Introduction on dynamic motion of opposite and parallel steering for electric vehicle

As car manufacturers progress in creating electric based transportation, demand on the research of stability, controllability and feasibility on electric vehicle increases. The conversion of mechanical to electric does not limit to the driving propulsion, but also to the drivetrain of an electric vehicle. The electric powered and by-wire control technology allow for manufacturers to build an independent four wheels steering (i4WS) of an all-wheel drive small in wheel electric vehicle. These i4WS provides extra mobility compared to conventional vehicle such as opposite steering, parallel steering, and zero-radius steering. However before any control can be applied, a basic knowledge and specification of every modes are needed. Thus in this paper, a research solely on the introduction of dynamic motion for opposite steering and parallel steering is addressed. A simulation was done to determine the steering characteristic for opposite steering and parallel steering during steady state cornering and lane changing. The negative steer angle indicates the wheel steer at a clockwise direction while positive angle indicates rotation at counter-clockwise. Results show that opposite steering increase the yaw rotation speed while decreasing the turning radius. However, parallel steering decrease the yaw rotational speed and increase the turning radius.