Direct Yaw Control Research Articles

Optimised coordinated chassis stability control using fuzzy genetic algorithm

Owing to proficient constraints of distinct vehicle subsystems, numerous individual active control systems are optimised individually in specific handling areas. Consequently, there is no solitary system which can be operative over the entire range of vehicle stability and handling. In this study, an optimised coordinated control system comprising two controllers namely direct yaw control (DYC) and active front steering (AFS) has been developed based on fuzzy logic control to boost vehicle handling, cornering stability, and rollover anticipation. Moreover, genetic algorithm has been accustomed to optimise the offered coordinated control system in two phases; initially, optimising the fuzzy logic controller for both DYC and AFS by linear scaling of the inputs and outputs of each controller, and by the weight of each rule. Different benchmark test manoeuvres have been carried out at different driving conditions to scrutinise the offered coordinated control effectiveness. Simulation results shows a significant enhancement in vehicle stability.

A centralized multilayer LPV/H∞ control architecture for vehicle’s global chassis control, and comparison with a decentralized architecture

This paper deals with the development of Global Chassis Controller where the Active Front steering, Direct Yaw Control and Active Suspensions, are coordinated together in the aim to improve the overall vehicle performance i.e maneuverability, lateral stability and rollover avoidance. The main contribution of this work is the integration of the Active suspension system (AS) in a centralized multilayer control architecture to control the roll angle. A polytopic approach is used to find the LPV/H∞ controller where an offline Linear Matrix Inequality (LMI) optimal solver is used to realize the optimality of this controller. The different layers of this architecture are detailed. The proposed LPV/H∞ controller is validated by simulation using Matlab/Simulink, and a comparison is done with a decentralized architecture that has been developed in the laboratory, to show the difference in behavior and performance of both strategies of control and the effectiveness of centralized one on the rollover avoidance.

Design and Analysis of DYC and Torque Vectoring using Multiple-Frequency Control Electronic Differential in an Independent Rear Wheel Driven Electric Vehicle

Electric vehicle (EV) are being embraced in recent times as they run on clean fuel, zero tail emission and are environment-friendly. Recent advancements in the field of power electronics and control strategies have made it possible to the advent in the vehicle dynamics, efficiency and range. This paper presents a design for traction control system (TCS) for longitudinal stability and Direct Yaw Control (DYC) for lateral stability simultaneous. The TCS and DYC is based on multiple frequency controlled electronic differential with a simple and effective approach. Along with it, some overviews have been presented on some state of the art in traction control system (TCS) and torque vectoring. The developed technique reduces nonlinearity, multisensory interfacing complexity and response time of the system. This torque and yaw correction strategy can be implemented alongside fuzzy control, sliding mode or neural network based controller. The effectiveness of the control method has been validated using a lightweight neighbourhood electric vehicle as a test platform. The acquired results confirm the versatility of proposed design and can be implemented in any DC motor based TCS/DYC.

Advanced Estimation Techniques for Vehicle System Dynamic State: A Survey.

In order to improve handling stability performance and active safety of a ground vehicle, a large number of advanced vehicle dynamics control systems—such as the direct yaw control system and active front steering system, and in particular the advanced driver assistance systems—towards connected and automated driving vehicles have recently been developed and applied. However, the practical effects and potential performance of vehicle active safety dynamics control systems heavily depend on real-time knowledge of fundamental vehicle state information, which is difficult to measure directly in a standard car because of both technical and economic reasons. This paper presents a comprehensive technical survey of the development and recent research advances in vehicle system dynamic state estimation. Different aspects of estimation strategies and methodologies in recent literature are classified into two main categories—the model-based estimation approach and the data-driven-based estimation approach. Each category is further divided into several sub-categories from the perspectives of estimation-oriented vehicle models, estimations, sensor configurations, and involved estimation techniques. The principal features of the most popular methodologies are summarized, and the pros and cons of these methodologies are also highlighted and discussed. Finally, future research directions in this field are provided.

A Global Chassis Control System Involving Active Suspensions, Direct Yaw Control and Active Front Steering

This paper aims to develop a Global Chassis Controller to coordinate the Active Front steering, Direct Yaw Control and Active Suspension controllers, in the ambition to improve the overall vehicle performance. A multilayer control architecture is adopted. It contains a local control layer and a decision layer. The local objectives for the sub-controllers in the control layer concern explicitly: maneuverability, lateral stability, rollover avoidance, and ride comfort. The sub-controllers are designed based on the super-twisting sliding mode theory. The decision layer is developed to promote/attenuate the local objectives of the sub-controllers, in order to remove the conflicts among the different objectives and extract the maximum benefit from the coordination using some evaluation criteria. This layer monitors the dynamics of the vehicle, calculates and sends scheduled gains to the sub-controllers, based on fuzzy logic rules and a stability criterion. Finally, the proposed Global Chassis Controller is validated on Matlab/Simulink using a vehicle model validated on the professional vehicle simulator “SCANeR Studio”. The results show the effectiveness of the proposed strategy.

Path Following Predictive Control for Autonomous Vehicles Subject to Uncertain Tire-ground Adhesion and Varied Road Curvature

This paper presents an integrated active steering control (ASC) and direct yaw control (DYC) strategy for improving path following performance of the vehicle subject to the uncertain tire-ground adhesion and road curvature conditions. To begin with, a model predictive control (MPC)-based path following controller is designed to deal with system state constraints and actuator actuation limitations. After that, a constrained weighted least square (CWLS)-based torque distributor is developed to distribute the target resultant yaw moment signal into the four executive wheels. Then, the developed control strategy and methods are implemented and evaluated on an eight degree of freedom (8DOF) nonlinear vehicle model include longitudinal, lateral, yaw, roll and four wheels’ rotation dynamics. In the end, simulation results compared with ASC strategy, under the uncertain tire-ground adhesion and varied road curvature cases, confirm the feasibility and efficiency of the presented strategy and methods even subject to the uncertain tire-ground adhesion and varied road curvature.

Direct yaw control based on a phase plan decomposition for enhanced vehicle stability

This paper introduces an advanced direct yaw control (DYC) by supervision with the aim of improving the safety of vehicles. The proposed DYC is based on a hierarchical approach and a global stabilizing yaw moment is calculated by combining two different controllers in order to control yaw rate and vehicle sideslip angle. The activation of each controller depends on the critical driving situation detected by the proposed supervisor. The latter is based on a yaw rate - sideslip angle phase plan decomposition by using the limits of the yaw motion variables. Finally, the global stabilizing yaw moment will be distributed on the four wheels through the control allocation by using differential braking.

Study on the vertical and lateral coupling dynamics control of the in-wheel motor-driven electric vehicles under multi-excitation

To study the coupling dynamics control in the vertical and lateral directions of the in-wheel motor (IWM)-driven electric vehicles under the steering input, road and electromagnetic excitation, a verified 16-degrees-of-freedom coupling dynamic model is given. To improve the vehicle coupling dynamics, a dynamics controller is designed based on the active suspension, active front steering (AFS) and direct yaw control (DYC) system. The dynamics controller includes a supervisory coordination layer controller and the above sub-system controller with different control algorithms, respectively. Finally, comparative analysis is carried out to verify the validity of the controller designed in this paper. The results show that, whether the road has a high or low adhesion coefficient, the controller developed in this paper is highly effective for the coupling dynamics of the IWM-driven vehicle. Especially, on a road with low adhesion coefficient, the control effect on the vehicle running stability and path track capacity is more obvious.

Vehicle dynamics control by using a three-dimensional stabilizer pendulum system

ABSTRACTActive safety systems of a vehicle normally work well on tyre–road interactions, however, these systems deteriorate in performance on low-friction road conditions. To combat this effect, an innovative idea for the yaw moment and roll dynamic control is presented in this paper. This idea was inspired by the chase and run dynamics animals like cheetahs in the nature; cheetahs have the ability to swerve while running at very high speeds. A cheetah controls its dynamics by rotating its long tail. A three-dimensional stabilizer pendulum system (3D-SPS) resembles the rotational motion of the tail of a cheetah to improve the stability and safety of a vehicle. The idea has been developed in a stand-alone 3D stabilizer pendulum system as well as in an integrated control system, which consists of an ordinary differential braking direct yaw control (DYC) and active steering control that is assisted by the 3D-SPS. The performance of the proposed 3D-SPS has been evaluated over a wide range of handling manoeuvres by using a comprehensive numerical simulation. The results show the advantage of 3D-SPS over conventional control approaches, which are ineffective on low-friction road conditions and high lateral acceleration manoeuvres. It should however be noted that the best vehicle dynamics performance is obtained when an integrated 3D-SPS and DYC and AFS is utilised.

Novel stability control strategy for distributed drive electric vehicle based on driver operation intention

In this paper, a novel direct yaw control method based on driver operation intention for stability control of a distributed drive electric vehicle is proposed. It was discovered that the vehicle loses its stability easily under an emergency steering alignment (EA) problem. An emergent control algorithm is proposed to improve vehicle stability under such a condition. A driver operation intention recognition module is developed to identify the driving conditions. When the vehicle enters into an EA condition, the module can quickly identify it and transfer the control method from normal direct yaw control to emergency control. Two control algorithms are designed. The emergency control algorithm is applied to an EA condition while the adaptive control algorithm is applied to other conditions except the EA condition. Both simulation results and real vehicle results show that: The driver module can accurately identify driving conditions based on driver operation intention. When the vehicle enters into EA condition, the emergent control algorithm can intervene quickly, and it has proven to outperform normal direct yaw control for better stabilization of vehicles.

A new formulation of the understeer coefficient to relate yaw torque and vehicle handling

ABSTRACTThe handling behaviour of vehicles is an important property for its relation to performance and safety. In 1970s, Pacejka did the groundwork for an objective analysis introducing the handling diagram and the understeer coefficient. In more recent years, the understeer concept is still mentioned but the handling is actively managed by direct yaw control (DYC). In this paper an accurate analysis of the vehicle handling is carried out, considering also the effect of drive forces. This analysis brings to a new formulation of the understeer coefficient, which is almost equivalent to the classical one, but it can be obtained by quasi-steady-state manoeuvres. In addition, it relates the vehicle yaw torque to the understeer coefficient, filling up the gap between the classical handling approach and DYC. A multibody model of a Formula SAE car is then used to perform quasi-steady-state simulations in order to verify the effectiveness of the new formulation. Some vehicle set-ups and wheel drive arrangements are simulated and the results are discussed. In particular, the handling behaviours of the rear wheel drive (RWD) and the front wheel drive (FWD) architectures are compared, finding an apparently surprising result: for the analysed vehicle the FWD is less understeering than for RWD. The relation between the yaw torque and the understeer coefficient allows to understand this behaviour and opens-up the possibility for different yaw control strategies.

Direct Yaw Control of Vehicle using State Dependent Riccati Equation with Integral Terms

Direct yaw control of four-wheel vehicles using optimal controllers such as the linear quadratic regulator (LQR) and the sliding mode controller (SMC) either considers only certain parameters constant in the nonlinear equations of vehicle model or totally neglect their effects to obtain simplified models, resulting in loss of states for the system. In this paper, a modified state-dependent Ricatti equation method obtained by the simplification of the vehicle model is proposed. This method overcomes the problem of the lost states by including state integrals. The results of the proposed system are compared with the sliding mode slip controller and statedependent Ricatti equation method using high fidelity vehicle model in the vehicle simulation software package, Carsim. Results show 38% reduction in the lateral velocity, 34% reduction in roll and 16% reduction in excessive yaw by only increasing the fuel consumption by 6.07%.

Control of an independent 4WD electric vehicle by DYC method

Current advances in the application of control systems to vehicle dynamics has made it practicable to improve the vehicle's longitudinal, lateral and vertical dynamics. Some of the examples of application of these systems to vehicle control are traction control (longitudinal dynamics) to prevent wheel slip, ESP (lateral dynamics) to prevent loss of stability, and active suspension (vertical dynamics) to increase ride comfort. In this paper, the vehicle lateral motion is controlled by direct yaw control (DYC) method. This uses the yaw moment produced by the longitudinal forces of the tyres, for stabilising the vehicle motion during critical cornering conditions. The system has been designed to give substantially enhanced active safety and dynamic handling control. The vehicle dynamics control algorithm is developed for a FOX vehicle by controlling couple traction/braking torque of the four in-wheel motors, from basic driving slogans. These are the steering angle, position of the accelerator pedal and brake by the position of the brake pedal, as shown in Figure 1.

A modified structure internal model robust control method for the integration of active front steering and direct yaw moment control

Taking into account the nonlinearity of vehicle dynamics and the variations of vehicle parameters, the integrated control strategy for active front steering (AFS) and direct yaw control (DYC) that can maintain the performance and robustness is a key issue to be researched. Currently, the H ∞ method is widely applied to the integrated control of chassis dynamics, but it always sacrifices the performance in order to enhance the stability. The modified structure internal model robust control (MSIMC) obtained by modifying internal model control (IMC) structure is proposed for the integrated control of AFS and DYC to surmount the conflict between performance and robustness. Double lane change (DLC) simulation is developed to compare the performance and the stability of the MSIMC strategy, the PID controller based on the reference vehicle model and the H ∞ controller. Simulation results show that the PID controller may oscillate and go into instability in severe driving conditions because of large variations of tire parameters, the H ∞ controller sacrifices the performance in order to enhance the stability, and only the MSIMC controller can both ensure the robustness and the high performance of the integrated control of AFS and DYC.

The Analysis of 4WD Vehicle Overtaking Based on Electric Wheels

In order to improve vehicle overtaking performance, the four-wheel driving technology based on electric wheels is analyzed. A four-wheel driving vehicle model has been built with ADAMS software, and the control strategy has been built with Simulink software. The driver steering and speed control model with variable ratio is built. The comparative overtaking simulation of four-wheel driving with and without Direct Yaw Control is processed. With the simulation, it can be found that the centroid yaw-rate of the vehicle with Direct Yaw Control is smaller, and vehicle movement track is closer to target track than the vehicle without DYC. The manipulation performance of vehicle is improved, and the labor intensity of the driver is reduced. This provides a certain amount of theoretical research for the four-wheel driving technology based on electric wheels.

A Direct Yaw Control Algorithm for On- and Off-Road Yaw Stability

A Direct Yaw Control Algorithm for On- and Off-Road Yaw Stability

Motion control of electric vehicles and prospects of supercapacitors

AbstractNovel motion control techniques for electric vehicles (EVs) on the basis of the quick torque generation in these vehicles have been developed at the Hori Laboratory. Because EVs are powered by electric motors, they have three major advantages: (i) motor torque generation is quick and accurate, (ii) a motor can be attached to each wheel, and (iii) motor torque can be estimated precisely. These advantages enable us to (i) easily realize high‐performance antilock braking systems and traction control systems with minor feedback control of each wheel, (ii) control chassis motion, for example, direct yaw control, and (iii) estimate road surface condition. We have developed test vehicles and confirmed the effectiveness of the proposed methods. Recently, we have manufactured small EVs that are powered only by supercapacitors. Supercapacitors have long operating life, large current density, and are environmental friendly. Furthermore, their energy level can be estimated from their terminal voltage. Because EVs powered by supercapacitors can run for more than 20 min by charging only for 30 s, recharging EVs will not be a major problem. In the future, EVs will be recharged via contactless power transfer. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

3306 二輪独立駆動可能な電気自動車のヨーモーメントオブザーバのロバスト性に関する検証(OS3-2:車両運動制御の電動化技術,OS3:交通・物流システムの制御,オーガナイズド・セッション(OS),第18回交通・物流部門大会(TRANSLOG2009))

We have proposed yaw moment observer (YMO) for a direct yaw control (DYC) of electric vehicles (EVs). So far, we applied YMO to various yaw-rate control systems, and verified the effectiveness of these systems. However, we carried out experiments only in the campus of the university, the robustness of YMO was not examined in high speed region. Various kind of variations like increase of vehicle inertia and tire friction will influence YMO. Then, in this paper we consider the robustness of YMO in high speed region on test road by simulations and experiment.

The Influence of Direct Yaw Control AWD Systems on Vehicle Stability and Response in All Driving Conditions

The Influence of Direct Yaw Control AWD Systems on Vehicle Stability and Response in All Driving Conditions

Design of a rollover index-based vehicle stability control scheme

This paper presents a rollover index (RI)-based vehicle stability control (VSC) scheme. A rollover index, which indicates an impending rollover, is developed by a roll dynamics phase plane analysis. A model-based roll estimator is designed to estimate the roll angle and roll rate of the vehicle body with lateral acceleration, yaw rate, steering angle and vehicle velocity measurements. The rollover index is computed using an estimated roll angle, estimated roll rate, measured lateral acceleration and time-to-wheel lift. A differential braking control law is designed using a direct yaw control method. The VSC threshold is determined from the rollover index. The effectiveness of the RI, the performance of the estimator and the control scheme are investigated via simulations using a validated vehicle simulator. It is shown that the proposed RI can be a good measure of the danger of rollover and the proposed RI-based VSC scheme can reduce the risk of a rollover.