CN-122009184-A - Cooperative control method and system for torque and rotation speed of automobile with intelligent chassis architecture

CN122009184ACN 122009184 ACN122009184 ACN 122009184ACN-122009184-A

Abstract

The invention discloses an automobile torque and rotating speed cooperative control method and system of an intelligent chassis framework, wherein a layered control strategy is adopted, and the method comprises the specific steps of firstly establishing a vehicle dynamics model and a PMSM mathematical model, constructing an MPC track tracking model based on the vehicle dynamics model by an upper layer, predicting time domain to adjust along with the speed and the curvature of a road, calculating an additional yaw moment, combining with a minimum tire load rate target to complete torque distribution, and adopting a non-singular rapid terminal sliding mode to control a design rotating speed controller to track a reference rotating speed based on the PMSM mathematical model by a lower layer, utilizing a high-order rapid terminal sliding mode to control a design load observer to estimate external load torque and feed back, and adopting a rotating speed proportion synchronous controller to synthesize rotating speed deviation and compensate, so that the rotating speed comparison of all wheels is realized. According to the intelligent chassis framework automobile track tracking method, the track tracking precision and the running stability of the intelligent chassis framework automobile are effectively improved through cooperative control of the torque and the rotating speed, the control robustness is high, and the intelligent chassis framework automobile track tracking method is suitable for various working conditions.

Inventors

HE ZHICHENG
WU GUANGFEI
CHEN XIANGJING
CAO WENLIANG
ZHOU ENLIN
HUANG YUANYI
CHEN DANHUA

Assignees

湖南大学

Dates

Publication Date: 20260512
Application Date: 20260409

Claims (10)

1. The intelligent chassis architecture automobile torque and rotation speed cooperative control method is characterized by comprising the following steps of: Establishing a voltage equation and a motor mechanical motion equation of the PMSM under a synchronous rotation coordinate system to form a PMSM mathematical model; based on the vehicle dynamics model, a track tracking model is constructed by taking the front wheel steering angle as a control quantity, and the output of the track tracking model in a prediction time domain is calculated by an MPC controller, wherein the prediction time domain is based on the speed and the road curvature regulation change; The method comprises the steps of designing a rotating speed controller based on a PMSM mathematical model, tracking a reference rotating speed through nonsingular rapid terminal sliding mode control, designing a load observer, realizing estimating external load torque based on high-order rapid terminal sliding mode control, feeding back to the rotating speed controller, designing a rotating speed proportion synchronous controller, integrating rotating speed deviation of each vehicle, calculating synchronous compensation, adjusting rotating speed of each wheel and realizing proportion synchronization of rotating speed of each wheel.
2. The method for cooperatively controlling the torque and the rotation speed of an automobile with an intelligent chassis architecture according to claim 1, wherein, The dynamic adjustment of the prediction time domain is realized by adopting a two-dimensional Gaussian function, and is expressed as follows: ; Wherein Np represents a prediction time domain, A represents a prediction time domain upper limit, V represents a real-time vehicle speed, V max represents a vehicle speed upper limit, sigma 1 represents a vehicle speed influence factor, sigma 2 represents a road curvature influence factor, and MRC represents road curvature within a pre-aiming distance.
3. The method for cooperatively controlling the torque and the rotation speed of an automobile with an intelligent chassis architecture according to claim 1, wherein, The final additional yaw moment is fused based on beta- The linear weighting method of the phase diagram stability criterion is expressed as follows: ; Where Δm ωz represents an additional yaw moment corresponding to the yaw-rate deviation, Δm βz represents an additional yaw moment corresponding to the centroid-side-angle deviation, and p represents a weight coefficient.
4. The method for cooperatively controlling the torque and the rotation speed of an automobile with an intelligent chassis architecture according to claim 1, wherein, The sliding mode surface of the nonsingular rapid terminal sliding mode control is expressed as: ; Wherein k 1 、k 2 is a positive constant, alpha 1 and beta 1 represent slip-form plane parameters, 1< alpha 1 <2,1<β 1 <2 and alpha 1 >β 1 , sgn represents a sign function; Omega r is the reference rotational speed, and, Is the actual mechanical angular velocity of the motor; Is an intermediate state quantity.
5. The method for cooperatively controlling the torque and the rotation speed of an automobile with an intelligent chassis architecture according to claim 1, wherein, The load observer regards the load torque as a system expansion state, and the constructed error state equation is expressed as: ; Wherein, the Representing a rotational speed estimation error; Representing torque estimation error, J being the motor moment of inertia, H being the observer control law, W being the equivalent load torque derivative, c representing the derivative of load torque.
6. The method for cooperatively controlling the torque and the rotation speed of an automobile with an intelligent chassis architecture according to claim 1, wherein, The rotation speed proportion synchronous controller comprises a proportion synchronous coefficient which is used for controlling the rotation speed proportion synchronization of each driving wheel, wherein the proportion synchronous coefficient is defined as the ratio of the reference rotation speed of each driving wheel to the running rotation speed of the vehicle, and is expressed as: ; Wherein, the Representing a reference rotational speed of an ith shaft jth wheel; in the form of a vehicle, expressed as: ; Wherein, the Represents the longitudinal vehicle speed, The turning radius is indicated as such, The wheel base is indicated by the number of wheel bases, Indicating the front wheel rotation angle; the rotational speed proportion synchronous controller compensates the control quantity of each corresponding hub motor through the synchronous error compensation controller, and is expressed as: ; Wherein, the Representing the corresponding scale-synchronization coefficient(s), And Representing the moment of inertia of the corresponding in-wheel motor, And Indicating the actual rotational speed of the corresponding in-wheel motor, Respectively representing the corresponding driving wheels.
7. The method for cooperatively controlling the torque and the rotation speed of an automobile with an intelligent chassis architecture according to claim 1, wherein, The torque distribution is constructed as an optimization problem with constraints, and the objective function is expressed as: ; Wherein, the Indicating the longitudinal force of the ith wheel, Indicating the vertical force of the ith wheel, Represents the road adhesion coefficient; The constraint conditions comprise total driving moment constraint, additional yaw moment constraint and motor torque constraint; Wherein the total drive torque constraint is expressed as: ; the additional yaw moment constraint is expressed as: ; Wherein, the 、、、 Longitudinal forces respectively representing the right front wheel, the left rear wheel and the right rear wheel; 、、、 The rotation angles of the right front wheel, the left rear wheel and the right rear wheel are respectively represented; representing the final additional yaw moment; The motor torque constraints are expressed as: ; wherein, the expression is T i which represents the torque of each wheel, r represents the rolling radius of the wheel, Indicating the desired longitudinal drive torque, Indicating the corresponding maximum torque of the motor, Denoted as the lateral force of the ith wheel.
8. The method for cooperatively controlling the torque and the rotation speed of an automobile with an intelligent chassis architecture according to claim 1, wherein, The track tracking model adopts linear discrete processing, and is expressed as: ; ; Wherein, the Representing control increments, A k representing a state matrix, B k representing an input matrix, C k representing an output matrix, d k representing model error compensation generated by a sampling period; Representing the output.
9. The method for cooperatively controlling the torque and the rotation speed of an automobile with an intelligent chassis architecture according to claim 1, wherein, In the rotation speed controller, the nonsingular rapid terminal sliding mode control law is expressed as: ; Wherein, the Representing q-axis reference current; , the reference rotational speed is indicated and, Representing the actual mechanical angular velocity of the motor; is an intermediate state quantity, tan h (#) represents a hyperbolic tangent function, Representing the pole pair number of the motor, Representing the flux linkage of the permanent magnet, Which is indicative of the load torque and, Represents the damping coefficient of the damping device, Indicating the surface of the sliding die and the surface of the sliding die, 、、、、、、 Is a controller parameter.
10. An intelligent chassis architecture automobile torque and rotation speed cooperative control system, configured to implement automobile torque and rotation speed cooperative control by an intelligent chassis architecture automobile torque and rotation speed cooperative control method according to any one of claims 1-9, and comprising: A vehicle dynamics model for describing lateral and longitudinal forces of front and rear tires of an automobile by a linear relationship; the PMSM mathematical model is used for describing a voltage equation and a motor mechanical motion equation of the PMSM under a synchronous rotation coordinate system; the track tracking model is used for calculating the output of the track tracking model in a prediction time domain through the MPC controller; The direct yaw moment control module is used for completing torque distribution of wheels with the aim of minimizing the tire load rate; the angular module rotating speed proportion synchronous controller comprises a rotating speed controller, a load observer and a rotating speed proportion synchronous controller; The rotating speed controller is used for tracking the reference rotating speed through nonsingular quick terminal sliding mode control; The load observer is used for realizing the estimation of external load torque based on the high-order quick terminal sliding mode control and feeding back the external load torque to the rotating speed controller; And the rotating speed proportion synchronous controller is used for integrating the rotating speed deviation of each vehicle, calculating synchronous compensation, adjusting the rotating speed of each wheel and realizing proportion synchronization of the rotating speeds of each wheel.

Description

Cooperative control method and system for torque and rotation speed of automobile with intelligent chassis architecture Technical Field The invention belongs to the technical field of intelligent control of automobiles, and particularly relates to an automobile torque and rotation speed cooperative control method and system of an intelligent chassis architecture. Background The intelligent chassis architecture realizes the modularized reconstruction of the chassis system by integrating the hub motor driving, steering, braking and suspension system with the wheel end assembly, obviously improves the transmission efficiency and expands the chassis performance boundary, and becomes an important development direction of the automobile industry. Meanwhile, the highly integrated design leads to the increase of unsprung mass of the vehicle, further amplifies the interference of road surface unevenness on the movement of wheels, aggravates the dynamic load fluctuation of the wheels and brings serious challenges to the stability control of the vehicle. In addition, compared with the traditional centralized driving architecture, the intelligent chassis architecture automobile has the advantages that the control variable is obviously increased, and is influenced by dynamic change factors such as road adhesion coefficient, load torque, motor parameters and the like, the parameters and the characteristics of each wheel show obvious uncertainty and time variability, and the realization difficulty of high-precision control of the automobile is greatly increased. In the control process of the existing intelligent chassis architecture automobile, the traditional automobile control thought is mostly used, wherein a vehicle dynamics model is taken as a basis, model prediction control MPC is adopted as a track tracking core algorithm, state parameters are acquired in real time through a sensor, a reference track is calculated, an optimal wheel corner instruction is solved by combining a rolling optimization strategy, meanwhile, an additional yaw moment is calculated according to the deviation of an actual yaw rate, a centroid side deflection angle and a reference value by matching a direct yaw moment control method, independent driving and braking capacities of an angle module are utilized, tire load rates are distributed based on an optimization algorithm, and longitudinal forces of all wheels are dynamically adjusted, so that cooperative control of track tracking and yaw stability is realized. However, the existing control method still has obvious defects that a moment control mode is generally adopted, only the distribution of instantaneous driving force can be ensured, but the speed constraint on each driving motor is lacked, and the synchronism of the rotating speeds of all wheels is not fully considered. When the motor parameters, the tire radius, the road surface attachment condition or the load torque are different, the deviation of the wheel rotation speed is easy to occur, the uneven wheel slip rate distribution is caused, the track tracking precision is directly affected, and under the complex working conditions of high-speed running, emergency lane changing or low-attachment road surface turning and the like of a vehicle, the rotation speed dyssynchrony among the wheels can further aggravate the yaw response fluctuation and the lateral instability of the vehicle body, even cause the understeer or oversteer phenomenon, and seriously threaten the running safety of the vehicle. Disclosure of Invention The technical problem to be solved by the invention is to overcome the defect that the intelligent chassis architecture automobile cannot effectively realize the cooperative control of the torque and the rotation speed in the control process in the prior art, so as to provide an intelligent chassis architecture automobile torque and rotation speed cooperative control method and system. A cooperative control method for the torque and the rotation speed of an automobile with an intelligent chassis architecture comprises the following steps: s1.1, building a vehicle dynamics model, and describing lateral force and longitudinal force of front tires and rear tires of an automobile by using a linear relation; s1.2, establishing a voltage equation and a motor mechanical motion equation of the PMSM under a synchronous rotation coordinate system to form a PMSM mathematical model; S2.1, based on the vehicle dynamics model, using a front wheel steering angle as a control quantity, constructing a track tracking model, and calculating the output of the track tracking model in a prediction time domain through an MPC controller, wherein the prediction time domain is based on the speed and the road curvature adjustment change; S2.2, respectively solving corresponding additional yaw moments by taking the expected yaw rate and the expected centroid side deviation angle of the linear two-degree-of-freedom vehicle model as tracking targets,