Active Vehicle Safety Using Integrated Control of Body Roll and Direct Yaw Moment

Abstract

This paper presents an integrated active roll control (ARC) and direct yaw control (DYC) system to improve both the rollover and cornering stability of the vehicle. The presented controller is developed based upon a combination of feedback and feedforward fuzzy logic control for roll control, and a fuzzy logic control for yaw rate.A full vehicle model is used to describe and simulate the vehicle dynamics. Additionally, a yaw-roll plane model is introduced to compare and therefor control the yaw rate, the side slip angle and the roll angle of the vehicle body. Five input variables are considered by the three controllers namely; the vehicle foreword speed, the steering wheel angle, the roll angle, the yaw rate and the side slip angle of the vehicle body. The control action of the direct yaw control DYC and the active roll control ARC both are carried out by generating a differential braking across the front wheels. The numerical modeling is carried out through the MATLAB / SIMULINK environment which suits the control and optimization process.Different simulation results are carried out by considering standard test maneuvers with different speeds such as J-turn, fishhook, and the lane change. The simulation results are compared during four cases namely; the uncontrolled system, the ARC controller only, the DYC controller only and the integrated ARC and DYC controllers. The results show a substantial improvement of the vehicle stability in term of vehicle lateral acceleration, side slip angle, the yaw rate and the roll angle for the developed integrated ARC and DYC controllers compared to that of the individual controller or the uncontrolled system. The main advantage of the proposed controller that it is relies on one actuation which is the differential braking. KEY WORDSActive roll control, direct yaw control, integrated control, fuzzy logic control ‫ـــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــــ‬ ‫ـــــــــــــــــــــــــــــــــــ‬ ‫ــــــــــــــــــــــــــــــــــ‬ ‫ـــــــــــــــــــــــــــــــــــــــ‬ * Egyptian Armed Force. AE Location of the origin of vehicle frame of reference from front and rear axle [m] , C f r Damping coefficient of front/rear suspension [N.s/m] , C f r α α Cornering stiffness of front, rear tires [N/rad] , , Tire forces expressed at wheel coordinate systems [N] g Gravitational acceleration [m/s 2 ] , , I I I xx yy zz Mass moment of inertia of the vehicle sprung mass [Kg.m 2 ] , , I I I xy yz zx Mass product moment of inertia of the vehicle sprung mass [Kg.m 2 ] I wi Mass moment of inertia of wheels [Kg.m 2 ] , K f r Stiffness coefficient of front/rear suspension spring [N/m] L Wheelbase (distance between front and rear axle) [m] M B i Braking moment applied to each wheel [N.m] M D i Driving moment applied at each wheel hub [N.m] M s Sprung mass of the vehicle [Kg] M t Total mass of the vehicle [Kg] M U i Resisting moment applied at each wheel hub [N.m] M wi Unsprung mass at each wheel [Kg] , , M M M X Y Z Net moments affecting the vehicle body [N...