One of the dominant virtue of Steer-By-Wire (SBW) vehicle is its capability to enhance handling performance by installing Active Front Steering (AFS) system without the driver’s interferences. Hence, this paper introduced an AFS control strategy using the combination of Composite Nonlinear Feedback (CNF) controller and Disturbance Observer (DOB) to achieve fast yaw rate tracking response which is also robust to the existence of disturbance. The proposed control strategy is simulated in J-curve and Lane change manoevres with the presence of side wind disturbance via Matlab/Simulink sotware. Futhermore, comparison with Proportional Integral Derivative (PID) and Linear Quadratic Regulator (LQR) controllers are also conducted to evaluate the effectiveness of the proposed controller. The results showed that the combined CNF and DOB strategy achieved the fastest yaw rate tracking capability with the least impact of disturbance in the AFS system installed in SBW vehicle.

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Composite Nonlinear Feedback With Disturbance Observer for Active Front Steering

The main purpose of controlling vehicle handling is to ensure that the vehicle follows the desired path. Vehicle yaw rate must be controlled in order to achieve a good vehicle handling. In this thesis, optimal Composite Nonlinear Feedback (CNF) controller with multi objective algorithms is proposed for the Active Front Steering (AFS) system in improving the vehicle yaw rate response. The model used to validate the performance of the controller is a 7 degree-of-freedom (DOF) nonlinear vehicle model. This vehicle model is also simplified to a 2 DOF bicycle model for the purpose of controller design. In designing the optimal CNF control, the parameter selection of optimal linear and non-linear gain parameters becomes very important to obtain a good system response. Optimization algorithms are utilized to minimize the complexity in selecting the best parameters. Hence, Multi Objective Particle Swarm Optimization (MOPSO) and Multi Objective Genetic Algorithm (MOGA) are proposed to produce the optimal CNF. Moreover, manual tuning method was utilized and has been compared with the proposed algorithms. As a result, the performance of the yaw rate response is improved with a 98 percent reduction in error. Hence, the vehicle handling can be improved and the vehicle will be able to travel safely on the desired path

Optimal composite nonlinear feedback control with multi objective algorithms for active front steering system

Yaw control is a part of an Active Front Steering (AFS) system, which is used to improve vehicle manoeuvrability. Previously, it has been reported that the yaw rate tracking performance of a linear Steer-by-Wire (SBW) vehicle equipped with a Composite Nonlinear Feedback (CNF) controller and a Disturbance Observer (DOB) is robust with respect to side wind disturbance effects. This paper presents further investigation regarding the robustness of the combination between a CNF and a DOB in a nonlinear environment through a developed 7-DOF nonlinear SBW vehicle. Moreover, in contrast to previous studies, this paper also contributes in presenting the validation works of the proposed control system in a real-time situation using a Hardware-in-Loop (HIL) platform. Simulation and validation results show that the CNF and DOB managed to reduce the influence of the side wind disturbance in nonlinearities.

http://journal.portalgaruda.org/index.php/EEI/article/download/1228/1024

Robust composite nonlinear feedback for nonlinear Steer-by-Wire vehicle’s Yaw control

The vehicle braking system is one of the crucial issues in the vehicle dynamics and automotive safety control. This research focuses on the implementation of a control scheme for allocation of the brake force for the Through-the-Road (TtR) four-wheel-drive (4WD) Hybrid Electric Vehicle (HEV) to investigate the vehicle yaw stability control. The development of the mathematical models of the vehicle dynamic that comprised of rigid body dynamics, tire dynamics, longitudinal force and lateral force from the literature review are one of the most crucial steps to make sure the result obtained is closed as possible to the actual system. Robust controller is designed to control the vehicle yaw stability based on the electronic brake force distribution (EBD) braking system. By applying the robust control scheme, the vehicle yaw stability can be enhanced against the external disturbances. The performance of the proposed controller is compared based on the transient response’s specifications to the reference signal response for the effectiveness analysis through simulation in the MATLAB/SIMULINK environment.

Robust electronic brake force distribution in hybrid electric vehicles

Vehicle stability control (VSC) is one of important topics in vehicle dynamics and active automotive control. This research is focusing on vehicle stability control by active steering system that utilizes steering control method to improve stability of the vehicle. This stability control system is solely based on kinematic and dynamics motion of vehicle. The development of mathematical model of vehicle dynamic that includes body and tyre dynamics is one of the most important steps to make sure the result obtain is close as possible to actual system. In the other hand, an analysis of transient state is very crucial in control system performance where one of the objectives is to track reference signal as fast as possible with minimum overshoot, fast settling time, and without exceed nature of actuator saturation limit. Hence, in order to achieve this target, a robust and high performance of control algorithm is essential for vehicle stability control. In this research project report, a Composite Nonlinear Feedback (CNF) strategy is used to control yaw rate of vehicle through active steering. Extensive computer simulation is performed with considering a various profile of cornering manoeuvres with external disturbance to evaluate its performance in different scenarios. The performance of the proposed controller is compared to conventional Proportional Integration and Derivative (PID) for effectiveness analysis.

Mohd Hanif

Papers

An active front steering control based on composite nonlinear feedback for vehicle yaw stability system