Figures 6 and 7 illustrate the phase portraits of vehicle planar motion for 2WS and 4WS, respectively.
Similar to the result from the phase portraits in the previous section, 4WS vehicle with high friction has the largest stable area, relatively, while 2WS vehicle with low friction has the smallest stable area under the same [v.
High-mu road surface and 4WS system are good for vehicle stability compared with low-mu and 2WS, respectively.
Caption: Figure 6: Phase portraits for 2WS vehicle.
a), (b), and (c) 2WS vehicles on high-mu road surface.