Research On Coordinated Control Of Active Roll Stabilizer And Active Front Steering System For Vehicle

The suspension system and the steering system are two important parts of thevehicle chassis. The performance of them directly influences handling stability, rideperformance and active safety of vehicle. The recently springing-up active rollstabilizer (ARS) and active front steering (AFS) are one class of suspension controlsystem and steering control system respectively. As a part of suspension control, ARScan generate anti-roll torque to reduce roll angle. AFS system can change vehiclesteering ratio to effectively improve vehicle handling stability and driving safety.Integrated control of steering and suspension system is an important research directionof the vehicle chassis integrated control. This paper conducts a research about thecoordinated control of ARS and AFS under this background.Firstly, the integrated system models (3-DOF) including ARS, AFS and tire modelare built in MATLAB/Simulink. Vehicle tests in CarSim, which represent real car tests,validate the accuracy of simulation model.Secondly, the factors affecting the stability of the vehicle roll motion is analyzeddetailedly. The control strategy of ARS is designed and simulated. The simulationresults show that the ARS can effectively improve the roll stability of the vehicle. Inorder to study ARS’s influence on ride performance, this paper researchs the integratedsystem model including ARS and active suspension. The simulation results show thatthe controller could preferably improve roll stability and ride performance of thevehicle, but be lack of improvement in vehicle yaw stability.Additionally, variable steering ratio curve of AFS is designed and researched. Thevehicle stability control is formulated and the ideal yaw rate is calculated based onlinear vehicle model. At the same time, the AFS controller is designed and simulated.The simulation results show that the proposed AFS controller can effectively improveyaw stability and active safety of the vehicle, and have some influence on the rollstability, too.Finally, the functionalities of coordinated control system and the coupling analysisof the subsystems are formulated in brief. Then, the mechanism and necessity for thecoordinated control of ARS and AFS is researched. The coordinated control strategy ofARS and AFS is designed and simulated with Simulink. The simulation results reflectthe effectiveness of the coordinated control strategy.