Coordination control of active front steering and direct yaw moment control based on stability judgment for AVs stability enhancement

Author(s):  
Xinxin Yao ◽  
Xianguang Gu ◽  
Ping Jiang

A coordination control strategy based on stability judgment is presented for autonomous vehicles (AVs) aiming to enhance the handling and stability performance. Firstly, the stability judgment scheme is used to evaluate the real-time stability level of vehicles based on the Self-Organizing Feature Map (SOFM) neural network and K-Means algorithm. Secondly, a coordination controller of active front steering (AFS) and direct yaw moment control (DYC) is designed to track the desired vehicle motion. To enhance the handling and stability of AVs, the weights of AFS and DYC controllers are adaptively adjusted according to the vehicle stability level. Finally, the effectiveness of the proposed method is verified in co-simulation environment of CarSim and Simulink, and a rapid control prototyping test is implemented to evaluate the feasibility and robustness. The results indicate that the stability judgment scheme and coordination control strategy for AVs can not only satisfy the requirements of path tracking accuracy but also enhance the handling and stability performance.

2001 ◽  
Author(s):  
M. A. Selby ◽  
W. J. Manning ◽  
M. D. Brown ◽  
D. A. Crolla

Abstract This paper studies the benefits of coordinating stability and steerability controllers to reduce vehicle deceleration during limit handling situations. The stability controller, DYC, uses the vehicle brakes to apply a restoring moment when the vehicle sideslip angle and sideslip velocity exceed fixed bounds. This use of the brakes interferes with the longitudinal dynamics of the vehicle in a way that drivers find undesirable. Active front steering (AFS) and active rear steering(ARS) can be used to tune the vehicle handling balance in the low to mid-range lateral-acceleration regime. Earlier work has shown that the use of AFS can reduce the interference observed using DYC alone. The levels of improvement achievable by coordinating AFS and ARS with DYC are quantified using open loop handling simulations tests by predicting the deceleration of the vehicle in an extreme manoeuvre. The results from these simulations are compared to assess the relative benefits of AFS and ARS when coordinated with DYC. The computer simulations are based on a four-degree of freedom vehicle model incorporating longitudinal, lateral, yaw, roll, and load transfer effects.


2018 ◽  
Vol 41 (9) ◽  
pp. 2428-2440 ◽  
Author(s):  
Jiaxu Zhang ◽  
Jing Li

This paper presents an integrated vehicle chassis control (IVCC) strategy to improve vehicle handling and stability by coordinating active front steering (AFS) and direct yaw moment control (DYC) in a hierarchical way. In high-level control, the corrective yaw moment is calculated by the fast terminal sliding mode control (FTSMC) method, which may improve the transient response of the system, and a non-linear disturbance observer (NDO) is used to estimate and compensate for the model uncertainty and external disturbance to suppress the chattering of FTSMC. In low-level control, the null-space-based control reallocation method and inverse tyre model are utilized to transform the corrective yaw moment to the desired longitudinal slips and the steer angle increment of front wheels by considering the constraints of actuators and friction ellipse of each wheel. Finally, the performance of the proposed control strategy is verified through simulations of various manoeuvres based on vehicle dynamic software CarSim.


Author(s):  
Jiaxing Yu ◽  
Xiaofei Pei ◽  
Xuexun Guo ◽  
JianGuo Lin ◽  
Maolin Zhu

This paper proposes a framework for path tracking under additive disturbance when a vehicle travels at high speed or on low-friction road. A decoupling control strategy is adopted, which is made up of robust model predictive control and the stability control combining preview G-vectoring control and direct yaw moment control. A vehicle-road model is adopted for robust model predictive control, and a robust positively invariant set calculated online ensures state constraints in the presence of disturbances. Preview G-vectoring control in stability control generates deceleration and acceleration based on lateral jerk, later acceleration, and curvature at preview point when a vehicle travels through a cornering. Direct yaw moment control with additional activating conditions provides an external yaw moment to stabilize lateral motion and enhances tracking performance. A comparative analysis of stability performance of stability control is presented in simulations, and furthermore, many disturbances are considered, such as varying wind, road friction, and bounded state disturbances from motion planning and decision making. Simulation results show that the stability control combining preview G-vectoring control and direct yaw moment control with additional activating conditions not only guarantees lateral stability but also improves tracking performance, and robust model predictive control endows the overall control system with robustness.


Energies ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 3339 ◽  
Author(s):  
Zhao ◽  
Lu ◽  
Zhang

A Stackelberg game-based cooperative control strategy is proposed for enhancing the lateral stability of a four-wheel independently driving electric vehicle (FWID-EV). An upper‒lower double-layer hierarchical control structure is adopted for the design of a stability control strategy. The leader‒follower-based Stackelberg game theory (SGT) is introduced to model the interaction between two unequal active chassis control subsystems in the upper layer. In this model, the direct yaw-moment control (DYC) and the active four-wheel steering (AFWS) are treated as the leader and the follower, respectively, based on their natural characteristics. Then, in order to guarantee the efficiency and convergence of the proposed control strategy, a sequential quadratic programming (SQP) algorithm is employed to solve the task allocation problem among the distributed actuators in the lower layer. Also, a double-mode adaptive weight (DMAW)- adjusting mechanism is designed, considering the negative effect of DYC. The results of cosimulation with CarSim and Matlab/Simulink demonstrate that the proposed control strategy can effectively improve the lateral stability by properly coordinating the actions of AFWS and DYC.


2021 ◽  
Vol 118 (4) ◽  
pp. 853-874
Author(s):  
Quan Min ◽  
Min Deng ◽  
Zichen Zheng ◽  
Shu Wang ◽  
Xianyong Gui ◽  
...  

Author(s):  
Ling Yu ◽  
Sunan Yuan

In order to improve the stability and safety of vehicles, it is necessary to control them. In this study, the integrated control method of drive-by-wire independent drive electric vehicle was studied. Firstly, the reference model of electric vehicle was established. Then, an integrated control method of acceleration slip regulation (ARS) and direct yaw moment control (DYC) was designed for controlling the nonlinearity of tyre, and the simulation experiment was carried out under the environment of MATLAB/SIMULINK. The results showed that the vehicle lost its stability when it was uncontrolled; under the control of a single DYC controller, r and β values got some control, but the vehicle stability was still low; under the integrated control of ARS+DYC, the vehicle stability was significantly improved; under the integrated control method, the overshoot, regulation time and steady-state error of the system were all small. Under the simulation of extreme conditions, the integrated control method also showed excellent performance, which suggested the method was reliable. The experimental results suggests the effectiveness of the integrated control method, which makes some contributions to the further research of the integrated control of electric vehicles.


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