaw torque is -50 N.m, the torque adjustment amount is -(50 N.m+50 N.m)=-100 N.m.

[0154] The required torque of the left front wheel is: 30-100=-70N.m.

[0155] In the same way, the required torque of all wheels can be determined.

[0156] Step S313 : determining a control strategy according to the required torque of each wheel and the maximum output torque of each hub motor.

[0157] Since the maximum output torque of the hub motor is limited, the control strategy needs to be determined based on the required torque of each wheel and the maximum output torque of each hub motor.

[0158] In one embodiment, the required torque of each wheel and the maximum output torque of each hub motor determine the driving control strategy, including:

[0159] For any wheel, if the maximum output torque of the hub motor is greater than or equal to the required torque of the corresponding wheel, the control strategy is determined as follows: the hub motor provides the required torque of the wheel;

[0160] If the maximum output torque of the hub motor is less than the required torque of the corresponding wheel, the control strategy is determined as: controlling the hub motor to output the maximum torque and compensating the target braking torque through the hydraulic circuit; the target braking torque is the difference between the required torque of the wheel and the maximum output torque of the hub motor.

[0161] For example, assuming the vehicle is in a slipping and unstable state at the same time, take the left front wheel as an example:

[0162] Assuming that the base torque of the left front wheel is 30 N.m, the additional anti-slip torque is -50 N.m, and the additional yaw torque is -50 N.m, the required torque of the left front wheel is: 30-50-50=-70 N.m.

[0163] That is, the left front wheel requires 70N.m of braking torque to prevent the vehicle from slipping and becoming unstable.

[0164] If the maximum output torque of the hub motor of the left front wheel is 80N.m, then the required torque of the left front wheel is provided by the hub motor.

[0165] If the maximum output torque of the in-wheel motor is less than the corresponding required torque and the vehicle is currently in a slipping state, the in-wheel motor is given priority to provide the maximum output torque, and the remaining insufficient torque is determined as the first remaining braking torque.

[0166] If the maximum output torque of the hub motor is less than the corresponding required torque and the vehicle is currently in an unstable state, the hub motor is given priority to provide the maximum output torque, and the remaining insufficient torque is determined as the second residual braking torque.

[0167] If the vehicle is currently in both a slipping state and an unstable state, the CDU will determine a final target braking torque based on the first residual braking torque and / or the second residual braking torque.

[0168] It is understood that if the vehicle is currently in a slipping state, the target braking torque is the first residual braking torque. If the vehicle is currently in an unstable state, the target braking torque is the second residual braking torque. If the vehicle is currently in a slipping state and an unstable state, the target braking torque is the sum of the first and second residual braking torques. The sum of the first and second residual braking torques can also be understood as the difference between the required torque and the maximum output torque of the hub motor.

[0169] Then the corresponding control strategy is: control the wheel hub motor to output the maximum torque, and compensate the target braking torque through the brake hydraulic circuit.

[0170] The brake hydraulic circuit is controlled by the IBC. That is, after the CDU determines the corresponding target braking torque, it will send a torque request to the IBC. After receiving the torque request, the IBC provides corresponding braking force to the wheels based on the target braking torque to prevent vehicle slippage and / or instability.

[0171] Continuing with the above example, let's assume the vehicle is both slipping and unstable. Let's take the left front wheel as an example:

[0172] Assuming that the base torque of the left front wheel is 30 N.m, the additional anti-slip torque is -50 N.m, and the additional yaw torque is -50 N.m, the required torque of the left front wheel is: 30-50-50=-70 N.m.

[0173] That is, the left front wheel requires 70N.m of braking torque to prevent the vehicle from slipping and becoming unstable.

[0174] If the maximum output torque of the left front wheel hub motor is -60N.m and the target braking torque is -10N.m, the CDU will send a torque request to the IBC, and the IBC will control the corresponding brake hydraulic pipeline to provide a target braking torque compensation of 10N.m.

[0175] This embodiment coordinates and allocates the maximum output torque provided by the distributed drive system and the braking torque provided by the chassis integrated control system based on the vehicle's state. This resolves the functional overlap between the distributed drive and chassis integrated control systems, achieves unified control of the distributed drive and chassis integrated control systems, and improves control resource utilization. Furthermore, when the vehicle is unstable, there is no need to reduce engine torque to suppress instability, thereby increasing the vehicle's maximum cornering speed and enhancing vehicle handling and driving stability.

[0176] Based on the same inventive concept as the previous embodiment, this embodiment further provides a power domain chassis controller, as shown in FIG4 . The power domain chassis controller CDU includes:

[0177] The driving intention analysis module 21 is configured to obtain the accelerator pedal opening of the vehicle;

[0178] The torque distribution module 22 is configured to determine the basic torque of each wheel according to the accelerator pedal opening;

[0179] a motor-driven anti-slip control module ETC configured to determine an additional anti-slip torque of the vehicle;

[0180] a motor torque vectoring control module TVC configured to determine an additional yaw torque of the vehicle;

[0181] The drive arbitration module 24 is configured to adjust each of the base torques based on the additional anti-slip torque and / or the additional yaw torque, and output the required torque of each wheel; and determine a control strategy according to the required torque of each wheel and the maximum output torque of each hub motor.

[0182] Continuing to refer to FIG. 4 , the power domain chassis controller CDU further includes: a vehicle state determination module 23 , a braking and driving anti-skid control module BTC, a braking stability control module VDC and a braking arbitration module 25 .

[0183] Specifically, first, the VCU will monitor the fault status of various vehicle components (such as IBC, power chassis domain controller and each wheel hub motor) in real time, and determine the vehicle fault level based on the fault status.

[0184] Then, the driving intention analysis module 21 analyzes the driving intention, obtains the corresponding accelerator pedal opening, and sends the accelerator pedal opening to the torque distribution module 22 .

[0185] The torque distribution module 22 distributes torque to each wheel according to the accelerator pedal opening and the vehicle fault level, determines the basic torque of each wheel, and sends the basic torque of each wheel to the drive arbitration module 24.

[0186] Then the vehicle state determination module 23 obtains the current driving parameters of the vehicle and determines the current vehicle state according to the current driving parameters, wherein the current driving parameters may include information such as steering wheel angle, vehicle speed, and wheel speed.

[0187] The vehicle state may include a slipping state and an unstable state, but at a certain moment the vehicle may only be in a slipping state, or only be in an unstable state, or both a slipping state and an unstable state.

[0188] Therefore, if the vehicle state determination module 23 determines that the vehicle is currently in a slipping state, the ETC module will determine the additional anti-slip torque required by the wheels and send the additional anti-slip torque to the driving arbitration module 24 .

[0189] If it is determined that the vehicle is currently in an unstable state, the TVC module will determine the additional yaw torque required by the wheels and send the additional yaw torque to the drive arbitration module 24 .

[0190] If the vehicle is currently in both a slipping state and an unstable state, the ETC module sends an additional anti-slip torque to the drive arbitration module 24 , and the TVC module also sends an additional yaw torque to the drive arbitration module 24 .

[0191] After receiving the additional anti-slip torque and / or additional yaw torque, the drive arbitration module 24 adjusts each base torque based on the additional anti-slip torque and / or additional yaw torque, and outputs the required torque of each wheel; then, drive arbitration is performed based on the required torque of each wheel and the maximum output torque of each hub motor to determine the corresponding control strategy.

[0192] For example, if the maximum output torque of the hub motor is greater than or equal to the required torque of the corresponding wheel, the control strategy is: the hub motor provides the required torque of the wheel; then the drive arbitration module 24 will send the required torque of each wheel to the corresponding hub motor for execution.

[0193] For example, assuming the vehicle is in a slipping and unstable state at the same time, take the left front wheel as an example:

[0194] Assuming that the base torque of the left front wheel is 30 N.m, the additional anti-slip torque is -50 N.m, and the additional yaw torque is -50 N.m, the required torque of the left front wheel is: 30-50-50=-70 N.m.

[0195] That is, the left front wheel requires 70N.m of braking torque to prevent the vehicle from slipping and becoming unstable.

[0196] If the maximum output torque of the hub motor of the left front wheel is 80N.m, then the required torque of the left front wheel is provided by the hub motor.

[0197] However, when the maximum output torque of the hub motor is less than the corresponding required torque and the vehicle is currently in a slipping state, the hub motor is given priority to provide the maximum output torque, and the remaining insufficient torque is determined as the first residual braking torque, and the BTC module sends the first residual braking torque to the braking arbitration module 25.

[0198] If the maximum output torque of the hub motor is less than the corresponding required torque and the vehicle is currently in an unstable state, the hub motor will be given priority to provide the maximum output torque, and the remaining insufficient torque will be determined as the second residual braking torque, and the VDC module will send the second residual braking torque to the brake arbitration module 25.

[0199] If the vehicle is currently in both a slipping state and an unstable state, the BTC module will send the first residual braking torque to the brake arbitration module 25 , and the VDC module will also send the second residual braking torque to the brake arbitration module 25 .

[0200] The braking arbitration module 25 determines a final target braking torque according to the first residual braking torque and / or the second residual braking torque.

[0201] It can be understood that if the vehicle is currently in a slipping state, the target braking torque is the first residual braking torque.

[0202] If the vehicle is currently in an unstable state, the target braking torque is the second residual braking torque.

[0203] If the vehicle is currently slipping and unstable, the target braking torque is the sum of the first and second residual braking torques. In this state, the sum of the first and second residual braking torques can also be understood as the difference between the required torque and the maximum output torque of the in-wheel motor.

[0204] Then the corresponding control strategy is: control the wheel hub motor to output the maximum torque, and compensate the target braking torque through the brake hydraulic circuit.

[0205] The brake hydraulic circuit is controlled by the IBC. That is, after the brake arbitration module 25 determines the corresponding target braking torque, it will send a torque request to the IBC. After receiving the torque request, the IBC provides corresponding braking force to the wheels based on the target braking torque to prevent vehicle slippage and / or instability.

[0206] Continuing with the above example, let's assume the vehicle is both slipping and unstable. Let's take the left front wheel as an example:

[0207] Assuming that the base torque of the left front wheel is 30 N.m, the additional anti-slip torque is -50 N.m, and the additional yaw torque is -50 N.m, the required torque of the left front wheel is: 30-50-50=-70 N.m.

[0208] That is, the left front wheel requires 70N.m of braking torque to prevent the vehicle from slipping and becoming unstable.

[0209] If the maximum output torque of the hub motor of the left front wheel is -60 N.m and the target braking torque is -10 N.m, the brake arbitration module 25 will send a torque request to the IBC, and the IBC will control the corresponding brake hydraulic pipeline to provide a target braking torque compensation of 10 N.m.

[0210] Since the power chassis domain controller described in the embodiments of the present invention is the controller used to implement the control method of the distributed drive electric vehicle according to the embodiments of the present invention, the specific structure and variations of the controller are well understood by those skilled in the art based on the methods described in the embodiments of the present invention, and therefore will not be described in detail here. All controllers used in the methods of the embodiments of the present invention fall within the scope of protection of the present invention.

[0211] Based on the same inventive concept as the aforementioned embodiment, the present invention also provides a vehicle, which includes the above-mentioned distributed drive electric vehicle control system and power chassis domain controller. The control system and power chassis domain controller of the distributed drive electric vehicle can refer to the corresponding description above, so they will not be repeated here.

[0212] The control method, controller, system and vehicle of the distributed drive electric vehicle provided by the present invention can bring at least the following beneficial effects:

[0213] The present invention provides a control method, controller, system, and vehicle for a distributed drive electric vehicle. The method comprises: obtaining the vehicle's accelerator pedal opening and vehicle fault level, determining the base torque of each wheel based on the accelerator pedal opening and the vehicle fault level; determining the vehicle's additional anti-slip torque; determining the vehicle's additional yaw torque; adjusting each base torque based on the additional anti-slip torque and the additional yaw torque, and outputting the required torque of each wheel; and determining a drive control strategy based on the required torque of each wheel and the maximum output torque of each wheel hub motor. Thus, when a vehicle integrates both a distributed drive system and a traditional chassis integrated control system, after determining the required torque of each wheel, a corresponding control strategy can be determined based on the maximum output torque of each wheel hub motor. If the maximum output torque is insufficient, the chassis integrated control system provides compensation. This achieves coordinated functional control of the distributed drive system and the chassis integrated control system, improves vehicle control resource utilization, and ensures vehicle control effectiveness.

[0214] As can be seen, the present invention addresses the torque requirements of the entire vehicle across all driving scenarios (normal driving, slipping, and instability) through driver intent analysis, torque distribution, unified drive anti-slip control, and unified yaw control. This resolves the functional overlap between distributed drive and chassis integrated control, achieving unified control of the distributed drive system and chassis integrated control system, and optimizing the algorithm complexity. This not only expands the stability boundaries of vehicles equipped with distributed drive, but also eliminates the need to reduce engine torque to suppress instability when the vehicle is unstable, thereby increasing the vehicle's maximum cornering speed and improving both handling and driving stability.

[0215] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A control method for a distributed drive electric vehicle, characterized in that: Applied in a power chassis domain controller, the method comprises: Acquire the accelerator pedal opening and the vehicle fault level of the vehicle, and determine the basic torque of each wheel according to the accelerator pedal opening and the vehicle fault level; determining an additional anti-slip torque of the vehicle and / or an additional yaw torque of the vehicle; adjusting each of the basic torques based on the additional anti-slip torque and / or the additional yaw torque, and outputting a required torque for each of the wheels; The control strategy is determined according to the required torque of each wheel and the maximum output torque of each hub motor.

2. The method according to claim 1, characterized in that Determining the basic torque of each wheel according to the accelerator pedal opening and the vehicle fault level includes: determining a first total basic torque of the vehicle according to the accelerator pedal opening; Adjusting the first total basic torque based on the fault level to obtain a corresponding total required torque; Allocating the total required torque into a front axle basic torque and a rear axle basic torque according to a torque distribution method; The average value of the front axle basic torque is determined as the basic torque of the left front wheel and the right front wheel, and the average value of the rear axle basic torque is determined as the basic torque of the left rear wheel and the right rear wheel.

3. The method according to claim 1, characterized in that The determining the additional anti-slip torque of the vehicle comprises: For any wheel, determining an actual slip rate of the wheel; Based on the PID algorithm of the additional anti-slip torque, the actual slip rate of the wheel and the ideal slip rate of the wheel are determined as input values ​​of the additional anti-slip torque PID algorithm, and a first output value is obtained accordingly; the first output value is the additional anti-slip torque.

4. The method according to claim 1, characterized in that The determining an additional yaw torque of the vehicle comprises: When it is determined that the steering wheel angle of the vehicle is not 0, acquiring an actual yaw angular velocity of the vehicle; Determining an angular velocity difference between the actual yaw velocity and the ideal yaw velocity; Based on the PID control algorithm of the additional yaw torque, the angular velocity difference is used as an input value of the additional yaw torque PID control algorithm, and a second output value is obtained accordingly; the second output value is the additional yaw torque of the vehicle.

5. The method according to claim 1, characterized in that The adjusting each of the basic torques based on the additional anti-slip torque and / or the additional yaw torque and outputting a required torque of each of the wheels includes: For any wheel, determining a torque adjustment amount according to the additional anti-slip torque and / or the additional yaw torque; The basic torque is adjusted according to the torque adjustment amount to obtain the required torque of the corresponding wheel; wherein, The required torque of the wheel is a torque sum of a basic torque required by the wheel and the torque adjustment amount.

6. The method according to claim 1, characterized in that The control strategy is determined according to the required torque of each wheel and the maximum output torque of each wheel hub motor, including: For any wheel, if the maximum output torque of the hub motor is greater than or equal to the required torque of the corresponding wheel, the control strategy is determined as: the hub motor provides the required torque of the wheel.

7. The method according to claim 1, characterized in that The control strategy is determined according to the required torque of each wheel and the maximum output torque of each wheel hub motor, including: If the maximum output torque of the hub motor is less than the required torque of the corresponding wheel, the control strategy is determined as: controlling the hub motor to output the maximum torque and compensating the target braking torque through the hydraulic circuit; the target braking torque is the difference between the required torque of the wheel and the maximum output torque of the hub motor.

8. A power chassis domain controller, characterized in that: The power chassis domain controller includes: A driving intention analysis module is configured to obtain an accelerator pedal opening of the vehicle; a torque distribution module, configured to determine a basic torque of each wheel according to the accelerator pedal opening; a motor drive anti-skid control module configured to determine an additional anti-skid torque for the vehicle; a motor torque vectoring control module configured to determine an additional yaw torque of the vehicle; The drive arbitration module is configured to adjust each of the basic torques based on the additional anti-slip torque and / or the additional yaw torque, and output the required torque of each wheel; and determine the control strategy according to the required torque of each wheel and the maximum output torque of each hub motor.

9. A control system for a distributed drive electric vehicle, characterized in that: The system comprises: The vehicle controller VCU is configured to obtain the vehicle fault level; The power chassis domain controller according to claim 8, configured to receive the fault level sent by the VCU, and determine the basic torque of each wheel based on the accelerator pedal opening of the vehicle and the vehicle fault level; Determine the additional anti-slip torque of the vehicle and / or the additional yaw torque of the vehicle; adjust each of the basic torques based on the additional anti-slip torque and / or the additional yaw torque, and output the required torque of each wheel; determine the control strategy according to the required torque of each wheel and the maximum output torque of each hub motor.

10. A vehicle, characterized in that: The vehicle includes the control system of the distributed drive electric vehicle as claimed in claim 9.

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