| Popis: |
In our previous research, we had used a linear bicycle model as a tool to evaluate the basic functions of robust steering control laws. Since, we have researched a dynamic bicycle model considered the parameter varying on the linear bicycle model. Especially, just after steering transient, the center of rotation of the vehicle is not at the center of gravity but near the rear tires on this model. The influence of the parameter varying of the plant should be considered that the center of rotation is transferred from near the rear tires to the center of gravity on the vehicle turning. There is few researches regarding the reverse action phenomenon of the sideslip system occurred at initial steering period. Rarely, it has only been noted that the time constant of the numerator of the transfer function of side slip system becomes negative at high velocity, but the physical meaning of that negative time constant has not been explained. In our previous research, we have researched the mechanism of inverse action phenomenon using linear bicycle model. We have clarified the relationship between the unstable zero, which is the cause of inverse action phenomenon, and each element of bicycle model, and considered the practical effects of inverse action phenomenon through linear analysis. At the time, we have not considered the effect of the zero of the plant on the lateral and directional control system of the vehicle, therefore we have not demonstrated the practicality of this research. Based on this research, we have developed the dynamic nonlinear bicycle model (DBM) varying the instantaneous center of rotation just after steering transient from near the rear tires to the center of gravity. By comparing the characteristics of this DBM with those of a conventional linear bicycle model (CBM), we report the effects of the inverse action phenomenon just after the inverse action and the unstable zero as characteristics of the plant. |
