Yaw Moment Control Method Research Articles

Explicit hybrid MPC for the lateral stabilization of electric vehicle system

This paper presents a hybrid Model Predictive Control (hMPC) approach to improve Electric Vehicle (EV) stability when cornering or in high-risk driving conditions. By using approximations of tire force characteristics, the EV system proposed in this study is considered as a Piecewise Affine (PWA) system which is a class of Hybrid Dynamical Systems (HDSs). First, a hybrid modeling of the studied system is developed within the PWA framework. Then, the synthesis of an explicit hybrid MPC law, based on the integration of the Active Front-wheel Steering control method (AFS) and Direct Yaw moment Control method (DYC), can be established. The purpose of the PWA-MPC is to force the yaw rate and sideslip angle of the EV system to follow the given references to guarantee lateral stability. The calculation of the control laws of this proposed approach is performed offline using multiparametric programming. Finally, this paper investigates the effectiveness of the designed controller by performing a set of simulations to analyze the efficiency and robustness of the proposed approach. A comparative study is addressed in this work to demonstrate the efficiency of the proposed hybrid MPC controller compared to the conventional MPC approach which considers the linear model of the system. Another simulations are carried out to assess the robustness of the proposed control, important disturbances and uncertainties were incorporated such as the change of the additional mass, the change of terrain and the high velocity. The simulation results show that the PWA EV system model with the designed controller is able to ensure lateral stability by keeping the sideslip angle and yaw rate tracking the ideal values.

Yaw Moment Control Based on Brake-by-Wire for Vehicle Stbility

This paper presents a new control strategy for vehicle stability based on brake-by-wire. However, there are few studies in the literature that compare the stability of a vehicle by systematic experimentation with or without controllers. In this paper, the complete experimental procedure is designed, and the experimental results are analyzed in detail. Firstly, the hydraulic model of the brake-by-wire is established based on its structure and working principles, and the yaw moment control method is proposed for the vehicle’s stability. The deviation between the desired values and actual values of the yaw rate and sideslip angle is taken as the input, and the fuzzy controller calculates the additional yaw moment for the vehicle stability. Next, the simulation under different conditions which contain the steering wheel step input, double lane change and turning is conducted, and the yaw rates and sideslip angles with and without stability control are compared, and the effectiveness of the control method is verified. Finally, the turning test is conducted based on brake-by-wire chassis to verify the proposed method. The experimental results show that the yaw rate decreased by 14% and the sideslip angle decreased by 25% when the brake control was applied. Furthermore, the proposed method performed well in improving the stability of the brake-by-wire chassis.

A novel assist-steering method with direct yaw moment for distributed-drive articulated heavy vehicle

This paper presents a novel assist-steering method for distributed-drive articulated heavy vehicles (DAHVs) to reduce its dependency on hydraulic steering method and improve the pressure characteristics of hydraulic struts. The objective is to realise the electrification of steering process for DAHVs, which is the basis of unmanned design with more stable control in the following studies. The theory and purpose of the proposed assist-steering method in this paper distinguishes it from the traditional direct yaw-moment control method or assist-steering methods in the previous studies, which easily produce interference with hydraulic steering method in DAHVs during steering process. In this paper, an accurate vehicle model is developed along with the field test for its satisfactory verification. Meanwhile, with the decoupling analyses of two different effects of steering methods on vehicle steering process, the assist-steering method is developed. In order to show the advantages brought on by this method, a case study is performed and analyzed. The results demonstrate that this proposed method can reduce the pressure of hydraulic steering system to about 41.2% without any changes of steering process, which is limited by the drive ability of wheel-side motor. Moreover, the pressure of inlet chamber in hydraulic struts is always reduced to about 40%–60% without any changes of the pressure in outlet chamber, which can improve the working performance of hydraulic steering system.

車両横加加速度に基づくヨーモーメント制御手法の検討(第4報)実車試験によるダブルレーンチェンジ操作に対する効果検証

車両横加加速度に基づくヨーモーメント制御手法の検討(第4報)実車試験によるダブルレーンチェンジ操作に対する効果検証

Integrated stability control of AFS and DYC for electric vehicle based on non-smooth control

ABSTRACTA controller which ensures the driving stability of a four-wheel-independent-drive electric vehicle (4WID-EV) is designed in this paper. The controller is structurally hierarchically designed. In order to keep the 4WID-EV running steadily, an upper-level controller integrating the active front-wheel steering control method (AFS) and direct yaw moment control method (DYC) is designed to keep the sideslip angle and yaw rate tracking the ideal values. A non-smooth control method is used to improve the closed-loop system's convergence and anti-disturbance performance. The additional yaw moment generated by the upper-level controller is distributed to four driving wheels by the lower-level controller. An optimal control algorithm is used in the lower-level controller to achieve the minimum sum of tire utilisation, and ensure the power performance and driving stability of the 4WID-EV. In order to verify the effectiveness of the designed controller, a simulation model of the stability control system is established based on Carsim-Matlab/Simulink. And the simulation is performed under double lane change road considering the disturbances. The results of the simulation show that the 4WID-EV with the designed controller achieves smaller sideslip angle than sliding-mode control and the actuator chatter is slight. Then the stability and safety of the 4WID-EV are greatly improved.

車両横加加速度に基づくヨーモーメント制御手法の検討（第3 報）

車両横加加速度に基づくヨーモーメント制御手法の検討（第3 報）

Drive system failure control for distributed drive electric vehicles

Aiming at the failure problem of distributed electric drive vehicle, the conventional control strategy of drive system failure is designed according to the characteristics of each wheel torque independent control and the redundant configuration of the power unit. On this basis, combined with the traditional body stability control technology, the direct yaw moment control method is used. The simulation results show that the conventional control method designed of the drive system failure can effectively improve the driving condition of the vehicle. The driving stability of the vehicle is further improved after the direct yaw torque control is applied.

A combined use of adaptive sliding mode control and unscented Kalman filter estimator to improve vehicle yaw stability

In this paper, an adaptive sliding mode controller is proposed to improve the vehicle yaw stability and enhance the lateral motion by direct yaw moment control method using active braking systems. As the longitudinal and lateral velocities of the vehicles as well as many other vehicle dynamics variables cannot be measured in a cost-efficient way, a robust control method combined with a state estimator is required to guarantee the system stability. Furthermore, some parameters such as the tyre–road friction coefficient undergo frequent changes, and the aerodynamics resistance forces are often exerted as a disturbance during the wide driving condition. So, an adaptive sliding mode controller is applied to make vehicle yaw rate to track its reference with robustness against model uncertainties and disturbances and a non-linear estimator based on unscented Kalman filter is used to estimate wheel slip, yaw rate, road friction coefficient, longitudinal and lateral velocities. The estimation algorithm directly uses non-linear equations of the system and does not need the linearization and differentiation. The designed controller, which is insensitive to system uncertainties, offers the adaptive sliding gains to eliminate the precise determination of the bounds of uncertainties. The sliding gain values are determined using a simple adaptation algorithm that does not require extensive computational load. Numerical simulations of various manoeuvres using a non-linear full vehicle model with seven degrees of freedom demonstrate the high effectiveness of the presented controller for improving the vehicle yaw stability and handling performance.

Direct yaw moment control for electric and hybrid vehicles with independent motors

Direct yaw moment control is an effective means to enhance vehicle stability and handling. The majority of the latest direct yaw moment control works employ sliding mode control to generate the target yaw moment. In this paper, a new sliding mode-based direct yaw moment control method is proposed for electric and hybrid vehicles equipped with independent motors. This method employs a novel switching function design to simultaneously track the desired yaw rate and vehicle side-slip. Comparative simulation results show that the proposed method outperforms the conventional direct yaw moment control method in terms of tracking the reference yaw rate, vehicle path and vehicle side-slip in various challenging driving scenarios.

A yaw-moment control method based on a vehicle's lateral jerk information

Previously, a new control concept called ‘G-vectoring control (GVC)’ to improve vehicle agility and stability was developed. GVC is an automatic longitudinal acceleration control method that responds to vehicle lateral jerk caused by the driver's steering manoeuvres. In this paper, a new yaw-moment control method, which generates a stabilising moment during the GVC command and has positive acceleration value and the driver's accelerator pedal input is zero, was proposed. A new hybrid control, which comprises GVC, electric stability control and this new control, was constructed, and it was installed in a test vehicle and tested on a snowy surface. The very high potential for improvement in both agility and stability was confirmed.

Study on Yaw-moment Control Method Based on Vehicle Lateral Jerk Information (Second Report)

Study on Yaw-moment Control Method Based on Vehicle Lateral Jerk Information (Second Report)

Performance enhancement of a sliding mode wheel slip controller by the yaw moment control

A sliding mode wheel slip controller is the subject of this paper. The proposed wheel slip controller was based on a quarter-car model and a friction force observer was applied to ensure the robustness of the controller with respect to the estimation error. It was applied to a non-linear full vehicle model. This controller showed good longitudinal performance in tracking reference slip ratio regardless of modelling errors and disturbances. However, when cornering was combined with braking or there was a yaw moment disturbance due to a μ-split road, it was difficult to achieve the desired performance using this controller. In this case, lateral motion must be considered in maintaining the control of the vehicle. A yaw moment control method using the modified reference yaw rate was investigated. The effectiveness of this control theory was verified through simulations of emergency manoeuvres using a developed non-linear full vehicle Simulink model.

An Advanced Vehicle Control Method using Independent Four-Wheel-Steering System.

This paper describes an advanced vehicle control method using independent four wheel steering system for vehicle handling and stability. At accelerating and at braking on a vehicle cornering, each tire force coefficient of the vehicle is quite different because of load transfer and non-linear characteristics of tire forces. Therefore, 4WS system is not effective for the vehicle control and stability at high lateral acceleration condition. If the tire force coefficient are controlled, it is possible that the vehicle has been more stable at high lateral acceleration cornering evan at critical situation. For the control, there are two kinds of method to control the tire force coefficient, one is direct yaw moment control method with traction and braking force and the other is with independent four wheel steering system. This paper shows the effect of the independent 4WS to the vehicle behavior.