The direct yaw-moment control system can significantly enhance vehicle stability in critical situations. In this paper, the direct yaw-moment control strategies are proposed for in-wheel electric vehicles by using sliding mode (SM) and nonlinear disturbance observer (NDOB) techniques. The ideal sideslip angle at the center of gravity and the yaw rate are first calculated based on a linear two degree of freedom vehicle model. Then, the actual sideslip angle is identified and estimated by constructing a state observer. On this basis, a traditional discontinuous SM direct yaw-moment controller is designed to guarantee that the sideslip angle and the yaw rate will approach the ideal ones as closely as possible. To tackle the chattering problem existing in the traditional SM controller, a second-order sliding mode (SOSM) controller is further designed by taking the derivative of the controller as the new control, which implies that the actual control can be an integration of the SOSM controller. Finally, to avoid the large gains in the derived controllers, by combining the NDOB with the derived controllers, the composite control schemes are also proposed. In comparison with the discontinuous first-order SM controller, the proposed SOSM controller is shown to be more effective.

Sliding Mode Direct Yaw-Moment Control Design for In-Wheel Electric Vehicles

The path-following problem for four-wheel independently actuated autonomous ground vehicles is investigated in this paper. A novel output constraint controller is proposed to deal with the lateral offset control in path following and maintain the vehicle lateral stability in the presence of tire sliding effects. The innovations of this work lie in the following two aspects: 1) A novel output constraint control strategy, namely, the hyperbolic projection method, is proposed to strictly bound the lateral offset to prevent the vehicle from transgressing the safety bound in path following; 2) an adaptive and robust linear quadratic regulator controller is adopted to obtain the optimal active front-wheel steering and direct yaw-moment control inputs with vehicle lateral stability consideration and to eliminate the effect of parameter uncertainties. CarSim–Simulink joint simulation results indicate that the proposed controller can compactly bound the lateral offset to avoid transgressing the safe boundary during path following, particularly in extreme driving conditions, in the presence of tire sliding effects and system uncertainties.

Output Constraint Control on Path Following of Four-Wheel Independently Actuated Autonomous Ground Vehicles

Variable time delays exist between the driver's inputs and the responses of the vehicle dynamic states during a critical steering course. And due to the delay of active brake actuators, a sideslip or a rollover may occur even to a vehicle with a traditional stability control system. In addition, the unnecessary intervention of rollover prevention controller may deteriorate yaw stability of a vehicle in these situations. To mitigate the adverse effect of time delay on vehicle stability control and to realize coordinated stability control, a novel three-dimensional dynamic stability controller (3DDSC) is designed for yaw stability control, yaw–roll stability control and rollover prevention control. The framework consists of a supervisor, an upper controller, and a lower controller. A nonlinear vehicle model is used in the supervisor to predict the vehicle's future states and to determine the control mode and the related controllable areas with active brake method. Then model predictive control is used in the upper controller to calculate the desired tire forces of four wheels under the constraints of the given controllable area; then, the desired tire forces are realized by a lower hydraulic pressure controller. The proposed 3DDSC is evaluated with a CarSim–MATLAB cosimulation and hardware-in-the-loop simulation. The results show that 3DDSC can achieve a seamless integration of lateral stability and rollover prevention in complicated steering maneuvers.

A Three-Dimensional Dynamics Control Framework of Vehicle Lateral Stability and Rollover Prevention via Active Braking With MPC

The autonomous vehicle is a mobile robot integrating multi-sensor navigation and positioning, intelligent decision making and control technology. This paper presents the control system architecture...

https://journals.sagepub.com/doi/pdf/10.5772/51314

Design of a Control System for an Autonomous Vehicle Based on Adaptive-PID

This paper proposes a novel integrated controller with three-layer hierarchical structure to coordinate the interactions among active suspension system (ASS), active front steering (AFS) and direct yaw moment control (DYC). First of all, a 14-degree-of-freedom nonlinear vehicle dynamic model is constructed. Then, an upper layer is designed to calculate the total corrected moment for ASS and intermediate layer based on linear moment distribution. By considering the working regions of the AFS and DYC, the intermediate layer is functionalised to determine the trigger signal for the lower layer with corresponding weights. The lower layer is utilised to separately trace the desired value of each local controller and achieve the local control objectives of each subsystem. Simulation results show that the proposed three-layer hierarchical structure is effective in handling the working region of the AFS and DYC, while the quasi-experimental result shows that the proposed integrated controller is able to improve the lateral and vertical dynamics of the vehicle effectively as compared with a conventional electronic stability controller.

Chassis Integrated Control for Active Suspension, Active Front Steering and Direct Yaw Moment Systems Using Hierarchical Strategy

This is the first book to combine classical vehicle dynamics with electronic control. The equation-based presentation of the theory behind vehicle dynamics enables readers to develop a thorough understanding of the key attribute to both a vehicle's driveability and its active safety. Supported by MATLAB tools, the key areas that affect vehicle dynamics are explored including tire mechanics, the steering system, vehicle roll, traction and braking, 4WS and vehicle dynamics, vehicle dynamics by vehicle and human control, and controllabiliy. As a professional reference volume, this book is an essential addition to the resources available to anyone working in vehicle design and development. Written by a leading authority in the field (who himself has considerable practical experience), the book has a unique blend of theory and practice that will be of immense value in this applications based field.* Get a thorough understand of why vehicles respond they way they do with a complete treatment of vehicle dynamics from theory to application* Full of case studies and worked examples using MATLAB/Simulink * Covers all variables of vehicle dynamics including tire and vehicle motion, control aspects, human control and external disturbances

Masato Abe

Papers

Vehicle Handling Dynamics: Theory and Application