Effect of Direct Yaw Moment Control Based on Steering Angle Velocity and Camber Angle Control 2014-01-2386
It has been reported that steering systems with derivative terms have a heightened lateral acceleration and yaw rate response in the normal driving range. However, in ranges where the lateral acceleration is high, the cornering force of the front wheels decreases and hence becomes less effective. Therefore, we applied traction control for the inner and outer wheels based on the steering angle velocity to improve the steering effectiveness at high lateral accelerations. An experiment using a driving simulator showed that the vehicle's yaw rate response improved for a double lane change to avoid a hazard; this improves hazard avoidance performance. Regarding improved vehicle control in the cornering margins, traction control for the inner and outer wheels is being developed further, and much research and development has been reported. However, in the total skid margin, where few margin remains in the forward and reverse drive forces on the tires, spinout is unavoidable. Therefore, we applied tire camber angle control to improve vehicle maneuverability in the total skid margin. An experiment using a driving simulator has confirmed that the vehicle's lateral acceleration at the turning limit can be improved by controlling the camber angle. Because of this, camber angle control promises to be more effective than traction control for the inner and outer wheels. By applying this type of steering control, it is possible to increase maneuverability and stability in the cornering margins.