CN114801781A - Fuzzy-sliding mode composite control system of four-wheel drive AFS/DYC integrated control system - Google Patents

Fuzzy-sliding mode composite control system of four-wheel drive AFS/DYC integrated control system Download PDF

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CN114801781A
CN114801781A CN202210564747.4A CN202210564747A CN114801781A CN 114801781 A CN114801781 A CN 114801781A CN 202210564747 A CN202210564747 A CN 202210564747A CN 114801781 A CN114801781 A CN 114801781A
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fuzzy
afs
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vehicle
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朴昌浩
王皓
石钧仁
刘平
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Chongqing University of Post and Telecommunications
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    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L15/00—Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles
    • B60L15/32—Control or regulation of multiple-unit electrically-propelled vehicles
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L15/00—Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles
    • B60L15/20—Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles for control of the vehicle or its driving motor to achieve a desired performance, e.g. speed, torque, programmed variation of speed
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W10/00—Conjoint control of vehicle sub-units of different type or different function
    • B60W10/119—Conjoint control of vehicle sub-units of different type or different function including control of all-wheel-driveline means, e.g. transfer gears or clutches for dividing torque between front and rear axle
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W30/00—Purposes of road vehicle drive control systems not related to the control of a particular sub-unit, e.g. of systems using conjoint control of vehicle sub-units
    • B60W30/02—Control of vehicle driving stability
    • B60W30/045—Improving turning performance
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60L—PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES; SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL; MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
    • B60L2240/00—Control parameters of input or output; Target parameters
    • B60L2240/40—Drive Train control parameters
    • B60L2240/42—Drive Train control parameters related to electric machines
    • B60L2240/423—Torque
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2520/00—Input parameters relating to overall vehicle dynamics
    • B60W2520/10—Longitudinal speed
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2520/00—Input parameters relating to overall vehicle dynamics
    • B60W2520/10—Longitudinal speed
    • B60W2520/105—Longitudinal acceleration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2520/00—Input parameters relating to overall vehicle dynamics
    • B60W2520/12—Lateral speed
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2520/00—Input parameters relating to overall vehicle dynamics
    • B60W2520/12—Lateral speed
    • B60W2520/125—Lateral acceleration
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2520/00—Input parameters relating to overall vehicle dynamics
    • B60W2520/26—Wheel slip
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2530/00—Input parameters relating to vehicle conditions or values, not covered by groups B60W2510/00 or B60W2520/00
    • B60W2530/10—Weight
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B60—VEHICLES IN GENERAL
    • B60W—CONJOINT CONTROL OF VEHICLE SUB-UNITS OF DIFFERENT TYPE OR DIFFERENT FUNCTION; CONTROL SYSTEMS SPECIALLY ADAPTED FOR HYBRID VEHICLES; ROAD VEHICLE DRIVE CONTROL SYSTEMS FOR PURPOSES NOT RELATED TO THE CONTROL OF A PARTICULAR SUB-UNIT
    • B60W2710/00—Output or target parameters relating to a particular sub-units
    • B60W2710/08—Electric propulsion units
    • B60W2710/083—Torque

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  • Transportation (AREA)
  • Mechanical Engineering (AREA)
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  • Automation & Control Theory (AREA)
  • Arrangement And Driving Of Transmission Devices (AREA)

Abstract

The invention discloses a fuzzy-sliding mode composite Control method of a four-wheel drive AFS (Active Front Steering)/DYC (Direct Yaw moment Control) integrated Control system, which is formed by using fuzzy Control as a Control target based on slip ratio and controlling an AFS (Active Front wheel corner) and a DYC (Direct Yaw moment) controller to obtain additional values based on a sliding mode variable structure. The method is utilized to design the AFS/DYC integrated controller based on the four-wheel drive electric automobile model, further distribute the weight of each controller, realize the switching among the controllers, and finally distribute the driving torque of each wheel according to the dynamic load. Compared with a non-integrated control method under the same working condition, the yaw stability of the four-wheel drive automobile under the high-speed running working condition can be effectively improved, when the automobile is unstable, the automobile can be recovered to a stable state through adding a front wheel turning angle and a yaw moment, the actual yaw speed can better track the ideal value of the yaw speed, and the transverse stability of the automobile under the limit working condition can be effectively improved.

Description

Fuzzy-sliding mode composite control system of four-wheel drive AFS/DYC integrated control system
Technical Field
The invention belongs to a torque distribution method of a four-wheel drive electric vehicle, in particular to a fuzzy control algorithm combined sliding mode variable structure algorithm composite control method of a four-wheel drive AFS/DYC integrated control system.
Background
The four-wheel drive-distributed electric automobile is different from a single-motor centralized drive type electric automobile, a hub motor is respectively arranged in each hub of the distributed drive type electric automobile, each wheel can be independently driven, and the control mode is flexible. When the vehicle is in a destabilizing state, the traditional vehicle can only provide braking force with equal proportion through two driving wheels to correct the posture of the vehicle, and the vehicle is easy to destabilize under the limit working condition. The distributed driving electric automobile can use four motors which are independently driven as power sources, and different driving and braking torque distribution of each driving wheel can be simultaneously realized through a control strategy which is reasonable in design.
The AFS system can provide an additional front wheel steering angle according to the driving condition of the vehicle to improve the steering stability of the vehicle, but the control effect of the system on a low-adhesion road surface is limited. The DYC system achieves the purpose of correcting the driver's oversteer or understeer by adjusting the longitudinal force of the tires to generate an additional yaw moment, but the direct yaw moment control has a large intervention on the longitudinal speed of the vehicle. In order to fully exert the advantages of the AFS and DYC systems, the AFS and DYC need to be cooperatively controlled to solve the coupling problem. Therefore, a fuzzy PID control and sliding mode variable structure composite control method based on slip ratio observation is provided. The method can distribute the weight of each controller to realize the switching among the controllers. Compared with the method without integrated control, the method can improve the instantaneity of torque distribution and effectively improve the yaw stability of the four-wheel drive automobile under the high-speed running condition.
Therefore, the fuzzy-sliding mode composite control system of the four-wheel drive AFS/DYC integrated control system is designed, and the transverse stability of the vehicle under the limit working condition can be effectively improved.
CN104443022B, a method and a system for controlling the stability of an electric vehicle with four wheels driven independently, which solves the technical problem that the performance of the whole vehicle is reduced due to the coupling when two safety systems of an electric vehicle ARS and a DYC work simultaneously in the prior art, the method comprises the following steps: when the vehicle turns, acquiring the steering wheel angle and the vehicle speed; acquiring a variable transmission ratio between a steering wheel and a rear wheel steering angle based on a vehicle speed and a vehicle speed transmission ratio mathematical model; acquiring a front wheel steering angle based on the steering wheel steering angle; acquiring an ideal state of the vehicle based on the variable transmission ratio vehicle ideal model, the vehicle speed and the front wheel steering angle; acquiring the actual state of the vehicle based on the nonlinear eight-degree-of-freedom model of the electric vehicle, the vehicle speed and the front wheel corner; acquiring a vehicle state error of a vehicle actual state relative to a vehicle ideal state; and (3) controlling to eliminate or reduce the vehicle state error through ARS + DYC or ARS respectively aiming at the condition that the vehicle works in a nonlinear region or a linear region so as to enable the vehicle to stably run. Because the four-wheel drive automobile needs to make torque distribution in the face of real-time changing environment, the calculation force requirements on the algorithm and the controller are very high, and the real-time property of the torque distribution of the automobile is not reflected in the patent if the algorithm is required to be ensured. The invention takes the influence of vertical shaft load transfer on the wheel adhesion capacity into consideration, the driving moment distributed by the wheels with large adhesion capacity is larger, and the driving moment distributed by the wheels with small adhesion capacity is smaller, thus effectively preventing the wheels from skidding, and carrying out torque distribution by adopting a dynamic load mode.
Disclosure of Invention
The present invention is directed to solving the above problems of the prior art. A fuzzy-sliding mode composite control system of a four-wheel drive AFS/DYC integrated control system is provided. The technical scheme of the invention is as follows:
a fuzzy-sliding mode composite control system of a four-wheel drive AFS/DYC integrated control system is established, and comprises the following steps: the system comprises a driver model, a seven-degree-of-freedom whole vehicle model, a tire model, a driving system model, a two-degree-of-freedom ideal model, a slip rate module, a torque distribution module, an AFS (active front wheel steering angle) controller, a DYC (direct yaw moment) controller and an AFS/DYC coordination integrated controller; the system comprises a driver model, a seven-degree-of-freedom whole vehicle model, a tire model, a driving system model, a two-degree-of-freedom ideal model, a slip rate module, a torque distribution module, an AFS controller, a DYC controller and an AFS/DYC coordination integrated controller, wherein the driver model is used for following a vehicle speed and outputting a driving torque at the current speed, the seven-degree-of-freedom whole vehicle model is used for analyzing longitudinal, lateral and yaw motions of the vehicle, the tire model is used for calculating a slip angle and a wheel slip rate of wheels, the driving system model is used for outputting a motor characteristic curve, the two-degree-of-freedom ideal model is used for obtaining a yaw rate and a mass center slip angle under an ideal state, the slip rate module is used for obtaining the slip rate of each wheel under a driving state, the torque distribution module is used for distributing the driving force and an additional yaw moment to each wheel, the AFS controller is used for obtaining a stable additional front wheel rotation angle, the DYC controller is used for distributing weights of each controller.
Obtaining an ideal yaw rate through a two-degree-of-freedom model, taking the difference value and the derivative of the yaw rate output by a whole vehicle model and the ideal yaw rate as the input of the sliding mode variable structure control, outputting an initial additional front wheel corner by an AFS controller, and outputting an initial additional yaw moment by a DYC controller; the AFS/DYC coordination integrated controller preferentially considers the longitudinal force of the wheel to perform stability control, and then considers the lateral force control; real-time observation is carried out through a slip rate module, the slip rate is taken as a control target, an integrated control factor is obtained through fuzzy control, the use proportion of AFS and DYC is further controlled, and a final additional yaw moment and an additional front wheel corner are further obtained; the torque distribution module takes the torque as input, outputs the torques of four tires in a dynamic load mode, inputs the torques into a seven-degree-of-freedom whole vehicle model to form a closed loop, and achieves the aim of controlling the stability of the vehicle under the combined action of an additional front wheel corner.
Further, the four-wheel drive seven-degree-of-freedom vehicle model is as follows:
Figure BDA0003657456010000031
Figure BDA0003657456010000032
Figure BDA0003657456010000033
wherein M is the mass of the whole vehicle;
Figure BDA0003657456010000034
longitudinal acceleration and lateral acceleration of the vehicle, respectively; omega z Is the yaw rate of the vehicle; i is z Is the moment of inertia of the vehicle about the z-axis; l is f ，L r The distances from the center of mass of the vehicle to the front axle and the rear axle, respectively; a. the f ，A r The wheel base of the front wheel and the wheel base of the rear wheel are respectively; alpha is alpha 1 ，α 2 ，α 3 ，α 4 The slip angles of the four tires respectively; delta f Is a front wheel corner; gamma is the yaw velocity of the vehicle; v. of x Is the longitudinal speed of the vehicle; v. of y Is the lateral speed of the vehicle; f x_i ，F y_i The longitudinal force and the lateral force applied to the tire are respectively represented by i-1, 2,3 and 4, which respectively represent a left front wheel, a right front wheel, a left rear wheel and a right rear wheel.
Further, the two-degree-of-freedom ideal model is as follows:
Figure BDA0003657456010000041
Figure BDA0003657456010000042
wherein k is f ，k r The sum of the cornering stiffness of the two wheels of the front axle and the rear axle respectively; m is the mass of the whole vehicle; omega z_ide An ideal yaw rate; beta is a z_ide Is an ideal centroid slip angle; v. of x Is the longitudinal speed of the vehicle; delta f Is a front wheel corner; l is the distance between the front and rear axes; k is a stability factor and
Figure BDA0003657456010000043
when the vehicle is turning, the tires are limited by the ground adhesion limit to generate limit values, the yaw rate of the vehicle will be limited, and therefore the desired yaw rate will satisfy the following formula;
|ω max |＝a(μg/v x )
wherein a is a safety factor; mu is the road surface adhesion coefficient; omega max Is the maximum yaw rate; g is the acceleration of gravity;
the corrected ideal yaw rate can be obtained finally:
Figure BDA0003657456010000044
wherein L is the distance between the front and rear axes; v. of x Is the longitudinal speed of the vehicle; delta f Is a front wheel corner; k is the stability factor.
Further, the AFS controller is designed as follows:
selecting a constant speed approach law;
Figure BDA0003657456010000045
wherein the content of the first and second substances,
Figure BDA0003657456010000046
is the slip form surface derivative; s is a slip form surface; epsilon is an approximation law constant, and the parameter indicates the speed at which the state point of the system approaches the sliding mode surface;
defining the yaw rate tracking error and its derivative as:
Figure BDA0003657456010000051
e ωz a yaw angular velocity tracking error; omega z The actual yaw rate; omega z_ide Is idealYaw angular velocity; the sliding mode switching surface function is defined as:
Figure BDA0003657456010000052
wherein s is ωz Is a slip form surface; c. C ωz Is a relative weight coefficient between the error and the rate of change of the error, and c ωz >0；
The simplification can obtain:
Figure BDA0003657456010000053
in order to have good state during the system moving to the sliding mode surface, the calculation formula of the additional front wheel steering angle is determined as follows:
Figure BDA0003657456010000054
wherein, K ω The constant is a positive constant for controlling the approaching speed to the sliding mode surface;
to reduce buffeting in sliding mode control, saturation function sat(s) is used ωz ) Instead of the sign function sgn(s) ωz ) In summary, the additional front wheel steering angle Δ δ is:
Figure BDA0003657456010000055
further, the DYC controller is designed as follows:
defining the yaw rate tracking error and its derivative as:
Figure BDA0003657456010000056
the sliding mode switching surface function is defined as:
Figure BDA0003657456010000057
wherein, c ωz Is a relative weight coefficient between the error and the rate of change of the error, and c ωz >0；
Is simplified to obtain
Figure BDA0003657456010000061
In order to have good state during the process that the system moves to the sliding mode surface, the calculation formula of the additional yaw moment is determined as follows:
Figure BDA0003657456010000062
further, the AFS/DYC coordination integrated controller is designed as follows:
this controller passes through the slip rate module to the slip rate is the control target, adopts fuzzy PID controller to acquire integrated control factor, and then controls the proportion of use of AFS and DYC, carries out the switching between AFS and DYC controller in real time, and wherein, slip rate module mathematical model is:
Figure BDA0003657456010000063
wherein λ is i Representing the slip ratio of each wheel; v. of wx_i Speed x of each wheel w An axial component; omega i Representing a rotational angular velocity of each wheel; r w Representing the radius of wheel rotation; wherein λ i The value range is [ -1,1 [)]When lambda is i When the speed is more than or equal to 0, the tire slips; when lambda is i If < 0, the tire slips.
Further, the fuzzy PID controller based on the slip rate is designed as follows:
the fuzzy controller takes the deviation of the slip rate and the change rate of the deviation as input quantities and corrects the parameter delta k p 、Δk i 、Δk d For the output quantity, the parameter K of the PID controller p 、K i 、K d Then there are:
Figure BDA0003657456010000064
wherein k is p '、k i '、k d ' is an initial preset value;
slip rate deviation is in its ambiguity domain [ -1, -0.6, -0.3, 0, 0.3, 0.6, 1]7 fuzzy subsets are defined above [ Negative Big (NB), Negative Middle (NM), Negative Small (NS), zero (Z), Positive Small (PS), Positive Middle (PM), Positive Big (PB)](ii) a The slip rate deviation change rate is in the fuzzy domain [ -6, -4, -2, 0, 2, 4, 6 [ -4 [ -2, 0, 2, 4 [ -6 [ ]]7 fuzzy subsets are defined above [ Negative Big (NB), Negative Middle (NM), Negative Small (NS), zero (Z), Positive Small (PS), Positive Middle (PM), Positive Big (PB)](ii) a Output quantity Deltak p 、Δk i 、Δk d All of the ambiguity domains of [ -6, -4, -2, 0, 2, 4, 6 [ -6 [ ]]The 7 fuzzy subsets defined in their domain of discourse are all [ Negative Big (NB), Negative Middle (NM), Negative Small (NS), zero (Z), Positive Small (PS), Positive Middle (PM), Positive Big (PB)]Fuzzy logic operation is carried out on the fuzzy control by adopting a Mamdani type fuzzy reasoning method, fuzzy is carried out by adopting an area gravity center method, and the expression of the final output quantity u is as follows:
Figure BDA0003657456010000071
wherein u (k) is the output of the controller; w is a i Activating the use degree for the ith fuzzy rule; y is i Is the geometric center.
Further, the torque distribution model is designed as follows:
Figure BDA0003657456010000072
wherein: t is the torque obtained during the speed stable control; r is the rolling radius of the vehicle tire; b is the distance between the tires; Δ M is an additional yaw moment; tau is i (i is 1,2,3,4) indicates the distribution ratio of the front left, front right, rear left, and rear right wheels, respectively.
Further, the driver model is designed as follows:
Figure BDA0003657456010000073
Figure BDA0003657456010000074
wherein, I w Is the moment of inertia; k is the reciprocal of the radius of the tire; r is the tire radius; v is the vehicle speed;
Figure BDA0003657456010000081
is the acceleration; m is the mass of the whole vehicle; t is e Is the driving torque; t is req The torque is expected for the motor; k is a radical of 1 ,k 2 ,k 3 Is a constant; τ is a time constant; g is the acceleration of gravity;
Figure BDA0003657456010000082
is the derivative of the drive torque.
Further, the tire model was designed as follows:
Figure BDA0003657456010000083
wherein alpha is i (i is 1,2,3,4) represents each wheel side slip angle; delta i (i ═ 1,2) represents the front wheel right and left cornering; v. of x_i ，v y_i (i ═ 1,2,3,4) respectively represent the longitudinal speed and lateral speed of the tire in the vehicle coordinate system.
Further, the driving system model is designed as follows:
Figure BDA0003657456010000084
wherein: p is rated power; n is the output rotating speed of the motor; n1 is the highest rotation speed of the motor when the motor works at constant torque; te is constant torque of motorRated torque of time, T i And outputting the torque for the motor.
The invention has the following advantages and beneficial effects:
the innovation of the invention is mainly that the design of the AFS/DYC coordination integrated controller in claim 6 is combined with the slip rate module and the fuzzy controller in claim 7, the controller in claim 6 performs real-time observation through the slip rate module, and the fuzzy PID controller is adopted to obtain the controller integration factor by taking the wheel slip rate as a control target, thereby controlling the use proportion of the AFS and the DYC, realizing real-time switching between the two controllers and ensuring the real-time performance between the controllers. The seven-degree-of-freedom whole vehicle model as claimed in claim 1 comprises vertical load forces of four tires, vertical shaft load transfer has a great influence on the wheel adhesion capability, wheels with large adhesion capability should distribute large driving torque, wheels with small adhesion capability should distribute small driving torque, so that torque distribution by means of dynamic load is adopted in claim 8, thereby effectively preventing wheels from skidding and improving the running stability of the vehicle.
Drawings
FIG. 1 is a diagram of a seven degree-of-freedom model of a complete vehicle according to a preferred embodiment of the present invention;
FIG. 2 is a detailed functional block diagram of the control system of the present invention;
FIG. 3 is a block diagram of the parameter self-tuning fuzzy PID system of the present invention;
FIG. 4 is a graph of input versus output for the fuzzy controller of the present invention;
FIG. 5 is a comparison of yaw rate curves for integrated and non-integrated control modes;
FIG. 6 is a graph comparing lateral displacement curves with and without integrated control;
FIG. 7 is a comparison plot of longitudinal vehicle speed curves with and without integrated control;
FIG. 8 is a graph comparing torque distribution with and without integrated control;
FIG. 9 is a graph comparing slip ratios with and without integrated control.
Detailed Description
The technical solutions in the embodiments of the present invention will be described in detail and clearly in the following with reference to the accompanying drawings. The described embodiments are only some of the embodiments of the present invention.
The technical scheme for solving the technical problems is as follows:
as shown in fig. 1, a fuzzy-sliding mode composite control system of a four-wheel drive AFS/DYC integrated control system includes: the system comprises a driver model, a seven-degree-of-freedom whole vehicle model, a tire model, a driving system model, a two-degree-of-freedom ideal model, a slip rate module, a torque distribution module, an AFS controller, a DYC controller and an AFS/DYC coordination integrated controller. The method comprises the steps of firstly establishing a seven-degree-of-freedom whole vehicle model, a tire model, a driving system model and a driver model, obtaining an ideal yaw rate through the two-degree-of-freedom model, using a difference value and a derivative of the yaw rate output by the whole vehicle model and the ideal yaw rate as input of sliding mode variable structure control, outputting an initial additional front wheel corner by an AFS controller, and outputting an initial additional yaw moment by a DYC controller. The AFS/DYC coordinated integrated controller gives priority to the longitudinal force of the wheels for stability control and gives priority to the lateral force control. And the slip rate module is used for observing in real time, the slip rate is taken as a control target, an integrated control factor is obtained by adopting fuzzy control, the use proportion of the AFS and the DYC is further controlled, and the final additional yaw moment and the additional front wheel turning angle are further obtained. The torque distribution module takes the torque as input, outputs the torques of four tires in a dynamic load mode, inputs the torques into a seven-degree-of-freedom whole vehicle model to form a closed loop, and achieves the aim of controlling the stability of the vehicle under the combined action of an additional front wheel corner.
Further, the four-wheel drive seven-degree-of-freedom vehicle model is as follows:
Figure BDA0003657456010000101
Figure BDA0003657456010000102
Figure BDA0003657456010000103
wherein M is the mass of the whole vehicle; omega z Is the yaw rate of the vehicle; i is z Is the moment of inertia of the vehicle about the z-axis; l is f ，L r The distances from the center of mass of the vehicle to the front axle and the rear axle, respectively; a. the f ，A r The wheel base of the front wheel and the wheel base of the rear wheel are respectively; alpha is alpha 1 ，α 2 ，α 3 ，α 4 The slip angles of the four tires respectively; delta f Is a front wheel corner; gamma is the yaw velocity of the vehicle; v. of x Is the longitudinal speed of the vehicle; v. of y Is the lateral speed of the vehicle; f x_i ，F y_i The longitudinal force and the lateral force applied to the tire are respectively represented by i-1, 2,3 and 4, which respectively represent a left front wheel, a right front wheel, a left rear wheel and a right rear wheel.
Further, the two-degree-of-freedom ideal model is as follows:
Figure BDA0003657456010000104
Figure BDA0003657456010000105
wherein k is f ，k r The sum of the cornering stiffness of the two wheels of the front axle and the rear axle respectively; m is the mass of the whole vehicle; omega z_ide An ideal yaw rate; beta is a z_ide Is an ideal centroid slip angle; v. of x Is the longitudinal speed of the vehicle; delta f Is a front wheel corner; l is the distance between the front and rear axes; k is a stability factor and
Figure BDA0003657456010000111
when the vehicle is turning, the tires are limited by the ground attachment limit to generate a limit value, the yaw rate of the vehicle will be limited, and thus the desired yaw rate will satisfy the following equation.
|ω max |＝a(μg/v x )
Wherein a is a safety factor; mu is the road surface adhesion coefficient; omega max Is the maximum yaw rate; g is the gravitational acceleration.
The corrected ideal yaw rate can be obtained finally:
Figure BDA0003657456010000112
wherein L is the distance between the front and rear shafts; v. of x Is the longitudinal speed of the vehicle; delta f Is a front wheel corner; k is the stability factor.
Further, the AFS controller is designed as follows:
the constant velocity approach law with the advantages of good robustness, strong real-time performance, small computation amount and the like is selected.
Figure BDA0003657456010000113
Wherein epsilon is an approximation law constant, which indicates at what rate the state point of the system approaches the sliding mode surface.
Defining the yaw rate tracking error and its derivative as:
Figure BDA0003657456010000114
the sliding mode switching surface function is defined as:
Figure BDA0003657456010000115
wherein, c ωz Is a relative weight coefficient between the error and the rate of change of the error, and c ωz >0。
The simplification can obtain:
Figure BDA0003657456010000121
in order to have good state during the system moving to the sliding mode surface, the calculation formula of the additional front wheel steering angle is determined as follows:
Figure BDA0003657456010000122
wherein, K ω To control the approach speed to the slip-form face, it is a positive constant.
To reduce buffeting in sliding mode control, saturation function sat(s) is used ωz ) Instead of the sign function sgn(s) ωz ) In summary, the additional front wheel steering angle Δ δ is:
Figure BDA0003657456010000123
further, the DYC controller is designed as follows:
defining the yaw rate tracking error and its derivative as:
Figure BDA0003657456010000124
the sliding mode switching surface function is defined as:
Figure BDA0003657456010000125
wherein, c ωz Is a relative weight coefficient between the error and the rate of change of the error, and c ωz >0。
Is simplified to obtain
Figure BDA0003657456010000126
In order to have good state during the process that the system moves to the sliding mode surface, the calculation formula of the additional yaw moment is determined as follows:
Figure BDA0003657456010000131
further, the AFS/DYC coordination integrated controller is designed as follows:
the controller obtains the integrated control factor by adopting the fuzzy PID controller through the slip rate observation module and taking the slip rate as a control target, further controls the use proportion of the AFS and the DYC, and switches between the AFS controller and the DYC controller in real time. Wherein, the mathematical model of the slip ratio module is as follows:
Figure BDA0003657456010000132
wherein λ is i Representing the slip ratio of each wheel; v. of wx_i Speed x of each wheel w An axial component; omega i Representing a rotational angular velocity of each wheel; r w Representing the radius of wheel rotation; wherein λ i The value range is [ -1,1 [)]When lambda is i When the speed is more than or equal to 0, the tire slips; when lambda is i If < 0, the tire slips.
Further, the fuzzy PID controller based on the slip rate is designed as follows:
the fuzzy controller takes the deviation of the slip rate and the change rate of the deviation as input quantities and corrects the parameter delta k p 、Δk i 、Δk d Is the output quantity. The parameter K of the PID controller p 、K i 、K d Then there are:
Figure BDA0003657456010000133
wherein k is p '、k i '、k d ' is an initial pre-set value.
Slip rate deviation is in its ambiguity domain [ -1, -0.6, -0.3, 0, 0.3, 0.6, 1]The 7 fuzzy subsets [ Negative Big (NB), Negative Middle (NM), Negative Small (NS), zero (Z), Positive Small (PS), Positive Middle (PM), Positive Big (PB) are defined above)]. The slip rate deviation change rate is in the fuzzy domain [ -6, -4, -2, 0, 2, 4, 6 [ -4 [ -2, 0, 2, 4 [ -6 [ ]]7 fuzzy subsets are defined above [ Negative Big (NB), Negative Middle (NM), Negative Small (NS), zero (Z), Positive Small (PS), Positive Middle (PM), Positive Big (PB)]. Output quantity Deltak p 、Δk i 、Δk d All of the ambiguity domains of [ -6, -4, -2, 0, 2, 4, 6 [ -6 [ ]]The 7 fuzzy subsets defined in their domain of discourse are all [ Negative Big (NB), Negative Middle (NM), Negative Small (NS), zero (Z), Positive Small (PS), Positive Middle (PM), Positive Big (PB)]. Fuzzy logic operation is carried out on the fuzzy control by adopting a Mamdani type fuzzy reasoning method, fuzzy is carried out by adopting an area gravity center method, and the expression of the final output u is as follows:
Figure BDA0003657456010000141
wherein u (k) is the output of the controller; w is a i Activating the use degree for the ith fuzzy rule; y is i Is the geometric center. Further, the torque distribution model is designed as follows:
Figure BDA0003657456010000142
wherein: t is the torque obtained during the speed stable control; r is the rolling radius of the vehicle tire; b is the distance between the tires; Δ M is an additional yaw moment; tau is i (i is 1,2,3,4) indicates the distribution ratio of the front left, front right, rear left, and rear right wheels, respectively.
The four-wheel drive seven-degree-of-freedom finished automobile model comprises the following components:
Figure BDA0003657456010000143
Figure BDA0003657456010000144
Figure BDA0003657456010000145
wherein M is the mass of the whole vehicle; omega z Is the yaw rate of the vehicle; I.C. A z Is the moment of inertia of the vehicle about the z-axis; l is f ，L r The distances from the center of mass of the vehicle to the front axle and the rear axle, respectively; a. the f ，A r The wheel base of the front wheel and the wheel base of the rear wheel are respectively; alpha is alpha 1 ，α 2 ，α 3 ，α 4 The slip angles of the four tires respectively; delta f Is a front wheel corner; gamma is the yaw velocity of the vehicle; v. of x Is the longitudinal speed of the vehicle; v. of y Is the lateral speed of the vehicle; f x_i ，F y_i The longitudinal force and the lateral force applied to the tire are respectively represented by i-1, 2,3 and 4, which respectively represent a left front wheel, a right front wheel, a left rear wheel and a right rear wheel.
FIG. 1 is a seven-degree-of-freedom model diagram of a whole vehicle, FIG. 2 is a detailed schematic block diagram of a control system of the invention, and according to the two drawings, it is easy to know,
the implementation comprises the following steps:
1) establishing a seven-degree-of-freedom steering dynamics model;
2) obtaining an ideal yaw angular velocity through a two-degree-of-freedom model;
3) the difference value and the derivative of the yaw velocity output by the whole vehicle model and the ideal yaw velocity are used as the input of the sliding mode variable structure control;
4) the AFS controller takes the difference value of the yaw rates in the step 3 as input and outputs the input as an initial additional front wheel corner; the DYC controller takes the difference value of the yaw rates in the step 3 as input and outputs an initial additional yaw moment;
5) by a slip rate observation module, taking the slip rate as a control target, acquiring an integrated control factor by adopting fuzzy control, and controlling the use proportion of an AFS controller and a DYC controller so as to further obtain a final additional yaw moment and an additional front wheel corner;
6) and (5) outputting the torques of the four tires by adopting a dynamic load mode by using the step 5 as input by the torque distribution module, and inputting the torques into a seven-degree-of-freedom finished automobile model to form a closed loop.
FIG. 3 is a diagram of a parameter self-tuning fuzzy PID system structure of the invention, FIG. 4 is a diagram of the relationship between the input and the output of the fuzzy controller of the invention, and the fuzzy PID controller based on slip rate is designed as follows:
the fuzzy controller takes the deviation of the slip rate and the change rate of the deviation as input quantities and corrects the parameter delta k p 、Δk i 、Δk d Is the output quantity. The parameter K of the PID controller p 、K i 、K d Then there are:
Figure BDA0003657456010000151
wherein k is p '、k i '、k d ' is an initial pre-set value.
Fuzzy logic operation is carried out on the fuzzy control by adopting a Mamdani type fuzzy reasoning method, fuzzy is carried out by adopting an area gravity center method, and the expression of the final output u is as follows:
Figure BDA0003657456010000161
wherein u (k) is the output of the controller; w is a i Activating the use degree for the ith fuzzy rule; y is i Is the geometric center.
FIG. 5 is a comparison graph of a yaw rate curve under the integrated control mode and the non-integrated control mode, FIG. 6 is a comparison graph of a lateral displacement curve under the integrated control mode and the non-integrated control mode, and FIG. 7 is a comparison graph of a longitudinal vehicle speed curve under the integrated control mode and the non-integrated control mode.
FIG. 8 is a graph comparing torque distribution curves for integrated control and for non-integrated control. FIG. 9 is a graph comparing slip ratio curves in an integrated control mode and a non-integrated control mode, and comparing the fuzzy-sliding mode composite control method of the four-wheel drive AFS/DYC integrated control system with the non-integrated control system, it can be known that compared with the non-integrated control method, the slip ratio and torque distribution control system actively distributes the driving force of front and rear axle wheels in real time according to the steering driving trend of the vehicle, so as to meet the requirement of the vehicle on stable driving and improve the transverse stability of the vehicle in high-speed driving.
The systems, devices, modules or units illustrated in the above embodiments may be implemented by a computer chip or an entity, or by a product with certain functions. One typical implementation device is a computer. In particular, the computer may be, for example, a personal computer, a laptop computer, a cellular telephone, a camera phone, a smartphone, a personal digital assistant, a media player, a navigation device, an email device, a game console, a tablet computer, a wearable device, or a combination of any of these devices.
It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises the element.
The above examples are to be construed as merely illustrative and not limitative of the remainder of the disclosure. After reading the description of the invention, the skilled person can make various changes or modifications to the invention, and these equivalent changes and modifications also fall into the scope of the invention defined by the claims.

Claims (8)

1. A fuzzy-sliding mode composite control system of a four-wheel drive AFS/DYC integrated control system is characterized by comprising: the system comprises a driver model, a seven-degree-of-freedom whole vehicle model, a tire model, a driving system model, a two-degree-of-freedom ideal model, a slip rate module, a torque distribution module, an AFS active front wheel steering controller, a DYC direct yaw moment controller and an AFS/DYC coordination integrated controller; the system comprises a driver model, a seven-degree-of-freedom whole vehicle model, a tire model, a driving system model, a two-degree-of-freedom ideal model, a slip rate module, a torque distribution module, an AFS controller, a DYC controller and an AFS/DYC coordination integrated controller, wherein the driver model is used for following a vehicle speed and outputting a driving torque at the current speed, the seven-degree-of-freedom whole vehicle model is used for analyzing longitudinal, lateral and yaw motions of the vehicle, the tire model is used for calculating a slip angle and a wheel slip rate of wheels, the driving system model is used for outputting a motor characteristic curve, the two-degree-of-freedom ideal model is used for obtaining a yaw rate and a mass center slip angle under an ideal state, the slip rate module is used for obtaining the slip rate of each wheel under a driving state, the torque distribution module is used for distributing the driving force and an additional yaw moment to each wheel, the AFS controller is used for obtaining a stable additional front wheel angle, the DYC controller is used for distributing weights of each controller;
obtaining an ideal yaw rate through a two-degree-of-freedom model, taking the difference value and the derivative of the yaw rate output by a whole vehicle model and the ideal yaw rate as the input of the sliding mode variable structure control, outputting an initial additional front wheel corner by an AFS controller, and outputting an initial additional yaw moment by a DYC controller; the AFS/DYC coordination integrated controller preferentially considers the longitudinal force of the wheel to perform stability control, and then considers the lateral force control; real-time observation is carried out through a slip rate module, the slip rate is taken as a control target, an integrated control factor is obtained through fuzzy control, the use proportion of AFS and DYC is further controlled, and a final additional yaw moment and an additional front wheel corner are further obtained; the torque distribution module takes the torque as input, outputs the torques of four tires in a dynamic load mode, inputs the torques into a seven-degree-of-freedom whole vehicle model to form a closed loop, and achieves the aim of controlling the stability of the vehicle under the combined action of an additional front wheel corner.
2. The fuzzy-sliding mode composite control system of the four-wheel drive AFS/DYC integrated control system as claimed in claim 1, wherein the seven-degree-of-freedom vehicle model of the four-wheel drive is:
Figure FDA0003657455000000011
Figure FDA0003657455000000012
Figure FDA0003657455000000021
wherein M is the mass of the whole vehicle;
Figure FDA0003657455000000022
longitudinal acceleration and lateral acceleration of the vehicle, respectively; omega z Is the yaw rate of the vehicle; i is z Is the moment of inertia of the vehicle about the z-axis; l is f ，L r The distances from the center of mass of the vehicle to the front axle and the rear axle, respectively; a. the f ，A r The wheel base of the front wheel and the wheel base of the rear wheel are respectively; alpha is alpha 1 ，α 2 ，α 3 ，α 4 The slip angles of the four tires respectively; delta f Is a front wheel corner; gamma is the yaw velocity of the vehicle; v. of x Is the longitudinal speed of the vehicle; v. of y Is the lateral speed of the vehicle; f x_i ，F y_i The longitudinal force and the lateral force applied to the tire are respectively represented by iq1, 2,3 and 4, which respectively represent a left front wheel, a right front wheel, a left rear wheel and a right rear wheel.
3. The fuzzy-sliding mode composite control system of the four-wheel drive AFS/DYC integrated control system as claimed in claim 2, wherein said two-degree-of-freedom ideal model is:
Figure FDA0003657455000000023
Figure FDA0003657455000000024
wherein k is f ，k r The sum of the cornering stiffness of the two wheels of the front axle and the rear axle respectively; m is the mass of the whole vehicle; omega z_ide An ideal yaw rate; beta is a beta z_ide Is an ideal centroid slip angle; v. of x Is the longitudinal speed of the vehicle; delta f Is a front wheel corner; l is the distance between the front and rear axes; k is a stability factor and
Figure FDA0003657455000000025
when the vehicle is turning, the tires are limited by the ground adhesion limit to generate limit values, the yaw rate of the vehicle will be limited, and therefore the desired yaw rate will satisfy the following formula;
|ω max |＝a(μg/v x )
wherein a is a safety factor; mu is the road surface adhesion coefficient; omega max Is the maximum yaw rate; g is gravity acceleration;
the corrected ideal yaw rate can be obtained finally:
Figure FDA0003657455000000031
wherein L is the distance between the front and rear shafts; v. of x Is the longitudinal speed of the vehicle; delta f Is a front wheel corner; k is the stability factor.
4. The fuzzy-sliding mode composite control system of the four-wheel drive AFS/DYC integrated control system as claimed in claim 3, wherein said AFS controller is designed as follows:
selecting a constant velocity approach law;
Figure FDA0003657455000000032
wherein the content of the first and second substances,
Figure FDA0003657455000000033
is the slip form surface derivative; s is a slip form surface; epsilon is an approximation law constant, and the parameter indicates the speed at which the state point of the system approaches the sliding mode surface;
defining the yaw rate tracking error and its derivative as:
Figure FDA0003657455000000034
e ωz a yaw angular velocity tracking error; omega z The actual yaw rate; omega z_ide An ideal yaw rate;
the sliding mode switching surface function is defined as:
Figure FDA0003657455000000035
wherein s is ωz Is a slip form surface; c. C ωz Is a relative weight coefficient between the error and the rate of change of the error, and c ωz >0；
The simplification can obtain:
Figure FDA0003657455000000036
in order to have good state during the system moving to the sliding mode surface, the calculation formula of the additional front wheel steering angle is determined as follows:
Figure FDA0003657455000000037
wherein, K ω The constant is a positive constant for controlling the approaching speed to the sliding mode surface;
to reduce jitter in sliding mode controlVibration phenomena, using saturation function sat(s) ωz ) Instead of the sign function sgn(s) ωz ) In summary, the additional front wheel steering angle Δ δ is:
Figure FDA0003657455000000041
5. the fuzzy-sliding mode composite control system of four-wheel drive AFS/DYC integrated control system as claimed in claim 4, wherein said DYC controller is designed as follows:
defining the yaw rate tracking error and its derivative as:
Figure FDA0003657455000000042
the sliding mode switching surface function is defined as:
Figure FDA0003657455000000043
wherein, c ωz Is a relative weight coefficient between the error and the rate of change of the error, and c ωz >0；
Is simplified to obtain
Figure FDA0003657455000000044
In order to have good state during the process that the system moves to the sliding mode surface, the calculation formula of the additional yaw moment is determined as follows:
Figure FDA0003657455000000045
6. the fuzzy-sliding mode composite control system of four-wheel drive AFS/DYC integrated control system as claimed in claim 5, wherein said AFS/DYC coordinated integrated controller is designed as follows:
this controller passes through the slip rate module to the slip rate is the control target, adopts fuzzy PID controller to acquire integrated control factor, and then controls the proportion of use of AFS and DYC, carries out the switching between AFS and DYC controller in real time, and wherein, slip rate module mathematical model is:
Figure FDA0003657455000000051
wherein λ is i Representing the slip ratio of each wheel; v. of wx_i Speed x of each wheel w An axial component; omega i Representing a rotational angular velocity of each wheel; r w Representing the radius of wheel rotation; wherein λ is i The value range is [ -1,1 [)]When lambda is i When the speed is more than or equal to 0, the tire slips; when lambda is i If < 0, the tire slips.
7. The fuzzy-sliding mode composite control system of the four-wheel drive AFS/DYC integrated control system as claimed in claim 6, wherein the fuzzy PID controller based on slip rate is designed as follows:
the fuzzy controller takes the deviation of the slip rate and the change rate of the deviation as input quantities and corrects the parameter delta k p 、Δk i 、Δk d For the output quantity, the parameter K of the PID controller p 、K i 、K d Then there are:
Figure FDA0003657455000000052
wherein k is p '、k i '、k d ' is an initial preset value;
slip rate deviation is in its ambiguity domain [ -1, -0.6, -0.3, 0, 0.3, 0.6, 1]7 fuzzy subsets are defined above [ Negative Big (NB), Negative Middle (NM), Negative Small (NS), zero (Z), Positive Small (PS), Positive Middle (PM), Positive Big (PB)](ii) a Slip rate deviation rate of changeIn its fuzzy domain [ -6, -4, -2, 0, 2, 4, 6]7 fuzzy subsets are defined above [ Negative Big (NB), Negative Middle (NM), Negative Small (NS), zero (Z), Positive Small (PS), Positive Middle (PM), Positive Big (PB)](ii) a Output quantity Deltak p 、Δk i 、Δk d All of the ambiguity domains of [ -6, -4, -2, 0, 2, 4, 6 [ -6 [ ]]The 7 fuzzy subsets defined in their domain of discourse are all [ Negative Big (NB), Negative Middle (NM), Negative Small (NS), zero (Z), Positive Small (PS), Positive Middle (PM), Positive Big (PB)]Fuzzy logic operation is carried out on the fuzzy control by adopting a Mamdani type fuzzy reasoning method, fuzzy is carried out by adopting an area gravity center method, and the expression of the final output quantity u is as follows:
Figure FDA0003657455000000053
wherein u (k) is the output of the controller; w is a i Activating the use degree for the ith fuzzy rule; y is i Is the geometric center.
8. The fuzzy-sliding mode composite control system of the four-wheel drive AFS/DYC integrated control system as claimed in claim 7, wherein the torque distribution model is designed as follows:
Figure FDA0003657455000000061
wherein: t is the torque obtained during the speed stable control; r is the rolling radius of the vehicle tire; b is the distance between the tires; Δ M is an additional yaw moment; tau is i (i is 1,2,3,4) indicates the distribution ratio of the front left, front right, rear left, and rear right wheels, respectively.
CN202210564747.4A 2022-05-23 2022-05-23 Fuzzy-sliding mode composite control system of four-wheel drive AFS/DYC integrated control system Pending CN114801781A (en)

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* Cited by examiner, † Cited by third party
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CN117445698A (en) * 2023-12-13 2024-01-26 广西大学 Electric automobile torque distribution layered control system and method driven by hub motor

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN117445698A (en) * 2023-12-13 2024-01-26 广西大学 Electric automobile torque distribution layered control system and method driven by hub motor
CN117445698B (en) * 2023-12-13 2024-04-23 广西大学 Layered control method for torque distribution of electric automobile driven by hub motor

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