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

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

This paper presents a passive actuator fault-tolerant (FT) controller for a class of overactuated nonlinear systems and its experimental investigations on an electric vehicle. As the actuator fault information is unknown before the fault detection and diagnosis procedure finishes, the passive FT control is of great necessity in maintaining system stability and achieving acceptable performance. In this paper, three types of actuator faults are considered, and a passive FT controller that works for all of the studied fault types is designed. By grouping control efforts that have similar effects on the system into the same subsystem, the proposed control method can automatically distribute the higher level control signals to the actuators while minimizing a defined cost function. The FT control method was applied to control of a four-wheel-independently-actuated (FWIA) electric ground vehicle. Experimental results obtained on a FWIA electric vehicle show the effectiveness of the proposed method.

Passive Actuator Fault-Tolerant Control for a Class of Overactuated Nonlinear Systems and Applications to Electric Vehicles

Gain-scheduled robust control for lateral stability of four-wheel-independent-drive electric vehicles via linear parameter-varying technique

Yaw stability control system plays a significant role in vehicle lateral dynamics in order to improve the vehicle handling and stability performances. However, not many researches have been focused on the transient performances improvement of vehicle yaw rate and sideslip tracking control. This paper reviews the vital elements for control system design of an active yaw stability control system; the vehicle dynamic models, control objectives, active chassis control, and control strategies with the focus on identifying suitable criteria for improved transient performances. Each element is discussed and compared in terms of their underlying theory, strengths, weaknesses, and applicability. Based on this, we conclude that the sliding mode control with nonlinear sliding surface based on composite nonlinear feedback is a potential control strategy for improving the transient performances of yaw rate and sideslip tracking control.

https://downloads.hindawi.com/archive/2014/437515.pdf

A Review of Active Yaw Control System for Vehicle Handling and Stability Enhancement

This paper introduces a new condition monitoring approach for extracting fault signatures in wind turbine blades by utilizing the data from a real-time Supervisory Control and Data Acquisition (SCADA) system. A hybrid fault detection system based on a combination of Generalized Regression Neural Network Ensemble for Single Imputation (GRNN-ESI) algorithm, Principal Component Analysis (PCA), and wavelet-based Probability Density Function (PDF) approach is proposed in this work. The proposed fault detection strategy accurately detects incipient blade failures and leads to improved maintenance cost and availability of the system. Experimental test results based on data from a wind farm in southwestern Ontario, Canada, illustrate the effectiveness and high accuracy of the proposed monitoring approach.

A New Hybrid Fault Detection Method for Wind Turbine Blades Using Recursive PCA and Wavelet-Based PDF

For four wheel independent motor-drive electric vehicle, the vehicle longitudinal and lateral motion can be controlled by distributing the driving and regenerative braking torques of four wheel motors. To meet the driving command of driver and keep the vehicle lateral stability, a hierarchical control system is proposed in this paper. In the upper layer, a nonlinear model predictive control is implemented to solve the nonlinear multiinput multioutput, over-actuated problem. The controller is based on a nonlinear three degree-of-freedom model with nonlinear tire model, considering wheel slips as virtual control input. In the lower layer, the wheel slips are manipulated by a PID controller for generating driving and regenerative braking torques of the independent motors. This proposed controller is tested in a hardware-in-the-loop system with four typical maneuvers, which are constant velocity, accelerating, decelerating, and low road adhesion coefficient situations to show different driver command. The results show that the driver command of longitudinal and lateral motion control are both satisfied.

Coordinated Longitudinal and Lateral Motion Control for Four Wheel Independent Motor-Drive Electric Vehicle

A yaw stability-control system is designed to make vehicle yaw rate follow its reference in this paper. Based on the sliding-mode and backstepping approach, the cascade control system is combined with a tire/road force observer and a yaw stability controller. The tire/road force observer considers wheel longitudinal force as an unknown input to wheel dynamics and uses the sliding-mode method to reconstruct it. The yaw stability controller is designed based on a model about vehicle yaw rate, and the wheel dynamics were chosen according to the vehicle situation. In backstepping framework, brake torque is calculated in two steps. The performance is evaluated in a critical cornering maneuver situation through simulation with a multibody vehicle dynamics software, and the result indicates that the proposed controller can significantly maintain vehicle stability for active safety.

Vehicle Yaw Stability-Control System Design Based on Sliding Mode and Backstepping Control Approach

By simultaneously utilizing preview and global road information, a comfort optimization strategy which combines vehicle speed planning and preview semi-active suspension control is designed for autonomous vehicles. Considering that the impact of vehicle speed at the suspension vibration source is always a barrier for preview suspension control, a processing method for the road data is novelly proposed. Then, to utilize the processed data and to handle the nonlinearity of semi-active actuators, a hybrid horizon-varying (HV) model predictive control (MPC) method is given. The method can adapt to speed variation and meanwhile take the most of the road data within a fixed preview length. Further, based on the global information and considering multiple road irregularities in a driving path, a speed planning problem is established in the spatial domain and a dynamic programming based solution is provided. The final speed trajectory can compromise the driving time, vertical vibration and longitudinal acceleration. Various simulation results have been employed to verify the superiority of the hybrid HV-MPC method and the significance of speed and suspension coordination for comfort improvement.

Ride Comfort Optimization via Speed Planning and Preview Semi-Active Suspension Control for Autonomous Vehicles on Uneven Roads

An motor torque fault diagnosis for four wheel independent motor-drive vehicle is presented in this paper. Focusing on the fault that the actual motor torques differ from the motor torques commanded by vehicle control unit, the fault parameters are introduced to represent the differences and a nonlinear vehicle dynamics model is built. This model considers vehicle body nonlinear dynamics, wheel dynamics, and tire nonlinear characteristics, and the fault parameters are set to be the coefficients of motor torque commands. Then the motor fault diagnosis problem is converted to these fault parameters identification problem, and unscented Kalman filter is implemented to identify them in real time. With the road test data of a four wheel independent motor-drive vehicle, the fault diagnosis method is testified to be effective both in normal and extreme handling situations.

Motor Torque Fault Diagnosis for Four Wheel Independent Motor-Drive Vehicle Based on Unscented Kalman Filter

This paper proposes a model predictive control (MPC) for autonomous vehicle path following control. To solve the control problem, a nonlinear path following model is used, which includes 2 degree-of-freedom single track vehicle dynamics model and path following error model. The control problem is to control vehicle to run on the reference path with the heading angle along the road orientation angle. Then, a controller based on MPC method is designed, and a C-based algorithm is implemented to solve the nonlinear optimization problem in real-time. The proposed control system is tested in a hardware-in-the-loop simulation platform and the robustness is tested by adding noise to lateral vehicle speed and modifying model parameters. It is testified that the control performance is satisfied in different situations.

Hongliang Zhou

Papers

Coordinated Longitudinal and Lateral Motion Control for Four Wheel Independent Motor-Drive Electric Vehicle

Vehicle Yaw Stability-Control System Design Based on Sliding Mode and Backstepping Control Approach

Ride Comfort Optimization via Speed Planning and Preview Semi-Active Suspension Control for Autonomous Vehicles on Uneven Roads

Motor Torque Fault Diagnosis for Four Wheel Independent Motor-Drive Vehicle Based on Unscented Kalman Filter

Design and evaluation of path following controller based on MPC for autonomous vehicle