Vehicle yaw motion control using takagi-sugeno modeling and quadratic boundedness via dynamic output feedback

International audienceThis paper presents the design and the simulation test of a Takagi-Sugeno (TS) fuzzy output feedback for yaw motion control. An integrated steering and differential braking controller based on invariant sets, quadratic boundedness theory and a common Lyapunov function has been developed. The TS fuzzy model is able to handle elegantly the nonlinear behavior the vehicle lateral dynamics. The computation of the control law has been achieved using Linear and Bilinear Matrix Inequalities (LMI-BMI) methods. Simulation test shows the controlled car is able to achieve the ISO3888-2 transient maneuver. Some design parameters can be adjusted to handle the tradeoff between safety constraints and comfort specifications

Improving transient performances of vehicle yaw rate response using composite nonlinear feedback

This paper studies and applied the composite nonlinear feedback (CNF) control technique for improving the transient performances of vehicle yaw rate response. In the active front steering control design and analysis, the linear bicycle model is used for controller design while the 7DOF nonlinear vehicle model is used as vehicle plant for simulation and controller evaluations. The vehicle handling test of the J-turn and single lane change maneuvers are implemented in computer simulations in order to evaluate the designed yaw rate tracking controller. The simulation results show that the CNF technique could improve the transient performances of yaw rate response and enhance the vehicle maneuverability

A Yaw Stability Control Algorithm for Four-Wheel Independently Actuated Electric Ground Vehicles considering Control Boundaries

A hierarchical control algorithm of direct yaw moment control for four-wheel independently actuated (FWIA) electric ground vehicles is presented. Sliding mode control is adopted to yield the desired yaw moment in the higher layer of the algorithm due to the possible modeling inaccuracies and parametric uncertainties. The conditional integrator approach is employed to overcome the chattering issue, which enables a smooth transition to a proportional + integral-like controller, with antiwindup, when the system is entering the boundary layer. The lower level of the algorithm is given to allocate the desired yaw moment to four wheels by means of slip ratio distribution and control for a better grasp of control boundaries. Simulation results, obtained with a vehicle dynamics simulator, Carsim, and the Matlab/Simulink, show the effectiveness of the control algorithm

Control strategies of series active variable geometry suspension for cars

This thesis develops control strategies of a new type of active suspension for high performance cars, through vehicle modelling, controller design and application, and simulation validation. The basic disciplines related to automotive suspensions are first reviewed and are followed by a brief explanation of the new Series Active Variable Geometry Suspension (SAVGS) concept which has been proposed prior to the work in this thesis. As part of the control synthesis, recent studies in suspension control approaches are intensively reviewed to identify the most suitable control approach for the single-link variant of the SAVGS. The modelling process of the high-fidelity multi-body quarter- and full- vehicle models, and the modelling of the linearised models used throughout this project are given in detail. The design of the controllers uses the linearised models, while the performance of the closed loop system is investigated by implementing the controllers to the nonlinear models. The main body of this thesis elaborates on the process of synthesising H∞ control schemes for quarter-car to full-car control. Starting by using the quarter-car single-link variant of the SAVGS, an H∞ -controlled scheme is successfully constructed, which provides optimal road disturbance and external force rejection to improve comfort and road holding in the context of high frequency dynamics. This control technique is then extended to the more complex full-car SAVGS and its control by considering the pitching and rolling motions in the context of high frequency dynamics as additional objectives. To improve the level of robustness to single-link rotations and remove the geometry nonlinearity away from the equilibrium position, an updated approach of the full-car SAVGS H∞ -controlled scheme is then developed based on a new linear equivalent hand-derived full-car model. Finally, an overall SAVGS control framework is developed, which operates by blending together the updated H∞ controller and an attitude controller, to tackle the comfort and road holding in the high frequency vehicle dynamics and chassis attitude motions in the low frequency vehicle dynamics simultaneously. In all cases, cascade inner position controllers developed prior to the work in this thesis are employed at each corner of the vehicle and combined with the control systems developed in this thesis, to ensure that none of the physical or design limitations of the actuator are violated under any circumstances.Open Acces

A Human Driver Model for Autonomous Lane Changing in Highways: Predictive Fuzzy Markov Game Driving Strategy

This study presents an integrated hybrid solution to mandatory lane changing problem to deal with accident avoidance by choosing a safe gap in highway driving. To manage this, a comprehensive treatment to a lane change active safety design is proposed from dynamics, control, and decision making aspects. My effort first goes on driver behaviors and relating human reasoning of threat in driving for modeling a decision making strategy. It consists of two main parts; threat assessment in traffic participants, (TV s) states, and decision making. The first part utilizes an complementary threat assessment of TV s, relative to the subject vehicle, SV , by evaluating the traffic quantities. Then I propose a decision strategy, which is based on Markov decision processes (MDPs) that abstract the traffic environment with a set of actions, transition probabilities, and corresponding utility rewards. Further, the interactions of the TV s are employed to set up a real traffic condition by using game theoretic approach. The question to be addressed here is that how an autonomous vehicle optimally interacts with the surrounding vehicles for a gap selection so that more effective performance of the overall traffic flow can be captured. Finding a safe gap is performed via maximizing an objective function among several candidates. A future prediction engine thus is embedded in the design, which simulates and seeks for a solution such that the objective function is maximized at each time step over a horizon. The combined system therefore forms a predictive fuzzy Markov game (FMG) since it is to perform a predictive interactive driving strategy to avoid accidents for a given traffic environment. I show the effect of interactions in decision making process by proposing both cooperative and non-cooperative Markov game strategies for enhanced traffic safety and mobility. This level is called the higher level controller. I further focus on generating a driver controller to complement the automated car’s safe driving. To compute this, model predictive controller (MPC) is utilized. The success of the combined decision process and trajectory generation is evaluated with a set of different traffic scenarios in dSPACE virtual driving environment. Next, I consider designing an active front steering (AFS) and direct yaw moment control (DYC) as the lower level controller that performs a lane change task with enhanced handling performance in the presence of varying front and rear cornering stiffnesses. I propose a new control scheme that integrates active front steering and the direct yaw moment control to enhance the vehicle handling and stability. I obtain the nonlinear tire forces with Pacejka model, and convert the nonlinear tire stiffnesses to parameter space to design a linear parameter varying controller (LPV) for combined AFS and DYC to perform a commanded lane change task. Further, the nonlinear vehicle lateral dynamics is modeled with Takagi-Sugeno (T-S) framework. A state-feedback fuzzy H∞ controller is designed for both stability and tracking reference. Simulation study confirms that the performance of the proposed methods is quite satisfactory

Mu-synthesis PID control of full-car with parallel active link suspension under variable payload

This paper presents a combined μ -synthesis PID control scheme, employing a frequency separation paradigm, for a recently proposed novel active suspension, the Parallel Active Link Suspension (PALS). The developed μ -synthesis control scheme is superior to the conventional H∞ control, previously designed for the PALS, in terms of ride comfort and road holding (higher frequency dynamics), with important realistic uncertainties, such as in vehicle payload, taken into account. The developed PID control method is applied to guarantee good chassis attitude control capabilities and minimization of pitch and roll motions (low frequency dynamics). A multi-objective control method, which merges the aforementioned PID and μ -synthesis-based controls is further introduced to achieve simultaneously the low frequency mitigation of attitude motions and the high frequency vibration suppression of the vehicle. A seven-degree-of-freedom Sport Utility Vehicle (SUV) full car model with PALS, is employed in this work to test the synthesized controller by nonlinear simulations with different ISO-defined road events and variable vehicle payload. The results demonstrate the control scheme's significant robustness and performance, as compared to the conventional passive suspension as well as the actively controlled PALS by conventional H∞ control, achieved for a wide range of vehicle payload considered in the investigation

Advanced robust control strategies of mechatronic suspensions for cars

Two novel mechatronic suspensions for road vehicles are studied in this thesis: the Series Active Variable Geometry Suspension (SAVGS) and the Parallel Active Link Suspension (PALS). The SAVGS and the PALS complement each other in terms of the vehicle categories they serve, which range from light high-performance vehicles (the Grand Tourer) to heavy SUV vehicles, respectively, based on the sprung mass and the passive suspension stiffness. Previous work developed various control methodologies for these types of suspension. Compared to existing active suspension solutions, both the SAVGS and the PALS are capable of low-frequency chassis attitude control and high-frequency ride comfort and road holding enhancement. In order to solve the limitation of both SAVGS and PALS robustness, mu-synthesis control methodologies are first developed for SAVGS and PALS, respectively, to account for structured uncertainties arising from changes to system parameters within realistic operating ranges. Subsequently, to guarantee robustness of both low-frequency and high-frequency vehicle dynamics for PALS, the mu-synthesis scheme is combined with proportional-integral-derivative (PID) control, employing a frequency separation paradigm. Moreover, as an alternative robustness guaranteeing scheme that captures plant nonlinearities and road unevenness as uncertainties and disturbances, a novel robust model predictive control (RMPC) based methodology is proposed for the SAVGS, motivated by the promise shown by RMPC in other industrial applications. Finally, aiming to provide further performance stability and improvements, feedforward control is developed for the PALS. Nonlinear simulations with a set of ISO driving situations are performed to evaluate the efficiency and effectiveness of the proposed control methods in this thesis.Open Acces

Stability Control of Triple Trailer Vehicles

While vehicle stability control is a well-established technology in the passenger car realm, it is still an area of active research for commercial vehicles as indicated by the recent notice of proposed rulemaking on commercial vehicle stability by the National Highway Traffic Safety Administration (NHTSA, 2012). The reasons that commercial vehicle electronic stability control (ESC) development has lagged passenger vehicle ESC include the fact that the industry is generally slow to adopt new technologies and that commercial vehicles are far more complex requiring adaptation of existing technology. From the controller theory perspective, current commercial vehicle stability systems are generally passenger car based ESC systems that have been modified to manage additional brakes (axles). They do not monitor the entire vehicle nor do they manage the entire vehicle as a system

기동성 및 횡 안전성을 위한 역삼륜형 퍼스널 모빌리티 차량의 인휠 모터 제어기 설계

학위논문 (석사)-- 서울대학교 대학원 : 공과대학 기계항공공학부, 2019. 2. 이경수.본 논문에서는 역삼륜형 퍼스널 모빌리티 차량의 동역학 모델 분석하였으며 이를 기반으로 기동성 및 횡 안정성 개선을 위한 인 휠 모터 제어기를 설계하였다. 퍼스널 모빌리티 차량의 동역학 모델링은 제어기를 설계하기에 앞서 시스템의 성능을 분석하기 위해 설계 및 사용되었다. 특히 모델링을 활용하여 다양한 주행 시나리오 기반으로 시뮬레이션 단계에서 동역학 특성을 검증하였다. 동역학적 특성을 기반으로 목표 요속도를 종 속도에 대한 함수식으로 설계하였다. 목표 요 속도를 추종하기 위한 요 모멘트가 제어기에서 생성되며 본 모멘트를 시스템에 가하여 회전 기동성 및 횡 안정성을 진행 속도에 따라 개선하고자 한다. 목표 요 모멘트는 차분 토크 지령으로 각 모터에 전달되며, 이 외에도 종방향 전복 방지 로직과 바퀴 과도슬립 방지 로직에 의해 각 모터의 토크 지령이 추가 처리된다. Matlab/Simulink를 활용하여 특정 주행 시나리오에서 제어기의 성능을 시뮬레이션 단계에서 검증하였다. 또한 설계된 제어기를 실차에 적용한 뒤 다양한 종 속도, 노면 조건 및 주행 시나리오에 따라 실차 실험이 진행되었다. 실차 실험 결과 저속에서 회전 반경이 급격히 줄어 기동성이 상승되었다. 또한 고속에서는 횡 가속도가 마찰 한계 값 미만으로 제한되어 횡 안정성 역시 확보되었다. 종 방향 전복 방지 및 바퀴 과도 슬립 방지 로직 역시 본 논문에서 설계된 제어기를 통해 성능이 검증되었다.This study proposes dynamic analysis and in-wheel motor control algorithm of three wheeled personal mobility vehicle considering maneuverability and lateral stability. A dynamic modeling of personal mobility vehicle is used to understand the characteristics of system, which presents strategy of motor control algorithm. Dynamic characteristics are demonstrated based on various driving scenario simulation. Considering dynamic characteristics, desired yaw rate is designed as a function of longitudinal velocity. Tracking desired yaw rate generates additional yaw moment which satisfies the purpose of improvement of maneuverability and stability along with longitudinal velocity. This additional yaw moment is distributed as differential torque command to each front right and left motor. Differential torque command is processed by torque saturation logic to prevent pitchover and longitudinal wheel slip. Numerical simulation results are presented with some specific driving scenario using Matlab/Simulink package to analyze controllers performance. Also, after embedding motor control algorithm into test vehicle, various vehicle tests are performed to verify the performance of designed controller at different speed, road condition, and driving scenario. According to test results, radius of curvature is significantly reduced at low longitudinal speed, which implicates the improvement of maneuverability. Also, lateral acceleration is upper bounded to prevent lateral instability of vehicle at high speed. Pichover and longitudinal slip is also prevented by in-wheel motor control algorithm.Contents Abstract i List of Figures v Nomenclature vii Chapter 1 Introduction 1 1.1 Research Background 1 1.2 Research Overview 2 Chapter 2 Modeling of personal mobility vehicle 3 2.1 Driving mechanism 4 2.2 Brush tire model 4 2.3 Wheel dynamics 7 2.4 Body dynamics 8 Chapter 3 In-wheel motor control algorithm 11 3.1 Overall control scheme 11 3.2 Yaw rate controller 12 3.3 Torque vectoring 19 3.4 State estimator 22 Chapter 4 Simulation results 25 4.1 Base models dyanmic characteristics 26 4.2 Controller performance verification 30 Chapter 5 Vehicle test results 34 5.1 Yaw rate controller verification 34 5.2 Wheel slip mitigation verification 40 5.3 Pitchover mitigation verification 42 5.4 Wheel acceleration estimator verification 43 Chapter 6 Conclusions 44 Bibliography 45 국문초록 48Maste

A Systematic Survey of Control Techniques and Applications: From Autonomous Vehicles to Connected and Automated Vehicles

Vehicle control is one of the most critical challenges in autonomous vehicles (AVs) and connected and automated vehicles (CAVs), and it is paramount in vehicle safety, passenger comfort, transportation efficiency, and energy saving. This survey attempts to provide a comprehensive and thorough overview of the current state of vehicle control technology, focusing on the evolution from vehicle state estimation and trajectory tracking control in AVs at the microscopic level to collaborative control in CAVs at the macroscopic level. First, this review starts with vehicle key state estimation, specifically vehicle sideslip angle, which is the most pivotal state for vehicle trajectory control, to discuss representative approaches. Then, we present symbolic vehicle trajectory tracking control approaches for AVs. On top of that, we further review the collaborative control frameworks for CAVs and corresponding applications. Finally, this survey concludes with a discussion of future research directions and the challenges. This survey aims to provide a contextualized and in-depth look at state of the art in vehicle control for AVs and CAVs, identifying critical areas of focus and pointing out the potential areas for further exploration