Mohd Hatta Mohammed Ariff

Active front steering for steer-by-wire vehicle via composite nonlinear feedback control

This paper proposes Composite Nonlinear Feedback (CNF) controller application for yaw rate tracking control of active front steering (AFS) for vehicle equipped by Steer-by-Wire (SBW). CNF controller is used in AFS system to achieve a fast tracking response of yaw rate according to the desired response and to generate correction steer angle input to enhance vehicle maneuverability. A 2-DOF linear vehicle model is used to design the controller and as the vehicle plant for the simulation evaluation. In order to analyze the proposed control strategy performance, the designed controller was simulated using J-curve and lane change maneuvers conditions and then compared with conventional Proportional Integral Derivative (PID) controller. The results show CNF has a fast yaw rate tracking capability and manage to improve vehicle maneuverability compared to conventional.

Direct Yaw Moment Control of Independent-Wheel-Drive Electric Vehicle (IWD-EV) via Composite Nonlinear Controller

This paper proposes the application of a new optimal based controller for vehicle handling and stability system based on well known model matching structure. The controller is known as the Composite Nonlinear Feedback (CNF) controller which is expected could further improve the conventional optimal based controller (i.e. Linear Quadratic Regulator (LQR)). This is due to the inclusion of an additional nonlinear term in its control law which further reduces the feedback error of vehicle system with the constraint of input saturation. The controller has been applied to the direct yaw moment compensation system as the correction input to enhance the vehicle dynamic behavior. Two selected maneuvers have been numerically simulated on the nonlinear vehicle model using MATLAB Simulink to examine its effectiveness. Results show improvements in the yaw tracking capability, hence reduces the effect of over steer or under steer during critical maneuvers.

Piecewise Trajectory Replanner for Highway Collision Avoidance Systems with Safe-Distance Based Threat Assessment Strategy and Nonlinear Model Predictive Control

This paper proposes an emergency Trajectory Replanner (TR) for collision avoidance (CA) which works based on a Safe-Distance Based Threat Assessment Strategy (SDTA). The contribution of this work is the design of a piecewise-kinematic based TR, where it replans the path by avoiding the invisible rectangular region created by SDTA. The TR performance is measured by assessing its ability to yield a maneuverable path for lane change and lane keeping navigations of the host vehicle. The reliability of the TR is evaluated in multi-scenario computational simulations. In addition, the TR is expected to provide a reliable replanned path during the increased nonlinearity of high-speed collisions. For this reason, Nonlinear Model Predictive Control (NMPC) is adopted into the design to track the replanned trajectory via an active front steering and braking actuations. For path tracking strategy, comparisons with benchmark controllers are done to analyze NMPC’s reliability as multi-actuators nonlinear controller of the architecture to the CA performance in high-speed scenario. To reduce the complexity of the NMPC formulation, Move Blocking strategy is incorporated into the control design. Results show that the CA system performed well in emergency situations, where the vehicle successfully replanned the obstacle avoidance trajectory, produced dependable lane change and lane keeping navigations, and at the same time no side-collision with the obstacle’s edges occurred. Moreover, the multi-actuators and nonlinear features of NMPC as the PT strategy gave a better tracking performance in high-speed CA scenario. Assimilation of Move Blocking strategy into NMPC formulation lessened the computational burden of NMPC. The system is proven to provide reliable replanned trajectories and preventing multi-scenario collision risks while maintaining the safe distance and time constraints.

Antilock Braking System Slip Control Modeling Revisited

The introduction of anti-lock braking system (ABS) has been regarded as one of the solutions for braking performance issues due to its notable advantages. The subject had been extensively being studied by researchers until today, to improve the performance of the todays vehicles particularly on the brake system. In this paper, a basic modeling of an ABS braking system via slip control has been introduced on a quarter car model with a conventional hydraulic braking mode. Results of three fundamental controller designs used to evaluate the braking performance of the modeled ABS systems are also been presented. This revisited modeling guide, could be a starting point for new researchers to comprehend the basic braking system behavior before going into more complex braking systems studies.

Independent-wheel-drive electric vehicle handling and stability assessment via composite nonlinear feedback controller

This paper presents the comparison of three control schemes for vehicle handling and stability performance that are; the direct yaw moment compensation, an integrated active steering with yaw moment compensation of rear and front steering control. The controller design structure is based on model matching approach in which the Composite Nonlinear Feedback (CNF) control theory is adopted as the control method. The performance of two vehicle dynamic responses (i.e. yaw rate and side slip) are investigated with the consideration of the wheel torque limitation. A lane change maneuver is selected as the simulated driving environment and the simulation is conducted via MATLAB/Simulink platform. Results shows that an integrated control is capable to cope with the system design limitation while the control performance of an independent torque correction approach (i.e. DYC only) is instead limited. Improvements in both desired response and torque demand can be noted, despite the inclusion of design constraint to the system.

Development of 4WIS SBW in-wheel drive compact electric vehicle platform

The increasing of population in urban area causing a drastic number of vehicle appears on the road. Besides of contributing a negative impact for surrounding environment due to CO2 gas emission, it is also causing a difficulty and reduce flexibility of people to move in short distance. In this paper a development of electric vehicle for urban usage is presented. The design of this electric vehicle involves mechanical structure, electronic module and control algorithm development. This two seated vehicle is equipped with Four Wheel Independent Steering (4WIS) system that is controlled using Steer by Wire (SBW) technology and the drive unit is using the state of art In-Wheel Drive electric DC motor (IWM). Result shows that, this Compact Electric Vehicle (CEV) can improve maneuverability during tight cornering angles by using All Wheel Steering (AWS) mode and also capable to perform a motion of 180* turning or Zero Point Turning (ZPT). The system architecture is proposed to integrate 4WIS with SBW.

Independent Torque Control of an Independent-Wheel-Drive Electric Vehicle

This paper focuses on designing a controller to enhance the traction and handling of an Independent-Wheel-Drive Electric Vehicle (IWD-EV). It presents a traction torque distribution controller for an IWD-EV in order to maintain vehicle handling and stability during critical maneuvers. The proposed controller is based on the Direct Yaw-moment Control (DYC) and Active Front Steering control (AFS) which intended to increase the handling and stability of the vehicle respectively by applying the yaw rate and the lateral acceleration as the control variables. The performance of the controller is evaluated by numerical simulations of two standard high speed maneuvers which are the double lane change (DLC) and J-Curve. The proposed scheme presents a new controller design for IWD-EV which can effectively improved the vehicle handling and stability.