Improve Vehicle Lateral Stability Research Articles

Coordinated torque distribution method of distributed drive electric vehicle to reduce control intervention sense

A coordinated torque distribution method (CTDM) combined with balanced torque vectoring distribution method (BTVDM) and differential braking distribution method (DBDM) is proposed to enhance vehicle lateral stability and improve ride comfort. The phase plane of sideslip angle and its angular velocity with three regions are used to evaluate vehicle lateral stability. The models of region boundary parameters considering vehicle velocity, steering angle, and road adhesion coefficient are established on the basis of the nonlinear partial least squares regression model (NLPLSRM). Vehicle lateral stability is dynamically evaluated on the basis of the vehicle state position in the phase plane. The distribution ratio of direct yaw moment (DYM) realised by DBDM and BTVDM is determined in accordance with the instability risk of vehicle lateral stability. Compared with BTVDM and DBDM, the proposed CTDM can correctly realise the accuracy of DYM and reduce vehicle velocity, which is beneficial to improving vehicle lateral stability. Numerical simulation results show that the proposed CTDM substantially improves vehicle lateral stability and reduces control intervention for ride comfort.

Quantized Output Feedback Control of AFS for Electric Vehicles With Transmission Delay and Data Dropouts

This article proposes a robust <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mathcal {H}_\infty $ </tex-math></inline-formula> output feedback control strategy to improve vehicle lateral stability through active front wheel steering with quantization error, transmission delay and data dropouts. Since vehicle lateral dynamics presents inherently uncertain challenges, the polytopic technique is used and the variation of tire cornering stiffness is compensated via norm-bounded uncertainty. Meanwhile, considering that the measurement outputs are inevitably suffer from network-induced constrains, i.e. the quantization error, transmission delay and data dropouts, which degrade the stability and handling performance of vehicle, a robust gain-scheduling <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mathcal {H}_\infty $ </tex-math></inline-formula> output feedback controller design strategy is proposed and the stability conditions are presented in the form of linear matrix inequalities that are derived from Lyapunov asymptotic stability and quadratic <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mathcal {H}_\infty $ </tex-math></inline-formula> performance. Finally, two simulation cases are carried out with MATLAB/Simulink-Carsim to validate the effectiveness of the proposed method.

Variable-Parameter-Dependent Saturated Robust Control for Vehicle Lateral Stability

This article proposes a novel gain-scheduling control method to improve vehicle lateral stability based on a variable-parameter-dependent approach. A time-varying velocity-dependent model to describe the vehicle lateral dynamic characteristics is constructed under cornering stiffness uncertainties and controller saturation. A novel Lyapunov function with variable-parameter-dependent Lyapunov matrix is established to develop the conditions. Using the proposed Lyapunov function, a general condition of the variable-parameter-dependent saturated robust yaw moment controller is provided in terms of time-varying parameter-dependent matrix inequalities. In order to obtain a tractable solution, a condition is further developed with finite linear matrix inequalities. Moreover, an optimal distribution method is adopted to generate the desired yaw moment based on torque allocation. These torques are computed by optimizing the distribution errors and tire workloads. Simulations results under both J-turn and double-lane changing scenarios are used to illustrate the merits of the proposed method. The control synthesis approach is also applicable to other applications involving time-varying parameters.

A Distributed Integrated Control Architecture of AFS and DYC Based on MAS for Distributed Drive Electric Vehicles

Reconstitution of control architecture creates a great challenge for distributed drive electric vehicles (DDEV), due to the emergence of a new distributed driving strategy. To this end, a novel distributed control architecture is proposed in this paper for integrated control of active front steering (AFS) system and direct yaw moment (DYC) system. First, a multi-agent system (MAS) is employed to construct a general framework, where AFS and DYC act as agents that work together to improve vehicle lateral stability and simultaneously reduce workloads of drivers during path tracking. The cooperative control strategies of two agents are obtained through Pareto-optimality theory to ensure optimal control performance of AFS and DYC. Then, on the basis of dynamic interaction between agents, terminal constraints, including terminal cost function and terminal input with local static feedback, are designed to guarantee the asymptotic stability of the close-loop system. Finally, virtual simulations are conducted to evaluate the proposed controller. The results indicate that the proposed control architecture can effectively preserve vehicle stability and reduce workloads of drivers, especially for the inexperienced driver. Furthermore, the hardware-in-loop (HIL) test results also demonstrate the feasibility of the proposed controller.

Lateral stability control of distributed driven electric vehicle based on sliding mode control

Aiming at the lateral stability control problem of distributed driven electric vehicles under high speed steering condition, a hierarchical control algorithm of direct yaw moment is designed. The upper control takes the 2-DOF vehicle model as the reference model and uses the sliding mode control to obtain the required yaw moment by tracking the desired yaw velocity and the desired vehicle side-slip angle. The lower control optimizes the distribution of four wheel torque with the minimum tire utilization rate. Finally, Carsim/Simulink was used for model building and co-simulation, and the control effect of PID algorithm was compared. The results show the hierarchical control algorithm achieves the expected goal of improving vehicle lateral stability.

Improving Vehicle Handling Stability Based on Combined AFS and DYC System via Robust Takagi-Sugeno Fuzzy Control

This paper presents a robust fuzzy $H_{\infty }$ control strategy for improving vehicle lateral stability and handling performance through integration of direct yaw moment control system (DYC) and active front steering. Since vehicle lateral dynamics possesses inherent nonlinearities, the main objective is dedicated to deal with the nonlinear challenge in vehicle lateral dynamics by applying Takagi-Sugeno (T-S) fuzzy modeling approach. First, the nonlinear Brush tire dynamics and the nonlinear functions of longitudinal velocity are represented via a T-S fuzzy modeling technique, and vehicle parametric uncertainties are handled by the norm-bounded uncertainties. An uncertain nonlinear vehicle lateral dynamic T-S fuzzy model is then obtained with multi-fuzzy-rules. The resulting robust fuzzy $H_{\infty }$ state-feedback controller is designed with the parallel-distributed compensation strategy and premise variables, and solved via a set of linear matrix inequalities derived from Lyapunov asymptotic stability and quadratic $H_{\infty }$ performance. Simulations for two different maneuvers are implemented with a high-fidelity, CarSimⓇ, full-vehicle model to verify the effectiveness of the developed approach. It is confirmed from the results that the proposed controller can effectively preserve vehicle lateral stability and enhance yaw handling performance.

Dynamics and Control of a Novel Active Yaw Stabilizer to Enhance Vehicle Lateral Motion Stability

In this paper, a novel active yaw stabilizer (AYS) system is proposed for improving vehicle lateral stability control. The introduced AYS, inspired by the recent in-wheel motor (IWM) technology, has two degrees-of-freedom with independent self-rotating and orbiting movements. The dynamic model of the AYS is first developed. The capability of the AYS is then investigated to show its maximum generation of corrective lateral forces and yaw moments, given a limited vehicle space. Utilizing the high-level Lyapunov-based control design and the low-level control allocation design, a hierarchical control architecture is established to integrate the AYS control with active front steering (AFS) and direct yaw moment control (DYC). To demonstrate the advantages of the AYS, generating corrective lateral force and yaw moment without relying on tire–road interaction, double lane change maneuvers are studied on road with various tire–road friction coefficients. Co-simulation results, integrating CarSim® and MATLAB/Simulink®, successfully verify that the vehicle with the assistance of the AYS system has better lateral dynamics stabilizing performance, compared with cases in which only AFS or DYC is applied.

A LQR-Based Controller with Estimation of Road Bank for Improving Vehicle Lateral and Rollover Stability via Active Suspension.

In this article, a Linear Quadratic Regulator (LQR) lateral stability and rollover controller has been developed including as the main novelty taking into account the road bank angle and using exclusively active suspension for both lateral stability and rollover control. The main problem regarding the road bank is that it cannot be measured by means of on-board sensors. The solution proposed in this article is performing an estimation of this variable using a Kalman filter. In this way, it is possible to distinguish between the road disturbance component and the vehicle’s roll angle. The controller’s effectiveness has been tested by means of simulations carried out in TruckSim, using an experimentally-validated vehicle model. Lateral load transfer, roll angle, yaw rate and sideslip angle have been analyzed in order to quantify the improvements achieved on the behavior of the vehicle. For that purpose, these variables have been compared with the results obtained from both a vehicle that uses passive suspension and a vehicle using a fuzzy logic controller.

Lateral stability control of fully electric vehicles

The problem of vehicle lateral stability control for fully electric vehicles is addressed in this paper using two different approaches. One of them is a novel integrated lateral stability control (ILSC) system and the second one is a regenerative braking based lateral stability control system (RB-LSC). The proposed ILSC system is based on corrective yaw moment calculation, braking torque distribution and electric motor torque reduction. The proposed second method — RB-LSC — is a simpler method than the ILSC system. In this method, electric motor torque is regulated according to the vehicle side slip error and/or the vehicle yaw rate error. The performances of the proposed methods are evaluated under severe road conditions and extreme maneuvers using the commercially available CarSim vehicle dynamics software. The results show that the proposed control systems improve vehicle lateral stability significantly.

The Application of HPWM in Improving Vehicle Lateral Stability

The application of the High-frequency pulse width modulation (HPWM) for improving vehicle lateral stability is investigated in the paper. Firstly, a hydraulic control unit (HCU) combined with a high-speed switching valve (HSV) for controlling hydraulic oil pressure by adjusting duty cycle is presented. Then, a typical control strategy is described based on the application of HPWM. Finally, by using a 15dofs vehicle model, a simulation is carried out to investigate the role of HPWM on improving vehicle lateral stability. The results show that HPWM is capable to control the output pressure of HSV accurately and improve vehicle lateral stability effectively.

Improving Vehicle Lateral Stability Based on Variable Stiffness and Damping Suspension System via MR Damper

The capability of a variable stiffness and damping (VSVD) suspension system via a magnetorheological (MR) damper on improving vehicle lateral stability is investigated in this paper. First, a type of the VSVD suspension system is briefly introduced with the application of variable damping to realize the capability of VSVD. Then, variable damping via the MR damper is extended, and the characteristics of damping force are presented with the Bouc-Wen model. Then, the proposed VSVD system is inserted into a full vehicle model as a front suspension system to control tire normal forces. A control strategy composed of a fuzzy controller that the output is wheel slip ratio and a simple on/off controller to model the application of VSVD is developed to illustrate its ability in improving vehicle stability. It is shown from simulation that VSVD can increase tire normal forces and make vehicles present better performance on lateral stability.

Analyze of Vehicle Active Rollover Control on Air Spring

Based on the working characteristics of air spring, vehicle active rollover control system is studied. First , vehicle rollover forecast algorithm is designed by using the vehicle rollover forecast technique TTR. Then vehicle active rollover control system is designed with air spring inflation/deflation characteristics. Simulation results show that the design of vehicle active rollover control system can predict rollover risk, achieve the timely warning of vehicle rollover, and can adjust the air spring stiffness timely, improve vehicle lateral stability, reduce vehicle rollover accident under the condition of rollover risk.

An optimal traction, braking, and steering coordination strategy for stability and manoeuvrability of a six-wheel drive and six-wheel steer vehicle

This paper describes an optimal traction, braking and steering coordination to improve vehicle lateral stability and manoeuvrability of a six-wheel driving/six-wheel steering (6WD/6WS) vehicle. The optimal coordination controller consists of an upper and lower level controller. The upper level controller determines front, middle steering angle, desired net yaw moment, and longitudinal net force according to the reference velocity and steering angle corresponding to a manual driver. The desired yaw moment is calculated by sliding-mode control theory. Based on the desired longitudinal net force, yaw moment, and tyre force information as inputs from the upper level controller, the lower level controller determines distributed lateral tyre forces and longitudinal tyre force on each wheel in proportion to the size of the friction circle of each wheel. The size of a friction circle is estimated using longitudinal/lateral velocity, yaw rate, wheel torque, and wheel angular velocity. Vehicle–driver–controller closed-loop simulations have been conducted to investigate the improved performance of the proposed optimal coordination controller over a conventional direct yaw moment controller (DYC) of the vehicle equipped with a mechanical drive system.

Robust Yaw Moment Control for Vehicle Handling and Stability

This paper presents a robust controller design method for improving vehicle lateral stability and handling performance. In particular, the practical load variation will be taken into account in the controller synthesis process such that the controller can keep the vehicle lateral stability and handling performance regardless of the load variation. Based on a two-degree-of-freedom (2-DOF) lateral dynamics model, a model-based TakagiSugeno fuzzy control strategy is applied to design such a controller and the sufficient conditions for designing such a controller are given in terms of linear matrix inequalities (LMIs) which can be solved efficiently using currently available numerical software. Numerical simulations are used to validate the effectiveness of the proposed control approach.

Unified Chassis Control for Rollover Prevention and Lateral Stability

This paper describes a unified chassis control (UCC) strategy to prevent vehicle rollover and improve vehicle lateral stability. A rollover index (RI), which indicates impending rollover, and a model-based roll state estimator are introduced to detect potential rollover. An RI/lateral stability-based rollover mitigation (ROM) controller is designed to reduce the danger of rollover without loss of vehicle lateral stability by integrating electronic stability control (ESC) and continuous damping control (CDC). Simulation results indicate that significant improvement in vehicle rollover prevention and lateral stability can be expected from the proposed UCC system.

Vehicle rollover risk and electronic stability control systems

Background:Electronic stability control (ESC) systems were developed to reduce motor vehicle collisions (MVCs) caused by loss of control. Introduced in Europe in 1995 and in the USA in 1996, ESC...

ACTIVE FRONT STEERING DURING BRAKING PROCESS

An active front steering(AFS) intervention control during braking for vehicle stability is presented. Based on the investigation of AFS mechanism, a simplified model of steering system is established and integrated with vehicle model. Then the AFS control on vehicle handling dynamics during braking is designed. Due to the difficulties associated with the sideslip angle measurement of vehicle, a state observer is designed to provide real time estimation. Thereafter, the controller with the feedback of both sideslip and yaw angle is implemented. To evaluate the system control, the proposed AFS controlled vehicle has been tested in the Hardware-in-the-loop-simulation (HILS) system and compared with that of conventional vehicle. Results show that AFS can improve vehicle lateral stability effectively without reducing the braking performance.

The Use of GPS for Vehicle Stability Control Systems

This paper presents a method for using global positioning system (GPS) velocity measurements to improve vehicle lateral stability control systems. GPS can be used to calculate the sideslip angle of a vehicle without knowing the vehicle model. This measurement is combined with other traditional measurements to control the lateral motion of the vehicle. Noise estimates are provided for all measurement systems to allow the sensors to be accurately represented. Additionally, a method to calculate the lateral forces at the tires is presented. It is shown that the tire estimation algorithm performs well outside the linear region of the tire. Results for the controller and force calculations are shown using a nonlinear model to simulate the vehicle and the force calculations are validated with experimental measurements on a test vehicle.