Vehicle Handling Stability Research Articles

A Robust Dynamic Game-Based Control Framework for Integrated Torque Vectoring and Active Front-Wheel Steering System

Distributed drive electric vehicles (DDEVs) eliminate the complex drivetrain. The independently driven in-wheel motors also endow the vehicle with more ability for improving maneuverability. To this end, this paper proposes an integrated control framework of torque vectoring (TV) and active front-wheel steering system (AFS) to ensure the vehicle lateral motion stability performance. First, the polytope method with finite vertices is employed to deal with the system uncertainties and simplify the modeling structure, based on which a distributed model predictive control is adopted to construct a dynamic interactive model between agents. Then, through introducing the game theory, a distributed parallel control scheme is developed to obtain the cooperative strategy of agents. Such a design can also satisfy the modular and scalable requirement for integrated chassis control. To ensure the system asymptotic stability, the terminal input combined with the terminal cost function are treated as the constraints in the game paradigm and then transformed as the linear matrix inequalities. Furthermore, a robust H <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\infty $</tex-math> </inline-formula> compensation method is used to suppress the system disturbance. Finally, the hardware-in-the-loop (HIL) tests are conducted to assess the control performance. The results verify the proposed integrated control scheme is effective to enhance the vehicle handling stability.

Research on left hard shoulder width of super multilane highway based on PTSU operation.

Part-time shoulder use (PTSU) is a traffic strategy that temporarily uses the shoulder as a lane when necessary. Research has shown that, when a hard shoulder is required to set the traffic function, the left hard shoulder is preferable. Super multilane highways are usually equipped with left hard shoulders of sufficient width, but the wide cross-sectional characteristics make it difficult for vehicles to turn into the emergency parking lane to avoid a breakdown or accident in the lane, which is an ideal implementation object of PTSU. In this study, two virtual simulation scenarios for PTSU were created: one with the left hard shoulder open and used as a travel lane, and the other with the left hard shoulder closed and its original function restored. Vehicle driving data were collected through driving simulation experiments to reveal the influence of the left hard shoulder on vehicle handling stability. The optimal width of the left hard shoulder was determined by ANOVA and comparison of the mean and standard deviation. The purpose of this study was to quantify the effect of the width of the left hard shoulder on the driving stability of vehicles in the inside lane under PTSU and determine the ideal shoulder width by comparing the stability parameters of vehicles.

Coordination Control of Active Steering and Direct Yaw Control for the Articulated Steering Vehicle

Lateral stability is vital to vehicle handling stability and traffic safety. It is also a crucial factor for the path-tracking ability of the vehicle in the intelligent transportation system (ITS). Most of the research focuses on vehicles with an Ackerman steering system. The ASV (articulated steering vehicle) has a lower steering radius. Thus, it is widely used in some special vehicles, such as mining and construction vehicles. The ASV has weaker lateral stability than the vehicle with an Ackerman steering system. To improve the stability of an ASV, the nonlinear lateral dynamic model is established and validated by field test. With the lateral dynamic model, the steering characteristic of the ASV is analyzed. Based on the stability criteria analysis, the vehicle sideslip angle and angular velocity phase portrait are chosen as the stability indicator. An integrated AASS (active articulated steering system) DYC (direct yaw control) controller based on the adaptive MPC (model predictive control) method is designed according to the track on the phase plane. The double lane-change and 0.7 Hz sine with dwell maneuver are initiated based on the integrated vehicle dynamic model. The results suggest that the provided controller has a better stability performance than the current antiwindup PID control algorithm. It lays a good foundation for the vehicle safety and path tracking of ASV in the ITS.

Research on steering coordination control strategy for distributed drive electric vehicles

The key problems of the steering system and vehicle handling stability of distributed drive electric vehicles are studied in the paper. According to the performance of the distributed drive electric vehicle, a seven-degree-of-freedom is established to match the parameters with the model of CarSim software. Based on the maneuverability improvement control algorithm of the active front wheel system [Active Front Steering (AFS)]/differential power steering system coupling redundancy between differential drive assist steering (DDAS), a AFS/DDAS system coordination control strategy is formulated to reduce the influence of undesirable cross-pendulum moments on vehicle stability. Through the requirements for vehicle stability, a distributed control strategy for the steering stratification of electric vehicles is developed. In the upper layer, the direct transverse moment controller is designed by the linear quadratic regulator algorithm, and the stability control area is divided into a stable region, a transition region, and an unstable region according to the center-of-mass deviation angle. Then the weights of the three subsystems are determined by judging the control area of the vehicle. The lower controller distributes the additional torque from the final calculation of the upper controller to the driving wheels through an allocation algorithm. Finally, using the CarSim/Simulink simulation platform and the dSPACE hardware-in-the-loop real-time simulation platform, the effectiveness and real-time performance of the steering coordination control strategy are verified by simulation experiments under typical working conditions, such as double shift line, step, and sinusoid.

Relevance analysis of the bushing stiffness of rear multi-link suspension to handling stability and ride comfort of vehicle and optimization research to improve both performances

This study focuses on the relevance of bushing stiffness for E-type multi-link suspension to handling stability and ride comfort of vehicle. The influence of bushing stiffness on suspension performance is illustrated theoretically from the force point of view. The principle of the influence of bushing stiffness on vehicle handling stability and ride comfort is described. In simulation study, the influences of specific bushing stiffness on vehicle handling stability and ride comfort are analyzed. The simulation results show that the bushings stiffness of the upper and lower control arm of the suspension significantly influences vehicle handling stability and the influences are more significant in the low frequency range. The vehicle ride comfort on the random road is mainly influenced by the bushing stiffness of the top mount of shock absorber, and on bump road by the bushing stiffness of the trailing arm mostly. Finally, the NSGA-II and MOPSO algorithms are used to optimize handling stability and ride comfort. The optimization results show that the handling stability and ride comfort of the vehicle could be improved with reasonable adjustment of the bushing stiffness. The results obtained in using the NSGA-II algorithm are more suited to the optimization requirements of this study.

Simulation Analysis Of Vehicle Four-Wheel Steering Control

In order to study the handling stability of four-wheel steering vehicle, the vehicle is simplified into a linear two-degree-of-freedom model. The fuzzy control technology is used to study the proportional feedforward + fuzzy feedback control strategy of four-wheel steering vehicle, and the fuzzy control toolbox in Matlab/Simulink is used to establish the four-wheel steering control system. The simulation results show that the fuzzy control can effectively improve the response of rear wheel steering, improve the maneuverability of the vehicle at low speed, reduce the turning radius, and improve the handling stability of the vehicle at high speed.

Design of compensatory backstepping controller for nonlinear magnetorheological dampers

• A novel magnetorheological fluid damper inverse model is constructed based on the radial basis function neural network. • The filter performance function is employed in the semi-active suspension system as the reference state. • A unified frame is developed to study the semi-active suspension system with various disturbances. The magnetorheological fluid semi-active suspension system has been widely employed in vehicles. In general, the output force of the magnetorheological fluid damper varies with service time and temperature, which will cause the controller performance to degrade or even fail. To conquer this problem, this study proposes a compensatory backstepping strategy for the magnetorheological fluid suspension system. First, the normalized phenomenological model is introduced to simulate the nonlinear characteristics of the magnetorheological fluid damper. Second, the adaptive radial-basis function neural network is employed to construct the inverse model of the magnetorheological fluid damper. Next, the reference state is calculated by the filter performance function to trade off the vehicle handling stability and ride comfort. Finally, the voltage-force compensator is constructed to improve the robustness of the controller under input time delay, external noise disturbance, and actuator failures. Furthermore, the performances of the magnetorheological fluid damper, inverse magnetorheological fluid model, and compensatory backstepping controller are simulated under bump and random excitations. It is found that the proposed compensatory backstepping controller shows good improvement in the semi-active suspension system with time delay, noise disturbance, and actuator failure.

Multiobjective Optimization of Vehicle Handling and Stability Based on ADAMS

In order to improve the steering characteristics, roll characteristics, and lateral characteristics of heavy commercial vehicles, a multiobjective handling stability comprehensive score optimization model (MHSCS optimization model) was proposed in this study. In this study, the main factors affecting the steering characteristics, roll characteristics, and lateral characteristics are determined by combining the road test method and ADAMS software simulation analysis method. Based on the above road tests and ADAMS software simulation analysis, the MHSCS optimization model was proposed with “understeering degree,” “vehicle roll angle”, and “rearward amplification (RWA)” as evaluation indexes, and the response surface method combined with genetic algorithm was used to carry out multiobjective optimization of heavy commercial vehicle. ADAMS simulation results show that the comprehensive improvement degree of steering characteristics, roll characteristics, and lateral characteristics of a heavy commercial vehicle after optimization is 15.26%. Finally, the field road test results show that the scoring error between the comprehensive scoring optimization model and the real vehicle test was controlled at 0.4%, which proves the accuracy of the optimization model established in this study and effectively improves the handling stability of heavy commercial vehicles.

Analysis of the Factors influencing Vehicle Handling Stability through Modelling, Equations and Python

Car handling stability means that the car can drive according to the given direction of the driver through the steering system and steering wheel when the driver does not feel too nervous or fatigue. Besides,when the car subject to external interference (uneven road, side wind, cargo or passenger partial load), it can resist interference and maintain a stable driving performance. This is very important to ensure driving safety and driving comfort. This paper mainly through the establishment of two degrees of freedom model, sets out a system of equations, solves the analysis of the change of each angle of inclination on the influence of manoeuvring stability, selected vehicle speed, used python to analyze the relationship between vehicle speed and angle of inclination, so as to analyze the relationship between the angle of inclination and the return torque and manoeuvring stability, and try to use ADAMS/CAR to form a whole vehicle dynamics model. Through the analysis of the data and results, it is achievable that the whole vehicle multi-body system could be optimized, so that the vehicle's handling stability can be significantly improved.

Hierarchical driving force allocation strategy for 4-WID electric vehicles

Focusing on the driving force distribution control method of four-wheel independent drive electric vehicles, a driving force distribution strategy with a hierarchical structure is proposed in this paper. The upper layer used a neural network to optimize the fuzzy rules and membership function so as to adapt to changes in the process parameters and subjectivity owing to the limitations of the fuzzy control rules acquired by human experience. The lower layer used the optimal distribution method based on rules, focusing on the minimum tire load ratio. The proposed control strategy was verified by Carsim/Simulink co-simulation and a hardware-in-the-loop experiment. The results show that the proposed control strategy can improve the handling stability of vehicles on roads with different levels of adhesion.

Optimization Design for Suspension System Based on Response Surface Method and NCGA Algorithm

For effective and quick selection of hard point coordinate parameters of suspension to improve the handling stability of vehicles, an optimization method was put forward to some certain suspension system by combining the response surface method and NCGA algorithm. A dynamics simulation model was established first to the Macpherson suspension system of some certain mini-van and the sensitivity analysis was carried out to hard point coordinates of the corresponding suspension to find the coordinate parameters whose sensitivities are higher; moreover, an approximate mathematical model was established between the wheel alignment parameters and the selected coordinate parameters in accordance with the response surface method and the corresponding accuracy verification was carried out; and the positioning parameters were grouped rationally and the unified objective function was established by utilizing the direct weighting method; in addition, optimization design was carried out to the established objective function by combining the neighborhood cultivation genetic algorithm (NCGA). Results indicate that the optimized positioning parameter variables are reduced in different degrees so as to further improve the handling stability of vehicles and verify some certain effectiveness of our methods.

Collaborative optimization of bushing installation angle and bushing stiffness of torsion beam suspension to improve the handing stability of the whole vehicle

Both the bushing installation angle and bushing stiffness of torsion beam suspension have important and complex effects on suspension characteristics and vehicle handling stability. For improving the vehicle handling stability by optimizing the two, this paper systematically analyzes the influence mechanism of the bushing installation angle and bushing stiffness of the torsion beam suspension on the suspension C characteristic. The nonlinear relationship between the bushing installation angle and the steady-state characteristics index in the local design space is discussed. The influence mechanism of the bushing installation angle and bushing stiffness on the frequency response characteristics is deeply analyzed, the variation relationship of the frequency characteristic index at the low frequency of 0.5 Hz under different bushing installation angles and bushing stiffnesses is obtained. Finally, the bushing stiffness, which has a great influence on the frequency characteristics, and the bushing installation angle are taken as the optimization variables, and the frequency characteristic index is taken as the optimization goal, and the multi-objective collaborative optimization of the frequency characteristic is carried out with the help of genetic algorithm. From the comparative analysis of transient and steady-state characteristics before and after optimization, it can be seen the vehicle handling stability has been improved.

Real-time Acquisition and Analysis Test Data of Commercial Vehicle Handling Stability Based on LABVIEW Virtual Instrument

Aiming at the problems of complex time-consuming and heavy data processing workload in the field test of commercial vehicle handling stability, a vehicle handling stability test solution based on virtual instrument technology is proposed. This solution is based on the existing test equipment and conditions, using LABVIEW virtual instrument, integrated application of GPS, AHRS and steering force angle tester to form a set of road test system solutions that can realize vehicle handling and stability. The system can meet the requirements of the national standard Controllability and Stability Test Procedure for Automobile (GB / T 6323-2014) to realize the vehicle handling stability test, and the system test is verified by the real vehicle test data, which provides a more efficient and convenient test method for the study of vehicle handling stability test.

Direct Yaw Moment Control with 4WD Torque-Vectoring for Vehicle Handling Stability and Agility

Direct Yaw Moment Control with 4WD Torque-Vectoring for Vehicle Handling Stability and Agility

Distributed Drive Electric Bus Handling Stability Control Based on Lyapunov Theory and Sliding Mode Control

To improve the handling stability of distributed drive electric buses, a vehicle stability control system based on direct yaw moment control (DYC) with a hierarchical control structure was designed. Considering that the vehicle dynamics system is highly nonlinear, a nonlinear controller based on Lyapunov stability theory was designed to calculate the required additional yaw moment of the vehicle in the upper controller. In the lower controller, the additional yaw moment is distributed to four wheel-side motors according to the equal proportion torque distribution method, and the direction of wheel-side motor output torque is determined based on the steering state of the vehicle. A co-simulation based on Simulink and Trucksim was conducted to verify the designed controller under two extreme conditions. Simulation results indicate that the proposed method performs feasibly and effectively in the handling stability of vehicles. Compared with traditional sliding mode control (SMC), the proposed control strategy can significantly reduce the chattering of the system, which provides a theoretical basis for the application of this yaw stability control method in engineering practice.

MPC-Based Integrated Control of Trajectory Tracking and Handling Stability for Intelligent Driving Vehicle Driven by Four Hub Motor

Aiming at the problem of trajectory tracking and handling stability of intelligent four hub-motor independent-drive electric vehicle at high speed, an integrated control strategy based on model predictive control (MPC) is proposed. Firstly, a kinematics preview model is established considering the adaptive change of preview distance with longitudinal vehicle speed. Secondly, combined with the proposed preview model and considering the vehicle dynamic characteristics, an upper level controller of MPC is created to track the lateral deviation, heading angle deviation, sideslip angle and yaw rate to obtain the optimal solution of front wheel angle and additional yaw moment, which realize the control of handling stability while ensuring the trajectory tracking accuracy at same time. Then considering the varying road adhesion and the influence of longitudinal slip at the four tires, a lower level controller composed of torque optimal control and sliding mode controller is designed to realize the optimal torque distribution of four hub motors. Finally, through the co-simulation of MATLAB / Simulink and CarSim and the hardware-in-the-loop experiment, it is verified that the proposed integrated control strategy can effectively improve the path tracking accuracy and ensure the vehicle handling stability at high speed. Compared with the general MPC strategy, who does not control the sideslip angle and yaw rate with no preview model, the cumulative lateral tracking error of the integrated control is reduced by 51.9% and 87.7% respectively.

Driving stability region solving method based on dissipation of energy

In the research of vehicle handling stability, it is important to analyze the vehicle driving stability region based on the driving torque and the front wheel steering angle bifurcation characteristics. Therefore, further simplifying and optimizing the method of solving the vehicle driving stability region is very useful. This paper proposes a new method for solving driving stability region based on dissipation of energy for the first time. This method has clear physical significance, and has a lot of advantages comparing with the classic methods: (1) The dissipation of energy is a quantitative indicator. (2) The calculation equation is simpler, and the calculation process is more intuitive. (3) This method is easier to expand, such as solving the driving stability region for higher degrees of freedom model.

Analysis and optimization of vehicle handling stability with considering front and rear suspension hard point coordinates

For the front double wishbone suspension, starting from the space analytic geometry, a method of describing the movement law of the its is proposed and kinematic analysis is performed, and then the expressions of front wheel alignment parameters are derived by the vector method. Based on the theory of space coordinate transformation, a method of analyzing the kinematics of the five-link suspension is proposed, and the toe angle and camber angle of the rear wheels are derived. The virtual kingpin of the rear suspension is approximated by the instant screw axis method to obtain the expressions of the kingpin alignment parameters. The sensitivity analysis of the impact of the hard point coordinates on the suspension performance indicators is obtained, and the hard point coordinates that are most sensitive to the front and rear suspension performance indicators are obtained. And this is used as the analysis object to explore the influence of the hard point coordinate changes on the wheel alignment parameters. The frequency response index of the vehicle is derived from the vehicle dynamics model, and the change law of the frequency response index of the vehicle in the low and high frequencies is obtained based on swept-sine input simulation. Finally, the sensitivity analysis of the vehicle handling stability is carried out on the hard point coordinates, and the more sensitive hard point coordinates are selected as the optimization variables. The vehicle frequency characteristic index is used as the optimization target, and the NSGA-II algorithm is used for multi-objective optimization. After optimization, the result shows that the handing stability of the vehicle in the low frequency range has been improved.

Research on intervention criterion and stability coordinated control of AFS and DYC

To improve vehicle handling stability, an intervention criterion and a coordinated control method for active front steering (AFS) and direct yaw moment control (DYC) are proposed. First, the intervention criterion of AFS/DYC stability control based on the working state of lateral tyre force is proposed. Next, a 7-DOF (degree-of-freedom) dynamics model is established, and a method for identifying nonlinear pure lateral force model based on onboard sensors and vehicle handling stability experiment is developed. Then, the mapping relationship between lateral tyre force saturation point and wheel angle is constructed to rapidly judge the working state of lateral tire force. Subsequently, a UKF-based state observer, a hierarchical control algorithm and the yaw moment distribution coefficient are designed for the proposed AFS/DYC control system. Finally, a fishhook test and a step input test are carried out on low adhesion coefficient roads to verify the effectiveness of the proposed AFS/DYC coordinated control method.

Evaluation of Vehicle Handling Stability Based on Interval TOPSIS and Entropy Weights

The purpose of this study is to evaluate the handling stability of vehicle from the perspective of users using a multi-criteria decision-making approach with interval numbers. In order to achieve this purpose, the evaluation criteria easy for drivers to understand were constructed based on questionnaire, the interval weights of the criteria were calculated using the entropy weight method with interval numbers, and the interval TOPSIS method was used to evaluate the vehicle handling stability. As the improvement of the method, a new method to determine the crisp value of the interval weight was given, and the relative closeness index used for ranking alternatives was extended to a new additive ranking index. The proposed method was used to evaluate the handling stability of 12 vehicles, and the results may provide some basis for vehicle R & D and design.