Vehicle Dynamic Control with 4WS, ESC and TVD under Constraint on Front Slip Angles

To enhance vehicle maneuverability and stability, a controller with 4-wheel steering (4WS), electronic stability control (ESC) and a torque vectoring device (TVD) under constraint on the front slip angles is designed in this research. In the controller, the control allocation method is adopted to generate yaw moment via 4WS, ESC and TVD. If the front steering angle is added for generating yaw moment, the steering performance of the vehicle can be further deteriorated. This is because the magnitude of the lateral tire forces are limited and the required yaw moment is insufficient. Constraint is imposed on the magnitude of the front slip angles in order to prevent the lateral tire forces from saturating. The driving simulation is performed by considering the limit of the front slip angle proposed in this study. Compared to the case that uses the existing 4WS, the results of this study are derived from the actuator combination that enhances performance while maintaining stability.

Review on LPV Approaches for Suspension Systems

This paper presents a detailed literature review about Linear Parameter Varying (LPV) approaches applied to vehicle suspension systems. Indeed many works have been devoted to vehicle (active and semi-active) suspension in the past 20 years, because this subsystem in the only one affecting passenger comfort and road holding. Moreover several studies have also been concerned with global vehicle dynamic control using the suspension systems in collaboration with other subsystems (steering, braking …). On the other hand, the LPV approaches have proved to be very efficient to control non linear systems as well as to provide some kind of adaptive control. Naturally many LPV methods have been developed for suspension systems in order to take into account the nonlinear characteristics of the dampers, to adapt the suspension performance to the passenger request or to the road profile, to make the suspension systems collaborate with other subsystems, or to provide a fault tolerant control in case of damper loss of efficiency. This survey paper will make a deep analysis about the recent studies dedicated to vehicle suspension systems aiming at providing a better insight on the type of LPV methods that have been considered.

Modeling and Control of Wheel Motor Based Articulated Vehicle System

This paper investigates an effectiveness of vehicle dynamic control (VDC) system based on torque vectoring technique using in-wheel-motors to improve the performance of articulated vehicle systems. A 10 degree-of-freedom (DOF) articulated vehicle model including a tractor and a single axle trailer has been developed and its responses are validated with commercial vehicle software of Trucksim. This model includes a nonlinear tire model (MF tire), a hydraulic damping at the hitch, and a traction system using in-wheel-motors at the trailer axle. In this paper, a yaw control system is developed to track the reference yaw rate with application of yaw moment at the trailer axle using torque distribution of in-wheel-motors. The effectiveness of the proposed control system is validated through simulation of sinusoidal steering maneuver on high mu and slippery road conditions. The simulation results show that in-wheel-motors can improve safety and performance of articulate vehicle systems.