Showing papers on "Vehicle dynamics published in 2000"

Decentralized overlapping control of a platoon of vehicles

Abstract: A methodology is proposed for longitudinal control design of platoons of automotive vehicles within intelligent vehicle/highway systems (IVHSs). The proposed decentralized overlapping control law is obtained by using the inclusion principle, i.e., by decomposing the original system model by an appropriate input/state expansion, and by applying the linear quadratic (LQ) optimization to the locally extracted subsystems. The local quadratic criteria directly reflect the desired system performance. Optimization is carried out by using a sequential algorithm adapted to the lower block triangular (LBT) structure of the closed-loop system model. Contraction to the original space provides a decentralized platoon controller which preserves the asymptotic stability and the steady-state behavior of the controller obtained in the expanded space. Conditions for eliminating the "slinky effect" and obtaining the strict string stability are defined; it is shown that the corresponding constraints on the controller parameters are not too restrictive. A new dynamic platoon controller structure, consisting of a reduced order observer and a static feedback map, is obtained by applying the inclusion principle to the decentralized overlapping platoon control design in the case when the information from the preceding vehicle is missing. Numerous simulation results show that the proposed methodology provides a reliable tool for a systematic and efficient design of platoon controllers within IVHS.

Demonstration of integrated longitudinal and lateral control for the operation of automated vehicles in platoons

Abstract: This paper presents the design and experimental implementation of an integrated longitudinal and lateral control system for the operation of automated vehicles in platoons. The design of the longitudinal control system include nonlinear vehicle dynamics, string-stable operation with very small inter-vehicle spacing, operation at all speeds from a complete stop to high-speed cruising, and the execution of longitudinal split and join maneuvers in the presence of communication constraints. The design of the lateral control system include high-speed operation using a purely "look down" sensor system and lane changing without transitional lateral position measurements. We also describes the design of an on-board supervisor that utilizes inter-vehicle communication and coordinates the operation of the lateral and longitudinal controllers in order to execute entry and exit maneuvers. Experimental results are included from the NAHSC demonstration of automated highways at San Diego, CA.

The Multibody Systems Approach to Vehicle Dynamics

Abstract: Preface Nomenclature Introduction Kinematics and Dynamics of Rigid Bodies Multibody Systems Simulation Software Modelling and Analysis of Suspension Systems Tyre Characteristics and Modelling Modelling and the Assembly of the Full Vehicle Simulation Output and Interpretation Active Systems References Appendix A-C

A Mathematical Model for Driver Steering Control, with Design, Tuning and Performance Results

Abstract: A mathematical model for the steering control of an automobile is described. The structure of the model derives from linear optimal discrete time preview control theory but it is non-linear. Its parameter values are obtained by heuristic methods, using insight gained from the linear optimal control theory. The driver model is joined to a vehicle dynamics model and the path tracking performance is demonstrated, using moderate manoeuvring and racing speeds. The model is shown to be capable of excellent path following and to be robust against changes in the vehicle dynamics. Application to the simulation of manoeuvres specified by an ideal vehicle path and further development of the model to formalise the derivation of its parameter values and to put it to other uses are discussed.

3D path following for autonomous underwater vehicle

Abstract: A new methodology is proposed for the design of path following systems for autonomous underwater vehicles. Global convergence to reference paths is achieved with a nonlinear control strategy that takes explicitly into account the dynamics of the vehicle. Formal convergence proofs are indicated. Simulation results with the model of a prototype autonomous underwater vehicle are presented to illustrate the performance of the path following system derived.

Finding Ultimate Limits of Performance for Hybrid Electric Vehicles

Abstract: Hybrid electric vehicles are seen as a solution to improving fuel economy and reducing pollution emissions from automobiles. By recovering kinetic energy during braking and optimizing the engine operation to reduce fuel consumption and emissions, a hybrid vehicle can outperform a traditional vehicle. In designing a hybrid vehicle, the task of finding optimal component sizes and an appropriate control strategy is key to achieving maximum fuel economy. In this paper we introduce the application of convex optimization to hybrid vehicle optimization. This technique allows analysis of the propulsion system’s capabilities independent of any specific control law. To illustrate this, we pose the problem of finding optimal engine operation in a pure series hybrid vehicle over a fixed drive cycle subject to a number of practical constraints including: • nonlinear fuel/power maps • min and max battery charge • battery efficiency • nonlinear vehicle dynamics and losses • drive train efficiency • engine slew rate limits We formulate the problem of optimizing fuel efficiency as a nonlinear convex optimization problem. This convex problem is then accurately approximated as a large linear program. As a result, we compute the globally minimum fuel consumption over the given drive cycle. This optimal solution is the lower limit of fuel consumption that any control law can achieve for the given drive cycle and vehicle. In fact, this result provides a means to evaluate a realizable control law's performance. We carry out a practical example using a spark ignition engine with lead acid (PbA) batteries. We close by discussing a number of extensions that can be done to improve the accuracy and versatility of these methods. Among these extensions are improvements in accuracy, optimization of emissions and extensions to other hybrid vehicle architectures. INTRODUCTION Two areas of significant importance in automotive engineering are improvement in fuel economy and reduction of emissions. Hybrid electric vehicles are seen as a means to accomplish these goals. The majority of vehicles in production today consist of an engine coupled to the road through a torque converter and a transmission with several fixed gear ratios. The transmission is controlled to select an optimal gear for the given load conditions. During braking, velocity is reduced by converting kinetic energy into heat. For the purposes of this introduction, it is convenient to consider two propulsion architectures: pure parallel and pure series hybrid vehicles. A parallel hybrid vehicle couples an engine to the road through a transmission. However, there is an electric motor that can be used to change the RPM and/or torque seen by the engine. In addition to modifying the RPM and/or torque, this motor can recover kinetic energy during braking and store it in a battery. By changing engine operating points and recovering kinetic energy, fuel economy and emissions can be improved. A series hybrid vehicle electrically couples the engine to the road. The propulsion system consists of an engine, a battery and an electric motor. The engine is a power source that is used to provide electrical power. The electrical power is used to recharge a battery or drive a motor. The motor propels the vehicle. This motor can also be used to recover kinetic energy during braking. For a given type of hybrid vehicle, there are three questions of central importance: • What are the important engine, battery and motor requirements? • When integrated into a vehicle, what is the best performance that can be achieved? • How closely does a control law approach this best performance? Answers to these questions can be found by solving three separate problems: • Solving for the maximum fuel economy that can be obtained for a fixed vehicle configuration on a fixed drive cycle independent of a control law. • Given a method to find maximum fuel economy, vary the vehicle component characteristics to find the optimal fuel economy. • Apply the selected control law to the system and determine the fuel consumption. Calculate the ratio between this control law’s fuel consumption and the optimal value to give a metric for how close the control law comes to operating the vehicle at its maximum performance. There are many hybrid vehicle architectures[1]. For the sake of simplicity, a pure series hybrid was chosen for this study. However, the methods used for series hybrid vehicles can be extended to apply to other hybrid vehicle architectures. This study was restricted to minimizing fuel economy. This method can be extended to include emissions. DISCUSSION: FINDING THE MAXIMUM FUEL ECONOMY FOR A GIVEN VEHICLE There are many approaches that can be used to determine the maximum fuel economy that can be obtained by a particular vehicle over a particular drive cycle. One common approach is to select a control law and then optimize that control law for the system. Other techniques search through control law architectures and control parameters simultaneously. Since these techniques select a control law before beginning the optimization, the minimum fuel economy found is always a function of the control law. This leaves open the question of whether selection of a better control law could have resulted in better fuel economy. The approach presented here finds the minimal fuel consumption of the vehicle independent of any control law. Because a control law is not part of the optimization, the fuel economy found is the best possible. It is noncausal in that it finds the minimum fuel consumption using knowledge of future power demands and past power demands. Therefore it represents a limit of performance of a causal control law. Furthermore, since the problem is formulated as a convex problem and then a linear program, the minimum fuel consumption calculated is guaranteed to be the global minimum solution. The discussion that follows details: 1. The formulation of the fuel economy minimization problem as a convex problem. 2. The reduction of this convex problem to a linear program. 3. Solution of the linear program to find the minimum fuel consumption. DESCRIBING THE PROBLEM To solve for maximum fuel economy, a model of the series hybrid vehicle is used. To simplify the model, the following assumptions are made: • The voltage on the electrical bus is constant. Voltage droop and ripple can be ignored. • The relationship between power output from the engine and fuel consumption can be assumed to be a fixed relationship that is not affected by transients. • The battery’s storage efficiency is constant. It does not change with state of charge or power levels. These simplifications are used to reduce the complexity of the resulting linear program and to maintain a problem description which is convex. These simplifications illustrate one of the challenges that arises in the application of convex analysis to engineering problems – finding a description of the problem which is convex.

Control system design for rotorcraft-based unmanned aerial vehicles using time-domain system identification

Abstract: This paper introduces the development of flight control system for rotorcraft-based unmanned aerial vehicle (RUAV). In this research, the linear time-invariant model valid for hover is sought. The system response data is acquired in carefully devised experiment procedure and then a linear time-invariant system model is obtained using the time-domain analysis method. The acquired model is used to design feedback controller consisting of inner-loop attitude feedback control, mid-loop velocity feedback control and the outer-loop position control. The proposed controller is implemented on an on-board digital computer and tested in a Berkeley RUAV and shows outstanding hovering performance.

An Extended Adaptive Kalman Filter for Real-time State Estimation of Vehicle Handling Dynamics

Abstract: This paper considers a method for estimating vehicle handling dynamic states in real-time, using a reduced sensor set; the information is essential for vehicle handling stability control and is also valuable in chassis design evaluation. An extended (nonlinear) Kalman filter is designed to estimate the rapidly varying handling state vector. This employs a low order (4 DOF) handling model which is augmented to include adaptive states (cornering stiffnesses) to compensate for tyre force nonlinearities. The adaptation is driven by steer-induced variations in the longitudinal vehicle acceleration. The observer is compared with an equivalent linear, model-invariant Kalman filter. Both filters are designed and tested against data from a high order source model which simulates six degrees of freedom for the vehicle body, and employs a combined-slip Pacejka tyre model. A performance comparison is presented, which shows promising results for the extended filter, given a sensor set comprising three accelerometers only. The study also presents an insight into the effect of correlated error sources in this application, and it concludes with a discussion of the new observer's practical viability.

Simulation tools, modelling and identification, for an automotive shock absorber in the context of vehicle dynamics

Abstract: For purpose of simulation of vehicle dynamics, a physical model of an automotive shock absorber has been developed and implemented in several software packages for multibody simulations. In the present paper, the damper model structure is shortly elaborated together with some measurement and estimation techniques to retrieve the model parameters, possibly from dynamometer measurements only. These techniques are illustrated on a shock absorber normally used on the front suspension of a BMW series 7.

Vehicle system controller design for a hybrid electric vehicle

Abstract: As a way to meet the challenge of developing more fuel efficient and lower emission producing vehicles, auto manufacturers are increasingly looking toward revolutionary changes to conventional powertrain technologies as a solution. One alternative under consideration is that of hybrid electric vehicles (HEV). An HEV combines some of the benefits of electric vehicles (efficient and clean motive power supplied by an electric motor, regenerative braking) with the features of a conventional vehicle that consumers expect (convenient refueling, long driving range). However, these benefits come with increased complexity in the powertrain design. Instead of having one motive power source, there are two that can each act independently or in combination. The complexity of an HEV powertrain together with the vehicle's many operating modes demand that a supervisory or hybrid controller be developed at the vehicle level to guarantee stable and consistent operation. Inherent in this controller is a logical structure to guide the vehicle through its various operating modes and a dynamic control strategy associated with each operating mode to specify the vehicle demands to each subsystem controller. Capturing all possible operating modes and guaranteeing smooth dynamic control transitions from one operating mode to the next are significant challenges in the controller design. A formal method for designing this supervisory controller has been developed. A description of the method and its application to an HEV will be presented.

Energy gauge for lead-acid batteries in electric vehicles

Abstract: This article proposes a new coulometric approach to calculate the state of charge of a lead-acid battery in electric vehicles. The main existing state of charge algorithms have two major defects: a state of charge definition not adapted to electric vehicle applications and the nonoptimal use of static performance of the accumulator to estimate its state under dynamic stresses. In order to improve these two weaknesses, we propose a new coulometric algorithm linked to the performance of the electric vehicle and where the ampere-hours virtually discharged are obtained by applying statistical equivalence coefficients to the real current profile. The evaluation of this new algorithm on real discharges reveals a significant improvement with less than 5% errors in all cases studied.

Vehicle dynamics and external disturbance estimation for vehicle path prediction

Abstract: This paper addresses the onboard prediction of a motor vehicle's path to help enable a variety of emerging functions in autonomous vehicle control and active safety systems. It is shown in simulation that good accuracy of path prediction is achieved using numerical integration of a linearized two degree of freedom vehicle handling model. To improve performance, a steady-state Kalman filter is developed to estimate the vehicle's lateral velocity and the magnitudes of external disturbances acting on the vehicle, specifically the lateral force and the yaw moment disturbances. A comparison is made between three models of external disturbance time variation; a piecewise-constant-in-time model is found to be sufficient. Finally, an algorithm is proposed to characterize path prediction uncertainty using a statistical characterization of the measurement and modeling errors. Simulation suggests that these algorithms may provide a useful suite of path prediction tools for a variety of applications.

Integrated chassis control system to enhance vehicle stability.

Abstract: Vehicle stability enhancement system, by controlling vehicle dynamics, is the latest active safety technology introduced since Antilock Brake System (ABS) and Traction Control System (TCS). This system provides the driver with enhanced vehicle stability and handling. It is the intent of this paper to provide an understanding of the fundamentals of control of vehicle stability. The paper describes a complete stability control algorithm. Starting with a model for the vehicle yaw-plane dynamics, we derive a desired vehicle response, using both time-domain and frequency-domain approaches. Control structures include both yaw rate feedback design, and full-state feedback design. The latter approach requires the estimation of vehicle side-slip velocity. Estimations based on integration of lateral acceleration, the use of algebraic equation using vehicle kinematics, and the use of a Luenberger observer are presented. Computation of the required wheel differential velocity to achieve control objectives is described. Finally, computer simulation is used to investigate and confirm the concepts being discussed.

Multi-Body Dynamics in Full-Vehicle Handling Analysis under Transient Manoeuvre

Abstract: This paper presents a 94 degrees of freedom non-linear multi-body dynamics model of a vehicle comprising front and rear suspensions, steering system, road wheels, tyres and vehicle inertia. The model incorporates all sources of compliance: stiffness and damping, all with non-linear characteristics. The model is used for the purpose of vehicle handling analysis. A simulation run, pertaining to a double lane change is undertaken in-line with the ISO 3888 standard.

Attitude control optimization for a small-scale unmanned helicopter

Abstract: This paper presents results from the attitude control optimization for a small-scale helicopter by using an identified model of the vehicle dynamics that explicitly accounts for the coupled rotor/stabilizer/fuselage (r/s/f) dynamics. The accuracy of the model is verified by showing that it successfully predicts the performance of the control system currently used for Carnegie Mellon's autonomous helicopter (baseline controller). Elementary stability analysis shows that the light damping in the coupled r/s/f mode, which is due to the stabilizer bar, limits the performance of the baseline control system. This limitation is compensated by a second order notch filter. The control system is subsequently optimized using the CONDUIT control design framework with a frequency response envelope specification, which allows the attitude control performance to be accurately specified while insuring that the lightly damped r/s/f mode is adequately compensated.

Validation and Use of SIMULINK Integrated, High Fidelity, Engine-In-Vehicle Simulation of the International Class VI Truck

Abstract: This work presents the development, validation and use of a SIMULINK integrated vehicle system simulation composed of engine, driveline and vehicle dynamics modules. The engine model links the appropriate number of single-cylinder modules, featuring thermodynamic models of the in-cylinder processes with transient capabilities to ensure high fidelity predictions. A detailed fuel injection control module is also included. The engine is coupled to the driveline, which consists of the torque converter, transmission, differential and prop shaft and drive shafts. An enhanced version of the point mass model is used to account for vehicle dynamics in the longitudinal and heave directions. A vehicle speed controller replaces the operator and allows the feedforward simulation to follow a prescribed vehicle speed schedule. For the particular case reported here, the simulation is configured for the International 4700 series, Class VI, 4x2 delivery truck powered by a V8 turbocharged, intercooled diesel engine. The integrated vehicle simulation is validated against transient data measured on the proving ground. Comparisons of predicted and measured responses of engine and vehicle variables during vehicle acceleration from 0 to 60 mph and from 30 to 50 mph show very good agreement. The simulation is also used to study trade-offs involved in redesigning control strategies for improved performance of the vehicle system.

The reaction stabilization of on-orbit robots

Abstract: The focus of this article is to examine the reaction moment effect of satellite-based manipulators and to investigate the feasibility of stabilizing the base platform during arm operations. The goal is not to advance the state of the art in adaptive control, but rather to illustrate the benefits of autonomous attitude stabilization through reaction moment compensation. A derivation of vehicle body dynamics using reaction wheels and thrusters as the primary input sources is given. The modifications to the Newton-Euler method necessary to accommodate a manipulator arm with a free-flying base are then outlined. Next, a quaternion-based feedback regulator design is adopted.

The Illinois Roadway Simulator: a mechatronic testbed for vehicle dynamics and control

Abstract: The Illinois Roadway Simulator (IRS) is a novel, mechatronic, scaled testbed used to study vehicle dynamics and controls. An overview of this system is presented, and individual hardware issues are addressed. System modeling results on the vehicles and hardware are introduced, and comparisons of the resulting dynamics are made with full-sized vehicles. Comparisons are made between dynamic responses of full-scale and IRS-scale vehicles. The method of dynamic similitude is a key to gaining confidence in the scaled testbed as an accurate representation of actual vehicles to a first approximation. The IRS is then used in a vehicle control case study to demonstrate the potential benefits of scaled investigations. The idea of driver-assisted control is formulated as a yaw-rate model-following problem based on the representation of the driver as a known disturbance model. The controller is designed and implemented to show that the vehicle's dynamics can be changed to match a prescribed reference model.

A new reinforcement learning vehicle control architecture for vision-based road following

Abstract: A new dynamic control architecture based on reinforcement learning (RL) has been developed and applied to the problem of high-speed road following of high-curvature roads. Through RL, the control system indirectly learns the vehicle-road interaction dynamics, knowledge which is essential to stay on the road in high-speed road tracking. First, computer simulation has been carried out in order to test stability and performance of the proposed RL controller before actual use. The proposed controller exhibited a good road tracking performance, especially on high-curvature roads. Then, the actual autonomous driving experiments successfully verified the control performance on campus roads in which there were shadows from the trees, noisy and/or broken lane markings, different road curvatures, and also different times of the day reflecting a range of lighting conditions. The proposed three-stage image processing algorithm and the use of all six strips of edges have been capable of handling most of the uncertainties arising from the nonideal road conditions.

Vehicle dynamics control with rollover prevention for articulated heavy trucks

Abstract: Rollover and jack-knifing of articulated heavy trucks are serious threats for motorists Active safety technologies have been demonstrated to have potential to reduce or prevent the occurrence of these types of accidents The Vehicle Dynamics Control (VDC) system utilizes differential braking to affect vehicle response and has been shown to be quite effective in controlling vehicle yaw response In this paper, a VDC system that improves yaw, lateral, and roll stability is presented The objectives of this VDC design are to prevent or reduce the likelihood of rollover and jackknifing and to make the vehicle more closely follow the driver's intended path A linear root locus study is performed to tune controller gains in a systematic fashion Nonlinear dynamics simulations of a generic articulated heavy truck are run with the TruckSim and Matlab/Simulink software to study the performance of the proposed VDC algorithm Human-in-the-loop driver models are used to obtain realistic steering inputs on predetermined test track The simulation results of maneuvers utilizing these driver models, as well as maneuvers utilizing prescribed steering inputs, are presented VDC is shown to stabilize the vehicle, rollover and jack-knifing are prevented and the vehicle more accurately follows the driver's intended path

Electromagnetic regenerative damping in vehicle suspension systems

Abstract: An analysis is presented of energy regeneration in vehicle suspension systems, using electromagnetic devices. Previous research has shown that the amount of energy dissipated in vehicle suspension systems may be worth regenerating for purposes such as electric vehicles, where energy efficiency is a primary concern. A generalised electromagnetic topology is proposed to assist in the design of an optimal regenerative damper. This leads to an analysis of the electrical and magnetic circuit designs of electromagnetic regeneration devices together with an analysis of rotating and linear dampers. Rotating electromagnetic dampers have the advantage of mechanical amplification, but degrade the vehicle dynamics. A solution to this problem is proposed, using extra dynamic elements in series with the rotating damper. The implementation of this design will allow the use of smaller, and cheaper, rotating electromagnetic regenerative devices for use in vehicle suspension systems.

Yaw control algorithm via sliding mode control

Abstract: Electronic controls have been developed to improve vehicle dynamics in automotive applications. Several luxury vehicle manufacturers have positioned themselves to offer increased vehicle stability by expanding the current anti-lock brake system (ABS) and traction control system (TCS) technology into the arena of yaw control. A yaw control algorithm is developed to give an additional measure of vehicle stability control during adverse driving maneuvers over a variety of road conditions. By measurements of vehicle states, the control algorithm determines the level of vehicle stability and intervenes as necessary through individual wheel braking to provide added stability and handling predictability. The control law is based on optimum search for minimum yaw rate via sliding mode control.

Carbody and Passengers in Rail Vehicle Dynamics

Abstract: The carbody plays an important role in rail vehicle dynamics.This thesis aims atdeveloping validated modelling methods tostudy its dynamics, how it is excited on trackand how itinteracts with the p ...

Robust longitudinal velocity tracking of vehicles using traction and brake control

Abstract: Vehicle longitudinal control is an essential part of advanced vehicle control systems. The paper is concerned with robust longitudinal velocity tracking of vehicles using traction control and brake control. First, a longitudinal vehicle model is introduced both for traction and braking modes. Then, for each mode, a robust velocity tracking controller is designed based on backstepping. At each step of constructing a candidate Lyapunov function, a scaling parameter is introduced for each added term to take into account badly scaled system states. The concepts of effective traction mass and effective braking mass are introduced in the vehicle longitudinal model such that the derived model is applicable to any types of traction and braking configuration of the vehicles. The designed controller is proved to be effective by simulation.

Adaptive emergency braking control using a dynamic tire/road friction model

Abstract: A controller for emergency braking of vehicles in automated highway systems (AHS) is designed. The scheme is based on the estimation of both the LuGre tire/road friction dynamic model and the braking system gain. The controller estimates the tire/road relative velocity which achieves maximum braking force based on a quasi-static solution of the LuGre friction model and sets the master cylinder pressure to track that relative velocity. This control system is designed to work in conjunction with antilock-braking-systems providing two advantages: less chattering during braking and a source of a priori information regarding safe spacing.

Handling and driving characteristics for six-wheeled vehicles

Abstract: Handling performance of six-wheeled special-purpose vehicles is investigated in this study. Six-wheel drive (6WD) vehicles are believed to have good performance in off-the-road manoeuvring ...

Active vehicle suspension control using intelligent feedback linearization

Abstract: Effective control of ride quality and handling performance are challenges for active vehicle suspension systems, particularly for off-road applications. Off-road vehicles experience large suspension displacements, where the nonlinear kinematics and damping characteristics of suspension elements are significant. These nonlinearities tend to degrade the performance of active suspension systems, introducing harshness to the ride quality and reducing off-road mobility. Typical control strategies rely on linear time-invariant models of the suspension dynamics. While these models are convenient, nominally accurate, and tractable due to the abundance of linear control techniques, they neglect the nonlinearities and time-varying dynamics present in real suspension systems. One approach to improving the effectiveness of active vehicle suspension systems, while preserving the benefits of linear control techniques, is to estimate and cancel the nonlinearities using feedback linearization. In this paper, the authors demonstrate an intelligent parameter estimation approach, using structured artificial neural networks, that continually "learns" the nonlinear parameter variations of a quarter-car suspension model. This estimation algorithm becomes the foundation for an intelligent feedback linearization (IFL) controller for active vehicle suspensions. Results are presented for real-time experimental tests and field evaluations on a military HMMWV. These results clearly demonstrate the viability and effectiveness of this approach as a tool for rapid, online development of vehicle suspension models and controllers.

The vehicle stability control responsibility improvement using steer-by-wire

Abstract: With the aim of improving vehicle stability through the introduction of active steering control, the authors undertook the development of a steer-by-wire system which is more effective than the direct yaw-moment control (DYC) while avoiding interference with driver steering. The vehicle stability control begins only after a change in vehicle behavior has been detected, and therefore in the case of full braking test on a /spl mu/-split road and in other situations requiring high responsiveness, the vehicle stabilizing effect is lowered due to time lag until the control starts, and a residual yaw angle is created after the stopping of the vehicle. In order to resolve these problems, a new type of control was developed whereby the driver's steering intent is detected based on the DYC behavior and front-wheel angle deviation between front-wheel rotational speeds. It was verified by on-vehicle testing that the addition control resulted in greater vehicle stability.